Search

• Supplementation with BYBG altered the expression of 47 innate immune system mRNA in response. • Supplementation with BYBG intake may improve innate immune response to both DAMP and PAMP. • Multiplex mRNA detection can be an effective to measure small expression changes associated with an orally consumed nutritional compound. Beta glucans are found in many natural sources, however, only Baker's Yeast Beta Glucan (BYBG) has been well documented to have structure–function effects that are associated with improved innate immune response to stressors (e.g., exercise, infection, etc.). The purpose was to identify a BYBG-associated mRNA expression pattern following exercise. Participants gave IRB-approved consent and were randomized to BYBG (Wellmune®; N=9) or Placebo (maltodextrin; N=10) for 6-weeks prior to performing 90 min of whole-body exercise. Paxgene blood samples were collected prior to exercise (PRE), after exercise (POST), two hours after exercise (2H), and four hours after exercise (4H). Total RNA was isolated and analyzed for the expression of 770 innate immune response mRNA (730 mRNA targets; 40 housekeepers/controls; Nanostring nCounter). The raw data were normalized against housekeeping controls and expressed as Log 2 fold change from PRE for a given condition. Significance was set at p < 0.05 with adjustments for multiple comparisons and false discovery rate. We identified 47 mRNA whose expression was changed after exercise with BYBG and classified them to four functional pathways: 1) Immune Cell Maturation (8 mRNA), 2) Immune Response and Function (5 mRNA), 3) Pattern Recognition Receptors and DAMP or PAMP Detection (25 mRNA), and 4) Detection and Resolution of Tissue Damage (9 mRNA). The identified mRNA whose expression was altered after exercise with BYBG may represent an innate immune response pattern and supports previous conclusions that BYBG improves immune response to a future sterile inflammation or infection. [ABSTRACT FROM AUTHOR]

• New application of DBS (Dry Blood Spot) technology for the monitoring of mRNA response to intervention study. • Optimization of existing RNA isolation methodologies to enable multiplex mRNA detection using Nanostring. • Potential application of DBS for tracking biological outcomes in large, field-based intervention studies. Monitoring immunological response to physical stressors in a field setting is challenging because existing methods require a laboratory visit and traditional blood collection via venipuncture. The purpose of this study was to determine if our optimized dry blood spot (DBS) methodology yields sufficient total RNA to quantify the effect of Baker's Yeast Beta Glucan supplementation (BYBG; Wellmune; 250 mg/d) on post-exercise mRNA expression. Participants had venous DBS samples collected prior to (PRE), and immediately (POST), 2 (2H), and 4 (4H) hrs after completion of a 90 min run/walk trial in a hot, humid environment. Total RNA extracted from DBS was analyzed using a 574-plex Human Immunology mRNA panel (Nanostring). BYBG supplementation was associated with the increased expression of 12 mRNAs (LTB4R, PML, PRFM1, TNFRSF14, LCK, MYD88, STAT3, CCR1, TNFSF10, LILRB3, MME, and STAT6) and decreased expression of 4 mRNAs (MAP4K1, IKBKG, CD5, and IL4R) across all post-exercise time points. In addition to individually changed mRNA targets, we found eleven immune-response pathways that were significantly enriched by BYBG following exercise (TNF Family signaling, immunometabolism, oxidative stress, toll-like receptor (TLR) signaling, Treg differentiation, autophagy, chemokine signaling, complement system, Th2 differentiation, cytokine signaling, and innate immune). The present approach showed that DBS samples can be used to yield useful information about mRNA biomarkers in an intervention study. We have found that BYBG supplementation induces changes at the mRNA level that support the immune system and reduce susceptibility to opportunistic infection (i.e., upper respiratory tract infection) and facilitate improved physical recovery from exercise. Future studies may look to use DBS sampling for testing other nutritional, health, or medical interventions. [ABSTRACT FROM AUTHOR]

Trained immunity refers to the memory acquired by innate immune cells, leading to cross-protection and non-specific responses to subsequent infection, thereby improving host survival. Trained immunity induction is a combined effect of immune signaling, metabolic changes, and epigenetic modifications. The present study evaluated the induction of markers of the phenomenon of trained immunity in common carp, which is trained using β-glucan. The mammalian target of rapamycin (mtor) and hypoxia-inducible factor (hif1α) , the metabolic basis of trained immunity; the histone deacetylase (hdac7), one of the markers of epigenetic modifications, metabolic activity of activated cells and expression profiles of proinflammatory cytokines viz. il6a , tnfαa2, and ifnγ were targeted in the study and analyzed in vivo. Besides in vivo analysis, in vitro analysis of mtorc2, hif1α, hdac7, and ifnγ were analyzed. In vitro analyses were performed on head kidney macrophages isolated and maintained in L-15 media and double trained with β-glucan at 100μg/mL. The culture supernatant was collected at different time intervals and processed for expression studies. Healthy common carp were injected with β-glucan at 20 mg/kg body weight for training followed by a resting phase for 6 days and were restimulated with the same dose. Head kidney was collected from the fish post-induction as well as post-restimulation. The expression profile of mtorc2, hdac7, and hif1α were found elevated post-stimulation of β-glucan. Further, a significantly upregulated expression profile of proinflammatory cytokines (ifnγ , il6a and tnfαa2) was observed. Increased glycolysis in the cells post-β-glucan stimulation was confirmed by the high lactate and LDH production detected in the cell culture supernatant. Overall, the study revealed the expression profile of the trained immunity markers and the increased metabolic activity in cells induced with β-glucan, which further validates that the action of trained immunity is indispensable in fish on encounter with a potential ligand. The study supports the existing reports on trained immunity in teleost fish with evidence at the genomic level. However, further studies are required to understand the responses and actions of trained immune cells during infection in detail. [Display omitted] • Expression profiles of trained immunity markers in common carp post immune training with β-glucan. • Elevated expression profiles of trained immunity markers and proinflammatory cytokines were observed post-training. • Increase in metabolic activity and production of metabolites revalidates the phenomenon of the metabolic shift in trained immune cells. [ABSTRACT FROM AUTHOR]

This study investigated the effects of two probiotics namely Clostridium butyricum and Bacillus subtilis , and one prebiotic known as algae-sourced β-1,3 glucan, on the overall performances of grass turtles (Chinemys reevesii) juveniles. Growth performance, immune responses, enzymatic antioxidant activities, intestinal histomorphology, and disease resistance against the challenge with Aeromonas veronii were assessed. Two hundred and sixteen (216) juvenile turtles with an average initial weight of 106.35 ± 0.03 g were divided into four groups, each containing three replicates with 18 turtles per each replicate, which were fed a basic diet (control group, GD) and a basal diet supplemented with C. butyricum 1.0 × 108 CFU per kg (GA group), or with B. subtilis 1.0 × 108 CFU per kg (GB group) and with algal-sourced β-1,3-glucan 50 mg per kg (GC group), respectively. After the turtles had been fed for 60 d, 90 d, and 120 d of the experimental period, the growth performance and survival rate (SR), intestinal digestive enzyme, hepatic and intestinal antioxidant capacity, serum biochemical indexes, and immune performance were measured. The results showed that the weight gain rate and SR were significantly enhanced (P < 0.05) after fed probiotics and algae-sourced β-1,3-glucan in all test times;The pepsin, amylase, acid phosphatase, total antioxidant capacity, triglyceride, alkaline phosphatase, urea nitrogen, cholesterol, total protein, IgA, IgG, IgM at 120 d were significantly enhanced (P<0.05) after fed C. butyricum. The intestinal villi heights, widths, and the thickness of the muscle layer were significantly higher in groups GA, GB, and GC than those reared within the GD control group (P < 0.05). After injecting the challenge by A. veronii the survival rate of grass turtles in the GA group (75%) was significantly higher than the other three groups (P<0.05), while there was no significant difference between the GB and GC groups compared with the control GD group, respectively (P>0.05). Overall, these results indicated that dietary supplementation with probiotics or algae-sourced β-1,3 glucan, exhibited positive effects on C. reevesii. In particular, C. butyricum , showed the greatest improvements relating to growth, immune response, antioxidant activity, intestinal health, and disease resistance. • Clostridium butyricum and Bacillus subtilis could improve the growth and Immunity of grass turtle Chinemys reevesiis. • Clostridium butyricum improved digestive enzyme activity and intestinal morphology of grass turtle. • Clostridium butyricum significantly improved the resistance of grass turtle to Aeromonas veronii. [ABSTRACT FROM AUTHOR]

β-glucans are produced by many organisms and could be used as supplementary feed to enhance immunity and growth in some aquatic animals. This study aimed to compare the effectiveness of β-glucans derived from two marine diatoms (Chaetoceros muelleri and Thalassiosira weissflogii) as growth promoters and immunity enhancers in banana shrimp (Penaeus merguiensis). Shrimp were divided into 3 groups: the control group was fed without β-glucan; the second and the third group were fed with 2 g kg−1 of β-glucan derived from C. muelleri and T. weissflogii , respectively. Shrimp were fed over a 30-day period to determine growth performance (final weight, weight gain, average daily gain (ADG), and feed conversion ratio (FCR)) at day 15 and day 30, respectively. The immune parameters determined were total hemocyte count (THC), phenoloxidase activity (PO) and immune gene expression. Survival rates were measured after 14 days of the feeding trial and Vibrio parahaemolyticus infection (6, 24, 48 h post infection). There was no significant difference (P > 0.05) for growth stimulation of shrimps between the two types of β-glucans (C. muelleri or T. weissflogii). Notably, shrimps fed with β-glucans had a higher final weight, weight gain, and ADG (P < 0.05) than shrimps fed with the control diet, while FCR of shrimps fed with both β-glucans was lower when compared to the control diet. Immune parameters, THC, PO, and gene expression of anti-lipopolysaccharide factor (ALF) and crustin were significantly higher (P < 0.05) in shrimps fed with β-glucans, especially with β-glucans from C. muelleri than the control group both before and after V. parahaemolyticus infection. Expression of penaeidin 3 and peroxiredoxin genes was significantly higher in shrimps fed with β-glucans after bacterial infection. Histopathology of hepatopancreas revealed an increase in blasenzellen hepatopancreatic epithelial cells (B cells) after 14 days of feeding which remained higher following infection with V. parahaemolyticus. The survival rate of shrimps fed with the diet containing β-glucan derived from either C. muelleri (82.2%) or T. weissflogii (77.8%) after V. parahaemolyticus infection was significantly higher than for the control group (51.1%) (P < 0.05). In conclusion, we propose that feeding banana shrimps with β-glucans derived from marine diatoms either C. muelleri or T. weissflogii at a 2 g kg−1 diet can significantly improve their growth performance and immunity. • β-glucans from diatom either C. muelleri or T. weissflogii had no toxicity and could be use as supplement for shrimp. • β-glucans derived from marine diatoms (C. muelleri and T. weissflogii) can improve banana shrimp growth and immunity. • β-1,3/1,6-glucan from C. muelleri is superior to β-1,3-glucan from T. weissflogii to promote shrimp growth and immunity. [ABSTRACT FROM AUTHOR]

The aim of this study was the induction and characterization of extracellular traps (ETs) produced by gilthead seabream (Sparus aura ta L.) head-kidney leucocytes. The cells were incubated several times (10, 30, 60, 120, and 180 min) with different concentrations of the stimulants diluted in RPMI-1640 culture medium: RPMI-1640 (control), β-glucan from Saccharomyces cerevisiae (BG, 0–400 μg mL−1), lipopolysaccharide from Escherichia coli (LPS, 0–10 μg mL−1), calcium ionophore A23187 (CaI, 0–5 μg mL−1), Phorbol 12-myristate 13-acetate (PMA, 0–1000 ng mL−1) and polyinosinic–polycytidylic acid sodium salt (Poly I:C, 0–200 μg mL−1). BG, LPS and CaI exerted only weak stimulatory activity, while PMA and poly I:C exerted a potent one. After stimulation of the leucocytes, ETs structures were quantified and visualised through staining of the chromatin with nucleic acid-specific dyes and immunocytochemical probing of characteristic proteins expected to decorate the structure. ETs structures had DNA and myeloperoxidase. The ETs morphology was studied by light and scanning electron microscopy. These data confirm that seabream leucocytes form ETs with different morphological properties, depending on the used stimulant. These results will be the basis for new studies to analyse the implication of this mechanism in fish immunity. All this new knowledge will have its application in fish farms when we learn to manipulate the innate immune response in order to mitigate microbial infections. [Display omitted] [ABSTRACT FROM AUTHOR]

Huge amounts of non-edible by-products could be generated from fruit industrial processes. They consist mainly of peels together with low amounts of pulp and seeds. These by-products pose an environmental hazard due to soil, air, and water pollution. Moreover, treating these by-products is very expensive and under strict governmental regulations. Nevertheless, they are an excellent source of bioactive constituents, such as phenols, flavonoids, terpenes, and glucans. Based on their constituents, these by-products can significantly enhance the antioxidant defense, immune response, and modulation of gut microbiota and host resistance against various diseases. Therefore, sustainable valorization of fruits by-products can efficiently obtain value-added products that improve the well-being of organisms and reduce environmental stress, in addition to earning an additional industrial income. Since aquaculture is a vital economic sector, there is urgent to look for inexpensive natural food additives that improve health and maintain high nutritional quality for farming organisms without harming the environment and human health. Therefore, using fruit wastes as feed additives represents a striking alternative for fruitful aquaculture. In order to make use of these value-added products, it is a dire need to determine their biological effects on aquaculture organisms by understanding their mechanism of action. In this context, this review will holistically address a comprehensive focus on utilizing fruits by-products and their immunostimulant and antioxidative action. • Fruit by-products contain abundant amounts of active substances concerned with immunostimulant and antioxidative roles. • Phenolic compounds, flavonoids, terpenes, fibers, and glucans are mainly presented in fruit by-products. • The incorporation of fruit by-products improved several aquatic animals' immune and antioxidative responses. • High resistance against infectious diseases was proved in aquatic animals fed fruit by-products. [ABSTRACT FROM AUTHOR]

Black spotted frogs have rich nutrition and delicious meat, and its market consumption has increased year by year. However, outbreaks of the diseases have caused huge losses to the breeding industry. The crooked head disease caused by Elizabethkingia miricola (E. miricola) is highly contagious and lethal, and there is no effective treatment method. Vaccination is the most promising strategy to prevent infectious diseases. Immersion vaccination has attracted many researchers because of its simplicity of operation in preventing infectious diseases. In addition, immersion vaccines can be more effective when used with adjuvants. In this study, we prepared inactivated E. miricola with 0.3% formaldehyde, and the black spotted frogs were vaccinated by soaking in inactivated E. miricola vaccine, anisodamine + vaccine mixture, β-glucan + vaccine mixture, chitosan + vaccine mixture for 60 min. PBS was used as a control. After being challenged by E. miricola , the survival rate of anisodamine + vaccine (57%) and chitosan + vaccine group (63%) was significantly higher than that of the control group (17%). By analyzing pathological sections, we found that the chitosan + vaccine and anisodamine + vaccine groups protected the brain, eye, liver and kidney tissues of the black spotted frogs compared to the control group, which was consistent with the trend of survival rate. In addition, chitosan + vaccine and anisodamine + vaccine groups had better effects on LZM, TSOD and C3 in serum than control group. Meanwhile, the numbers of the percentage of leukocytes/haemocytes in the peripheral blood of immunized black spotted frogs increased. The anisodamine + vaccine group (5.3%) and chitosan + vaccine (5.38%) group were significantly higher than the blank control group (2.24%), which indicate that the two groups induced a more significant immune response and were more resistant to bacterial invasion. The tissue bacterial loads in liver, brain, kidney and eye were significantly lower in the anisodamine + vaccine and chitosan + vaccine groups than that of the control group. This study explored and demonstrated the good efficiency of chitosan and anisodamine as adjuvants for immunization by immersion and provided a reference for improving the efficiency of immunization by immersion. • Inactivated E. miricola vaccine prevents black spotted frogs crooked head disease. • Chitosan or anisodamine improves the protection rate after E. miricola infection. • Chitosan or anisodamine as adjuvant significantly enhances the immune responses. • Chitosan or anisodamine as adjuvant alleviates tissue damage. [ABSTRACT FROM AUTHOR]

Leucine-rich repeat (LRR)-only proteins have been proved to be involved in the innate immune responses as they could mediate protein-protein or protein-ligand interactions. In the present study, a novel LRR-only protein (Lv LRRop-1) was identified and characterized from Pacific white shrimp Litopenaeus vannamei. The complete cDNA sequence of Lv LRRop-1 contains an open reading frame (ORF) of 1488 bp, which encoded a polypeptide of 495 amino acids with a predicted molecular mass of 55.67 kDa and a calculated theoretical isoelectric point of 6.435. There are five LRR motifs, six LRR_TYP motifs in the protein sequence of Lv LRRop-1 with consensus signature sequences of LxxLxxLxLxxNxL. The Lv LRRop-1 mRNA transcripts could be detected in all the tested tissues, including eyestalk, gill, gonad, heart, hemocytes, hepatopancreas, intestine, muscle, nerve and stomach, especially highest in hemocytes and hepatopancreas. The mRNA transcripts of Lv LRRop-1 increased within the first 6 h in hemocytes and hepatopancreas after Vibrio parahaemolyticus or white spot syndrome virus (WSSV) challenges. The recombinant Lv LRRop-1 could bind four typical pathogen-associated molecular patterns (PAMPs), including lipopolysaccharide (LPS), peptidoglycan (PGN), glucan (GLU) and polycytidine-polycytidylic acid (poly IC), in a dose-dependent manner, and inhibit the growth of bacteria Micrococcus luteu s. These data indicated that Lv LRRop-1 could play a pivotal role in the innate immune response of shrimps as a kind of pattern recognition receptor (PRR). • Molecular characterization of a novel LRR-only protein in Litopenaeus vannamei • Its expression profiles and pattern recognition ligands spectrum were investigated • It could inhibit the growth of bacteria Micrococcus luteu s [ABSTRACT FROM AUTHOR]

Disease prevention by vaccination is, on economic, environmental and ethical grounds the most appropriate method for pathogen control currently available to the aquaculture sector. However, vaccine administration in aquatic animals faces obvious technical problems not encountered in other land animals. Thus, oral vaccines are highly demanded by the aquaculture sector that requests alternatives to the labor-intensive injectable vaccines that require individual handling of fish, provoking stress-related immunosuppression and handling mortalities. Despite this, most previous attempts to obtain effective oral vaccines have failed both in fish and mammals. This could be a consequence of very restricted tolerance mechanisms in the intestine given the fact that this mucosa is at the frontline upon antigen encounter and has to balance the delicate equilibrium between tolerance and immunity in a microbe rich aquatic environment. In this context, the search for an optimal combination of antigen and adjuvant that can trigger an adequate immune response able to circumvent intestinal tolerance is needed for each pathogen. To this aim, we have explored potential of molecules such as β-glucans, flagellin, CpG and bacterial lipopolysacharide (LPS) as oral adjuvants. For this, we have determined the effects of these adjuvants ex vivo in rainbow trout intestine tissue sections, and in vitro in leucocytes isolated from rainbow trout spleen and intestine. The effects were evaluated by analyzing the levels of transcription of different genes related to the innate and adaptive immune response, as well as evaluating the number of IgM-secreting cells. LPS seems to be the molecule with stronger immunostimulatory potential, and could safely be used as a mucosal adjuvant in rainbow trout. Moreover, the designed strategy provides a fast methodology to screen adjuvants that are suitable for oral vaccination, providing us with valuable information about how the intestinal mucosa is regulated in fish. • Two simple methodologies to evaluate the potential of mucosal adjuvants were designed. • CpGs increase the amount of IgM-secreting cells in splenic and not in gut cultures. • LPS has the stronger transcriptional effects on gut explants among the tested molecules. • LPS increases the amount of IgM-secreting cells in gut cultures. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the combined effects of sulfated β-Glucan from Saccharomyces cerevisiae (sGSC) on growth performance, antioxidant ability, nonspecific immunity, and intestinal flora of the red swamp crayfish (Procambarus clarkii). Four experimental diets (sGSC25, sGSC50, sGSC100 and sGSC200) with different levels of sGSC (0.025%, 0.05%, 0.1% and 0.2% in diet, respectively) were fed to juvenile crayfish (average weight: 2.5 ± 0.5 g) for 8 weeks. The control diet was given with 2000 mg/kg GSC (GSC200 group). The based control diet was given without sGSC or GSC (blank group). Each group had 3 parallel test pools, 20 crayfish were reared in each pool. At the end of the growth trial, adding dietary 0.025%–0.1% sGSC could significantly improve the growth performance, antioxidant capacity and immunity of crayfish. Compared with GSC, sGSC had a better effect at lower concentration. Higher concentration of sGSC (>0.1%) would cause some side effects. sGSC also could improve the structure of the intestinal flora and optimize the function of the flora. sGSC would increase the abundances of probiotics such as Hafnia and Acinetobacter , and decreases the abundances of maleficent bacteria such as Enterobacteriaceae. Higher concentration of sGSC (>0.1%) would increase the abundance of Aeromonas. To conclude, 0.025%–0.1% sGSC can be used as a supplement in crayfish feed to increase growth, immunity, and antioxidant capacity and improve the structure of intestinal flora. These results provided a theoretical basis for the application of sGSC instead of GSC in crayfish breeding. It will be necessary to further study the optimal concentration of sGSC in feed additives in different growth stages of crayfish in the future. • Dietary sGSC increased crayfish antioxidant ability and immunity. • Dietary sGSC increases probiotics and reduces harmful bacteria in intestinal flora. • There was dose-dependent on the dietary levels of sGSC for Procambarus clarkii. • The appropriate dietary level of sGSC was 0.025%–0.1%. [ABSTRACT FROM AUTHOR]

Peptidoglycan recognition proteins (PGRPs) belong to a member of pattern-recognition receptors (PRRs), which proposed as antibacterial protein. The present study investigated the antibacterial effect of BpPGRP5 in great blue-spotted mudskipper (Boleophthalmus pectinirostris). BpPGRP5 transcript was detected in all tested tissues with the highest expression level in spleen, and its expression was significantly upregulated in spleen, intestine, and kidney following Aeromonas veronii infection. rBpPGRP5 was found to interact with several polysaccharides and bacteria, including Gram-negative bacteria (Escherichia coli and A. veronii) and Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus). rBpPGRP5 inhibited the proliferation of E. coli , S. aureus , L. monocytogenes , and A. veronii in a Zn2+-dependent manner. Furthermore, in vivo studies revealed that intraperitoneal injection of rBpPGRP5 improved the survival rate of A. veronii -infected B. pectinirostris , accompanied by decreased bacterial load in the blood, kidney, intestine, and spleen. Taken together, our results indicated that BpPGRP5 is an antimicrobial protein that protects B. pectinirostris against bacterial infection. • BpPGRP5 transcripts were altered in B. pectinirostris after A. veronii infection. • RBpPGRP5 bound to Lys-PGN, Dap-PGN, LTA, β-Glucan, Mannan, E. coli , A. veronii , L. monocytogenes , and S. aureus. • RBpPGRP5 administration improved the outcomes of A. veronii infected B. pectinirostris. [ABSTRACT FROM AUTHOR]

β-glucans are carbohydrates present in the cell wall of many fungi, which are often used as immunostimulants in feeds for farmed species. Their capacity to activate innate immune responses directly acting on innate cell populations has been widely documented in fish. However, whether they can affect the functionality of adaptive immune cells has been scarcely explored. In this context, in the current work, we have determined the effects of β-glucans on rainbow trout blood IgM+ B cells in the presence or absence of 2,4,6-trinitrophenyl hapten conjugated to lipopolysaccharide (TNP-LPS), a model antigen. For this, rainbow trout peripheral blood leukocytes were incubated with different doses of β-glucans or media alone in the presence or absence of TNP-LPS for 48 h. The size, levels of expression of surface MHC II, antigen processing and phagocytic capacities and proliferation of IgM+ B cells were then studied by flow cytometry. The number of IgM-secreting cells in the cultures was also estimated by ELISpot. β-glucans significantly decreased the levels of surface MHC II expression and the antigen processing capacities of these cells, especially in the presence of TNP-LPS, while they increased their phagocytic activity. On their own, β-glucans slightly activated the proliferation of IgM+ B cells but reduced that induced by TNP-LPS. In contrast, β-glucans significantly increased the number of cells secreting IgM in the cultures. This effect of β-glucans on the IgM-secreting capacity of B cells was also confirmed through a feeding experiment, in which the IgM-secreting capacity of blood leukocytes obtained from fish fed a β-glucan-supplemented diet for one month was compared to that of leukocytes obtained from fish fed a control diet. Altogether, these findings contribute to increase our knowledge regarding the effects of β-glucans on fish adaptive responses. • β-glucans significantly reduce the levels of surface MHC II and antigen-presenting capacities of trout blood IgM+ B cells. • β-glucans increase the proliferation of IgM+ B cells on their own, but reduce that induced by TNP-LPS. • β-glucans increase the size of trout IgM+ B cells and the number of cells secreting IgM in blood leukocyte cultures. • A β-glucan-supplemented diet increases the percentage of IgM+IgD− B cells and number of IgM secreting cells in blood. [ABSTRACT FROM AUTHOR]

To improve the shelf-life of food products rich in lipids, it is important to minimize the lipid oxidation that occurs during processing, since this oxidation not only decreases shelf-life but also induces off-flavors. To evaluate the oxidation of lipids in the production of one β-glucan-rich and one protein-rich food supplement made from oats (Avena sativa), the neutral and polar lipid profile, hexanal content, peroxide value, avenanthramides and lipase activity were measured at all production steps. The concentration of antioxidants in the form of avenanthramides was also investigated. This study shows that oat lipases were fully inactivated in the wet processing part of the processing line, and the total lipid content per dry weight increased with the progression of steps toward the oat protein product. Processing had no apparent effect on avenanthramide levels. Lipid oxidation markers increased in certain processing steps. The most significant increase in hexanal and peroxide values could be seen in the spray-drying step of the process, while a much smaller increase was seen for the drum-drying. The main conclusion is that the most important factor to prolong the shelf-life of the product is to minimize the oxidation in the drying step. [Display omitted] • Study of production steps for oat ingredients enriched with β-glucan and proteins. • Hexanal and peroxide levels significantly increased with spray-drying. • Shelf-life is less affected by drum-drying than by spray-drying. • Wet processing inactivated endogenous oat lipases. • Avenanthramides remained the same throughout the processing steps. [ABSTRACT FROM AUTHOR]

Oat beverage has become increasingly popular, yet its processing removes valuable nutritional components and results in waste stream. This study evaluated the use of ultrasound as a pre-treatment technology to improve nutrient recovery in oat beverage preparation. Various ultrasound power levels (60, 240, and 960 W) and treatment times (1, 5, and 9 min) were investigated for their effects on physical and chemical changes during oat beverage preparation. Ultrasound effectively reduced the size of larger oat grain fibrous particles while largely leaving smaller size compounds unaffected. Partial disintegration of cell wall structures was also observed under confocal laser scanning microscopy. This resulted in a significant increase (up to 39%) in β-glucan recovery with minor alteration to its molecular weight in oat beverage, preserving its inherent health benefits. Protein recovery was not improved, but ultrasound led to partial unfolding of tertiary structure, improving protein solubility and foaming properties of oat beverage, which could be beneficial in developing coffee-based beverages and desserts. The shear-thinning behavior of oat beverage was maintained after ultrasound treatment, benefiting processing efficiency and mouthfeel. Overall, these findings highlight the potential of ultrasound as a sustainable pre-treatment technology to enhance the nutritional quality and physicochemical properties of oat beverage. • Ultrasound increased the β-glucan recovery with minimum reduction on the M w. • 240–960 W ultrasound treatments promoted protein unfolding and improved foaming properties. • Shear-thinning behavior was preserved in ultrasound treated oat beverages. [ABSTRACT FROM AUTHOR]

Intelectins are immune lectins expressed in chordates, including several fish species, in which intelectins are known to be upregulated upon infection. However, the basic biochemical properties and bacteria binding specificities of several fish intelectins are not well studied. We focus our investigation on zebrafish intelectin-2 (DrIntL-2) that is predominantly expressed in the gastrointestinal tract. The disulfide-linked oligomeric state and the cysteine responsible for intermolecular disulfide bonds are identified. DrIntL-2 is a globular particle of around 30 nm. In addition to the typical exocyclic 1,2-diol ligands, DrIntL-2 binds β-1,3-glucan and recognizes Salmonella typhimurium and Pseudomonas aeruginosa. This investigation not only shed light on the fish innate immunity that will be essential for the aquaculture industry, but will also provide a foundation for further application of DrIntL-2 in bacteria detection and identification. • Intelectin is an emerging class of immune lectin. • Zebrafish intelectin-2 is a disulfide-linked dimer that further oligomerizes. • Zebrafish intelectin-2 recognizes Salmonella and Pseudomonas bacteria. • Ligands for zebrafish intelectin-2 are exocyclic 1,2-diols and β-1,3-glucan. • Molecular modeling suggests the pyranoside ring binding mechanism. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of dietary recombinant human lysozyme (RHL) on the growth, immune response, anti-oxidative activity, intestinal morphology, intestinal microflora and disease resistance of shrimp Litopenaeus vannamei. Shrimps with an initial body weight of 2.36 ± 0.02 g were fed diets supplemented with 0 (control group, R0), 0.0025% (R1), 0.005% (R2), 0.01% (R3), 0.02% (R4) and 0.04% (R5) of RHL, respectively. After a 10-week feeding trial, the final body weight, survival rate, weight gain ratio and protein efficiency rate of the shrimps in dietary RHL supplemented groups were significantly higher than that in the control group, while feed conversion ratio was significantly lower (P < 0.05). The total haemocyte count, total anti-oxidative capacity, respiratory burst, activities of phagocytosis, nitric oxide synthase, phenol oxidase and lysozyme in serum were significantly higher in dietary RHL supplemented groups than those in the control group (P < 0.05). Meanwhile, the intestinal pile height and wall thickness were significantly higher in dietary RHL supplemented groups than those in the control group (P < 0.05). Dietary RHL significantly improved the expressions of immune-related genes in gill, such as lipopolysaccharide-β-glucan binding protein, Toll, immune deficiency, heat shock protein 70 and Crustin (P < 0.05). The abundance of proteobacteria and bacteroidetes in intestine was higher, while the abundance of firmicutes and cyanobacteria was lower than those in the control group at the phylum level. In addition, dietary RHL supplementation significantly improved the protective ability of shrimp against V. parahaemolyticus infection (P < 0.05). Based on the broken-line model analysis for weight gain ratio after the feeding trial, the optimal level of dietary RHL supplementation for shrimp was estimated to be 0.006375%. • Recombinant human lysozyme (RHL) had antibacterial activity in vitro. • Dietary supplementation of RHL improved the growth and feed utilization of shrimp. • The immunity and disease resistance of shrimp were increased by appropriate dietary RHL supplementation. • The optimal level of dietary RHL supplementation was determined as 0.006375% for shrimp. [ABSTRACT FROM AUTHOR]

The overuse of antibiotics in aquaculture has led to serious concerns on microbial resistance and chemical residues. Novel sources of immunostimulants could help to solve this problem by stimulating the immune system to fight against pathogens. Therefore, this study aims to explore the immunostimulant potential of Cystobacidium benthicum -β-glucans (Cb -βG) using thymus cells from Totoaba (Totoaba macdonaldi), a recently farmed fish species in Mexico. The Cb -βG was characterized and tested for its own antioxidant capacity. Then, a Cb -βG safety experiment was carried out in thymus cells by evaluating the effects on immune parameters and immune-related genes. Cb -βG had a molecular weight of 2.32 kDa, comprised of β-1,3–1,6-glucan (53.4%), and showed strong antioxidant capacity compared to that of the positive antioxidant control. Cb -βG had no toxic effects of thymus cells and enhanced phagocytic, respiratory burst, myeloperoxidase and superoxide activities. Additionally, immune-related genes implicated in recognition and effector functions of yeast glucans were up-regulated (Toll like receptor 2, C-type lectin family 17 member A, colony-stimulating factor 1 receptor 2, macrophage mannose receptor 1, and Interleukin-1β). In conclusion, the glucan -characterized physically-chemically from the yeast C. benthicum (Cb -βG)- was safe, had strong antioxidant capacity to scavenge free radicals, and stimulated immune parameters and immune-related gene expressions on thymus cells from Totoaba macdonaldi. • Cystobacidium benthicum -β-glucans (Cb -βG) was chemically characterized. • Cb -βG had own antioxidant capacity. • Cb -βG enhanced in immune parameters and immune-related genes in Totoaba macdonaldi thymus cells. • Cb -βG could be considered a potential immunostimulant for farmed Totoaba in Mexico. [ABSTRACT FROM AUTHOR]

An eight-week feeding trial was performed to assess the effect of different dietary levels (0, 0.5, 1.0, and 1.5%) of β-glucan (sourced from Saccharomyces cerevisiae) on growth, survival, immunological parameters (immune gene expression, lysozyme, and antiprotease), total antioxidant status, thermal tolerance, and disease resistance of Tor putitora fry. Feeding of moderate doses (0.5 and 1.0%) of β-glucan significantly improved survival but not weight gain percentage as compared to that received unsupplemented control and highest dose (1.5%) of glucan. Supplementation of β-glucan in diets differentially influenced the mRNA expression of cytokine and other immune genes. For instance, transcripts of cytokines such as tnf-α and il-1β were significantly upregulated, while ifn-γ and il-10 were unaffected by β-glucan intake. Also, the relative mRNA expression of tlr-5 and hepcidin1 along with lysozyme and antiprotease activities were remained largely unchanged by dietary glucan administration. In contrast, β-glucan induced mRNA expression of defensin1 and c3 while decreased the transcript level of mhc-1. On the other hand, dietary inclusion of β-glucan markedly improved total antioxidant levels and extended the thermal tolerance limits at both the ends, as shown by increased CT max and lower CT min than the control group. After feeding β-glucan for eight weeks, the fish were bath challenged with a bacterial pathogen, Aeromonas salmonicida. The challenge study results revealed that β-glucan intake improved most of the studied immune parameters, resulting in lower mortality. Overall, dietary inclusion of β-glucan (0.5–1.0%) was efficient in improving the immune responses, thermal tolerance, and disease resistance of T. putitora fry. • Effects of dietary β-glucan in golden mahseer, Tor putitora fry were elucidated. • Dietary β-glucan enhanced thermal tolerance limits of T. putitora fry. • β-glucan significantly improved survival but not weight gain of T. putitora fry. • Dietary β-glucan modulated the expression of cytokines and other immune genes. • β-glucan improved resistance of T. putitora fry against A. salmonicida infection. [ABSTRACT FROM AUTHOR]

β-1,3-glucans, natural polysaccharide groups, exert immunomodulatory effects to improve the innate response and disease resistance in aquatic species and mammals. However, this β-glucan stimulant is yet to be assayed in swimming crab (Portunus trituberculatus) hemocytes. In this study, we explored the immunomodulatory effect of β-1,3-glucans (derived from Euglena gracilis) via in vitro 24 h stimulation assays in swimming crab hemocytes. We found that this algal β-1,3-glucans in crab hemocytes significantly elevated cellular enzymes related parameters, including phenoloxidase (PO), lysozyme, acid phosphatase (ACP) activities, and superoxide anion generation (O 2 −) rate both at intracellular (P < 0.05) and extracellular (P < 0.05) levels. Besides, alkaline phosphatase (AKP) in hemocytes exhibited no significant differences across the groups (P > 0.05). β-glucan significantly influenced (P < 0.05) the activities of the antioxidant enzyme, superoxide dismutase (SOD) in hemocytes. Moreover, the relative mRNA expression of numerous immune-related genes, including proPO, TLR-2, Alf-1, NOX, Lysozyme, Crustin-1, and Cuznsod, was significantly higher stimulated hemocytes than in control (P < 0.05). We also reported the dose-dependent antiparasitic activity against Mesanophyrs sp., in stimulated hemocytes than in the control (P < 0.05). The present study collectively demonstrated that β-glucan potentially stimulates innate immunity by elevating cellular enzyme responses and up-regulating the mRNA expression of genes associated with crab innate immunity. Thus, β-glucan is a promising immunostimulant for swimming crab farming in crustaceans aquaculture. • β-glucan affects the immune parameters and gene expression in crab hemocytes. • Stimulating hemocytes enhances immune activities and gene expression. • Stimulated hemocytes have significant antiparasitic effects against Mesanophrys sp. • β-glucan is a promising immunostimulant for swimming crab farming. [ABSTRACT FROM AUTHOR]

Oat β -glucan is catabolized by gut microbiota, however, the interaction relationship between β -glucan and gut microbiota is unclear. We aim to investigate the primary intestinal microbial species responsible for oat β -glucan degradation and explore their interaction. The result of in vitro fermentation showed that β -glucan significantly altered gut microbiota composition and primary microbial species responding to β -glucan was Lactobacillus. A total of 4 strains of Lactobacillus murinus were in vitro obtained and inoculated in the medium containing β -glucan as the sole carbon source to verify their association with β -glucan, and result showed that 4 strains of L. murinus could indeed degrade β -glucan. Genome analysis suggested that 4 strains of L. murinus contained abundant carbohydrate enzymes-encoding genes, among which genes encoding glycoside hydrolases family 1 (GH1) were most likely associated with β -glucan degradation. Further analysis revealed that GH1 could bind to β -glucan units through hydrogen bonding. Our study provides a novel insight into the research on interplay between dietary components and gut microbiota, and strategy for the exploration of potential carbohydrate hydrolase from gut microbiota for cereal β -glucan processing. [Display omitted] • The relationship between oat β -glucan and gut microbiota was systematically evaluated. • The effect of oat β -glucan on gut microbiota at the species level was clarified. • 4 strains of Lactobacillus murinus primarily responding to β -glucan were in vitro obtained. • Intestinal oat β -glucan degradation was closely related to GH1 enzymes of Lactobacillus murinus. [ABSTRACT FROM AUTHOR]

This study explored pilot scale air classification of flours from two barley varieties: CDC Austenson (hulled) and CDC Valdres (hull-less) for the production of protein enriched food ingredients. The objective was to understand the effect of repeat milling and air classification cycles on the shift of proteins and other components including starch, β-glucan, fiber and ash. Protein enrichment was achieved for both varieties, with 2.13 and 1.75 times increase in protein content for CDC Austenson and CDC Valdres, respectively, after the first fractionation cycle. Repeat cycles led to further protein separation for both varieties, resulting in an effective protein separation efficiency of 47–52% w/w towards the fine fractions. The fine fractions were also enriched with fat and ash. Whereas, the coarse fractions were enriched in total, soluble and insoluble dietary fibers as well as β-glucan. Starch distribution varied between varieties, with CDC Austenson showing a shift towards coarse fractions, while towards fine fraction for CDC Valdres due to its smaller granule size. This study established a pilot scale process for fractionation of barley. The compositional data of these fractions will aid the development and use of barley as a food ingredient in foods including snacks (starch-rich) and meat alternatives (protein-rich). [Display omitted] • Pilot scale fractionation of barley enriched its protein by at least 1.75 times. • Repeated fractionation led to ∼50% protein separation efficiency in fine fractions. • Fine fractions had more protein, fat, ash; coarse ones had more fibers, β-glucan. • A scalable barley fractionation process was established for various food uses. [ABSTRACT FROM AUTHOR]

The novel processing of black mash bean flour through the synergistic combination of gelatinization and fermentation via Saccharomyces cerevisiae MK-157 and Lactobacillus sp. E14 was explored. The results of the atomic force microscopy (AFM) indicated significant structural transformative changes in the nanomorphological features. Specifically, the average particle size has been decreased to 122.65 nm for raw mash bean flour (RMBF) and 66 nm for gelatinized and fermented flour (GMBF) via S. cerevisiae MK-157. The enhanced beta-glucan distribution of fermented samples was highlighted by fluorescence microscopy, exhibiting health-promoting qualities. The RMBF fermented by S. cerevisiae MK-157 showed the strongest FRAP-IC 50 (18.58 mg/mL) and DPPH inhibition-IC 50 (54.62 mg/mL). Additionally, fermentation elevated the total phenol content (TPC) which resulted in 2.68% increase for GMBF fermented by Lactobacillus E14. Similarly, the largest increase (5.02 %) in total flavonoid content (TFC) was observed for GMBF fermented by S. cerevisiae MK-157. Certain metabolites, such as lactic acid, which contribute to the antioxidant capacity were identified by 1H NMR. Thermogravimetric analysis showed remarkable thermal stability regarding residual masses of 27.54% for GMBF fermented by S. cerevisiae MK-157 and 32.18% for RMBF fermented by Lactobacillus E14 at 500 °C. Thus, the current study may contribute to the development of the legume processing. • The combination of gelatinization and fermentation of Mash beans was explored. • AFM indicated particle size reduction (122.6 nm) by S. cerevisiae MK-157. • S. cerevisiae MK-157 showed FRAP-IC 50 (18.58 mg/mL) and DPPH-IC 50 (54.62 mg/mL). • TGA showed thermal stability of residual masses (32.18%) by Lactobacillus E14. • Fluorescence microscopy highlighted the enhanced distribution of beta-glucan. [ABSTRACT FROM AUTHOR]

Oat β-glucan, recognized, a key functional component of oats, presents challenges in its determination due to low efficiency, cumbersome operations, and high costs, thereby posing obstacles to the large-scale production and industrialization of oats. This study aimed to clarify the quantitative relationship between β-glucan content and near-infrared (NIR) spectra in oat grains. Utilizing 63 oat grain varieties as test materials, this study analyzed their β-glucan content and NIR spectra. The focus of the research lay in evaluating the impact of various preprocessing and modeling methods on the accuracy of NIR spectroscopy for detecting β-glucan content in oat grains. The results indicated that the successive projections algorithm-multiple linear regression (SPA-MLR) model with square preprocessing, along with the partial least squares regression (PLSR) and support vector machine regression (SVR) models under multiplicative scattering Correction (MSC) preprocessing, achieved high accuracy, with correlation coefficients (R2) of 0.84, 0.66, and 0.76, respectively. The SPA-MLR model, employing square preprocessing, exhibited optimal performance, with an R2 of 0.84, root mean square error (RMSE) of 0.55, mean absolute error (MAE) of 0.46, and a ratio of performance to standard deviation (RPD) of 2.45, proving effective in accurately determining the β-glucan content in oat grains. • Preprocessing influenced the NIR spectra of oat grain β-glucan. • Square preprocessing excelled in SPA-MLR model. • Quantitative Relationship between β-Glucan Content and NIR Spectra. • The optimized model detects oat grain β-glucan via NIR spectra. [ABSTRACT FROM AUTHOR]

Considering the prevalent coexistence of dietary fiber and polyphenols in wheat flour-based products, the effects of oat β-glucan (OβG), tea polyphenols (TP), and the combination of the two (OβG + TP) on the rheological properties and microstructure of dough were investigated. The increasing concentration of OβG (from 1 g/100 g to 5 g/100 g) decreased the water absorption of dough by 11.8%, whereas increased the resistance to extension by 26.7%. However, the addition of TP (from 0.5 g/100 g–2 g/100 g) induced a reverse trend. In the "OβG + TP" system, OβG exerted a more remarkable influence on water absorption and pasting properties than TP due to its viscosity and gel-forming properties. However, TP had a more profound impact on degree of softening, stability, and extensibility of dough, which may be due to its strong reducibility and preferential reaction with gluten protein. At a low concentration (≤OβG + TP-(3 + 1)), TP had a predominant influence on viscoelasticity, whereas at a high concentration (OβG + TP-(5 + 2)), OβG showed a predominant impact. Besides, the destruction of gluten structure and starch exposure were more remarkable with the increasing concentration of OβG + TP. • OβG has a greater effect on water absorption and pasting properties than TP in dough. • TP has a stronger effect on the stability, extensional properties and of dough than OβG. • The effect of OβG and TP on dough viscoelasticity depends on their concentration. • Coexistence of OβG and TP significantly affects the microstructure of dough. [ABSTRACT FROM AUTHOR]

To determine the optimal degree of milling (DOM) for processing highland barley rice (HBR), a comprehensive assessment of the nutritional composition, polyphenol content, antioxidant capacity, edible quality, and aroma compounds was conducted in 10 cooked HBR with varying DOM. Gas chromatography-ion mobility spectroscopy (GC-IMS) and relative odor activity value (ROAV) analysis were employed to identify the key volatile flavor compounds in cooked HBR. The results demonstrated that an increase in DOM led to a decrease in protein, fat, fiber, ash, total phenol, total flavonoid contents, and antioxidant activity of the cooked HBR. Conversely, total starch and β-glucan exhibited an increasing trend. The cooked HBR achieved its optimal overall sensory quality when the milling mass loss rate reached 14.54%. Additionally, 35 aroma substances in different cooked HBR samples were identified, including alcohols, aldehydes, ketones, and esters. Out of these compounds, 14 were deemed key volatile flavor compounds with a ROAV ≥1, and 7 compounds significantly contributed to the flavor differences among the samples. A comprehensive analysis found that a DOM of 14.54% was more suitable for preserving the nutritional function and improving the flavor characteristics of cooked HBR. This study offers valuable theoretical support for the development of HBR products. [Display omitted] • Milling reduced most of the nutrients, phenolics and antioxidant capacity of highland barley rice (HBR). • Milling led to increased starch and β-glucan and improved edible quality of HBR. • Fourteen key aroma compounds of cooked HBR were screened based on GC-IMS and ROAV. • Seven key aroma compounds were crucial for tracking the flavor change of cooked HBR. • Optimal milling degree for processing HBR was comprehensively selected to be 14.54%. [ABSTRACT FROM AUTHOR]

The malting process takes one week to steep, germinate, and kiln barley to make malt. Making quality malt is critically important to achieve the desired attributes of the finished beer, and the process is time-intensive and costly. Malt quality is assessed by indicators including β-glucan quantity, α-amylase activity, Free Amino Nitrogen (FAN) content, and overall extract concentration in the finished malt. Here, we report Pulsed Electric Field (PEF) treatment of barley to accelerate malt production. A small-scale trial of 250 g to 1.00 kg barley, was evaluated for germination at two PEF treatment conditions, generically referred to as "low" and "high", that resulted in increased barley rootlet length during germination of 1.3 mm longer than was observed for the control. Large-scale trials of 1.00 kg–3.00 kg barley, resulted in an increase in germination rate and a decrease of β-glucan concentration in the PEF treated barley. Micromalted barley using PEF parameters of 1.0 kV/cm and 15.0 kJ/kg displayed a reduction in β-glucan concentration by 38%, and increase in malt extract by 1.5%, FAN by 6.2%, and α-amylase by 8.4%, supporting the hypothesis that PEF treated barley generates more and better malt, leading to greater efficiency in the beer making process. • Pulsed Electric Field (PEF) accelerated the rate of germination for barley. • The concentration of β-glucan for PEF treated barley was significantly reduced from control. • The quality and quantity of malt extract was improved by PEF treatment. [ABSTRACT FROM AUTHOR]

As a series of our previous studies reported, recombinant yeast can be the oral vaccines to deliver designed protein and DNA, as well as functional shRNA, into dendritic cells (DCs) in mice for specific immune regulation. Here, we report the further optimization of oral yeast-based vaccine from two aspects (yeast characteristics and recombinant DNA constitution) to improve the effect of immune regulation. After screening four genes in negative regulation of glucan synthesis in yeast (MNN9 , GUP1 , PBS2 and EXG1), this research combined HDR-based genome editing technology with Cre-loxP technology to acquire 15 gene-knockout strains without drug resistance-gene to exclude biosafety risks; afterward, oral feeding experiments were performed on the mice using 15 oral recombinant yeast-based vaccines constructed by the gene-knockout strains harboring pCMV-MSTN plasmid to screen the target strain with more effective inducing mstn-specific antibody which in turn increasing weight gain effect. And subsequently based on the selected gene-knockout strain, the recombinant DNA in the oral recombinant yeast-based vaccine is optimized via a combination of protein fusion expression (OVA-MSTN) and interfering RNA technology (shRNA-IL21), comparison in terms of both weight gain effect and antibody titer revealed that the selected gene-knockout strain (GUP1 Δ EXG1 Δ) combined with specific recombinant DNA (pCMV-OVA-MSTN-shIL2) had a better effect of the vaccine. This study provides a useful reference to the subsequent construction of a more efficient oral recombinant yeast-based vaccine in the food and pharmaceutical industry. • Acquired 15 gene knock-out yeast strains combined HDR-based genome editing technology with Cre-loxP technology. • Screened 2 modified yeast strains which have better efficacy from 15 vaccines. • Developed an enhanced oral delivery vaccine based on yeast characteristics and recombinant DNA constitution. [ABSTRACT FROM AUTHOR]

The effects of dietary β-glucan on innate immune responses have been shown in a number of different vertebrate species. However, there is conflicting information about the period of administration (shorter vs. longer), and it is also unclear to what extent β-glucan's effects can be observed post-treatment in fish. Thus, we fed Nile tilapia for 0 (control group; 45 days of control diet), 15 (30 days of control followed by 15 days of β-glucan), 30 (15 days of control followed by 30 days of β-glucan) or 45 days with a diet containing 0.1% of β-glucan (MacroGard®). We evaluated the growth performance at the end of the β-glucan feeding trial and the innate immune function immediately after the feeding trial and 7 and 14 days post-feeding trial. In addition, at day 10 post-feeding trial, we assessed the tilapia's resistance against a bacterial infection. No significant differences were observed in growth performance between the groups; however, fish fed with β-glucan for 30 and 45 days had higher (approx. 8%) relative weight gain compared to the control. Regardless of the administration period, fish fed with β-glucan had higher innate immune responses immediately after the feeding trial such as lysozyme activity in plasma, liver and intestine and respiratory burst compared to the control, and in general these differences were gradually reduced over the withdrawal period (up to 14 days). No differences were observed in the plasma hemolytic activity of the complement or myeloperoxidase activity in plasma or intestine. Moreover, fish from the control group had early mortalities (2 vs. 4–5 days post-infection, respectively) and a lower survival rate (60 vs. 80%, respectively) compared to fish fed with β-glucan for 15 or 30 days, and, interestingly, fish fed for 45 days with β-glucan had no mortality. This study indicates that regardless of the administration period (i.e., 15 up to 45 days), the β-glucan improved the innate immune responses and the tilapia's resistance to disease, and this protection could be observed up to 10 days post-feeding trial, adding in vivo evidence that β-glucan may contribute to a trained innate immunity. Additionally, we showed that a longer period of administration did not cause immunosuppression as previously hypothesized but promoted further growth and immune performance. These findings are relevant to the aquaculture industry and demonstrate that a longer β-glucan feeding protocol may be considered to achieve better results. • We tested administration periods of β-glucan and their prolonged effect in fish immunity. • Regardless of the administration period, β-glucan enhanced the immune responses. • Although small, β-glucan's effects were observed up to 14 days post-feeding trial. • All fish fed with β-glucan had higher protection against the bacterial challenge. • Longer administration did not exhaust the immune function but rather improved it further. [ABSTRACT FROM AUTHOR]

In this study, the effect of dietary supplementation of mannan oligosaccharide (MOS) + β-glucan (Immunogen®) was investigated on growth performance, body composition, gut microflora, innate immune responses and gene expression of some proinflammatory cytokines in shabout (Tor grypus). Shabout fingerlings (35 ± 1.2 g) were fed with basal diet (control) or basal diet supplemented with Immunogen® at 0.5, 1 and 1.5% of feed for 90 days. According to the results, growth parameters were significantly improved in fish fed with prebiotic (1 and 1.5%) for 90 days (p < 0.05). The carcass protein content was significantly higher in fish nourished by prebiotic at 1.5% of feed for 90 days compared to fish received the basal diet (p < 0.05). Feeding with various levels of Immunogen® resulted in the significant promotion of the population of intestinal Lactobacillus spp. in the prebiotic-treated groups relative to the control group (p < 0.05). Serum total globulin was significantly higher in all prebiotic groups relative to the control group at day 60. Serum bactericidal and lysozyme activities were significantly (p < 0.05) elevated after feeding with dietary prebiotic at all intervals (days 30, 60 and 90). However, the highest serum bactericidal activities were recorded in fish fed with Immunogen® at 1.5% of diet (p < 0.05). The transcription levels of interleukin 1 beta (IL-1β), interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) were significantly increased in the head kidney of fish treated with dietary prebiotic at all intervals. The results show that dietary supplementation with Immunogen®, particularly at the level of 1.5%, can positively alter growth parameters, carcass protein, intestinal microflora and immune responses of shabout. • Dietary MOS + β-glucan (Immunogen®) improved growth performance and carcass protein content in shabout. • The population of Lactobacillus spp. increased in fish fed with prebiotic at 1.5% of feed. • Serum lysozyme and bactericidal activities were enhanced in the prebiotic-fed fish. • Dietary supplementation with MOS + β-glucan promoted the expression of IL-1β, IL-8 and TNF-α in head kidney of shabout. [ABSTRACT FROM AUTHOR]

α-1,3-Glucan is a homopolymer composed of D-glucose (Glc) and it is an extracellular polysaccharide found in dental plaque due to Streptococcus species. α-1,3-Glucanase from Streptomyces thermodiastaticus strain HF3-3 (Agl-ST) has been identified as a thermostable α-1,3-glucanase, which is classified into glycoside hydrolase family 87 (GH87) and specifically hydrolyzes α-1,3-glucan with an endo-action. The enzyme has a potential to inhibit the production of dental plaque and to be used for biotechnological applications. Here we show the structure of the catalytic unit of Agl-ST determined at 1.16 Å resolution using X-ray crystallography. The catalytic unit is composed of two modules, a β-sandwich fold module, and a right-handed β-helix fold module, which resembles other structural characterized GH87 enzymes from Bacillus circulans str. KA-304 and Paenibacillus glycanilyticus str. FH11, with moderate sequence identities between each other (approximately 27% between the catalytic units). However, Agl-ST is smaller in size and more thermally stable than the others. A disulfide bond that anchors the C-terminal coil of the β-helix fold, which is expected to contribute to thermal stability only exists in the catalytic unit of Agl-ST. • Agl-ST specifically hydrolyzes α-1,3-glucan. • X-Ray crystal structure of a catalytic unit of Agl-ST at 1.16 Å resolution. • A catalytic unit composed of a β-sandwich and a right-handed β-helix. • Agl-ST more thermally stable than the other α-1,3-glucanases. • A disulfide bond in the β-helix fold expected to contribute to thermal stability. [ABSTRACT FROM AUTHOR]

The disposal of cacao pod husk, a byproduct of cacao bean processing, can cause serious adverse environmental impacts, motivating scientist to explore and develop potential beneficial applications of this resource. Dried cacao pod husk was extracted with ethanol to obtain a 10.6% pectin of cacao pod husks (pCPH), and its effects on the immunocompetence of Litopenaeus vannamei were estimated. Measured variables included total haemocyte count, differential haemocyte count, phenoloxidase activity, respiratory bursts, as well as phagocytic activity and clearance efficiency against Vibrio alginolyticus after receiving pCPH at 0, 1.5, 3, and 6 μg shrimp−1 for 0, 1, 3 and 7 days via injection, and their resistance to thermal stress and V. alginolyticus infection were further evaluated. No significant differences were observed in total haemocyte count, differential haemocyte count, and respiratory bursts in shrimp receiving pCPH at 1.5 μg shrimp−1 for 1 day; however, these variables were significantly elevated after 3 days of injection, compared to the control group. The significantly increased phenoloxidase activity was assessed in shrimp receiving pCPH at 1.5, 3 and 6 μg shrimp−1 within 3 days, and activity returned to the baseline after 7 days. Furthermore, the reduced phenoloxidase activity per granulocytes or respiratory bursts per haemocytes maintained homeostasis following the variation of haemogram. For gene expression assessments in haemocytes, the immune-related genes of the lipopolysaccharide and β-1,3-glucan binding protein, prophenoloxidase II and anti-lipopolysaccharide factor as well as innate immune signaling pathway-related genes of toll-like receptors 1 and 3 significantly increased after shrimp received pCPH for 1 day. The increases in phagocytic activity and clearance efficiency were only detected in shrimp receiving pCPH at 6 μg shrimp−1 within 7 days, compared to the control. There was no significant difference in the mortality ratio of shrimp against hyperthermal stress when they received pCPH for 1 day, and the significant higher resistance to hypothermal stress and V. alginolyticus infection were found in shrimp received pCPH at 6 μg shrimp−1 for 1 days than those in the other treatments. It is therefore found that pCPH triggers immune responses serving as an immunostimulant capable of enhancing resistance against V. alginolyticus and hypothermal stress. • Pectin of cacao pod husk (pCPH) enhance immunocompetence of shrimp. • The survival ratio against hypothermal stress and pathogen infection are promoted by pCPH. • pCPH induce LGBP, proPOII, TLR1, TLR3, and ALF gene expression in haemocytes. [ABSTRACT FROM AUTHOR]

Vaccination is one of the strategies for preventing Vibrio harveyi infection in marine-cultured animals. In this study, we prepared a formalin-killed cells of V. harveyi ZJ0603 vaccine (FKC) combined with β-glucan to immune pearl gentian grouper. The results indicated that the expression levels of IgM, TNF-α, MHC-Iα, IL-1β and IL-16 significantly increased in the spleen of the vaccinated fish. Antibody titers, activities of lysozyme and superoxide dismutase were significantly prompted in blood of the vaccinated fish. After 35 d post-vaccination, all fish were challenged intraperitoneally by virulent V. harveyi , and the relative percentage of survival (RPS) of FKC+β-glucan, FKC, β-glucan and PBS were 68 ± 5.7%, 55 ± 8.5%, 42 ± 7.5% and 32 ± 6.9%, respectively. These results demonstrated that β-glucan could be as a potential adjuvant of FKC and provide good protective effect against V. harveyi infection in the pearl gentian grouper culture. • Vibrio harveyi formalin-killed cells (FKC) vaccine are evaluated the immune responses and protective effect by combined with β-glucan in pear gentian grouper for the first time. • The accumulated relative percent survival (RPS) of fishes were significantly improved when β-glucan as adjuvant to used. • Immune-related genes were remarkably higher expression level of combined with adjuvant group in post-vaccination compared with only used of vaccine, adjuvants or PBS. • Antibody titers, lysozyme and superoxide dismutase were significantly elevated in the vaccinated fish. [ABSTRACT FROM AUTHOR]

Immunostimulants are key molecules in aquaculture since they heighten defensive responses and protection against pathogens. The present study investigated the treatment of Senegalese sole larvae with a whole-cell crude extract of the microalgae Nannochloropsis gaditana (Nanno) and programming of growth and the immune system. Larvae at hatch were treated with the Nanno extracts for 2 h and thereafter were cultivated for 32 days post-hatch (dph) in parallel with an untreated control group (CN). Dry weight and length at 21 days post-hatch (dph) were higher in post-larvae of the Nanno than CN group. These differences in weight were later confirmed at 32 dph. To evaluate changes in the immune response associated with Nanno-programming treatments, the Nanno and CN post-larvae were supplied with two bioactive compounds yeast β-glucan (Y) and a microalga extract from the diatom Phaeodactylum tricornutum (MAe). The bioactive treatments were administrated to the treatment groups through the live prey (artemia metanauplii, 200 artemia mL−1) enriched for 30 min with MAe or Y (at 2 mg mL−1 SW) or untreated prey in the case of the negative control (SW). The effect of the treatments was assessed by monitoring gene expression, enzyme activity and mortality over 48 h. The post-larvae sole supplied with the bioactive compounds Y and MAe had increased mortality at 48 h compared to the SW group. Moreover, mortality was higher in Nanno-programmed than CN post-larvae. Lysozyme and total anti-protease enzymatic activities at 6 and 24 h after the start of the trial were significantly higher in the Nanno and MAe supplied post-larvae compared to their corresponding control (CN and SW, respectively). Immune gene transcripts revealed that il1b, cxc10 and mx mRNAs were significantly different between Nanno and CN post-larvae at 6 and 24 h. Moreover, the expression of il1b , tnfa , cxc10, irf3 , irf7 and mx was modified by bioactive treatments but with temporal differences. At 48 h after bioactive treatments, Y and SW post-larvae were challenged with the lymphocystis disease virus (LCDV). No difference existed in viral copy number between programming or bioactive treatment groups at 3, 6 and 24 h after LCDV challenge although the total number of copies reduced with time. Gene expression profiles in the LCDV-challenged group indicated that post-larvae triggered a wide defensive response compared to SWC 24 h after challenge, which was modulated by programming and bioactive compound treatments. Cluster analysis of expressed genes separated the SW and Y groups indicating long-lasting effects of yeast β-glucan treatment in larvae. A noteworthy interaction between Nanno-programming and Y-treatment on the regulation of antiviral genes was observed. Overall, the data demonstrate the capacity of microalgal crude extracts to modify sole larval plasticity with long-term effects on larval growth and the immune responses. • Crude extracts of microalga Nannochloropsis gaditana modified larval programming for growth performance in sole post-larvae. • Yeast β-glucan and microalgal extract activated immune gene responses but modulated by larval programming in sole post-larvae. • LCDV DNA copies were not modified by programming or bioactive treatments. • LCDV activated a wide defensive response modulated by yeast β-glucan and Nanno-programming. [ABSTRACT FROM AUTHOR]

Shrimp lack adaptive immune systems and mainly rely on the cellular and humoral defences, involving the haemocytes (functionally analogous to vertebrate leukocytes) in non-self matter recognition, elimination, and in downstream coagulation. Furthermore, the linkage between stress-induced catecholamine (CA), a class of biogenic amines (BAs), releasing and immunological responses has been detected in shrimp. Varied isotypes of protein kinase C (PKC) regulate multiple cellular processes following their specific location and distribution within the cells, and a novel PKC identified in Litopenaeus vannamei (termed as LvnPKC) is proposed to mediate signaling transduction of immunocompetence and BA biosynthesis. In the present study, we analyzed the effects of the LvnPKC-silenced haemocytes by co-incubating with its dsRNA on the immune responses specific to prophenoloxidase (proPO) and antioxidant systems as well as phagocytic activity. In addition, the capability of haemocytes to produce BAs was assessed. The results revealed that LvnPKC-silenced haemocytes can induce interference in phenoloxidase and superoxide dismutase activities, respiratory bursts, and phagocytic activity; meanwhile, the disturbed gene expressions of proPO activating enzyme, proPOII, lipopolysaccharide- and β-1,3-glucan-binding protein, and cytosolic manganese superoxide dismutase were detected. The same deviated pattern was observed in tyrosine, dopamine, and norepinephrine levels, and in dopamine β-hydroxylase (DBH) activity and gene expressions of tyrosine hydroxylase, DOPA decarboxylase, and DBH involving in BA biosynthesis. Taken together, these results suggest that the immunocompetence and BA biosynthesis of haemocytes can be mediated via LvPKC signaling transduction, which proved the presence of a neuroendocrine-immune regulatory network in haemocytes. • LvnPKC had been knocked down efficiently in haemocyte co-incubated with its dsRNA. • Immunocompetence was deviated in LvnPKC-silenced haemocytes. • The disturbed BA biosynthesis occurred in haemocytes co-incubated with LvnPKC-dsRNA. • Haemocytes possess neuroendocrine-immune regulatory network in Litopenaeus vannamei. [ABSTRACT FROM AUTHOR]

β-Glucans have long been used as an immunostimulant in aquaculture. However, the relationship of its structure to its immunomodulatory properties are poorly understood. In this study, the particle size and chemical structure of β-glucans extracted from wild-type strain of baker's yeast (Saccharomyces cerevisiae) and its null-mutant yeasts Gas1 were characterised. Using Sigma β-glucan as a reference, the immunomodulatory properties of these polysaccharides in the germ-free Artemia franciscana model system in the presence of Vibrio harveyi bacterial challenge were investigated. The survival of the A. franciscana nauplii, upon challenge with V. harveyi , was significantly higher in all three glucan-treated groups compared to the control. The glucan Gas1 with a lower degree of branching and shorter side chain length had the most prominent V. harveyi -protective effects. The particle size did not affect the nauplii survival when challenged with V. harveyi. Results also showed that the salutary effect of the tested glucans was associated with the upregulation of innate immune genes such as lipopolysaccharide and β-1,3-glucan-binding protein (lgbp), high mobility group box protein (hmgb), and prophenoloxidase (proPO). Interestingly, the up-regulation of superoxidase dismutase (sod) and glutathione-s-transferase (gst) was only observed in Gas1 treated group, indicating that Gas1 could function to induce higher reactive oxygen species and stronger immunomodulatory function in A. franciscana , and therefore higher survival rate. The expression of heat shock protein 70 (hsp70), peroxinectin (pxn), and down syndrome cell adhesion molecule (dscam) remain unaltered in response to glucan treatment. Taken together, this study provides insights into the structure-function relationship of β-glucan and the results confirmed that β-glucan can be an effective immunostimulant in aquaculture, especially the Gas1 glucan. • The structure of β-glucan influences their bioactivity, and the Gas1 glucan was shown to be more effective. • The Gas1 glucan with a lower degree of branching and shorter side chain length prone to enhance the oxidative burst activity. • Homologs of several immune-related genes were firstly identified in the Artemia franciscana transcriptome. [ABSTRACT FROM AUTHOR]

This study was conducted to examine the combinatory effects of β-glucan and oxytetracycline (OTC) on hybrid giant tiger groupers (Epinephelus fuscoguttatus × Epinephelus lanceolatus). In vitro tests, OTC significantly reduced superoxide anion production and phagocytic activity in primary head kidney leukocytes. However, this suppressive effect was alleviated by co-treatment with β-glucan. Subsequently, feeding trials were performed to investigate the potential immunomodulatory effects of dietary β-glucan alone or in combination with OTC on groupers. A total of 210 healthy groupers (368.00 ± 51.03 g) were divided into six groups. Group 1 was the control group, group 2 (BG) received 5 g β-glucan per kg feed weight, groups 3–5 received 5 g/kg β-glucan in combination with 10, 30, or 50 mg OTC/kg fish weight/day (groups M1, M2, and M3, respectively), and group 6 (O) received 50 mg OTC/kg fish weight/day. Fish were sampled to determine the innate immunity parameters and residual OTC levels in the muscle tissue during a 28-day feeding regimen. Residual OTC levels were considerably higher in groups M3 and O compared with the other groups, and peaked on day 14. This was followed by a slight decrease on day 28, despite a continuous supply of OTC. Notably, fish fed with OTC alone had significantly decreased phagocytic rates and superoxide anion production observed in head kidney leukocytes, as well as poorer protection against Vibrio alginolyticus infection. These immunosuppressive effects were not observed in the fish fed with β-glucan in combination with a lower dose of OTC (group M2). Thus, these data suggest that the combination of dietary β-glucan and OTC exerts synergistic immunostimulating effects that protect groupers from bacterial infection. • Oxytetracycline (OTC) suppresses phagocytosis and O 2 − production in head kidney cells. • β-glucan can alleviate the immunosuppressive effects mediated by OTC in vitro. • Residual OTC levels were detected in the muscle tissue of fish fed with OTC and β-glucan. • Dietary β-glucan in combination with OTC improves the parameters of innate immunity. • A combination of β-glucan and OTC provides better protection against bacterial infection than either alone. [ABSTRACT FROM AUTHOR]

The protective role of β-glucan (BG) on liver function, histopathology, immune and antioxidant related gene expressions in Nile tilapia exposed to subacute deltamethrin (DLM) was investigated for 30 days. Fish (28.18 ± 1.34 g) of the 1st and 2nd groups fed the control diet, while the 3rd and 4th groups fed BG at 0.5 g/kg and the 2nd and 4th groups were exposed to DLM (15 μg/L) in rearing water. DLM-treated fish displayed a considerable increase in blood biochemical parameters (creatinine, urea and bilirubin) as well as hepatic enzymes (ALP, AST and ALT) (P < 0.05). Blood total protein, globulin, albumin, WBCs, RBCs, Hb, phagocytic index, phagocytic and lysozyme activities were significantly decreased in fish subjected to DLM (P < 0.05). Fish fed BG showed significantly the lowest cortisol and glucose levels, while fish exposed to DLM without feeding BG showed the highest cortisol and glucose levels (P < 0.05) after 15 and 30 days. Additionally, DLM toxicity caused downregulation in antioxidant (CAT and GPx) and immune (IL-1β and IL-8) related gene expressions, while and IFN-γ , HSP70 and CASP3 were upregulated. The histopathological examination of Nile tilapia exposed to DLM revealed damage in gills, intestine, spleen and liver which confirmed the toxic effects. Conversely, BG presented protective effects and restored the above-mentioned parameters when fish exposed to DLM and fed BG. Thus, BG supplementation exhibited defensive effects against DLM toxicity in Nile tilapia through improving blood biochemical responses, immune, and antioxidant related gene expressions as well as histopathological effects. • Deltamethrin (DLM)-treated fish showed increased blood creatinine, urea, bilirubin, ALP, AST and ALT. • Blood immune responses were decreased in fish exposed to DLM. • DLM downregulated CAT , GPx , IL-1β , IL-8 and IFN-γ genes, while HSP70 and CASP3 were upregulated. • Nile tilapia exposed to DLM revealed abnormal histopathological alterations. • β-glucan presented protective effects and restored the aforementioned parameters. [ABSTRACT FROM AUTHOR]

As one of the most important fish in freshwater aquaculture, gibel carp (Carassius auratus gibelio) is easily susceptible to Cyprinid herpesvirus 2 (CyHV-2). Immersion vaccination has attracted many researchers due to its simple operation in preventing infectious diseases. However, the unavoidable disadvantage is that the immersion vaccine must be used with adjuvants to get a better performance. In this study, gibel carps were vaccinated by a 60 min bath in a β-propiolactone-inactivated Cyprinid herpesvirus 2, mixed with DTT, β-glucan, anisodamine and scopolamine, respectively. After immunization, the fishs were challenged by CyHV-2 in 2 weeks. By analyzing pathological section, we found that β-glucan, anisodamine and scopolamine groups protected the gibel carp compared to the control group, which was consistent with the trend of survival rate. Specifically, β-glucan group in serum appeared best on lysozyme, TSOD and complement C3. Real time quantitative RT-PCR results demonstrated that in both spleen and head kidney tissues, mRNA expressions of typical Th1 immune response cytokines IL-2 and IFN-γ2 in β-glucan group and anisodamine group were significantly higher than other groups and the level of immunoglobulins related to systemic immunity (IgM) and mucosal immunity (IgZ) were also enhanced in the immune period. DTT group slightly affected immune gene and serum enzyme activity, while did not show an adjuvant effect on survival rate. In addition, four adjuvant groups could obviously inhibit CyHV-2 replication. This study explored and proved the good efficiency of β-glucan or anisodamine as immersion immune adjuvant and also provided reference for improving the efficiency of immersion immunity. • The vaccine can enter the fish and stimulate the immune response through the hypertonic immersion immune pathway. • β-glucan and anisodamine as immersion immune adjuvant improves the survival rate of gibel carp against CyHV-2. • β-glucan as adjuvant reinforces inflammatory response, Th1 type immune response and the expression level of IgM and IgZ. • DTT, β-glucan, anisodamine and scopolamine strengthen the vaccine inhibiting CyHV-2 replication. [ABSTRACT FROM AUTHOR]

One Pediococcus acidilactici strain, named PA-GY2 was isolated from the gut of cultured Macrobrachium rosenbergii. In order to better examine the potential scope and applicability of this strain in M. rosenbergii culture, based on the control diet, four experimental diets containing single or combined immunostimulants were produced by supplementing with yeast (Saccharomyces cerevisiae , SC) or/and β-glucan (G), then fed to the prawns (6.70 g ± 0.74) in five groups, which were named as group C (control group), P (PA-GY2), PS (PA-GY2 + SC, 1:1), PG (PA-GY2 + G) and PGS (PA-GY2 + SC + G), respectively. After a 60-day feeding trial, growth performance, feed utilization, immune response and disease resistance of prawns were evaluated in the present study. Results indicated that (1) The growth performance of the prawns in group PS and PGS were significantly improved. The prawns in group PGS presented the lowest feed coefficiency (FC), while prawns in group C presented the highest FC. (2) The protease activity was significantly improved by dietary immunostimulants supplementation, meanwhile, prawns in the group PS presented the highest lipase activity. (3) The highest total hemocyte count and respiratory burst activity were found in the group P and PG, respectively. The phagocytic index of the prawns in the group C was significantly lower than those in group P and PGS. (4) Dietary PA-GY2 single or combined with SC or/and β-glucan increased the immune related genes expression, including some antibacterial and antioxidant enzymes, while decreased the tumor necrosis factor-α gene expression, which led to the decreased cumulative mortality rate of prawns during the Aeromonas hydrophila challenge test. Based on the results of growth performance, digestive enzymes activity and immune response of M. rosenbergii , PA-GY2 supplementation, single or combined with SC or/and β-glucan could be suggested as promising immunostimulants in prawns farming. • One probiotic Pediococcus acidilactici strain, named PA-GY2, was isolated from the gut of cultured Macrobrachium rosenbergii. • PA-GY2 strain could effectively increase the total hemocyte count and phagocytosis, as well as the expression levels of genes encoding lysozyme, SOD, lectins and Hsp 70, while decrease the gene expression of TNF-α of M. rosenbergii. • PA-GY2 combined supplementation with Saccharomyces cerevisiae or/and β-glucan also could enhance the activities of digestive enzymes, the total intestinal population of PA-GY2, the growth performance and the gene expression of proPO, CAT, GPxs and Toll-receptors of M. rosenbergii. • Dietary PA-GY2, single or combined with Saccharomyces cerevisiae or/and β-glucan could decrease the gene expression of TNF-α, and enhance the disease resistance of M. rosenbergii against Aeromonas hydrophila. • PA-GY2 supplementation, single or combined with SC or/and β-glucan could be suggested as promising immunostimulants in prawns farming. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the toxic effects of diazinon on growth performance, hepato-renal function, antioxidant system, innate immune response and comparing the protective role of dietary Chlorella vulgaris (CV) algae and β-glucan in intoxicated Nile tilapia (Oreochromis niloticus). One hundred and eighty healthy Nile tilapia (20 ± 6.1 g) were distributed equally into four groups; control group, DZN group (0.28 mg/L), DZN-CV group (5% CV) and DZN-β-glucan group (0.1% β-glucan) and treatments conducted for about 60 days. The results revealed that administration of DZN significantly increased serum liver enzymes, uric acid, creatinine, and malondialdehyde (MDA) in different tissues. Meanwhile, glutathione (GSH) and superoxide dismutase (SOD) in different tissues, as well as IgM, C-reactive protein (CRP), respiratory burst, lysozyme and bactericidal activities were significantly decreased in DZN group. In addition, expression of TNF-α gene was up-regulated and IL-10 was down-regulated in spleen of DZN intoxicated fish. The treatment of DZN exposed fish with CV and β-glucan supplemented diets ameliorated hepatic damage and enhanced antioxidant activity and innate immune responses. Furthermore, dietary Chlorella vulgaris and β-glucan have a potent anti-inflammatory effect as they remarkably increased the expression of IL-10 and decreased TNF-α gene expression. The results also revealed that fish in DZN-CV group had the highest survival rate, final body weight (FBW) and body weight gain (BWG). On the other hand, feed conversion ratio (FCR), specific growth rate (SGR), and protein efficiency ratio (PER) of control, DZN-CV, and DZN- β-glucan were higher than DZN group. However, the hepatosomatic index (HSI) and spleen-somatic index (SSI) were higher in DZN group than other experimental groups. Overall, CV and β-glucan can be recommended as a feed supplement to improve immunosuppression, oxidative damage, growth performance and hemato-biochemical alterations induced by DZN toxicity in Nile tilapia. • Chlorella vulgaris (CV) algae and β-glucan relieved hepatorenal toxicity by induced Diazinon in Nile tilapia, Oreochromis niloticus. • CV and β-glucan modulated oxidative stress of diazinon on spleen, liver and gills of Oreochromis niloticus and enhanced innate immune responses. • CV and β-glucan reduced inflammation induced by diazinon via down-regulating gene expression of TNF-α and up-regulating IL-10 gene expression. • Chlorella vulgaris and β-glucan also increase growth performance and survival rate of Nile tilapia upon exposure to diazinon toxicity. [ABSTRACT FROM AUTHOR]

This study discloses the nanoscale silicate platelet-supported nZnO (ZnONSP) applied as novel feed additives in aquaculture. The preparation of the nanohybrid (ZnO/NSP = 15/85, w/w) was characterized by UV–visible spectroscopy, powder X-ray diffraction and transmission electron microscope. The effects of ZnONSP on growth, zinc accumulation, stress response, immunity and resistance to Vibrio alginolyticus in white shrimp (Penaeus vannamei) were \demonstrated. To evaluate the safety of ZnONSP, shrimps (2.0 ± 0.3 g) were fed with ZnONSP containing diets (200, 400 and 800 mg/kg) for 56 days. Dietary ZnONSP did not affect the weight gain, specific growth rate, feed conversion ratio, survival rate, zinc accumulation, and the expression of heat shock protein 70 in tested shrimps. To examine the immunomodulatory effect of ZnONSP, shrimps (16.6 ± 2.4 g) were fed with the same experimental diets for 28 days. Dietary ZnONSP improved the immune responses of haemocyte in tested shrimps, including phagocytic rate, phagocytic index, respiratory burst, and phenoloxidase activity, and upregulated the expression of several genes, including lipopolysaccharide, β-1,3-glucan binding protein, peroxinectin, penaeidin 2/3/4, lysozyme, crustin, anti-lipopolysaccharide factor, superoxide dismutase, glutathione peroxidase, clotting protein and α-2-macroglobulin. In the challenge experiment, shrimps (17.2 ± 1.8 g) were fed with ZnONSP containing diets (400 and 800 mg/kg) for 7 days and then infected with Vibrio alginolyticus. Notably, white shrimps that received ZnONSP (800 mg/kg) showed significantly improved Vibrio resistance, with a survival rate of 71.4 % at the end of 7-day observation. In conclusion, this study discovers that ZnONSP is a new type of immunomodulatory supplement that are effective on enhancing innate cellular and humoral immunities, and disease resistance in white shrimp. • Nanoscale silicate platelet supported nZnO (ZnONSP) is applied in aquaculture. • Dietary ZnONSP do not affect growth, stress status and zinc accumulation in shrimp. • Dietary ZnONSP enhance the innate cellular and humoral immunities of white shrimp. • Dietary ZnONSP increase shrimp resistance against Vibrio alginolyticus. [ABSTRACT FROM AUTHOR]

β-glucan from brewer's spent yeast is a novel ingredient approved to be included in the human diet. This paper evaluated the effects of β-glucan extracted from spent brewer's yeast on the physico-chemical, rheological, textural, microstructure, and molecular characteristics of common and durum wheat pasta, at different addition levels. The results showed a decrease in dough viscous and elastic moduli, while the resistance to deformation and hardness raised as the addition level increased. Pasta quality parameters were influenced by the β-glucan content depending on the wheat type, with lower pasta firmness (2.76 and 3.40 N for common and durum controls vs. 2.76–1.97 and 3.35–2.73 N for common and durum enriched pasta respectively), increased carbohydrate content (from 85.63% to 85.91–86.95% in common wheat pasta, and from 81.89 to 82.12–82.28% in durum pasta), cooking loss (from 4.73% in common control to 4.91% for 4% common wheat-β-glucan pasta, and from 3.68 in durum control to 5.05% for 4% durum wheat-β-glucan), and darker color being obtained. Pasta microstructure and molecular FT-IR characteristics confirmed the presence of β-glucan in cooked pasta and depicted protein denaturation and contribution to the final product matrix. These results represent new insights into the development of convenient matrices for functional ingredient incorporation. [Display omitted] • Pasta characteristics depend on the β-glucan level and type of wheat flour. • Dough visco-elastic moduli decreased as the β-glucan level was higher. • β-glucan lowers pasta firmness and L* and increases carbohydrates and cooking loss. • β-glucan induces protein matrix dilution confirmed by microstructure and FT-IR. • At <1% addition level the pasta quality is not negatively affected by yeast β-glucan. [ABSTRACT FROM AUTHOR]

To compensate the absence of viscoelastic gluten network, water-binding and viscosity-forming ingredients, hydrocolloids, are commonly used in gluten-free doughs. Currently, hydrocolloids are often E coded while many consumers prefer "clean-label" alternatives. For instance, microbial and cereal β-glucans are known to produce viscosity. In this study, the technological potential of these β-glucans as natural hydrocolloids was evaluated in gluten-free oat baking. Microbial β-glucan was produced by fermentation with P. claussenii using oat bran concentrate (OBC) as a raw material. Oat β-glucan was studied as various forms of OBC: as untreated OBC, pre-treated OBC suspension, and water-extractable fraction of OBC suspension (oat β-glucan extract). The baking properties after natural hydrocolloid additions were compared to a reference oat bread which was baked with common commercial hydrocolloids (psyllium, HPMC). The levels of hydrocolloids in the doughs were optimised by a test baking method. Among the hydrocolloids studied, the best bread properties were achieved with oat β-glucan extract as a hydrocolloid, as the breads resulted in similar specific volume and 37% lower staling rate compared to oat breads baked with commercial hydrocolloids. Thus, oat β-glucan extract provided a feasible and "clean-label" alternative for commercial hydrocolloids in gluten-free oat baking. • Oat β-glucan extract functioned well as a hydrocolloid in gluten-free oat baking. • Water-extraction increased β-glucan solubilisation and some structure was formed. • Additionally, removal of water-insoluble matter from oat bran concentrate was crucial. • With oat β-glucan extract, psyllium and HPMC could be replaced. • Oat β-glucan extract improved crumb properties and storage stability of oat bread. [ABSTRACT FROM AUTHOR]

In the present study, a sialic acid-binding lectin was cloned and characterized from Manila clam Ruditapes philippinarum (designed as RpSabl). The open reading frame of RpSabl encoded a polypeptide of 162 amino acids with a calculated molecular mass of 17.7 kDa. Analysis of the conserved domain suggested that RpSabl was a new member of the sialic acid-binding lectins family. In non-stimulated clams, RpSabl transcripts were constitutively expressed in all five tested tissues, especially in hepatopancreas. After Vibrio anguillarum challenge, the expression of RpSabl mRNA in hepatopancreas was significantly up-regulated at 3 h (3.8-fold, P < 0.05), 6 h (4.9-fold, P < 0.05), 12 h (12.3-fold, P < 0.01) and 24 h (9.7-fold, P < 0.01), while RpSabl transcripts in hemocytes was only significantly up-regulated at 6 h (8.5-Fold, P < 0.01). RNAi-mediated knockdown of RpSabl transcripts affected the survival rates of Manila clam against V. anguillarum , perhaps mainly due to the inhibited expression of antibacterial effectors (e.g. lysozyme and defensin). Moreover, recombinant protein of RpSabl (rRpSabl) possessed binding activities towards lipopolysaccharides (LPS), peptidoglycan (PGN) and glucan in vitro. Coinciding with the Pathogen-associated molecular patterns (PAMPs) binding assay, rRpSabl displayed broad bacterial-agglutination properties towards Vibrio harveyi , Vibrio splendidus , V. anguillarum , Enterobacter cloacae and Aeromonas hydrophila. Meanwhile, the phagocytosis and encapsulation ability of hemocytes could be significantly enhanced by rRpSabl incubation. All these results showed that RpSabl could function as a versatile molecule involved in the innate immune responses of R. philippinarum. • A sialic acid binding lectin (Sabl) was identified from the manila clam Ruditapes philippinarum. • Recombinant RpSabl possessed broad bacterial-agglutination properties perhaps benefiting from its PAMPs binding abilities. • RpSabl could function as an opsonin to promote phagocytosis and encapsulation of hemocytes against non-self. [ABSTRACT FROM AUTHOR]

In crustaceans, it has been suggested that specific protection against pathogens could be triggered by vaccines and biological response modifiers; although the specific mechanisms of this protection have not been clarified yet. In the crayfish Cherax quadricarinatus , a humoral lectin (CqL) binds its own granular hemocytes through a specific receptor (CqLR) and increases the production of reactive oxygen species (ROS). In the present study, we challenged in vivo crayfishes with immunostimulants, β-glucan (200 μg/kg) or LPS (20 μg/kg), and identified the participation of cellular and humoral mechanisms. The stimulants generated a complex modification in the total hemocytes count (THC), as well as in the proportion of hemocyte subsets. At 2 h after the challenge, the largest value in THC was observed in either challenged crayfishes. Furthermore, at the same time, hyaline hemocytes were the most abundant subset in the hemolymph; after 6 h, granular hemocytes (GH) were the most abundant hemocyte subset. It has been observed that a specific subset of GH possesses a CqLR that has been related to ROS production. After 2 and 6 h of the β-glucan challenge, a significant increase in CqLR expression was observed in the three circulating hemocyte subsets; also, an increased expression of CqL was detected in a granular hemocytes sub-population. After 2 and 6 h of stimulation, the specific activity of the serum lectin challenged with β-glucan was 250% and 160% higher than in the LPS-treated-group, respectively (P < 0.05). Hemocytes from challenged crayfishes were stimulated ex vivo with CqL, ROS production was 180% higher in hemocytes treated with β-glucan + CqL than in hemocytes treated with LPS + CqL (P < 0.05). The results evidence the effectivity of immune stimulators to activate specific crayfish defense mechanisms, the participation of CqL and its receptor (CqLR) could play an important role in the regulation of immune cellular functions, like ROS production, in Cherax quadricarinatus. • β-glucan and LPS generates a complex modification in the total and differential hemocytes counts. • β-glucan challenge increases CqLR expression in the three hemocyte subsets. • β-glucan increases expression of CqL in a granular hemocytes sub-population. • β-glucan increases the specific activity of serum lectin. • ROS production increases in hemocytes treated with β-glucan + CqL compared to LPS + CqL. [ABSTRACT FROM AUTHOR]

In the present study, a sialic acid-binding lectin was identified and characterized from Manila clam Ruditapes philippinarum (designed as RpSABL-1). Multiple alignments strongly suggested that RpSABL-1 was a new member of the sialic acid-binding lectin family. In non-stimulated clams, RpSABL-1 transcripts were constitutively expressed in all five tested tissues, especially in hepatopancreas. After Vibrio anguillarum challenge, the expression of RpSABL-1 mRNA was significantly up-regulated at 6 h (P < 0.05), 12 h (P < 0.01) and 24 h (P < 0.01). Recombinant RpSABL-1 protein (rRpSABL-1) displayed apparent binding activities towards lipopolysaccharides (LPS) and peptidoglycan (PGN), but not to glucan or chitin in vitro. Coinciding with the PAMPs binding assay, rRpSABL-1 exhibited obvious agglutination activities against Gram-positive bacterium Staphyloccocus aureus , Gram-negative bacteria Escherichia coli, V. anguillarum and Vibrio harveyi. Meanwhile, rRpSABL-1 showed antibacterial activities against E. coli , and biofilm formation of E. coli could also be inhibited after incubated with rRpSABL-1. Moreover, the encapsulation, phagocytosis and chemotactic ability of hemocytes could be enhanced by rRpSABL-1. All these results suggested that RpSABL-1 could function as a pattern recognition receptor with versatile functions in the innate immune responses of R. philippinarum. • A sialic acid binding lectin (SABL) was identified from the manila clam Ruditapes philippinarum. • Recombinant RpSABL-1 showed a broad agglutination spectrum against Gram-positive and Gram-negative bacteria. • RpSABL-1 could function as a pattern recognition receptor with broad recognition spectrum. [ABSTRACT FROM AUTHOR]

Omnivorous fish species such as the common carp (Cyprinus carpio) are able to biosynthesise long chain polyunsaturated fatty acids (LC-PUFAs) from plant oil PUFA precursors, but the influence of the amount and quality of the LC-PUFAs biosynthesised from these oils on the immunocompetence status of the fish has received little attention. This study aims to evaluate whether the conversion of PUFA by carp induces a sufficient biosynthesis of LC-PUFA to maintain a good immunocompetence status in this species. Six iso-nitrogenous (crude protein = 39.1%) and iso-lipidic (crude lipids = 10%) diets containing three different lipid sources (cod liver oil (CLO) as fish oil; linseed oil (LO) and sunflower oil (SFO) as plant oils) were formulated with or without β-glucan supplementation at 0.25 g/kg diet. Juvenile carp (16.3 ± 0.6 g initial body weight) were fed a daily ration of 4% body weight for 9 weeks and then infected at day 64 with the bacteria Aeromonas hydrophyla. No significant differences in survival rate, final body weight, specific growth rate and feed conversion rate were observed between diets. After bacterial infection, mortality rate did not differ between fish fed CLO and plant oil-based diets, indicating that the latter oils did not affect the overall immunocompetence status of common carp. Plant oil-based diets did not alter lysozyme activity in healthy and infected fish. No negative effects of plant oils on complement activity (ACH50) were observed in healthy fish, even if both plant oil-based diets induced a decrease in stimulated fish two days after infection. Furthermore, the levels of various immune genes (nk , lys , il-8 , pla , pge , alox) were not affected by plant oil-based diets. The expression of pla and pge genes were higher in SFO-fed fish than in CLO ones, indicating that this plant oil rich in linoleic acid (LA) better stimulated the eicosanoid metabolism process than fish oil. In response to β-glucan supplementation, some innate immune functions seemed differentially affected by plant oil-based diets. LO and SFO induced substantial LC-PUFA production, even if fish fed CLO displayed the highest EPA and DHA levels in tissues. SFO rich in LA induced the highest ARA levels in fish muscle while LO rich in α-linolenic acid (ALA) sustained higher EPA production than SFO. A significantly higher fads−6a expression level was observed in SFO fish than in LO ones, but this was not observed for elovl5 expression. In conclusion, the results show that common carp fed plant oil-based diets are able to produce substantial amounts of LC-PUFA for sustaining growth rate, immune status and disease resistance similar to fish fed a fish oil-based diet. The differences in the production capacity of LC-PUFAs by the two plant oil-based diets were associated to a differential activation of some immune pathways , explaining how the use of these oils did not affect the overall immunocompetence of fish challenged with bacterial infection. Moreover, plant oil-based diets did not induce substantial negative effects on the immunomodulatory action of β-glucans, confirming that these oils are suitable for sustaining a good immunocompetence status in common carp. • Common carp fed plant oil-based diets are able to produce substantial amounts of LC-PUFA for sustaining growth rate, immune status and disease resistance. • Plant oil-based diets did not induce substantial negative effects on the immunomodulatory action of β-glucans. • Linseed oil and sunflower oil are suitable for sustaining a good immunocompetence status in common carp. [ABSTRACT FROM AUTHOR]

One bottleneck to sustainability of fish aquaculture is the control of infectious diseases. Current trends include the preventive application of immunostimulants and prebiotics such as polysaccharides. The present study investigated how yeast β-glucan (Y), microalgal polysaccharide-enriched extracts (MAe) and whole Phaeodactylum tricornutum cells (MA) modulated the gut microbiome and stimulated the immune system in Senegalese sole (Solea senegalensis) when administered by oral intubation. Blood, intestine and spleen samples were taken at 3 h, 24 h, 48 h and 7 days after treatment. The short-term response (within 48 h after treatment) consisted of up-regulation of il1b and irf7 expression in the gut of the Y treated group. In contrast, administration of MAe decreased expression of tnfa and the chemokine cxc10 in the gut and spleen. Both treatments down-regulated the expression of irf3 with respect to the control group. Lysozyme activity in plasma decreased at 48 h only in the MAe-treated soles. Medium-term response consisted of the up-regulation of clec and irf7 expression in the gut of the Y, MAe and MA groups and of il1b mRNAs in the spleen of the MA group compared to the control group. Microbiome analysis using 16S rDNA gene sequencing indicated that the intestine microbiome was dominated by bacteria of the Vibrio genus (>95%). All the treatments decreased the relative proportion of Vibrio in the microbiome and Y and MAe decreased and MA increased diversity. Quantitative PCR confirmed the load of bacteria of the Vibrio genus was significantly decreased and this was most pronounced in Y treated fish. These data indicate that orally administrated insoluble yeast β-glucans acted locally in the gut modulating the immune response and controlling the Vibrio abundance. In contrast, the MAe slightly reduced the Vibrio load in the intestine and caused a transient systemic anti-inflammatory response. The results indicate that these polysaccharides are a promising source of prebiotics for the sole aquaculture industry. • Insoluble yeast β-glucans increased il1b mRNAsand reduced Vibrio loads in the gut indicating a major local action. • Microalgal extracts triggered a systemic response with a decrease of innate immune defenses and reduction of Vibrio loads. • Whole-cell microalgae increased the diversity of gut microbiota. [ABSTRACT FROM AUTHOR]

Flavonoids exert a wide variety of biological functions that are highly attractive for the pharmaceutical and healthcare industries. However, their application is often limited by low water solubility and poor bioavailability, which can generally be relieved through glycosylation. Glycosyltransferase C (GtfC), a metagenome-derived, bacterial glycosyltransferase, was used to produce novel and rare rhamnosides of various flavonoids, including chrysin, diosmetin, biochanin A, and hesperetin. Some of them are to our knowledge firstly described within this work. In our study we deployed a new metabolic engineering approach to increase the rhamnosylation rate in Escherichia coli whole cell biotransformations. The coupling of maltodextrin metabolism to glycosylation was developed in E. coli MG1655 with the model substrate hesperetin. The process proved to be highly dependent on the availability of maltodextrins. Maximal production was achieved by the deletion of the phosphoglucomutase (pgm) and UTP-glucose-1-phosphate uridyltransferase (galU) genes and simultaneous overexpression of the d TDP-rhamnose synthesis genes (rmlABCD) as well as glucan 1,4-alpha-maltohexaosidase for increased maltodextrin degradation next to GtfC in E. coli UHH_CR5-A. These modifications resulted in a 3.2-fold increase of hesperetin rhamnosides compared to E. coli MG1655 expressing GtfC in 24 h batch fermentations. Furthermore, E. coli UHH-CR_5-A was able to produce a final product titer of 2.4 g/L of hesperetin-3′- O -rhamnoside after 48 h. To show the versatility of the engineered E. coli strain, biotransformations of quercetin and kaempferol were performed, leading to production of 4.3 g/L quercitrin and 1.9 g/L afzelin in a 48 h time period, respectively. So far, these are the highest published yields of flavonoid rhamnosylation using a biotransformation approach. These results clearly demonstrate the high potential of the engineered E. coli production host as a platform for the high level biotransformation of flavonoid rhamnosides. Image 1 • GtfC produced so far unidentified rhamnosides of chrysin, diosmetin, biochanin A and hesperetin. • Overexpression of co-substrate dTDP-rhamnose synthesis genes rmlBDAC increases rhamnosylation. • Deletion of phosphoglucomutase and UTP-glucose-1-phosphate uridylytransferase increases rhamnosylation. • Coupling of Escherichia coli maltodextrin metabolism to flavonoid rhamnosylation. • The availability of dextrins is essential for high level rhamnosylation. [ABSTRACT FROM AUTHOR]