Search

[Display omitted] • Effective resource utilization of vinegar residue (VR). • Coproducing amino acid-rich xylooligosaccharides (XOS) and humic-like acid from VR. • Optimizing the reaction conditions for maximum XOS yield of 19.88 %. In order to address the issue of low amino acid retention in the production of xylooligosaccharides (XOS) through hydrothermal pretreatment at high temperatures, a novel approach combining low temperature acid hydrolysis and enzymatic hydrolysis was employed. This innovative method not only allows for the production of amino acid-rich XOS, but also yields a valuable byproduct known as humic-like acid (HLA) from vinegar residue (VR). Under the optimal pretreatment conditions (89 °C, 6 h, 1.2 % sulfuric acid), the yield of XOS was 19.88 %. Furthermore, the hydrolyzate extracted from the acid pretreated VR had a content of 2.65 g/L amino acids (corresponding to the retention rate of 82.0 %), and the HLA yield of the sample was 10.51 %. Comprehensive analyses, such as Fourier transform infrared spectroscopy, elemental analysis, total acidic functional group, and nuclear magnetic resonance were employed to examine the structure and composition of the produced HLA, indicating that it was similar to that of natural commercial humic acid (CHA) extracted from minerals. Through this innovative approach, the production of amino acid-rich XOS and HLA from VR offers a sustainable solution that not only addresses the issue of low amino acid retention but also maximizes the potential of VR as a valuable resource. [ABSTRACT FROM AUTHOR]

Magnetic nickel oxide multi‐walled carbon nanotubes (MWCNT‐NiO) were employed in the immobilization of xylanase from Thermomyces lanuginosus, after modification with (3‐glycidoxypropyl)trimethoxysilane or 3‐aminopropyltriethoxysilane (APTES). The APTES‐derivatized MWCNT‐NiO particles were activated with glutaraldehyde to immobilize T. lanuginosus xylanase via covalent attachment. The (3‐glycidoxypropyl)trimethoxysilane‐derivatized MWCNT‐NiO particles were directly used for the covalent immobilization of T. lanuginosus xylanase, or the formed epoxy groups were converted to aldehyde groups. The free xylanase had maximum activity at pH 7.5, whereas the immobilized samples showed an optimum pH of 7.0. The optimum temperature was 60°C for the xylanase samples. The thermal stability of xylanase increased at 7 and/or 12 folds after immobilization. The results of xylooligosaccharide synthesis showed that the main formed xylooligosaccharides were xylobiose, xylotriose, and xylotetraose for the immobilized xylanase samples. Furthermore, an effect of the enzyme loading could be found, an increase in this parameter promoted that xylobiose and xylotriose amounts slightly increased, whereas xylotetraose amount slightly decreased. The immobilized xylanase samples retained at least 80% of their initial activity after five reuses at pH 7.0 and 60°C. The results show that the new xylanase preparations were easily separable, thermally stable, and reusable in the synthesis of xylooligosaccharides. [ABSTRACT FROM AUTHOR]

Spent mushroom substrate (SMS), a lignocellulosic waste after mushroom production is generally discarded without proper management. There is increasing interest in the sustainable transformation of lignocellulosic waste into high-value products. Within this context, the present study investigated the potential of the SMS from the cultivation of Pleurotus pulmonarius and Auricularia auricula on rubber tree wood sawdust as substrates for xylooligosaccharides (XOS) production. SMS samples from these two edible mushrooms were extracted using alkaline xylan extraction, producing maximum true recovery amounts of xylan in the range 34.61%–37.49% using 18% NaOH at 70 °C for 3 h. Production of XOS from alkaline-extracted xylan from the SMS samples of both mushroom species using economically crude xylanases from Aspergillus flavus KUB2 resulted in XOS (X2–X5) production of 241.47–249.04 mg/g, with X3 as the predominant XOS product. The produced XOS had excellent prebiotic activity and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and contained high total phenolic contents. The combined beneficial bioactivities in terms of prebiotic and antioxidant properties suggested that the XOS produced from sawdust-based SMS samples of P. pulmonarius and A. auricula could be promising ingredients for both food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Corncob biomass (CCB), an agricultural residue having highest xylan content forms a potential source of platform chemicals such as xylooligosaccharides (XOS) and xylose. This study aims at evaluating the synergistic effect of Sonophotocatalysis (SP) for enhanced extraction of corncob xylan. The effect of different pretreatment methods namely Sonocatalysis (US + ZnO), Photocatalysis (PC), Ultrasonication at 20% amplitude (US 20) and Sonophotocatalysis at amplitude of 20% (SP 20) were studied. Amongst, SP 20 resulted in two folds and five folds enhanced xylan extraction compared to US 20 and PC, respectively. The temperature change from 30 ± 2 to > 90 ± 2 °C by varying sonication amplitude (20%, 50%, 70% and 90%) and extraction time (15, 30 and 60 min) were studied. The results indicated that 90.1 ± 1.8% of CCB xylan could be extracted within 15 min of extraction when pretreated with SP 90. This reaction condition resulted in 14.59 ± 1% of xylose and 84.5 ± 2.01% of total XOS relative to the initial xylan content. The CCB pretreated with SP 90 resulted in 36% and 83% increased xylan extraction compared to US and PC, respectively. The thin layer chromatography analysis substantiates the result obtained in quantitative analysis. The compositional analysis of pretreated CCB with SP 90 showed higher cellulose (52.5 ± 1.5%), lignin (15.1 ± 0.9%) content and reduced hemicellulose (3.5 ± 0.7%). FTIR studies revealed that variation in the peak band at 1730 cm−1 which is characteristic peak for hemicellulose proved breakage of ester linkage between lignin and hemicellulose when CCB pretreated by SP 90. The particle size distribution of US and SP 90 pretreated reduced from 417 ± 1.5 to 170 ± 1.2 µm. SEM analysis revealed distinguished difference in the structure of CCB between untreated and pretreated samples. From our study it was evident that combination of US and PC resulted in enhanced extraction of CCB xylan with reduced time and mild reaction condition without the use of additional chemicals. Further the extracted xylan was simultaneously hydrolyzed into xylose and XOS of DP (2–4) i.e. X2, X3 and X4. This shows that SP could be a promising process for one pot production of XOS and xylose from CCB xylan. Highlights: Preliminary results showed SP @ amplitude of 20% (SP 20) resulted enhanced xylan extraction compared to US and PC respectively. The temperature change from 30 ± 2 to 90 ± 2 °C by varying sonication amplitude (20%, 50%, 70% and 90%) and extraction time (15, 30 and 60 min) were studied. SP 90 resulted in 90.1 ± 1.8% of CCB xylan extraction within 15 min along with xylose and XOS's were obtained as hydrolyzed products. [ABSTRACT FROM AUTHOR]

Objective: To investigate the influence of xylooligosaccharides on skin inflammation, behavioral characteristics, neurotransmitters, and gut flora in a mouse model of atopic dermatitis (AD) induced by 2,4-dinitrofluorobenzene (DNFB). Methods: The AD mouse model was created by administration of DNFB for 14 consecutive days. The scoring atopic dermatitis index, enzyme-linked immunosorbent assay (ELISA), histopathology, and immunohistochemical analyses were used to assess inflammation and depression-like behaviors. Furthermore, high-throughput 16S rRNA gene sequencing was used to determine the composition of fecal microbiota. Results: Xylooligosaccharides treatment reduced the number of scratches and skin thickness, mast cell infiltration and the levels of immunoglobulin (Ig) E and T-helper cytokines compared with the AD model group. Meanwhile, xylooligosaccharides treatment reduced the immobility time of mice in the forced swimming test and increased the total movement distance and movement distance in the center area in the open-field test. Furthermore, 5-hydroxytryptamine and dopamine expression in the brain was increased following xylooligosaccharides treatment. Using network pharmacology, gene ontology analysis showed that the targets were mainly enriched in phosphatase binding and the regulation of leukocyte differentiation, which ameliorated AD mainly through the hypoxia inducible factor-1 and phosphatidylinositide 3-kinase-protein kinase B pathways. 16S rRNA gene sequencing, diversity indices, and gut microbial taxonomic composition analysis showed DNFB-induced changes in intestinal microbiota diversity in AD mice. Comparative analysis indicated that xylooligosaccharides intake improved the gut microbiome by dramatically enhancing the concentration of Lactobacillus while decreasing the concentration of Bacteroides in mice. Conclusion: Xylooligosaccharides reduce inflammatory dermatosis and related depression-like behaviors via regulating intestinal homeostasis, having medicinal value as a nutritional and functional ingredient.

Lignocellulosic biomass (LCB) comprising of wheat bran, coconut husk, rice husk, cereals straw, and other hardwood and softwoods is a good source for the production of xylooligosaccharides (XOS) (prebiotic). XOS produced are nondigestible carbohydrates being stable under stomach pH and digestive enzymes so they can be easily delivered to the intestine in native form, thus stimulating the growth of probiotics. Here we review about the raw material, production, purification, and application of XOS with health benefits. Importance of XOS being valuable food ingredient is increasing as they perform a variety of functions, including reduction in cholesterol levels, gastrointestinal health maintenance, anticancer and antioxidant properties, and modulation of immune system. We also discuss the different characterization methods which are necessary to determine the degree of polymerization (DP) of XOS. Low DP (xylobiose and xylotriose) is usually preferred for the application of XOS in various sectors. This review emphasizes the growing significance of XOS as a prebiotic, serving as nourishment for probiotics. [ABSTRACT FROM AUTHOR]

Xylooligosaccharides (XOS) are prebiotics of significant biological value that can be obtained through cost‐effective purification of agricultural waste. The present research featured in vitro and in vivo investigation of prebiotic effects of xylooligosaccharides derived from wheat bran powder and brewer's spent grain. Prebiotic activity of Lactobacillus. fermentum, Lactobacillus. casei, and Bifidobacterium spp. was investigated in vitro using standard selective media. 16S rRNA quantitative PCR used for in vitro and in vivo investigation quantified relative abundance of Bifidobacterium spp., Lactobacillus spp., and Akkermansia. muciniphila in samples of fecal matter, cecal content, and intestinal tissue. Research revealed a favorable association between XOS concentration and both bacterial count and diameter of resultant colonies. The standard strain of L. casei showed no noticeable effect on growth rate. Bifidobacterium spp. proliferation in intestinal tissue was validated via in vivo tests using XOS obtained from wheat bran powder and brewer's spent grain. Findings indicated increased prevalence of the A. muciniphila species and the presence of XOS showed a protective function in preserving the structural integrity of intestinal mucus secretions. The presence of XOS in food indicated direct association with proliferation of Bifidobacterium spp. and A. muciniphila spp. Study results suggest that XOS extracted through enzymatic hydrolysis in Mongolian food industry by‐products such as wheat bran products and brewer's spent grain exhibit prebiotic properties that justify XOS manufacture on a large scale and incorporation of XOS as nutritional enhancement in food products and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy is a major etiological factor in heart failure in diabetic patients, characterized by mitochondrial oxidative metabolism dysfunction, myocardial fibrosis, and marked glycogen elevation. The aim of the present study is to evaluate the effect of endurance training and prebiotic xylooligosaccharide (XOS) on the activity of key oxidative enzymes, myocardial collagen, and glycogen distribution as well as some serum biochemical risk markers in streptozotocin-induced type 1 diabetic rats. Male Wistar rats (n = 36) were divided into four diabetic groups (n = 9): sedentary diabetic rats on a normal diet (SDN), trained diabetic rats on a normal diet (TDN), trained diabetic rats on a normal diet with an XOS supplement (TD-XOS), and sedentary diabetic rats with an XOS supplement (SD-XOS). The results show that aerobic training managed to increase the enzyme activity of respiratory Complex I and II and the lactate dehydrogenase in the cardiomyocytes of the diabetic rats. Furthermore, the combination of exercise and XOS significantly decreased the collagen and glycogen content. No significant effects on blood pressure, heart rate or markers of inflammation were detected. These results demonstrate the beneficial effects of exercise, alone or in combination with XOS, on the cardiac mitochondrial enzymology and histopathology of diabetic rats. [ABSTRACT FROM AUTHOR]

This study identified a salt-tolerant GH11 xylanase, Xynst, which was isolated from a soil bacterium Bacillus sp. SC1 and can resist as high as 4 M NaCl. After rational design and high-throughput screening of site-directed mutant libraries, a double mutant W6F/Q7H with a 244% increase in catalytic activity and a 10 °C increment in optimal temperature was obtained. Both Xynst and W6F/Q7H xylanases were stimulated by high concentrations of salts. In particular, the activity of W6F/Q7H was more than eight times that of Xynst in the presence of 2 M NaCl at 65 °C. Kinetic parameters indicated they have the highest affinity for beechwood xylan (Km = 0.30 mg mL−1 for Xynst and 0.18 mg mL−1 for W6F/Q7H), and W6F/Q7H has very high catalytic efficiency (Kcat/Km = 15483.33 mL mg−1 s−1). Molecular dynamic simulation suggested that W6F/Q7H has a more compact overall structure, improved rigidity of the active pocket edge, and a flexible upper-end alpha helix. Hydrolysis of different xylans by W6F/Q7H released more xylooligosaccharides and yielded higher proportions of xylobiose and xylotriose than Xynst did. The conversion efficiencies of Xynst and W6F/Q7H on all tested xylans exceeded 20%, suggesting potential applications in the agricultural and food industries. [ABSTRACT FROM AUTHOR]

Abstract Objective New characterized carbohydrate-active enzymes are needed for use as tools to discriminate complex carbohydrate structural features. Fungal glycoside hydrolase family 3 (GH3) β-xylosidases have been shown to be useful for the structural elucidation of glucuronic acid (GlcA) and arabinofuranose (Araf) substituted oligoxylosides. A homolog of these GH3 fungal enzymes from the bacterium Segatella baroniae (basonym Prevotella bryantii), Xyl3C, has been previously characterized, but those studies did not address important functional specificity features. In an interest to utilize this enzyme for laboratory methods intended to discriminate the structure of the non-reducing terminus of substituted xylooligosaccharides, we have further characterized this GH3 xylosidase. Results In addition to verification of basic functional characteristics of this xylosidase we have determined its mode of action as it relates to non-reducing end xylose release from GlcA and Araf substituted oligoxylosides. Xyl3C cleaves xylose from the non-reducing terminus of β-1,4-xylan until occurrence of a penultimate substituted xylose. If this substitution is O2 linked, then Xyl3C removes the non-reducing xylose to leave the substituted xylose as the new non-reducing terminus. However, if the substitution is O3 linked, Xyl3C does not hydrolyze, thus leaving the substitution one-xylose (penultimate) from the non-reducing terminus. Hence, Xyl3C enables discrimination between O2 and O3 linked substitutions on the xylose penultimate to the non-reducing end. These findings are contrasted using a homologous enzyme also from S. baroniae, Xyl3B, which is found to yield a penultimate substituted nonreducing terminus regardless of which GlcA or Araf substitution exists.

Phenolics produced during xylooligosaccharide production might inhibit xylanases and enhance the antioxidant and antimicrobial activities of XOS. The effects of phenolic compounds on xylanases may depend on the type and concentration of the compound, the plant biomass used, and the enzyme used. Understanding the effects of phenolic compounds on xylanases and their impact on XOS is critical for developing viable bioconversion of lignocellulosic biomass to XOS. Understanding the complex relationship between phenolic compounds and xylanases can lead to the development of strategies that improve the efficiency and cost-effectiveness of XOS manufacturing processes and optimise enzyme performance. [ABSTRACT FROM AUTHOR]

Xylooligosaccharides (XOS), as prebiotic oligomers, are increasingly receiving attention as high value-added products produced from lignocellulosic biomass. Although the XOS contains a series of different degrees of polymerization (DP) of xylose units, DP 2 and 3 (xylobiose (X2) and xylotriose (X3)) are regarded as the main active components in food and pharmaceutical fields. Therefore, in the study, in order to achieve the maximum production of XOS with the desired DP, a combination strategy of sequential auto-hydrolysis and xylanase hydrolysis was developed with corncob as raw material. The evidences showed that the hemicellulosic xylan could be effectively decomposed into various higher DP saccharides (> 4), which were dissolved into the auto-hydrolysate; sequentially, the soluble saccharides could be rapidly hydrolyzed into XOS with desired DP by xylanase hydrolysis. Finally, a maximum XOS yield of 56.3% was achieved and the ratio of (X2 + X3)/XOS was over 80%; meanwhile, the by-products could be controlled at lower levels. Overall, this study provides solid data that support the selective and precise preparation of XOS from corncob, vigorously promoting the application of XOS as functional sugar products. [ABSTRACT FROM AUTHOR]

Xylan is the most abundant constituent of hemicellulose fraction of lignocellulosic biomass. Short xylooligosaccharides (XOS), obtained via xylan hydrolysis, have well-known prebiotic and antioxidant properties that are beneficial for human and animal health. In this study, two alternative pretreatment strategies (alkali and hydrothermal) and three different enzymes were applied for enzymatic XOS production from sugarcane bagasse. The enzymatic hydrolysis was performed with nine different combinations of recombinant endo-xylanases from GH11 and GH10 families and GH11 xylobiohydrolase. Hydrothermal pretreatment followed by optimized enzymatic hydrolysis yielded up to 96 ± 1 mg of XOS per gram of initial biomass, whereas enzymatic hydrolysis of alkali-pretreated sugarcane bagasse rendered around 47.6 ± 0.2 mg/g. For both alkali and hydrothermal routes, the maximum yields of short-length XOS were obtained using the GH10 xylanase alone. Furthermore, differences in XOS profiles obtained by controlled mixtures of the enzymes have been evaluated. For both routes, the best yields of short-length XOS were obtained using the GH10 xylanase alone, which is consistent with the notion that sugarcane xylan substitutions partially hinder GH11 xylanase activity. The results presented here show that a green and cost-effective hydrothermal pretreatment path for xylooligosaccharides production, rendered considerably better XOS yields. [ABSTRACT FROM AUTHOR]

Objective: New characterized carbohydrate-active enzymes are needed for use as tools to discriminate complex carbohydrate structural features. Fungal glycoside hydrolase family 3 (GH3) β-xylosidases have been shown to be useful for the structural elucidation of glucuronic acid (GlcA) and arabinofuranose (Araf) substituted oligoxylosides. A homolog of these GH3 fungal enzymes from the bacterium Segatella baroniae (basonym Prevotella bryantii), Xyl3C, has been previously characterized, but those studies did not address important functional specificity features. In an interest to utilize this enzyme for laboratory methods intended to discriminate the structure of the non-reducing terminus of substituted xylooligosaccharides, we have further characterized this GH3 xylosidase. Results: In addition to verification of basic functional characteristics of this xylosidase we have determined its mode of action as it relates to non-reducing end xylose release from GlcA and Araf substituted oligoxylosides. Xyl3C cleaves xylose from the non-reducing terminus of β-1,4-xylan until occurrence of a penultimate substituted xylose. If this substitution is O2 linked, then Xyl3C removes the non-reducing xylose to leave the substituted xylose as the new non-reducing terminus. However, if the substitution is O3 linked, Xyl3C does not hydrolyze, thus leaving the substitution one-xylose (penultimate) from the non-reducing terminus. Hence, Xyl3C enables discrimination between O2 and O3 linked substitutions on the xylose penultimate to the non-reducing end. These findings are contrasted using a homologous enzyme also from S. baroniae, Xyl3B, which is found to yield a penultimate substituted nonreducing terminus regardless of which GlcA or Araf substitution exists. [ABSTRACT FROM AUTHOR]

Enhancing root development is pivotal for boosting crop yield and augmenting stress resilience. In this study, we explored the regulatory effects of xylooligosaccharides (XOSs) on lettuce root growth, comparing their impact with that of indole-3-butyric acid potassium salt (IBAP). Treatment with XOS led to a substantial increase in root dry weight (30.77%), total root length (29.40%), volume (21.58%), and surface area (25.44%) compared to the water-treated control. These enhancements were on par with those induced by IBAP. Comprehensive phytohormone profiling disclosed marked increases in indole-3-acetic acid (IAA), zeatin riboside (ZR), methyl jasmonate (JA-ME), and brassinosteroids (BRs) following XOS application. Through RNA sequencing, we identified 3807 differentially expressed genes (DEGs) in the roots of XOS-treated plants, which were significantly enriched in pathways associated with manganese ion homeostasis, microtubule motor activity, and carbohydrate metabolism. Intriguingly, approximately 62.7% of the DEGs responsive to XOS also responded to IBAP, underscoring common regulatory mechanisms. However, XOS uniquely influenced genes related to cutin, suberine, and wax biosynthesis, as well as plant hormone signal transduction, hinting at novel mechanisms of stress tolerance. Prominent up-regulation of genes encoding beta-glucosidase and beta-fructofuranosidase highlights enhanced carbohydrate metabolism as a key driver of XOS-induced root enhancement. Collectively, these results position XOS as a promising, sustainable option for agricultural biostimulation. [ABSTRACT FROM AUTHOR]

Acidic xylooligosaccharides (XOS), also called aldouronics, are hetero-oligomers of xylose randomly branched with 4-O-methyl-D-glucuronic acid residues linked by α(1 → 2) bonds, which display bioactive properties. We have developed a simple and integrated method for the production of acidic XOS by enzymatic hydrolysis of a glucurono-xylan from beechwood. Among the enzymes screened, Depol 670L (a cellulolytic preparation from Trichoderma reesei) displayed the highest activity (70.3 U/mL, expressed in reducing xylose equivalents). High-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) analysis revealed the formation of a neutral fraction (corresponding to linear XOS, mainly xylose and xylobiose) and a group of more retained products (acidic XOS), which were separated using strong anion-exchange cartridges. The acidic fraction contained a major product, characterized by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and mono- and two-dimensional nuclear magnetic resonance spectroscopy (NMR) as 2′-O-α-(4-O-methyl-α-D-glucuronosyl)-xylobiose (X2_MeGlcA). Starting from 2 g of beechwood xylan, 1.5 g of total XOS were obtained, from which 225 mg (11% yield) corresponded to the aldouronic X2_MeGlcA. The acidic XOS exhibited higher antioxidant activity (measured by the ABTS·+ discoloration assay) than xylan, whilst neutral XOS displayed no antioxidant activity. This work demonstrates that it is possible to obtain a safe and natural antioxidant by enzymatic biotransformation of hardwood hemicellulose. [ABSTRACT FROM AUTHOR]

To reduce the cost of pretreatment, an advanced formic acid pretreatment directly using spent liquor was developed for corn cob valorisation in this work. The spent liquor pretreatment showed a satisfactory lignocellulose fractionation effect, and a high enzymatic hydrolysis efficiency over 95% was achieved even when the spent liquor was recycled 5 times. Based on this result, the direct recycling of the spent liquor for pretreatment could lead to a threefold increase in the amount of corn cob processed and reduce energy consumption on the recovery unit by 80%. Meanwhile, the recycling strategy of spent liquor also could bring an enrichment of xylooligosaccharides (XOS) in the spent liquor. A total of 56.0 g/L XOS was obtained with a high proportion of XOS in spent liquor, which favoured XOS separation and purification during the downstream process of XOS production. The developed strategy shows a good potential on the industrialization of formic acid pretreatment for biorefineries. [ABSTRACT FROM AUTHOR]

Abstract Background Dietary supplementation of xylooligosaccharides (XOS) has been found to influence gut health by manipulating cecal microbiota and producing microbe-origin metabolites. But no study investigated and compared the effect of in ovo feeding of xylobiose (XOS2) and xylotriose (XOS3) in chickens. This study investigated the effect of in ovo feeding of these XOS compounds on post-hatch gut health parameters in chickens. A total of 144 fertilized chicken eggs were divided into three groups: a) non-injected control (CON), b) XOS2, and c) XOS3. On the 17th embryonic day, the eggs of the XOS2 and XOS3 groups were injected with 3 mg of XOS2 and XOS3 diluted in 0.5 mL of 0.85% normal saline through the amniotic sac. After hatching, the chicks were raised for 21 d. Blood was collected on d 14 to measure plasma immunoglobulin. Cecal digesta were collected for measuring short-chain fatty acids (SCFA) on d 14 and 21, and for microbial ecology and microbial metabolic pathway analyses on d 7 and 21. Results The results were considered significantly different at P

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The lignocellulosic residue cassava peel is an unexplored source of bioactive compounds, such as hemicellulose-based xylooligosaccharides (XOS) that present prebiotic properties. In this sense, this work aimed to produce XOS from cassava peels that were pretreated with NaOH (xylan extraction and lignin removal) followed by enzymatic hydrolysis (endo-1–4-β-xylanase). The cassava peels were pretreated sequentially: starch removal, alkaline hydrolysis, and enzymatic hydrolysis. The aqueous-mechanical reduction and sieving for 15 cycles removed ≈16% of starch (iodometric method). The alkaline pretreatments were carried out with 2, 4, and 6% (w/v) NaOH, 1:100/solid:liquid at 121 °C and 1.1 bar for 30 or 60 min. The enzymatic kinetics was evaluated with enzyme concentration at 0.5, 1.5, and 3.0% (v/v). The highest alkaline hydrolysis reached 34.20% of lignin removal (2% (w/v) NaOH for 30 min). The highest XOS yield was 396.5 mg XOS/g xylan after 48 h and 3.0% enzyme concentration. Regarding the mass balance, from 300 g of cassava peels (an agroindustrial residue), it is possible to obtain up to 3.27% XOS. Therefore, the fractionation of hemicellulose from cassava peels was technically viable from the concepts of biorefinery and bioeconomy, being one of the first researches to approach the extraction of xylan from cassava peel to obtain XOS through an enzymatic route with a highly promising yield. Highlights: • The high starch content is a drawback to producing cassava peel-based xylooligosaccharides. • Delignification and extraction of xylan from cassava peels by alkaline hydrolysis were performed. • Xylooligosaccharides were produced by enzymatic hydrolysis with endo-1–4-β-xylanase. • The highest yield of cassava peel-based xylooligosaccharides, already reported. [ABSTRACT FROM AUTHOR]

Background: Dietary supplementation of xylooligosaccharides (XOS) has been found to influence gut health by manipulating cecal microbiota and producing microbe-origin metabolites. But no study investigated and compared the effect of in ovo feeding of xylobiose (XOS2) and xylotriose (XOS3) in chickens. This study investigated the effect of in ovo feeding of these XOS compounds on post-hatch gut health parameters in chickens. A total of 144 fertilized chicken eggs were divided into three groups: a) non-injected control (CON), b) XOS2, and c) XOS3. On the 17th embryonic day, the eggs of the XOS2 and XOS3 groups were injected with 3 mg of XOS2 and XOS3 diluted in 0.5 mL of 0.85% normal saline through the amniotic sac. After hatching, the chicks were raised for 21 d. Blood was collected on d 14 to measure plasma immunoglobulin. Cecal digesta were collected for measuring short-chain fatty acids (SCFA) on d 14 and 21, and for microbial ecology and microbial metabolic pathway analyses on d 7 and 21. Results: The results were considered significantly different at P < 0.05. ELISA quantified plasma IgA and IgG on d 14 chickens, revealing no differences among the treatments. Gas chromatography results showed no significant differences in the concentrations of cecal SCFAs on d 14 but significant differences on d 21. However, the SCFA concentrations were lower in the XOS3 than in the CON group on d 21. The cecal metagenomics data showed that the abundance of the family Clostridiaceae significantly decreased on d 7, and the abundance of the family Oscillospiraceae increased on d 21 in the XOS2 compared to the CON. There was a reduction in the relative abundance of genus Clostridium sensu stricto 1 in the XOS2 compared to the CON on d 7 and the genus Ruminococcus torques in both XOS2 and XOS3 groups compared to the CON on d 21. The XOS2 and XOS3 groups reduced the genes for chondroitin sulfate degradation I and L-histidine degradation I pathways, which contribute to improved gut health, respectively, in the microbiome on d 7. In contrast, on d 21, the XOS2 and XOS3 groups enriched the thiamin salvage II, L-isoleucine biosynthesis IV, and O-antigen building blocks biosynthesis (E. coli) pathways, which are indicative of improved gut health. Unlike the XOS3 and CON, the microbiome enriched the pathways associated with energy enhancement, including flavin biosynthesis I, sucrose degradation III, and Calvin-Benson-Bassham cycle pathways, in the XOS2 group on d 21. Conclusion: In ovo XOS2 and XOS3 feeding promoted beneficial bacterial growth and reduced harmful bacteria at the family and genus levels. The metagenomic-based microbial metabolic pathway profiling predicted a favorable change in the availability of cecal metabolites in the XOS2 and XOS3 groups. The modulation of microbiota and metabolic pathways suggests that in ovo XOS2 and XOS3 feeding improved gut health during the post-hatch period of broilers. [ABSTRACT FROM AUTHOR]

Xylooligosaccharides (XOSs) are being explored as prebiotics in fish diets; however, their effects and modes of action have not been well evaluated. Reports have shown that dietary XOS has the potential to improve the proliferation of beneficial gut microbes, and their metabolites, and enhance disease resistance in several fish species. In contrast, other studies report no substantial changes in immune and growth parameters compared to control groups. Like all prebiotics, the mode of action of XOS is based on their selective stimulation of beneficial gut microbiota, which will outcompete and prevent pathogen proliferation in the gut, and produce metabolites that modulate host immune responses. The reports of improved growth performance of XOS fed fish may be due to improved intestinal microbiome, enhanced glycolysis activity and elevated gastrointestinal enzymatic activities. Dietary XOSs have different effects on fish performance depending on the fish species and the structure of XOSs (degree of XOS polymerization and substitution). Nevertheless, further research is essential to determine the optimal dosage, degree of polymerization, and substitution levels required to improve each fish species' gut health and growth performance. This review highlights the prebiotic effects of XOSs, their mechanism of action, and knowledge gaps. [ABSTRACT FROM AUTHOR]

An uncharacterized gene encoding a glycoside hydrolase family 43-like enzyme from Clostridium boliviensis strain E-1 was identified from genomic sequence data, and the encoded enzyme, CbE1Xyn43-l, was produced in Escherichia coli. CbE1Xyn43-l (52.9 kDa) is a two-domain endo-ß-xylanase consisting of a C-terminal CBM6 and a GH43-like catalytic domain. The positions of the catalytic dyad conserved in GH43, the catalytic base (Asp74), and proton donor (Glu240) were identified in alignments including GH43-enzymes of known 3D-structure from different subfamilies. CbE1Xyn43-l is active at pH 7.0-9.0, with optimum temperature at 65°C, and a more than 7 days' half-life in irreversible deactivation studies at this temperature. The enzyme hydrolyzed birchwood xylan, quinoa stalks glucuronoarabinoxylan, and wheat arabinoxylan with xylotriose and xylotetraose as major hydrolysis products. CbE1Xyn43-l also released xylobiose from pNPX2 with low turnover (kcat of 0.044 s-1) but was inactive on pNPX, showing that a degree of polymerization of three (DP3) was the smallest hydrolyzable substrate. Divalent ions affected the specific activity on xylan substrates, which dependent on the ion could be increased or decreased. In conclusion, CbE1Xyn43-l from C. boliviensis strain E-1 is the first characterized member of a large group of homologous hypothetical proteins annotated as GH43-like and is a thermostable endo-xylanase, producing xylooligosaccharides of high DP (xylotriose and xylotetraose) producer. IMPORTANCE The genome of Clostridium boliviensis strain E-1 encodes a number of hypothetical enzymes, annotated as glycoside hydrolase-like but not classified in the Carbohydrate Active Enzyme Database (CAZy). A novel thermostable GH43-like enzyme is here characterized as an endo-ß-xylanase of interest in the production of prebiotic xylooligosaccharides (XOs) from different xylan sources. CbE1Xyn43-l is a two-domain enzyme composed of a catalytic GH43-l domain and a CBM6 domain, producing xylotriose as main XO product. The enzyme has homologs in many related Clostridium strains which may indicate a similar function and be a previously unknown type of endo-xylanase in this evolutionary lineage of microorganisms. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass is an abundant renewable resource which amounts to 1.3 billion tonnes per year and can be used in a variety of sustainable applications. It is primarily made up of tightly bound cellulose, hemicellulose, and lignin. However, hemicellulose dissolution and delignification pose significant challenges to the utilisation of reducing sugar. To solve this issue, alkaline pretreatment was utilised. The aim of lignocellulosic biomass pretreatment is to break down the complex structure of the biomass and provide better access to the components that can be converted into useful reducing sugar. Response Surface Methodology (RSM) was used to identify the optimal values for the factors influencing the pretreatment. The optimisation parameters were sodium hydroxide concentration (1 - 4 % w/v), pretreatment time (15 - 60 minutes), and solid loading (6 - 16% w/v). Rice husk, which was used as biomass, was hydrolysed enzymatically to produce reduced sugar. The optimum conditions for producing the highest reducing sugar of 15.18 mg/mL from rice husk were 1.67% w/v sodium hydroxide pretreatment, 59.44 minutes of pretreatment time, and 7.67% w/v solid loading. As a result, less alkaline reagents can be used with a longer pretreatment time, thus lowering the cost of pretreatment. Therefore, this shows that RSM was one of the best methods to replace the conventional technique for optimising the parameters of rice husk alkaline pretreatment for reducing sugar production. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the changes in the physical properties and gelation mechanism of xylooligosaccharides (XOS)-milk system during heat treatment. Firstly, the preparation conditions of XOS-milk gels were optimized using sensory evaluation. At the optimal XOS concentration, the changes in pH, color, gel strength, water-holding capacity, and rheological parameters of the XOS-milk system were studied during heat treatment. The gelation mechanism was analyzed by using solubility, particle size, and polyacrylamide gel electrophoresis analysis. The results showed that the XOS-milk gel was evaluated to be the highest sensory score at an XOS addition level of 5% (w/v) for 6 h of heat treatment. The pH of the XOS-milk system decreased with the increase of heating time (pH5.40 at 8 h), and the gel strength increased (144.4 g at 8 h). The system exhibited solid-like properties (G'>G'') after heat treatment for 2 h. The water-holding capacity initially increased (53.1% at 6 h) and then decreased (49.1% at 8 h) with prolonged heat treatment. Particle size and polyacrylamide gel electrophoresis analysis showed that milk proteins aggregated after heat treatment. The formation of gel network structure was observed using the scanning electron microscope (SEM). The solubility analysis showed that ionic bonds were the main driving force for protein aggregation and gel network formation, which contributed from 46.8% to 66.3% in samples of different heating time, while hydrophobic interactions and hydrogen bonds displayed the less contribution. As the heat treatment being prolonged, the total contribution of non-covalent bonds such as ionic bonds gradually decreased, which may be related to the formation of Maillard-related covalent bonds. Therefore, XOS promoted the formation of the heat-induced milk gel and its properties might have the potential to be used for the development of new milk products.

Health-conscious consumers seek convenient ways of incorporating different functional ingredients into their diets. Gummy candies are among the most popular confectionery products but generally regarded as nutritionally empty. A gelatin–sugar matrix, providing a highly appreciated sensory experience of sweetness and chewiness, could be used to deliver various bioactive compounds, especially those carrying an unpleasant taste. This work aimed to formulate gelatin gummies based on the mountain germander extract (MGe) as a source of phenylethanoid glycosides (PhEG). Sucrose and glucose syrup contents were partially or completely substituted with combinations of xylitol, maltitol and prebiotic poly- and oligosaccharides. Chemical, textural and sensory parameters were evaluated after production and 2 months of storage. Formulations containing fructooligosaccharides and xylooligosaccharides maintained a characteristic appearance during storage at all three levels of sugar (high, low and none), whereas inulin-added and plain (i.e., without prebiotic) candies suffered from mold contamination or appearance/textural changes. The color of the candies noticeably changed and appeared darker. The PhEG were shown to be stable during the candies' production (approximately 90%) and generally maintained their contents during storage. Texture parameters, except hardness, exhibited high positive correlations and resembled the commercial product. Sensory-wise, a moderate bitterness intensity with a decreasing tendency, along with the high transparency and preservation of the characteristic shape facilitated high general acceptance. Gummy candies with prebiotics were shown to be a highly suitable matrix for the bitter MGe, delivering up to 40 mg of PhEG and 4.5 g of prebiotics in one serving size. This study provides a reference for implementing herbal extracts and emerging prebiotics (XOS) in functional confectionery. [ABSTRACT FROM AUTHOR]

In recent decades, consumer preference and attention to foodstuff presented as healthy and with desirable nutritional information, has increased significantly. In this field, the meat industry has a challenging task since meat and meat products have been related to various chronic diseases. Functional ingredients have emerged in response to the increasing demand for healthier and more nutritious foods. On this matter, oligosaccharides such as fructooligosaccharides (FOS), xylooligosaccharides (XOS), galactooligosaccharides (GOS), and chitooligosaccharides (COS) have been presented as suitable ingredients for the meat industry with the aim of obtaining healthier meat derivatives (e.g. with low fat or sugar content, reduced amount of additives, and desirable functional properties, etc.). However, studies considering application of such oligomers in the meat sector are scarce. In addition, a large number of issues remain to be solved related both to obtaining and characterizing the oligosaccharides available in the industry and to the effect that these ingredients have on the features of meat products (mainly physicochemical and sensory). The study of new oligosaccharides, the methodologies for obtaining them, and their application to new meat products should be promoted, as well as improving knowledge about their effects on the properties of functional meat foods. [ABSTRACT FROM AUTHOR]

Poultry production faces several challenges, with feed efficiency being the main factor that can be influenced through the use of different nutritional strategies. Xylooligosaccharides (XOS) are functional feed additives that are attracting growing commercial interest due to their excellent ability to modulate the composition of the gut microbiota. The aim of the study was to apply crude and purified fungal xylanases, from Trichoderma harzianum, as well as a recombinant glycoside hydrolase family 10 xylanase, derived from Geobacillus stearothermophilus T6, as additives to locally produced chicken feeds. A Box–Behnken Design (BBD) was used to optimize the reducing sugar yield. Response surface methodology (RSM) revealed that reducing sugars were higher (8.05 mg/mL, 2.81 mg/mL and 2.98 mg/mL) for the starter feed treated with each of the three enzymes compared to the treatment with grower feed (3.11 mg/mL, 2.41 mg/mL and 2.62 mg/mL). The hydrolysis products were analysed by thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) analysis and showed that the enzymes hydrolysed the chicken feeds, producing a range of monosaccharides (arabinose, mannose, glucose, and galactose) and XOS, with xylobiose being the predominant XOS. These results show promising data for future applications as additives to poultry feeds. [ABSTRACT FROM AUTHOR]

Simple Summary: Newborns are susceptible to infectious disease, and early life represents a critical developmental window of the immune system, which is important for preventing and fighting disease. There is evidence that nucleotides, oligosaccharides and vitamins can positively influence immune function; however, the evidence that is specifically applicable to cats is limited. This current study fed domestic short hair kittens either a dry format control diet or a test diet fortified with nucleotides, short-chain fructooligosaccharides, xylooligosaccharides, β-carotene and vitamin E until the kittens reached 28 weeks of age. The kittens followed a routine preventative medication schedule for vaccination and a suite of health, metabolism and immune parameters were measured at regular intervals throughout the study. All kittens remained healthy and did not display any clinically relevant signs of adverse health. Antibodies are produced following infection or vaccination. The level of antibody, the proportion of kittens who demonstrated an acceptable response to vaccination and the proportion of kittens who reached the recognised protective level of antibody were greater in kittens fed the test diet. The test diet group demonstrated a stronger antibody-mediated response to vaccination. Antibodies play a role in preventing disease; thus, this suggests that the test diet supports immune defence against immune challenges. Nucleotides, short-chain fructooligosaccharides (scFOS), xylooligosaccharides (XOS), β-carotene and vitamin E are reported to enhance immune function; however, the evidence of this in cats is limited. The aim of this study was to determine the immunomodulatory effects of these ingredients in kittens. Forty domestic short hair kittens were designated in litters to control or test diet for 28 weeks. Test diet was fortified with 0.33 g nucleotides, 0.45 g scFOS, 0.3 g XOS, 0.7 mg β-carotene and 66.5 mg vitamin E per 100 g diet. Kittens were vaccinated against feline parvovirus (FPV) and herpesvirus (FHV) at 10, 14 and 18 weeks. Kittens remained healthy, with no measured evidence of adverse health. Serum FPV and FHV antibody titres were significantly (p < 0.05) higher in the test diet group at week 23 and 27, respectively. A significantly (p < 0.05) higher proportion of test diet group kittens demonstrated an adequate response (four-fold titre increase) to FHV vaccination and a significantly (p < 0.05) higher proportion reached a protective antibody titre for FHV. Serum IgM was significantly (p < 0.05) higher in the test diet group. The test diet group demonstrated a stronger humoral immune response to vaccination, suggesting the diet supports immune defence, enabling a greater response to immune challenges. [ABSTRACT FROM AUTHOR]

Abstract Background Sustainable strategies for enteric methane (CH4) mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure. The present study aimed to investigate the effects of dietary xylooligosaccharides (XOS) and exogenous enzyme (EXE) supplementation on milk production, nutrient digestibility, enteric CH4 emissions, energy utilization efficiency of lactating Jersey dairy cows. Forty-eight lactating cows were randomly assigned to one of 4 treatments: (1) control diet (CON), (2) CON with 25 g/d XOS (XOS), (3) CON with 15 g/d EXE (EXE), and (4) CON with 25 g/d XOS and 15 g/d EXE (XOS + EXE). The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period. The enteric CO2 and CH4 emissions and O2 consumption were measured using two GreenFeed units, which were further used to determine the energy utilization efficiency of cows. Results Compared with CON, cows fed XOS, EXE or XOS + EXE significantly (P

Enhancing root development is pivotal for boosting crop yield and augmenting stress resilience. In this study, we explored the regulatory effects of xylooligosaccharides (XOSs) on lettuce root growth, comparing their impact with that of indole-3-butyric acid potassium salt (IBAP). Treatment with XOS led to a substantial increase in root dry weight (30.77%), total root length (29.40%), volume (21.58%), and surface area (25.44%) compared to the water-treated control. These enhancements were on par with those induced by IBAP. Comprehensive phytohormone profiling disclosed marked increases in indole-3-acetic acid (IAA), zeatin riboside (ZR), methyl jasmonate (JA-ME), and brassinosteroids (BRs) following XOS application. Through RNA sequencing, we identified 3807 differentially expressed genes (DEGs) in the roots of XOS-treated plants, which were significantly enriched in pathways associated with manganese ion homeostasis, microtubule motor activity, and carbohydrate metabolism. Intriguingly, approximately 62.7% of the DEGs responsive to XOS also responded to IBAP, underscoring common regulatory mechanisms. However, XOS uniquely influenced genes related to cutin, suberine, and wax biosynthesis, as well as plant hormone signal transduction, hinting at novel mechanisms of stress tolerance. Prominent up-regulation of genes encoding beta-glucosidase and beta-fructofuranosidase highlights enhanced carbohydrate metabolism as a key driver of XOS-induced root enhancement. Collectively, these results position XOS as a promising, sustainable option for agricultural biostimulation.

Rice husk is a readily available residue which can be used for producing bioproducts in a biorefinery context. In this study, the hemicellulose fraction was hydrolyzed in a hydrothermal process to produce xylooligosaccharides (XOS), whereas the cellulosic hydrolysate was used for red pigment production by Monascus ruber Tieghem IOC 2225. The highest XOS (X2-X4) production (24 g per 1 kg of rice husk) was achieved at 180 °C for 68 min in a non-stirred Parr reactor (50 mL). Subsequently, using a stirred parr reactor (1 L) at 180 °C for 60 min, 40 g of XOS (42% of xylobiose, 35% of xylobiose, 13% of xylotriose, 7% of xylotetraose, and 3% of xylopentaose) per 1 kg of rice husk were obtained. The XOS was then purified by using ultrafiltration (UF) with two diafiltration membranes at 6.5 pH, recovering approximately 92% of total XOS. Further purification was conducted with nanofiltration (NF) at 3.8 pH, recovering approximately 86.4% of XOS in the retentate. This process yielded XOS with a purity of 77%. Additionally, the enzymatic process yielded 132 g/kg of sugar, and the hydrolysate was used to produce 2.1 UA490nm of red pigment by fungi after 7 days.

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Research background. The development of a novel process for the production of xylooligosaccharides (XOS) based on the 4R concept is made possible by the integration of numerous techniques, especially enzymatic modification together with the physical pretreatment of renewable materials. This study aims to integrate the use of agricultural wastes for the production of xylanase by a new strain of Penicillium sp. and value-added products, XOS. Experimental approach. For the production of xylanase, a solid-state fermentation was performed using wheat bran as substrate. To obtain the most active crude extract of xylanase, the time frame of cultivation was first adjusted. Then, the downstream process for xylanase purification was developed by combining different membrane separation units with size exclusion chromatography. Further characterisation included determination of the optimal pH and temperature, determination of the molecular mass of the purified xylanase and analysis of kinetic parameters. Subsequently, the hydrolytic ability of the partially purified xylanase in the hydrolysis of alkali-extracted hemicellulose from soybean hulls was investigated. Results and conclusions. Our results show that Penicillium rubens produced extracellular xylanase at a yield of 21 U/g during solid-state fermentation. Using two ultrafiltration membranes of 10 and 3 kDa in combination with size exclusion chromatography, a yield of 49 % and 13-fold purification of xylanase was achieved. The purified xylanase (35 kDa) cleaved linear bonds β-(1→4) in beechwood xylan at a maximum rate of 0.64 μmol/(min·mg) and a Michaelis constant of 44 mg/mL. At pH=6 and 45 °C, the purified xylanase showed its maximum activity. The xylanase produced showed a high ability to hydrolyse the hemicellulose fraction isolated from soybean hulls, as confirmed by thin-layer chromatography. In the hydrothermally pretreated hemicellulose hydrolysate, the content of XOS with different degrees of polymerisation was detected, while in the non-pretreated hemicellulose hydrolysate, the content of xylotriose and glucose was confirmed. Novelty and scientific contribution. Future research focusing on the creation of new enzymatic pathways for use in processes to convert renewable materials into value-added products can draw on our findings. [ABSTRACT FROM AUTHOR]