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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department 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.)

Because of the association with other complex polysaccharides, extracting and utilizing cellulose from lignocellulosic materials requires the combined action of a broad range of carbohydrate‐active enzymes, including multiple glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs). The interplay between these enzymes and the way in which Nature orchestrates their co‐existence and combined action are topics of great scientific and industrial interest. To gain more insight into these issues, we have studied the lignocellulose‐degrading abilities of an enzyme from Caldibacillus cellulovorans (CcLPMO10‐Man5), comprising an LPMO domain, a GH5 mannanase domain and two family 3 carbohydrate‐binding modules (CBM3). Using a natural softwood substrate, we show that this enzyme promotes cellulase activity, i.e., saccharification of cellulose, both by removing mannan covering the cellulose and by oxidatively breaking up the cellulose structure. Synergy with CcLPMO10‐Man5 was most pronounced for two tested cellobiohydrolases, whereas effects were smaller for a tested endoglucanase, which is in line with the notion that cellobiohydrolases and LPMOs attack the same crystalline regions of the cellulose, whereas endoglucanases attack semi‐crystalline and amorphous regions. Importantly, the LPMO domain of CcLPMO10‐Man5 is incapable of accessing the softwood cellulose in absence of the mannanase domain. Considering that LPMOs not bound to a substrate are sensitive to autocatalytic inactivation, this intramolecular synergy provides a perfect rationale for the evolution of modular enzymes such as CcLPMO10‐Man5. The intramolecular coupling of the LPMO with a mannanase and two CBMs ensures that the LPMO is directed to areas where mannans are removed and cellulose thus becomes available. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the impact of adding 1% processed coconut meal (hydrolyzed copra meal, HCM) to the diets of weaned pigs, comparing it to regular coconut meal (CM) and a control diet with no coconut meal. Processed to enhance digestibility, HCM showed better digestion than CM. Both treatments supported a diverse gut microbiome, with potential benefits for producing beneficial fatty acids crucial for gut health. More research is needed to fully evaluate HCM's impact on pig growth and health, but initial findings suggest that incorporating HCM could enhance digestive health and overall well-being in young pigs. This study aimed to compare the effects of hydrolyzed copra meal (HCM) inclusion at 1% on its in vitro digestibility and the microbiota and cecum fermentation using the gut microbiota of weaned swine, targeting microbial community and short-chain fatty acids (SCF). For this reason, three treatments were considered: control (no copra meal), 1% non-hydrolyzed copra meal (CM), and 1% HCM. Non-defatted copra meal was hydrolyzed and analyzed (reducing sugars and total carbohydrates) in our laboratory. For digestion, microbiota identification, and fermentation assays, fresh fecal samples from two weaned pigs (1 month old) were used. Three replicates of each treatment were employed. HCM was more digestible, with approximately 0.68 g of hydrolysate recovered after simulated digestion compared to 0.82 g of hydrolysate recovered from CM. This was shown by Scanning Electron Microscope (SEM) images. Also, the three swine shared the majority of microbial species identified at the phylum and family levels. There were no differences (p > 0.05) between treatments in the microbial community and SCFA during fermentation. However, higher Chao-1 and Shannon indexes were observed in CM and HCM treatments. HCM was also found to be capable of preserving Actinobacterota and Proteobacteria at the phylum level, while at the family level, both treatments may help Lactobacillaceae, Peptostreptococcaceae, Lachnospiraceae, and Ruminococcaceae survive in the long term. Also, there was a potential trend of increasing acetic acid and butyric acid in the CM and HCM treatments. While HCM shows promise in potentially modulating the gut microbiota of weaned swine, additional research is required to investigate the effects of higher doses of HCM on swine performance parameters. [ABSTRACT FROM AUTHOR]

This experiment aimed to discuss and reveal the effect and mechanism of mannanase on intestinal inflammation in broilers triggered by a soybean meal diet. In this experiment, 384 Arbor Acres broilers at 1 d old were randomly divided into 3 treatment groups. The broilers were fed a corn-soybean meal basal diet, a low-energy diet (metabolizable energy reduced by 50 kcal/kg), and a low-energy diet supplemented with 100 mg/kg mannanase for 42 d. The low-energy diet increased feed conversion ratio from 0 to 42 d, reduced ileal villus height and villus height-to-crypt depth ratio and upregulated the expression of nuclear factor kappa B (NF-κB) in the ileum (P

The present study was conducted to evaluate the effect of two different β-mannanases on growth performance and nutrient retention of broiler chickens fed a diet with low energy and amino acid density. A total of 312 one-day-old male broiler chickens (Ross 308) were placed in floor pens and fed a standard starter diet for 16 days. They were then randomly moved to stainless steel cages and distributed into three groups, with 13 replicates of 8 chickens each. The control group received a corn-soybean meal-based grower diet with reduced metabolizable energy by ∼100 kcal/kg and a 10-12% reduction of digestible amino acids (lysine, methionine, and threonine). Titanium oxide was added at 0.5% of diet as an indigestible marker. The other groups were fed the same diet supplemented with either β-mannanase A derived from Thermothelomyces thermophilus (100 g β-mannanase/MT grower diet) or β-mannanase B derived from Paenibacillus lentus (350 g β-mannanase/MT grower diet). The trial lasted for 7 days from d 17 to d 23, comprising 4 days of acclimatization followed by 3 days of sample collection. Final body weight (d 23), body weight gain (d 17-23), and feed intake (d 17-23) of broiler chickens did not differ among the groups. However, both β-mannanases significantly improved the feed conversion ratio during d 17-23 (P = 0.039) and nitrogen retention (P = 0.028) in broiler chickens compared to the control group. Moreover, dietary supplementation with β-mannanase A significantly increased dry matter retention (P = 0.050), organic matter retention (P = 0.028), and nitrogen-corrected apparent metabolizable energy (AMEn; P = 0.033) compared to the control group. In conclusion, supplemental β-mannanase, regardless of the product, improved the growth performance of broiler chickens by improving nutrient retention and dietary AMEn.

The utilization of enzymes in various industrial applications has attracted increasing attention in recent years. However, their production costs and instability in extreme environments are two significant factors that limit their use in industry. Mannanase production from Bacillus mojavensis using spent coffee grounds (SCGs), which are inexpensive and most abundant domestic industrial waste, was increased about 32-fold with optimization of submerged fermentation (SmF) medium using Plackett–Burman design (PBD) and response surface methodology–Box–Behnken design (RSM–BBD). Moreover, BmMan production in a 5-L stirred bioreactor resulted in an enzyme titer of 32.55 U/mL. BmMan was partially purified 2.28-fold with 63.01% yield using ultrafiltration and ammonium sulfate precipitation techniques. The molecular weight of partially purified mannanase (BmMan) was estimated by zymography to be 24 kDa. Biochemical characterization of BmMan showed that optimal pH and temperature for catalysis were 4.0 and 70 °C, respectively. BmMan showed a half-life of 40.8, 150.2, 210.2, and 387.6 min at 80, 70, 60, and 50 °C, respectively. Subjecting to bivalent cations and chemicals, Ag2+, Ca2+, Ni2+, Mg2+, Mn2+, Fe2+, DTT, Triton X-100, SDS, and β-mercaptoethanol enhanced BmMan activity. Additionally, BmMan was compatible with methanol, DMSO, isopropanol, and butanol. The clarity and nutritional value of grape juice were improved after the treatment with the enzyme. Ultrafiltrate obtained by passing cell-free culture liquid through a 10-kDa molecular weight cutoff (MWCO) membrane exhibited antimicrobial and antioxidant activity without showing genotoxicity. To the best of our knowledge, this is the first report describing the thermostable and acidophilic mannanases produced by Bacillus taxa and the first study suggesting the multiple uses of SCGs. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing 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.)

ABSTRACT: As an enzyme, β-mannanase (BM) can be widely used as feed additive to improve the growth performance of animals. This experiment aimed to determine the effect of the addition of BM to low-energy diet on the immune function and intestinal microflora of broiler chickens. In this study, 384 one-day-old Arbor Acres broilers were randomly divided into 3 groups (8 replicates per group): positive control (PC, received a corn-soybean meal basal diet), negative control (NC, received a low-energy diet with Metabolizable Energy (ME) reduced by 50 kcal/kg) and NC + BM group (NC birds + 100 mg/kg BM). All birds were raised for 42 d. The results showed that BM mitigated the damage of immune function in peripheral blood of broilers caused by the decrease of dietary energy level by increasing the Concanavalin A (Con A) index of stimulation (SI) and macrophages phagocytic activity in the peripheral blood of broilers at 42 d (P < 0.05). The analysis of cecum flora showed that the low-energy diet significantly reduced the observed_species index (P < 0.01), Chao1 index and ACE index (P < 0.05), which reduced the abundance and evenness of species in the cecum of broilers at 21 d. It also significantly reduced the relative abundance of Candidatus_Arthromitus and significantly increased the relative abundance of Pseudomonas in the cecum of broilers at 21 d, while also significantly increasing the relative abundance of Monoglobus at 42 d. BM significantly increased the relative abundance of Lachnospiraceae_UCG-001 and Lachnospiraceae_bacterium_615 in the cecum of broilers at 21 d. In addition, BM inhibited microbial Fatty acid degradation by decreasing the activity of glutaryl-CoA dehydrogenase. Collectively, BM could improve intestinal health by enhancing the immune function of broilers, promoting the proliferation of beneficial bacteria and reducing the number of harmful bacteria, regulating intestinal flora, thereby alleviating the adverse effects of lower dietary energy levels.

This study aimed to compare the effects of hydrolyzed copra meal (HCM) inclusion at 1% on its in vitro digestibility and the microbiota and cecum fermentation using the gut microbiota of weaned swine, targeting microbial community and short-chain fatty acids (SCF). For this reason, three treatments were considered: control (no copra meal), 1% non-hydrolyzed copra meal (CM), and 1% HCM. Non-defatted copra meal was hydrolyzed and analyzed (reducing sugars and total carbohydrates) in our laboratory. For digestion, microbiota identification, and fermentation assays, fresh fecal samples from two weaned pigs (1 month old) were used. Three replicates of each treatment were employed. HCM was more digestible, with approximately 0.68 g of hydrolysate recovered after simulated digestion compared to 0.82 g of hydrolysate recovered from CM. This was shown by Scanning Electron Microscope (SEM) images. Also, the three swine shared the majority of microbial species identified at the phylum and family levels. There were no differences (p > 0.05) between treatments in the microbial community and SCFA during fermentation. However, higher Chao-1 and Shannon indexes were observed in CM and HCM treatments. HCM was also found to be capable of preserving Actinobacterota and Proteobacteria at the phylum level, while at the family level, both treatments may help Lactobacillaceae, Peptostreptococcaceae, Lachnospiraceae, and Ruminococcaceae survive in the long term. Also, there was a potential trend of increasing acetic acid and butyric acid in the CM and HCM treatments. While HCM shows promise in potentially modulating the gut microbiota of weaned swine, additional research is required to investigate the effects of higher doses of HCM on swine performance parameters.

Lactobacillus plantarum là một loại vi khuẩn sinh axit lactic quan trọng trong thực phẩm. Nhiều nghiên cứu đã báo cáo về hiệu quả sử dụng vi khuẩn này để tổng hợp enzyme tự do. Tuy nhiên, rất ít nghiên cứu về việc phát triển L. plantarum như chất mang an toàn để sản xuất enzyme cố định. Ở nghiên cứu này, vector tái tổ hợp pPgm_1261ManB đã được thiết kế để biểu hiện và cố định beta-mannanase (ManB) lên bề mặt L. plantarum WCFS1 một cách liên tục nhờ protomor thường trực Pgm từ L. acidophilus NCFM. Với mục tiêu đó, hai đoạn pgm và lp1261-manB-myc được khuếch đại nhờ phản ứng PCR sử dụng khuôn lần lượt là vector pUC và pSIP_1261ManB với các cặp mồi tương ứng. Hai sản phẩm PCR được lai với nhau nhờ phương pháp PCR mở rộng vùng chồng lấp. Đoạn lai sau đó được gắn vào vector pSIP409GusA và tạo ra plasmid tái tổ hợp pPgm_1261ManB. Vector này tiếp tục được biến nạp vào tế bào biểu hiện L. plantarum nhằm nghiên cứu sự biểu hiện và cố định liên tục ManB trên bề mặt lợi khuẩn L. plantarum.

A thermophilic fungus, named HBFH10, was isolated from Luzhou-flavor Daqu and identified as Rhizopus microsporus. A new β-mannanase gene (RmMan134) from Rhizopus microsporus HBHF10, was cloned using degenerate primers, expressed, and characterized. The cloned RmMan134 gene had a total length of 552 bp without introns, encoding 183 amino acids and one stop codon. The expressed enzyme was composed of one signal peptide sequence of 19 amino acid residues and the catalytic region of the GH134 family. The optimal pH and temperature for the recombinant enzyme were 6.0 and 50 ℃, respectively. It had high thermal and pH stability. Its molecular mass was estimated to be approximately 18.5 kDa, and it was a glycosylated molecule. When konjac gum was used as the substrate, the Km and Vmax values of RmMan134 were 0.66 mg/mL and 57.1 μmol/(min·mg), respectively. RmMan134 exhibited the best clarification efficiency for orange juice, resulting in a 23.8% increase in its clarity, followed apple juice (11%) and peach juice (7%). Moreover, RmMan134 significantly increased the yield of grape juice by about 7%. Overall, RmMan134 has good application prospects in juice processing.

Konjac glucomannan (KGM) is a high-molecular-weight polysaccharide that was originally extracted from the corms (underground storage organs) of Amorphophallus konjac. KGM and its oligomers have been reported as dietary fibers that exhibit an array of health benefits. The depolymerization of KGM via enzymatic hydrolysis at different conditions gives products of low viscosity and can be used for coating materials in microencapsulation. In the present study, konjac glucomannan hydrolysates (KGMHs) were produced by enzymatic hydrolysis using commercial mannanase at pH 4.5 at 70 °C for 5–120 min, then KGMHs' molecular weight (Mw), Degree of Polymerization (DP) and their bioactivities were determined. A longer hydrolysis time resulted in KGMH of a lower DP. Oligoglucomannans (Mw < 10,000) could be obtained after hydrolysis for 20 min. The DP of KGMH rapidly decreased during an early stage of the hydrolysis (first 40 min); DP reached around 7 at the end of the hydrolysis. Antioxidant activities were determined by the DPPH radical scavenging and FRAP assays of KGMHs prepared at pH 4.5 and evaluated at pH 2.0–8.0 depending on pH. KGMH having lower Mw exhibited higher antioxidant activities. KGMHs having the smallest molecular weight (Mw = 419) exhibited the highest DPPH radical scavenging activity. Mw and pH have a greater impact on KGMHs' bioactivities which can be useful information for KGMHs as functional ingredients. [ABSTRACT FROM AUTHOR]

The digestibility of palm kernel meal can be increased using mannanase. Enzyme application in the field requires a preservation process. The aim of this study was to evaluate the stability of liquid Eupenicillium javanicum BS4 mannanase resulting from solid state fermentation with the addition of a preservative (glycerol, sorbitol, or mannitol) at storage temperatures of 4 °C and at room temperature. Enzymes were produced using solid state fermentation with coconut cake as substrate and E. javanicum BS4 inoculum. The preservation evaluated the stability of the enzyme in three conditions: in submerged culture and solid state fermentation, filtration and non-filtration treatments, and different concentrations of the preservative. Each treatment was added with each preservation agent and included a negative control. Enzyme activity (U/mL) and saccharification activity (U/mL) were observed during incubation. The half-life of the enzyme activity was determined by the log curve of the enzyme activity. The half-life of the enzyme under solid state fermentation was longer than enzyme-submerged culture. Filtration treatment produced more stable results. The addition of mannitol and sorbitol (polyol) at a concentration of 20% gave similar results during incubation. Increasing the concentration of mannitol was not possible at it caused crystallization. Although the enzyme activity and saccharification fluctuated over the incubation period, 30% sorbitol was the best preservative. The results of saccharification can be used as a parameter in the field for determining enzyme addition to feed containing high palm kernel meal. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department 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.)

Mannan oligosaccharides (MOSs) are excellent prebiotics that are usually obtained via the enzymatic hydrolysis of mannan. In order to reduce the cost of preparing MOSs, immobilized enzymes that demonstrate good performance, require simple preparation, and are safe, inexpensive, and reusable must be developed urgently. In this study, β-mannanase was immobilized on calcium alginate (CaAlg). Under the optimal conditions of 320 U enzyme addition, 1.6% sodium alginate, 2% CaCl2, and 1 h of immobilization time, the immobilization yield reached 68.3%. The optimum temperature and pH for the immobilized β-mannanase (Man-CaAlg) were 75 °C and 6.0, respectively. The Man-CaAlg exhibited better thermal stability, a high degree of pH stability, and less substrate affinity than free β-mannanase. The Man-CaAlg could be reused eight times and retained 70.34% of its activity; additionally, the Man-CaAlg showed 58.17% activity after 30 days of storage. A total of 7.94 mg/mL of MOSs, with 4.94 mg/mL of mannobiose and 3.00 mg/mL of mannotriose, were generated in the oligosaccharide production assay. It is believed that this convenient and safe strategy has great potential in the important field of the use of immobilized β-mannanase for the production of mannan oligosaccharides. [ABSTRACT FROM AUTHOR]

Abstract Carbon catabolite repression (CCR) enables preferential utilization of easily metabolizable carbon sources, implying the presence of mechanisms to ensure discriminatory gene repression depending on the ambient carbon sources. However, the mechanisms for such hierarchical repression are not precisely understood. In this report, we examined how deletion of pkaA and ganB, which encode cAMP signaling factors, and creA, which encodes a well-characterized repressor of CCR, affects CCR of hemicellulase genes in the filamentous fungus Aspergillus nidulans. β-Xylanase production increased not only in ΔcreA but also in ΔpkaA and ΔganB, with the highest level observed in their double deletants, irrespective of the presence or absence of d-glucose. Expression of the β-xylanase genes in the presence of d-glucose was de-repressed in all the deletion mutants, with significantly higher tolerance against d-glucose repression in ΔpkaA and ΔganB than in ΔcreA. In the presence of galactomannan and d-glucose, partial de-repression of β-mannanase production was detected in ΔcreA, but not in ΔpkaA and ΔganB. The double deletion of creA/pkaA and creA/ganB led to earlier production. Release from d-glucose repression of the β-mannanase genes was partial in the single deletants, while nearly full de-repression was observed in ΔcreAΔpkaA and ΔcreAΔganB. The contribution of PkaA and GanB to CCR by d-xylose of the β-mannanase genes was very minor compared to that of CreA. Consequently, the present study revealed that cAMP signaling plays a major role in CCR of hemicellulase gene expression in a manner that is clearly independent from CreA.

The present study investigated whether supplementing fibre-degrading enzymes can ameliorate the severity of subclinical necrotic enteritis (NE) in broiler chickens offered wheat- or maize-based diets. A total of 1,544 mixed-sex broiler chickens were assigned to 16 experimental treatments as a 2 × 2 × 4 factorial arrangement of treatments. The factors were the following: NE challenge, yes or no; diet type, wheat- or maize-based; and enzyme supplementation, control (no enzyme), family 10 xylanase (XYN10), family 11 xylanase (XYN11) or β-mannanase (MAN). Each treatment was replicated 6 times, with 16 birds per replicate pen. A three-way challenge × diet type × enzyme interaction occurred for body weight at 21 d of age (P = 0.025) and overall feed conversion ratio (P = 0.001). In the non-challenged birds fed the wheat-based diet, supplementing MAN increased d 21 body weight compared to the control. In challenged birds fed the maize-based diet, supplemental XYN11 impeded body weight and overall FCR compared to the control. Birds offered the maize-based diet presented heavier relative gizzard weights at both 16 and 21 d of age (P

Sustainability of regenerated cellulosic fibres could be improved by using paper grade pulp instead of dissolving pulp as a raw material in the fibre spinning process. However, the use of paper grade pulp calls for adjustment of the molar mass distribution (MMD) prior to dissolution to obtain good solubility and spinnability. The objective of this work was to adjust MMD of softwood and eucalyptus kraft pulps by enzymatic treatments at high pulp consistency. The reduction of the MMD of eucalyptus kraft pulp was found to require a nearly 30-fold higher dose of endoglucanase compared to the treatment of softwood pulp. Interestingly, when xylanase was used in combination with endoglucanase to treat eucalyptus kraft pulp, 27% of the xylan was dissolved and the required endoglucanase dose could be decreased from 0.57 to 0.06 mg/g. The endoglucanase dose could be further decreased to 0.028 mg/g when 67% of xylan was removed chemically before the enzymatic treatment. This suggests that xylan hinders endoglucanase action on eucalyptus kraft pulp. For softwood pulp, the addition of xylanase and mannanase had only a minor impact on the treatment efficiency. The different processabilities of softwood and eucalyptus kraft pulps are suggested to originate from the deviating cellulose accessibility which is affected by the fibre structures as well as their hemicellulose composition and localisation. The effect of the treatment consistency was further studied with softwood kraft pulp. Treatment at high consistency clearly enhanced the endoglucanase action whereas the effect of solid content on the hemicellulase action was modest. [ABSTRACT FROM AUTHOR]

Introduction: β-Mannanase is a plant cell wall remodeling enzyme involved in the breakdown of hemicellulose and plays an important role in growth by hydrolyzing the mannan-like polysaccharide, but its function in adaptation to salt stress has been less studied. Methods: Based on cloned the mannanase (MAN) gene from Mirabilis jalapa L., the study was carried out by heterologously expressing the gene in Arabidopsis thaliana, and then observing the plant phenotypes and measuring relevant physiological and biochemical indicators under 150 mM salt treatment. Results and discussion: The results indicate that MirMAN is a protein with a glycohydrolase-specific structural domain located in the cell wall. We first found that MirMAN reduced the susceptibility of transgenic Arabidopsis thaliana to high salt stress and increased the survival rate of plants by 38%. This was corroborated by the following significant changes, including the reduction in reactive oxygen species (ROS) levels, increase in antioxidant enzyme activity, accumulation of soluble sugars and increase of the expression level of RD29 in transgenic plants. We also found thatthe heterologous expression of MirMAN promoted root growth mainly by elongating the primary roots and increasing the density of lateral roots. Meanwhile, the expression of ARF7, ARF19, LBD16 and LBD29 was up-regulated in the transgenic plants, and the concentration of IAA in the roots was increased. Those results indicate that MirMAN is involved in the initiation of lateral root primordia in transgenic plants through the IAA-ARF signalling pathway. In conclusion, MirMAN improves plant salt tolerance not only by regulating ROS homeostasis, but also by promoting the development of lateral roots. Reflecting the potential of the MirMAN to promote root plastic development in adaptation to salt stress adversity. [ABSTRACT FROM AUTHOR]

Summary: The β‐mannanase present in the commercial enzyme Pectinex Ultra SP‐L was characterised and tested for its ability to hydrolyse copra meal for the production of mannooligosaccharides (MOS). The optimum pH and temperature for the mannanase activity were 4.0 and 65 °C, respectively. The relative activity of the β‐mannanase of the commercial preparation Pectinex Ultra SP‐L on copra meal was 49% when compared to the complete hydrolysis of locust bean gum, indicating its potential to hydrolyse the agricultural waste. The maximum MOS concentration of 25 g L−1 was obtained from the hydrolysis of 300 g L−1 copra meal with Pectinex Ultra SP‐L at 55 °C for 2 h. The hydrolysate consisted of ~45% oligosaccharides and the rest were monosaccharides. Mannobiose and mannotriose were the only oligosaccharides present in the mixture, with mannobiose accounting for 90%. A simple and efficient method to obtain oligosaccharides from copra meal using a commercial pectinolytic enzyme is presented. [ABSTRACT FROM AUTHOR]

In order to figure out the induction mechanisms of glycoside hydrolase genes in Aspergillus aculeatus, we screened approximately 9,000 transfer DNA (T-DNA)-inserted mutants for positive regulators involved in the induction. Since the mutants possess the orotidine 5′-monophosphate decarboxylase gene as a reporter gene to monitor the cellulose-responsive expression of the cellobiohydrolase I gene (cbhI), candidate strains were isolated by counterselection against 5-fluoroorotic acid (5-FOA). One 5-FOA-resistant mutant harboring the T-DNA at the uge5 locus showed reduced cellulose utilization and cbhI expression. A. aculeatus Uge5 is homologous to Aspergillus fumigatus uge5 (Afu5g10780; E-value, 0.0; identities, 93%), which catalyzes the conversion of uridine diphosphate (UDP)-glucose to UDP-galactopyranose. The uge5 deletion mutant in A. aculeatus (Δuge5) showed reduced conidium formation on minimal media supplemented with galactose, locust bean gum (LBG), and guar gum as a carbon source. β-1,4-Endoglucanase and β-1,4-mannanase production in submerged culture containing LBG was reduced to 10% and 6% of the control strain at day 5, respectively, but no difference was observed in cultures containing wheat bran. The expression of major cellulolytic and mannolytic genes in the presence of mannobiose in Δuge5 was reduced to less than 15% of the control strain, while cellobiose-responsive expression was only modestly reduced at early inducing time points. Since all test genes were controlled by a transcription factor ManR, these data demonstrate that Uge5 is involved in inducer-dependent selective expression of genes controlled via ManR. Key points: • UDP-glucose 4-epimerase (Uge5) regulates expression of glycosyl hydrolase genes. • ManR regulates both cellobiose- and mannobiose-responsive expression. • Uge5 plays a key role in mannobiose-responsive expression. [ABSTRACT FROM AUTHOR]

Konjac glucomannan (KGM) is a high-molecular-weight polysaccharide that was originally extracted from the corms (underground storage organs) of Amorphophallus konjac. KGM and its oligomers have been reported as dietary fibers that exhibit an array of health benefits. The depolymerization of KGM via enzymatic hydrolysis at different conditions gives products of low viscosity and can be used for coating materials in microencapsulation. In the present study, konjac glucomannan hydrolysates (KGMHs) were produced by enzymatic hydrolysis using commercial mannanase at pH 4.5 at 70 °C for 5–120 min, then KGMHs’ molecular weight (Mw), Degree of Polymerization (DP) and their bioactivities were determined. A longer hydrolysis time resulted in KGMH of a lower DP. Oligoglucomannans (Mw < 10,000) could be obtained after hydrolysis for 20 min. The DP of KGMH rapidly decreased during an early stage of the hydrolysis (first 40 min); DP reached around 7 at the end of the hydrolysis. Antioxidant activities were determined by the DPPH radical scavenging and FRAP assays of KGMHs prepared at pH 4.5 and evaluated at pH 2.0–8.0 depending on pH. KGMH having lower Mw exhibited higher antioxidant activities. KGMHs having the smallest molecular weight (Mw = 419) exhibited the highest DPPH radical scavenging activity. Mw and pH have a greater impact on KGMHs’ bioactivities which can be useful information for KGMHs as functional ingredients.

The effects of feeding diets containing sunflower and wheat middlings pre-treated with fibredegrading enzymes were investigated. Based on hatch body weight (BW), 288 Ross-708 male broiler chicks were placed in cages (six birds/cage). Diets were: 1) positive control (PC), a maize-soybean positive control; 2) negative control (NC), PC plus untreated sunflower meal (USM) and wheat middlings (UWM); and 3) four test diets in which USM and UWM were replaced with pre-treated sunflower (TSM) and wheat middlings (TWM) at 25% (NC25), 50% (NC50), 75% (NC75) and 100% (NC100). The pretreated feedstuffs were mixed with 1% of FDE in a ratio of 1:2 w/w for feedstuff:water and incubated for 24 hours at 40 °C, and oven-dried before feed preparation. Diets were formulated for two phases (starter, 0-21 d) and finisher (22-42 d). Diets were allocated in a completely randomized design (eight replicates per diet) and birds had free access to feed and water. Bodyweight (BW) and feed intake (FI) were monitored by phase, and one bird per cage was sacrificed on days 21 and 42 for samples. The BW and BW gain (BWG) of NC up to NC50 were not different relative to PC, but NC75 and NC100 were lower than PC throughout the study. On day 21, liver weight had increased linearly and on day 42, tibia length and diameter linearly decreased with the inclusion of TSM and TWM. In conclusion, TSM and TWM at low levels did not affect performance while high inclusion levels reduced the performance of the broilers. [ABSTRACT FROM AUTHOR]

Mannanases from microorganisms are important biotechnologically as they are involved in the hydrolysis of complex polysaccharides of plant tissues into simple molecules. The major mannan-degrading enzymes are β-mannanases, β-mannosidases and β-glucosidase. This study aimed to isolate and screen for mannanase-producing yeasts from citrus wastes and to produce, optimize, purify and characterize the enzyme. One hundred and two (102) yeasts were isolated from different citrus wastes obtained from five different markets and screened for their mannanase producing ability. Gum Arabic was used as a substrate for the production of mannanase enzyme by yeasts isolates using submerged fermentation. Candida sp. LES2, Candida sp. OS12, Pichia sp. and Pichia kudriavzevii (AUMC 10190) were the yeast isolates with the best potential of mannanase production. Incubation period, pH, temperature, carbon and nitrogen source were optimized under submerged fermentation for the production of mannanase. The mannanase produced by Pichia kudriavzevii (AUMC 10190) was optimally active at pH 7.0 (202.10 U/ml) and its temperature is stable at 60 °C. Pichia kudriavzevii (AUMC 10190) was optimally active at 35 °C (147.91U/ml). Mannanase enzyme produced by Pichia kudriavzevii (AUMC 10190) had a purification fold of 2.14 with a specific activity of 134.53U/ml proving that yeasts obtained from citrus wastes have the ability to produce mannanase enzyme under optimized condition. In conclusion, Pichia kudriavzevii (AUMC 10190) isolated from citrus waste is potential yeast for the production of mannanase under suitable condition for higher yield. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing or hydro-frac fluids can impede well production due to the damage caused to the reservoir formation and fracture face, generated from adverse interactions with reservoir rock. Understanding the mechanisms of hydraulic fracturing, optimum treatment designs, and pumping/pressure profiles is critical for hydro-frac success. However, to realize the full potential of fracturing and the mitigation strategies for reservoir and fracture conductivity damage during and after its occurrence, fracturing must be considered during the design phase itself. This article provides a brief overview of hydro-frac techniques, including design, optimization, modeling, commonly used proppants, and fracturing fluid benefits and consequences based on critically reviewed case studies. However, the primary focus of this article is on the potential of fracture conductivity damage and the intrinsic mechanisms in hydraulic fracturing. The article presents updated information on various damage mitigation processes established through laboratory investigation and field implementation. The authors expect that the provided workflow in this article will be helpful to researchers and stimulate engineers to a great extent. [ABSTRACT FROM AUTHOR]

Simple Summary: Mannooligosaccharides (MOS) can promote growth and immunity in aquatic animals. Although most commercial MOS are derived from yeast, the use of MOS from copra meal, a waste product of the coconut industry, is of interest. MOS from copra meal, when given as a dietary supplement to shrimp, could help improve resistance to pathogenic Vibrio and could also act as an immunostimulant. Our objective was to identify bacterial isolates that could be used as probiotics for shrimp and together with MOS as synbiotics to synergistically improve shrimp performance and feed utilization. In this study, two bacterial candidates, Man26 and Man122, were isolated from shrimp intestines and screened for mannanase, the enzyme for mannan digestion. The crude enzymes were evaluated for their biological properties and potential application in the digestion of feedstuffs in vitro. Both strains were able to produce and secrete mannanase to digest MOS and other mannan-rich materials and could tolerate a wide pH range. The addition of crude enzymes significantly increased the reducing sugars of copra meal, palm kernel cake, and soybean meal (p < 0.05) as well as protein release. The synergistic effect of our bacteria and MOS on shrimp growth performance will be further explored in the field. Prebiotics such as mannan-oligosaccharides (MOS) are a promising approach to improve performance and disease resistance in shrimp. To improve prebiotic utilization, we investigated the potential probiotics and their feasibility of synbiotic use in vitro. Two bacterial isolates, Man26 and Man122, were isolated from shrimp intestines and screened for mannanase, the enzyme for mannan digestion. The crude mannanase from both isolates showed optimal activities at pH 8 with optimum temperatures at 60 °C and 50 °C, respectively. The enzymes remained stable at pH 8–10 for 3 h (>70% relative activity). The thermostability range of Man26 was 20–40 °C for 20 min (>50%), while that of Man122 was 20–60 °C for 30 min (>50%). The Vmax of Man122 against locust bean gum substrate was 41.15 ± 12.33 U·mg−1, six times higher than that of Man26. The Km of Man26 and Man122 were 18.92 ± 4.36 mg·mL−1 and 34.53 ± 14.46 mg·mL−1, respectively. With the addition of crude enzymes, reducing sugars of copra meal, palm kernel cake, and soybean meal were significantly increased (p < 0.05), as well as protein release. The results suggest that Man26 and Man122 could potentially be used in animal feeds and synbiotically with copra meal to improve absorption and utilization of feedstuffs. [ABSTRACT FROM AUTHOR]

Carbon catabolite repression (CCR) enables preferential utilization of easily metabolizable carbon sources, implying the presence of mechanisms to ensure discriminatory gene repression depending on the ambient carbon sources. However, the mechanisms for such hierarchical repression are not precisely understood. In this report, we examined how deletion of pkaA and ganB, which encode cAMP signaling factors, and creA, which encodes a well-characterized repressor of CCR, affects CCR of hemicellulase genes in the filamentous fungus Aspergillus nidulans. β-Xylanase production increased not only in ΔcreA but also in ΔpkaA and ΔganB, with the highest level observed in their double deletants, irrespective of the presence or absence of d-glucose. Expression of the β-xylanase genes in the presence of d-glucose was de-repressed in all the deletion mutants, with significantly higher tolerance against d-glucose repression in ΔpkaA and ΔganB than in ΔcreA. In the presence of galactomannan and d-glucose, partial de-repression of β-mannanase production was detected in ΔcreA, but not in ΔpkaA and ΔganB. The double deletion of creA/pkaA and creA/ganB led to earlier production. Release from d-glucose repression of the β-mannanase genes was partial in the single deletants, while nearly full de-repression was observed in ΔcreAΔpkaA and ΔcreAΔganB. The contribution of PkaA and GanB to CCR by d-xylose of the β-mannanase genes was very minor compared to that of CreA. Consequently, the present study revealed that cAMP signaling plays a major role in CCR of hemicellulase gene expression in a manner that is clearly independent from CreA. [ABSTRACT FROM AUTHOR]

Palm kernel cake (PKC) is a by-product of palm kernel oil extraction with moderate nutritional value, containing 30–35% β-mannan, which is indigestible, slows growth, and reduces feed efficiency. PKC can be improved by mannanase hydrolysis, but the effectiveness of mannanase is dependent on the microbial source. Thus, the effect of steam pretreatment and bacterial mannanases on PKC quality was investigated. PKC was pretreated by steaming and hydrolyzed in the small intestine by various mannanases. The contents of reducing sugar, total sugar, and protein release were measured. Steamed PKC had a significant increase in protein (16.95 ± 0.14 to 20.98 ± 0.13%) and a substantial decrease in hemicellulose (29.52 ± 0.44 to 3.46 ± 0.88%) and lignin (8.94 ± 0.28 to 1.40 ± 0.22%). Mannanases from Escherichia coli -KMAN-3 and E. coli -Man6.7 recorded the highest activities, followed by commercial mannanase, Bacillus circulans NT6.7 and B. amyloliquefaciens NT6.3 mannanases, orderly. B. circulans NT6.7 and B. amyloliquefaciens NT6.3 had multi-activities that include glucanase (3.10 ± 0.04% and 2.47 ± 0.02%) and amylase (1.74 ± 0.03% and 1.38 ± 0.04%), respectively. B. amyloliquefaciens NT6.3 mannanase hydrolyzed steamed PKC to release more reducing sugar, total sugar, and protein than hydrolyzed raw PKC. In raw and steamed PKC, B. amyloliquefaciens NT6.3 mannanase produced the highest reducing sugar release. As a result, steam pretreatment and mannanase hydrolysis, particularly from B. amyloliquefaciens , can be used to increase the functioning of PKC and develop new feed ingredients for monogastric animals at a reasonable cost. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effect of two different β-mannanases on growth performance and nutrient retention of broiler chickens fed a diet with low energy and amino acid density. A total of 312 one-day-old male broiler chickens (Ross 308) were placed in floor pens and fed a standard starter diet for 16 days. They were then randomly moved to stainless steel cages and distributed into three groups, with 13 replicates of 8 chickens each. The control group received a corn-soybean meal-based grower diet with reduced metabolizable energy by ∼100 kcal/kg and a 10-12% reduction of digestible amino acids (lysine, methionine, and threonine). Titanium oxide was added at 0.5% of diet as an indigestible marker. The other groups were fed the same diet supplemented with either β-mannanase A derived from Thermothelomyces thermophilus (100 g β-mannanase/MT grower diet) or β-mannanase B derived from Paenibacillus lentus (350 g β-mannanase/MT grower diet). The trial lasted for 7 days from d 17 to d 23, comprising 4 days of acclimatization followed by 3 days of sample collection. Final body weight (d 23), body weight gain (d 17-23), and feed intake (d 17-23) of broiler chickens did not differ among the groups. However, both β-mannanases significantly improved the feed conversion ratio during d 17-23 (P = 0.039) and nitrogen retention (P = 0.028) in broiler chickens compared to the control group. Moreover, dietary supplementation with β-mannanase A significantly increased dry matter retention (P = 0.050), organic matter retention (P = 0.028), and nitrogen-corrected apparent metabolizable energy (AMEn; P = 0.033) compared to the control group. In conclusion, supplemental β-mannanase, regardless of the product, improved the growth performance of broiler chickens by improving nutrient retention and dietary AMEn., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest associated with this publication and no significant financial support that could influence the outcome., (Copyright © 2024. Published by Elsevier Inc.)

The aim of this study was to assess possible beneficial effects of dietary β-mannanase supplementation on the nutrient digestibility, growth performance, digestive and metabolic enzyme activity, and immune response of common carp (Cyprinus carpio) fed plant protein-rich diets. An experiment was conducted in triplicate, and a total of 225 fingerlings of common carp with an average body weight of 13.17 ± 0.12 g were stocked in 15 fiberglass tanks (15 fish/tank). Five dietary treatments (control 35% crude protein, plant-rich basal diet without supplement and four diets supplemented with β-mannanase from two sources (commercially available and locally isolated), each at two dosage levels (500 and 1,000 U/kg diet) were prepared and fed to respective groups of fish, twice a day (8:00 AM and 4:00 PM) at 4 % body weight. During the trial, changes in the level of DO and temperature ranged from 5.5 to 6.1 mg L−1 and 21.5 to 23.5°C, respectively. At the end of the feeding experiment, all fish in each tank were weighed and counted to determine growth parameters, while for the study of other indices, nine samples/treatment group were selected. The results of the study indicated a positive effect of both sources and dosage levels of β-mannanase supplementation on all studied indices, that is, significantly improved (P < 0.05), growth performance (%weight gain, specific growth rate), survival %, hematological indices (RBC, Hb, HCT, and MCHC), immunological indices (lysozyme activity, WBC, respiratory burst activity, and phagocytic activity), improved apparent digestibility of nutrients (crude protein, crude fat, and carbohydrates), and digestible energy. Furthermore, higher activity (P < 0.05) of the digestive enzymes (cellulase, lipase, and protease) and upregulation of MyoD gene in muscle and TNF-α gene in liver, intestine, and muscle were also observed, while the activity of serum AST (serum aspartate aminotransferase) and ALT (alanine transaminase) as compared to control group was significantly decreased (P < 0.05). Based on the results, β-mannanase supplementation (500 U/kg) could be recommended for obtaining better carp production when low-cost plant protein-rich diets are used.

Mannan oligosaccharides (MOSs) are excellent prebiotics that are usually obtained via the enzymatic hydrolysis of mannan. In order to reduce the cost of preparing MOSs, immobilized enzymes that demonstrate good performance, require simple preparation, and are safe, inexpensive, and reusable must be developed urgently. In this study, β-mannanase was immobilized on calcium alginate (CaAlg). Under the optimal conditions of 320 U enzyme addition, 1.6% sodium alginate, 2% CaCl2, and 1 h of immobilization time, the immobilization yield reached 68.3%. The optimum temperature and pH for the immobilized β-mannanase (Man-CaAlg) were 75 °C and 6.0, respectively. The Man-CaAlg exhibited better thermal stability, a high degree of pH stability, and less substrate affinity than free β-mannanase. The Man-CaAlg could be reused eight times and retained 70.34% of its activity; additionally, the Man-CaAlg showed 58.17% activity after 30 days of storage. A total of 7.94 mg/mL of MOSs, with 4.94 mg/mL of mannobiose and 3.00 mg/mL of mannotriose, were generated in the oligosaccharide production assay. It is believed that this convenient and safe strategy has great potential in the important field of the use of immobilized β-mannanase for the production of mannan oligosaccharides.

The primary challenge in utilizing palm kernel meal (PKM, an agricultural by-product) as non-ruminant livestock feed is its high fibre content, predominantly in the form of mannan. Microbial fermentation offers an economically favourable alternative to enzyme supplementation for breaking down fibre in lignocellulosic biomass. In a recent study, our group isolated a B. subtilis strain F6 with a fast response time for mannanase production upon exposure to PKM. This work focuses on improving the mannanase production of the B. subtilis strain to achieve greater fibre hydrolysis of PKM without extending fermentation time. Mannanase GmuG, sourced from B. subtilis F6 and verified for its hydrolytic activity on PKM fibre, was homologously expressed using a replicative plasmid (pBE-S). Enzyme production was systematically improved by optimizing various regulatory elements, including the promoter, ribosome binding site, and signal peptide. Consequently, the neutral detergent fibre content of PKM was substantially reduced by 36.4 % in 22 h of solid-state fermentation using the engineered strain. Lastly, the highest mannanase-producing strain was examined for scaled-up fermentation. The impacts of fermentation on fibre and protein contents, as well as the surface morphology of PKM, were analysed. The outcomes of this study offer an efficient method for robust mannanase expression in B. subtilis and its potential application in the biotransformation of PKM and other mannan-rich bioresources for improved feed utilization. [Display omitted] • Effective fibre hydrolysis relies on strain selection and robust enzyme expression. • Strain variations are crucial for adapting to unconventional substrates. • Over 60-fold mannanase enhancement via plasmid optimization in B. subtilis. • Mannanase expression improved fibre hydrolysis from 10 % to 36 %. • Transcriptome data aids promoter identification under specific growth conditions. [ABSTRACT FROM AUTHOR]

The role of mannanases is diverse and they are used in many industrial applications, in animal feed, in the food industry and in healthcare. They are also applied in biomass processing, because they play an important role in the breakdown of hemicellulose. Among the mannanase inhibitors, heavy metal ions and general enzyme inhibitors are mainly mentioned. Unfortunately, almost no data are available on carbohydrate-based natural inhibitors of mannanases. According to the literature, carbohydrates do not play an important role in the inhibition of mannanases, so neither do oligosaccharides. This is in contrast to the action and inhibition of other O-glycosyl hydrolases. My hypothesis is that mannanases, like other polysaccharide-degrading enzymes, work in the same way and can be inhibited by oligosaccharides. Evidence from docking and modeling results supports and makes probable the hypothesis that oligosaccharides can inhibit the activity of mannanases, similar to the inhibition of other O-glycosyl hydrolases. Among natural carbohydrate oligomers, several potential mannanase inhibitors have been identified and characterized. In addition to expensive research, it is very important to use research based on cheaper modeling to explore the processes. The results obtained are novel and forward-looking, enabling in-depth and targeted research to be carried out. • Explore of potential specific and natural mannanase inhibitors based on carbohydrate oligomers • Among the natural carbohydrate oligomers, we indicated and identified several potential mannanase inhibitors. • Instead of expensive research, it is very important to explore processes based on modeling. • Molecular docking, molecular modeling [ABSTRACT FROM AUTHOR]

Background: Designer cellulosomes are self-assembled chimeric enzyme complexes that can be used to improve lignocellulosic biomass degradation. They are composed of a synthetic multimodular backbone protein, termed the scaffoldin, and a range of different chimeric docking enzymes that degrade polysaccharides. Over the years, several functional designer cellulosomes have been constructed. Since many parameters influence the efficiency of these multi-enzyme complexes, there is a need to optimise designer cellulosome architecture by testing combinatorial arrangements of docking enzyme and scaffoldin variants. However, the modular cloning procedures are tedious and cumbersome. Results: VersaTile is a combinatorial DNA assembly method, allowing the rapid construction and thus comparison of a range of modular proteins. Here, we present the extension of the VersaTile platform to facilitate the construction of designer cellulosomes. We have constructed a tile repository, composed of dockerins, cohesins, linkers, tags and enzymatically active modules. The developed toolbox allows us to efficiently create and optimise designer cellulosomes at an unprecedented speed. As a proof of concept, a trivalent designer cellulosome able to degrade the specific hemicellulose substrate, galactomannan, was constructed and optimised. The main factors influencing cellulosome efficiency were found to be the selected dockerins and linkers and the docking enzyme ratio on the scaffoldin. The optimised designer cellulosome was able to hydrolyse the galactomannan polysaccharide and release mannose and galactose monomers. Conclusion: We have eliminated one of the main technical hurdles in the designer cellulosome field and anticipate the VersaTile platform to be a starting point in the development of more elaborate multi-enzyme complexes. [ABSTRACT FROM AUTHOR]

The food enzyme mannan endo‐1,4‐β‐mannosidase (1,4‐β‐d‐mannan mannanohydrolase, EC 3.2.1.78) is produced with the genetically modified Aspergillus niger strain NZYM‐NM by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in coffee processing. Based on the maximum use levels, dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.956 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,151.7 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of more than 1,200. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use. [ABSTRACT FROM AUTHOR]

Background: Manno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain. Results: Galactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose. Conclusions: The effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum, which would have potential application in the biotechnological applications.How to cite: Zhang R, Li X-Y, Cen X-L, et al. Enzymatic preparation of manno-oligosaccharides from locust bean gum and palm kernel cake, and investigations into its prebiotic activity. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.11.001

This experiment was conducted to evaluate the effect of supplementing enzyme cocktail on growth performance, digestibility of nutrients, and monosaccharide concentration in ileum and ceca of broiler chickens fed wheat-based diets. A total of 600 male broilers (42.26 ± 1.76 g, 0 day old) were used for 35 days of feeding trial consisting of 2 phases (starter phase from d 0 to 21 and finisher phase from d 21 to 35). Four dietary treatments were prepared based on wheat diets containing four levels of enzyme cocktail supplementation at 0, 0.2, 0.3, and 20 g/kg. Overall, dietary enzyme cocktail supplementation decreased feed conversion ratio (linear p = 0.007; quadratic p = 0.013) and improved (linear p < 0.05) the apparent ileal digestibility of dry matter (DM), crude protein, and soluble and insoluble non-starch polysaccharides. The apparent total tract digestibility of DM and gross energy were increased (linear p < 0.01) with increasing supplementation levels of the dietary enzyme cocktail. The concentrations of arabinose, xylose, mannose, and glucose in ileal digesta were linearly increased (p < 0.01) with increasing enzyme cocktail supplementation levels. In addition, the quadratic effect was observed (quadratic p = 0.046) in mannose concentration of ileal digesta. The concentration of arabinose, xylose, mannose, and galactose in cecal digesta was increased (linear p < 0.05) with increasing dietary enzyme cocktail supplementation levels. The supplementation of enzyme cocktail efficiently increased the utilization of nutrients in broiler and there was no adverse effects of high dosage supplementation level.

Abstract The food enzyme mannan endo‐1,4‐β‐mannosidase (1,4‐β‐d‐mannan mannanohydrolase, EC 3.2.1.78) is produced with the genetically modified Aspergillus niger strain NZYM‐NM by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in coffee processing. Based on the maximum use levels, dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.956 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,151.7 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of more than 1,200. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

BackgroundCarbohydrate binding modules (CBMs) bind polysaccharides and help target glycoside hydrolases catalytic domains to their appropriate carbohydrate substrates. To better understand how CBMs can improve cellulolytic enzyme reactivity, representatives from each of the 18 families of CBM found in Ruminoclostridium thermocellum were fused to the multifunctional GH5 catalytic domain of CelE (Cthe_0797, CelEcc), which can hydrolyze numerous types of polysaccharides including cellulose, mannan, and xylan. Since CelE is a cellulosomal enzyme, none of these fusions to a CBM previously existed.ResultsCelEcc_CBM fusions were assayed for their ability to hydrolyze cellulose, lichenan, xylan, and mannan. Several CelEcc_CBM fusions showed enhanced hydrolytic activity with different substrates relative to the fusion to CBM3a from the cellulosome scaffoldin, which has high affinity for binding to crystalline cellulose. Additional binding studies and quantitative catalysis studies using nanostructure-initiator mass spectrometry (NIMS) were carried out with the CBM3a, CBM6, CBM30, and CBM44 fusion enzymes. In general, and consistent with observations of others, enhanced enzyme reactivity was correlated with moderate binding affinity of the CBM. Numerical analysis of reaction time courses showed that CelEcc_CBM44, a combination of a multifunctional enzyme domain with a CBM having broad binding specificity, gave the fastest rates for hydrolysis of both the hexose and pentose fractions of ionic-liquid pretreated switchgrass.ConclusionWe have shown that fusions of different CBMs to a single multifunctional GH5 catalytic domain can increase its rate of reaction with different pure polysaccharides and with pretreated biomass. This fusion approach, incorporating domains with broad specificity for binding and catalysis, provides a new avenue to improve reactivity of simple combinations of enzymes within the complexity of plant biomass.

Any members of the human gut micro biota including members of the gut micro biota that promote health like bifid bacterium bifidbacterium spp. Catabolize manna's for food. Few informationis available in the gut ecological niche regarding the enzymology of man nan deconstruction, below the biochemical properties if the first 5 subfamily 8 glycoside hydrolase (GH5 8) manna n as e derived from the biochemical properties of probiotic. The relationship between gut micro biota and biochemical metabolism to explore the relationship between gut micro biota. In traycomponents and some substances which are produced by the host, the primary intestinal microbe: bacteria and microbial species associated with dietary carbohydrates metabolism, strictly anaerobic and gram positive strain of specified bifid bacteria known as, B. Lon gum (60 percent of the sample)was the most commonly identified species followed by B. bifida (60 percent of the samples), while B. Brief (21 percent). [ABSTRACT FROM AUTHOR]

Mannose and mannooligosaccharide acted as prebiotic that consumed by probiotic bacteria. Mannanase were the second most important enzymes for the hydrolysis of hemicelluloses, beside xylanase. The objective research was to obtain eminent strains of Bacillus sp. in mannan degradation which can potentially be a probiotic candidate. The study employed a completely randomized design using four concentration levels repeated six times. Halotolerant Bacteria were isolated from mangrove ecosystem at Hanura beach, Teluk Pandan, Pesawaran District in Lampung Province. They are grown on the sea water complete agar media. Mannan degradation isolates were then characterized to determine their character with a variety of tests, including resistance to pH, salt, and metal ions, pathogenicity, and determination of mannanase production duration. Thirty strains are found to grow at 3-6% salt content, and 9 of them have mannanolytic activity. They grow optimally at pH 7-10. Seven isolates were proven to be positively hydrolyzed blood agar in the pathogenicity test. The addition of Iron (III) Chloride increased the enzyme activity by 11.12% in IBK3 isolates at 96 hours of cultivation period which was 0.05 UmL-1. It acted as cofactors of enzymatic reactions. Strains Bacillus sp., were able to degrade mannan substrate. It quantified using Index of mannanolytic. Strain IBK3 has the highest index of mannanolytic activity as much as 10.74. Their ability to grow in salt media indicated that they were halotolerant. They were more likely to live at base rather than acid habitat. Only IBK3 and ID2K1 showed non-pathogenic isolates. Only FeCl3 addition has proven to rise up enzymatic activity.