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Tundo, Silvio, Giulia Mandalà, Luca Sella, Francesco Favaron, Renesh Bedre y Raviraj M. Kalunke. "Xylanase Inhibitors: Defense Players in Plant Immunity with Implications in Agro-Industrial Processing". International Journal of Molecular Sciences 23, n.º 23 (30 de noviembre de 2022): 14994. http://dx.doi.org/10.3390/ijms232314994.
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Xylanase inhibitors (XIs) are plant cell wall proteins largely distributed in monocots that inhibit the hemicellulose degrading activity of microbial xylanases. XIs have been classified into three classes with different structures and inhibition specificities, namely Triticum aestivum xylanase inhibitors (TAXI), xylanase inhibitor proteins (XIP), and thaumatin-like xylanase inhibitors (TLXI). Their involvement in plant defense has been established by several reports. Additionally, these inhibitors have considerable economic relevance because they interfere with the activity of xylanases applied in several agro-industrial processes. Previous reviews highlighted the structural and biochemical properties of XIs and hypothesized their role in plant defense. Here, we aimed to update the information on the genomic organization of XI encoding genes, the inhibition properties of XIs against microbial xylanases, and the structural properties of xylanase-XI interaction. We also deepened the knowledge of XI regulation mechanisms in planta and their involvement in plant defense. Finally, we reported the recently studied strategies to reduce the negative impact of XIs in agro-industrial processes and mentioned their allergenicity potential.
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Dhiman, Saurabh Sudha, Jitender Sharma y Bindu Battan. "Industrial applications and future prospects of microbial xylanases: A review". BioResources 3, n.º 4 (30 de octubre de 2008): 1377–402. http://dx.doi.org/10.15376/biores.3.4.1377-1402.
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Microbial enzymes such as xylanases enable new technologies for industrial processes. Xylanases (xylanolytic enzyme) hydrolyze complex polysaccharides like xylan. Research during the past few decades has been dedicated to enhanced production, purification, and characterization of microbial xylanase. But for commercial applications detailed knowledge of regulatory mechanisms governing enzyme production and functioning should be required. Since application of xylanase in the commercial sector is widening, an understanding of its nature and properties for efficient and effective usage becomes crucial. Study of synergistic action of multiple forms and mechanism of action of xylanase makes it possible to use it for bio-bleaching of kraft pulp and for desizing and bio-scouring of fabrics. Results revealed that enzymatic treatment leads to the enhancement in various physical properties of the fabric and paper. This review will be helpful in determining the factors affecting xylanase production and its potential industrial applications in textile, paper, pulp, and other industries.
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Brennan, YaLi, Walter N. Callen, Leif Christoffersen, Paul Dupree, Florence Goubet, Shaun Healey, Myrian Hern�ndez et al. "Unusual Microbial Xylanases from Insect Guts". Applied and Environmental Microbiology 70, n.º 6 (junio de 2004): 3609–17. http://dx.doi.org/10.1128/aem.70.6.3609-3617.2004.
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ABSTRACT Recombinant DNA technologies enable the direct isolation and expression of novel genes from biotopes containing complex consortia of uncultured microorganisms. In this study, genomic libraries were constructed from microbial DNA isolated from insect intestinal tracts from the orders Isoptera (termites) and Lepidoptera (moths). Using a targeted functional assay, these environmental DNA libraries were screened for genes that encode proteins with xylanase activity. Several novel xylanase enzymes with unusual primary sequences and novel domains of unknown function were discovered. Phylogenetic analysis demonstrated remarkable distance between the sequences of these enzymes and other known xylanases. Biochemical analysis confirmed that these enzymes are true xylanases, which catalyze the hydrolysis of a variety of substituted β-1,4-linked xylose oligomeric and polymeric substrates and produce unique hydrolysis products. From detailed polyacrylamide carbohydrate electrophoresis analysis of substrate cleavage patterns, the xylan polymer binding sites of these enzymes are proposed.
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Liang, Fangfang, Yi Mo, Suleman Shah, Ying Xie, Arshad Mehmood, Hesheng Jiang y Yafen Guo. "Characterization of Two Wheat-Derived Glycoside Hydrolase Family-10 Xylanases Resistant to Xylanase Inhibitors". Journal of Food Quality 2022 (5 de abril de 2022): 1–10. http://dx.doi.org/10.1155/2022/9590243.
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Xylanase inhibitors inhibit the activities of microbial xylanases and seriously compromise the efficacy of microbial xylanases added to modify cereals. Cereal endogenous xylanases are unaffected by these xylanase inhibitors, but little information is available regarding their effects in improving cereal quality, a neglected potential application. As a strategy for circumventing the negative effects of xylanase inhibitors, the objective of this study was to use genetic engineering to obtain sufficient amounts of active endo-1,4-β-D-xylanase from wheat to analyze the characteristics of its structure. The endo-1,4-β-D-xylanase from wheat was heterologously expressed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), western blotting, MALDI-TOF/TOF (MS) analyses, and enzyme activity determination confirmed 2 active endo-1,4-β-D-xylanases (EXY3 and EXY4) were successfully obtained. The molecular weights (MW) and isoelectric point (pI) of EXY3 were 36.108 kDa and 5.491, while those of the EXY4 protein were 41.933 kDa and 5.726. They both contained the same catalytic domain of GH10 xylanases from G266 to V276 and have the same catalytic site, Glu273. They shared the same putative N-glycosylation sites (N62-T63-S64 and N280–V281–S282) and 3 putative O-glycosylation sites (Ser8, Ser9, and Thr21), but EXY4 had an additional O-glycosylation site (Thr358). EXY3 was smaller than EXY4 by 51 amino acids because of a nonsense mutation and premature termination. They both had the 8-fold beta/alpha-barrel (TIM-barrel) fold. The specific activities of EXY3 and EXY4 were 152.0891 and 67.2928 U/mg, respectively. This work demonstrates a promising way to obtain wheat xylanases by genetic engineering; the properties of the enzymes indicate their potential application in cereal-based industries.
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Anand, Deepsikha, Jeya Nasim, Sangeeta Yadav y Dinesh Yadav. "Bioinformatics Insights Into Microbial Xylanase Protein Sequences". Biosciences, Biotechnology Research Asia 15, n.º 2 (27 de junio de 2018): 275–94. http://dx.doi.org/10.13005/bbra/2631.
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Microbial xylanases represents an industrially important group of enzymes associated with hydrolysis of xylan, a major hemicellulosic component of plant cell walls. A total of 122 protein sequences comprising of 58 fungal, 25 bacterial, 19actinomycetes and 20 yeasts xylanaseswere retrieved from NCBI, GenBank databases. These sequences were in-silico characterized for homology,sequence alignment, phylogenetic tree construction, motif assessment and physio-chemical attributes. The amino acid residues ranged from 188 to 362, molecular weights were in the range of 20.3 to 39.7 kDa and pI ranged from 3.93 to 9.69. The aliphatic index revealed comparatively less thermostability and negative GRAVY indicated that xylanasesarehydrophilicirrespective of the source organisms.Several conserved amino acid residues associated with catalytic domain of the enzyme were observed while different microbial sources also revealed few conserved amino acid residues. The comprehensive phylogenetic tree indicatedsevenorganismsspecific,distinct major clusters,designated as A, B, C, D, E, F and G. The MEME based analysis of 10 motifs indicated predominance of motifs specific to GH11 family and one of the motif designated as motif 3 with sequence GTVTSDGGTYDIYTTTRTNAP was found to be present in most of the xylanases irrespective of the sources.Sequence analysis of microbial xylanases provides an opportunity to develop strategies for molecular cloning and expression of xylanase genes and also foridentifying sites for genetic manipulation for developing novel xylanases with desired features as per industrial needs.
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Oyinlola, Ayodeji Adedapo y Felix Akinsola Akinyosoye. "Isolation, Screening and Optimization of Xylanase Producing Fungi from Rhizosphere Soil of Cassava Tuber". International Journal of Advance Research and Innovation 9, n.º 4 (2021): 19–29. http://dx.doi.org/10.51976/ijari.942103.
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Microbial xylanases have attracted a great deal of attention, due to their biotechnological potential in various industrial processes. In this study, the isolation, screening and optimization of xlanase-producing fungi from rhizosphere soil of cassava tuber under submerged fermentation were carried out. Altogether, eight fungal strains were isolated from the rhizosphere soil of cassava. All the fungal isolates were screened positive for xylanase activity on mineral salt medium supplemented with araboxylan as sole carbon source. The process parameters were optimized using one factor at a time technique. The identities of the isolates authenticated as Debaryomyces nepalensis and Penicillium polonicum by molecular techniques were regarded as good xylanase producers and they were selected for optimization studies. In order to maximize enzyme synthesis from fungi, the effect of nutritional and environmental conditions on xylanase production was investigated. The optimal incubation periods for maximal xylanase production by Penicillium polonicum and Debaryomyces nepalensis were 120 and 144 hours respectively while the optimal pH and temperature for xylanase production were 5.0 and 50oC respectively by Penicillium polonicum and Debaryomyces nepalensis. The best carbon sources for xylanase production from both fungi were found to be xylan. As a result of this, both fungal species have significant potential as sources of xylanases for industrial and biotechnological applications.
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Moscetti, Ilaria, Silvio Tundo, Michela Janni, Luca Sella, Katia Gazzetti, Alexandra Tauzin, Thierry Giardina, Stefania Masci, Francesco Favaron y Renato D'Ovidio. "Constitutive Expression of the Xylanase Inhibitor TAXI-III Delays Fusarium Head Blight Symptoms in Durum Wheat Transgenic Plants". Molecular Plant-Microbe Interactions® 26, n.º 12 (diciembre de 2013): 1464–72. http://dx.doi.org/10.1094/mpmi-04-13-0121-r.
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Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.
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Tremblay, L. y F. Archibald. "Production of a cloned xylanase in Bacillus cereus and its performance in kraft pulp prebleaching". Canadian Journal of Microbiology 39, n.º 9 (1 de septiembre de 1993): 853–60. http://dx.doi.org/10.1139/m93-127.
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Xylanase production from a Bacillus subtilis gene cloned into a strain of Escherichia coli was monitored. Although this gene was expressed in E. coli at several temperatures, efficient xylanase secretion did not occur; the observed protein release apparently depended on cell leakage or lysis. Screening for a better microbial protein secretor free of cellulase selected Bacillus cereus No. 518. A bidirectional vector plasmid (pMK3) was employed to carry the cloned gene into this B. cereus strain. Transformation was carried out by electroporation. Total xylanase production by the new pMK3-borne gene in B. cereus was similar to that from E. coli but the xylanase was shown to be normally secreted. The xylanase gene products from the E. coli and B. cereus hosts were shown to function identically. Both xylanases improved the delignification of unbleached softwood and hardwood kraft pulps, thus reducing the Cl2 required to achieve a given degree of bleaching, without altering the physical properties of the fibers. Using a target kappa number (lignin content) of 5, xylanase pretreatment of aspen kraft (chemical) pulp led to a 22% savings of chlorine. Adsorbable organic halogens in the bleachery effluent were also lowered by more than 50%.Key words: Bacillus subtilis, endoxylanase gene, bleaching, kraft pulp properties.
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Vandeplas, S., R. D. Dauphin, P. Thonart, A. Théwis y Y. Beckers. "Effect of the bacterial or fungal origin of exogenous xylanases supplemented to a wheat-based diet on performance of broiler chickens and nutrient digestibility of the diet". Canadian Journal of Animal Science 90, n.º 2 (1 de junio de 2010): 221–28. http://dx.doi.org/10.4141/cjas09067.
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Two identical experiments were carried out to study the effects of four xylanases from bacterial or fungal origin supplemented to a wheat-based diet, on growth performance of broiler chickens and nutrient digestibilities. Experimental treatments consisted of a control basal diet containing 600 g kg-1 wheat (C), and the basal diet supplemented with 0.1 g kg-1 Grindazyme G from Aspergillus niger (G), 0.1 g kg-1 Belfeed B1100MP from Bacillus subtilis (B), 0.1 g kg-1 Roxazyme G from Trichoderma viride (R), or 0.0125 g kg-1 of a xylanase from Aspergillus aculeatus (A). Each experimental diet was given to four groups of six chickens each. Growth performance and feed conversion ratio (FCR) were recorded weekly, from 7 to 21 d of age. In the second experiment, a digestion balance trial was performed from 27 to 31 d of age to evaluate the nitrogen-corrected apparent metabolizable energy (AMEn) and the digestibilities of nitrogen, crude fat, starch and crude fibre. From 7 to 21 d of age, xylanase supplementation led to increased final body weight and daily weight gain, by 3.7 and 4.5 % (P < 0.05), respectively, without significant difference according to the xylanase origin. Xylanase supplementation significantly increased the AMEn (+2.6 %), and the digestibilities of crude fibre (+58.9 %) and nitrogen (+1.6 %). Increase in AMEn as well as in crude fat and starch digestibilities were significantly different according to the xylanase, but were not dependent on fungal or bacterial origin. In conclusion, the microbial origin of xylanases supplemented to wheat-based diets influenced neither the performance of broiler chickens nor the improvement in nutrient digestibilities.Key words: Broiler, growth performance, nutrient digestibility, wheat, xylanase
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Cui, Shixiu, Tianwen Wang, Hong Hu, Liangwei Liu, Andong Song y Hongge Chen. "Investigating the expression of F10 and G11 xylanases in Aspergillus niger A09 with qPCR". Canadian Journal of Microbiology 62, n.º 9 (septiembre de 2016): 744–52. http://dx.doi.org/10.1139/cjm-2015-0394.
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There exist significant differences between the 2 main types of xylanases, family F10 and G11. A clear understanding of the expression pattern of microbial F10 and G11 under different culture conditions would facilitate better production and industrial application of xylanase. In this study, the fungal xylanase producer Aspergillus niger A09 was systematically investigated in terms of induced expression of xylanase F10 and G11. Results showed that carbon and nitrogen sources could influence xylanase F10 and G11 transcript abundance, with G11 more susceptible to changes in culture media composition. The most favorable carbon and nitrogen sources for high G11 and low F10 production by A. niger A09 were xylan (2%) and (NH4)2C2O4 (0.3%), respectively. Following cultivation at 33 °C for 60 h, the highest xylanase activity (1132 IU per gram of wet mycelia) was observed. On the basis of differential gene expression of F10 and G11, as well as their different properties, we deduced that the F10 protein initially targeted xylan and hydrolyzed it into fragments including xylose, after which xylose acted as the inducer of F10 and G11 gene expression. These speculations also accounted for our failure to identify conditions favoring the high production of F10 but a low production of G11.
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Liu, Ning, Xing Yan, Meiling Zhang, Lei Xie, Qian Wang, Yongping Huang, Xuguo Zhou, Shengyue Wang y Zhihua Zhou. "Microbiome of Fungus-Growing Termites: a New Reservoir for Lignocellulase Genes". Applied and Environmental Microbiology 77, n.º 1 (5 de noviembre de 2010): 48–56. http://dx.doi.org/10.1128/aem.01521-10.
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ABSTRACTFungus-growing termites play an important role in lignocellulose degradation and carbon mineralization in tropical and subtropical regions, but the degradation potentiality of their gut microbiota has long been neglected. The high quality and quantity of intestinal microbial DNA are indispensable for exploring new cellulose genes from termites by function-based screening. Here, using a refined intestinal microbial DNA extraction method followed by multiple-displacement amplification (MDA), a fosmid library was constructed from the total microbial DNA isolated from the gut of a termite growing in fungi. Functional screening for endoglucanase, cellobiohydrolase, β-glucosidase, and xylanase resulted in 12 β-glucosidase-positive clones and one xylanase-positive clone. The sequencing result of the xylanase-positive clone revealed an 1,818-bp open reading frame (ORF) encoding a 64.5-kDa multidomain endo-1,4-β-xylanase, designated Xyl6E7, which consisted of an N-terminal GH11 family catalytic domain, a CBM_4_9 domain, and aListeria-Bacteroidesrepeat domain. Xyl6E7 was a highly active, substrate-specific, and endo-acting alkaline xylanase with considerably wide pH tolerance and stability but extremely low thermostability.
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Rao, Mala, A. J. Varma y Sumedha S. Deshmukh. "Production of single cell protein, essential amino acids, and xylanase by Penicillium janthinellum". BioResources 5, n.º 4 (4 de octubre de 2010): 2470–77. http://dx.doi.org/10.15376/biores.5.4.2470-2477.
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Microbial biomass having 46% crude protein content and enriched with essential amino acids as well as extracellular xylanase activity (100-150 IU/ml) was produced by an efficient fungal strain, Penicillium janthinellum (NCIM St-F-3b). Optimization studies for maximum xylanase and biomass production showed that the fungus required a simple medium containing bagasse hemicellulose as carbon source and ammonium sulphate as the nitrogen source. Therefore bagasse, which is a waste product of the sugar industry, can be efficiently used in microbioal biomass protein preparation for animal feed.
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Jay N Patel, Fenil A Parmar y Vivek N Upasani. "Screening of microorganisms for hydrolyases with commercial potential". World Journal of Advanced Research and Reviews 13, n.º 1 (30 de enero de 2022): 092–101. http://dx.doi.org/10.30574/wjarr.2022.13.1.0751.
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Advancement in green chemistry has increased the use of microbial hydrolyases in various industries and chemical processes because of high catalytic efficiency, specificity, cost-effectiveness and eco-friendly nature. Bioconversion of tannins such as tannic acid is achieved by tannin acyl hydrolase, also known as tannase. It converts tannic acid into glucose and gallic acid by catalyzing the hydrolysis of ester and depside linkages in tannic acid. Tyrosinase is monophenol and O-diphenol oxidase a copper containing enzyme catalyzes the oxidation of tyrosine and generates different types of pigment such as melanin. Xylanases hydrolyze xylan into its constituent sugar with the help of several debranching enzymes. Microbial strains isolated from various sources were screened for these hydrolyases: Bhavnagar marine salterns (Bacillus megaterium BVUC_01 and Bacillus licheniformis BVUCh_02); Okhamadhi marine salterns Aspergillus versicolor; Spoiled/infected pomegranate (Xenoacremonium falcatum, two strains PGF1 and PGF4, Bacillus velezensisPGF2 and Candida freyschussiiPGF3. The other laboratory maintained bacterial cultures namely, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi were also used in this study. Asp. versicolor and Xen. falcatum (PGF1) produced all the three enzymes (tannase, tyrosinase and xylanase). B. licheniformis, B. megaterium, B. subtilis, B. velezensis produced tyrosinase and xylanase. Xen. falcatum (PGF4) and PGF2 produced tannase and xylanase. PGF3 produced tannase and tyrosinase. While, Bacillus megaterium and Salmonella typhi showed only tyrosinase activity. Candida freyschussii showed tannase activity. Staphylococcus aureus did not produce any of these enzymes.
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Beliën, Tim, Steven Van Campenhout, Johan Robben y Guido Volckaert. "Microbial Endoxylanases: Effective Weapons to Breach the Plant Cell-Wall Barrier or, Rather, Triggers of Plant Defense Systems?" Molecular Plant-Microbe Interactions® 19, n.º 10 (octubre de 2006): 1072–81. http://dx.doi.org/10.1094/mpmi-19-1072.
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Endo-β-1,4-xylanases (EC 3.2.1.8) are key enzymes in the degradation of xylan, the predominant hemicellulose in the cell walls of plants and the second most abundant polysaccharide on earth. A number of endoxylanases are produced by microbial phytopathogens responsible for severe crop losses. These enzymes are considered to play an important role in phytopathogenesis, as they provide essential means to the attacking organism to break through the plant cell wall. Plants have evolved numerous defense mechanisms to protect themselves against invading pathogens, amongst which are proteinaceous inhibitors of cell wall-degrading enzymes. These defense mechanisms are triggered when a pathogen-derived elicitor is recognized by the plant. In this review, the diverse aspects of endoxylanases in promoting virulence and in eliciting plant defense systems are highlighted. Furthermore, the role of the relatively recently discovered cereal endoxylanase inhibitor families TAXI (Triticum aestivum xylanase inhibitor) and XIP (xylanase inhibitor protein) in plant defense is discussed.
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Lu, H., H. Yan, H. M. Masey O’Neill, C. Bradley, M. R. Bedford, P. Wilcock, C. H. Nakatsu, O. Adeola y K. M. Ajuwon. "Effect of timing of postweaning xylanase supplementation on growth performance, nutrient digestibility, and fecal microbial composition in weanling pigs". Canadian Journal of Animal Science 100, n.º 1 (1 de marzo de 2020): 27–36. http://dx.doi.org/10.1139/cjas-2019-0021.
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Effect of timing of xylanase supplementation to weanling pigs and its effect on growth performance, nutrient digestibility, and fecal microbiota was investigated. A total of 128 weanling pigs [(Hampshire × Duroc) × (Yorkshire × Landrace); 6.2 ± 0.6 kg body weight (BW); weaning age: 21 d] were assigned to four treatments, with eight replicate pens and four pigs per pen. Treatments were a combination of two dietary treatments (without or with xylanase) in two periods; (period 1, days 0–14) and period 2 (days 14–42): xylanase–xylanase, xylanase–control, control–xylanase, and control–control. Fecal microbiota diversity and apparent total tract digestibility (ATTD) were determined. From days 0–14, pigs had lower (P < 0.01) BW, average daily gain (ADG), and feed efficiency when xylanase was included in the diets. The final BW (P < 0.05) and overall ADG (P < 0.02) at day 42 were greater when xylanase was supplemented from day 14 compared with supplementation from day 0. The apparent ileal digestibility and ATTD of dry matter, gross energy, nitrogen, and phosphorus were increased (P < 0.05) by xylanase. Xylanase significantly decreased (P < 0.05) the relative abundance of Veillonella spp. and tended (P = 0.08) to decrease the relative abundance of Megasphaera spp. in period 2 compared with the non-supplemented group.
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Wang, Xiaoli, Danlei Li, Yibin Xu, Xiaoqing Ding, Shuang Liang, Lingyu Xie, Yongxia Wang y Xiuan Zhan. "Xylanase Supplement Enhances the Growth Performance of Broiler by Modulating Serum Metabolism, Intestinal Health, Short-Chain Fatty Acid Composition, and Microbiota". Animals 14, n.º 8 (15 de abril de 2024): 1182. http://dx.doi.org/10.3390/ani14081182.
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This study aimed to investigate the effects of different levels of xylanase supplementation in a wheat-based diet on growth performance, short-chain fatty acids, intestinal health, microbial composition, and serum metabolism. A total of 1200 male chicks were randomly assigned to four wheat-based diet treatments: Group C (adding 0 mg/kg of xylanase), Group L (adding 50 mg/kg of xylanase), Group M (adding 100 mg/kg of xylanase), and Group H (adding 150 mg/kg of xylanase). The experiment lasted for 56 days. The results indicated that Group H broilers experienced a decreased feed-to-gain ratio throughout the study period. Additionally, dietary supplementation with xylanase led to an increase in the physical barrier, as indicated by increased VH and VH/CD in the gut (p < 0.05). Furthermore, levels of D-lactic acid and endotoxin were reduced. Xylanase supplementation also increased the abundance of Muc-2, ZO-1, and Occludin (p < 0.05). Moreover, xylanase supplementation enhanced the activity of sucrase and maltase in the duodenum (p < 0.05), which may be attributable to the upregulation of the abundance of SI and MGA (p < 0.05). Furthermore, xylanase addition promoted propionic acid produced by specific bacteria, such as Phascolarctobacterium, and influenced the microbial composition to some extent, promoting intestinal health. Additionally, 150 mg/kg of xylanase supplementation increased the amino acid, peptide, and carbohydrate content and upregulated the metabolism of amino acids related to histidine, cysteine, methionine, and other pathways (p < 0.05). These findings suggest adequate xylanase supplementation can enhance nutritional digestibility and absorption, improve growth performance, stimulate endogenous enzyme activity, optimize intestinal morphology and barrier function, and positively influence acid-producing bacteria and amino acid metabolic pathways.
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Majumdar, B., A. R. Saha, S. Sarkar, S. K. Sarkar, S. P. Mazumdar, L. Chattopadhyay y S. Barai. "An insight into the sequential changes in enzymatic activities during retting of jute (Corchorus spp. L.)." Journal of Environmental Biology 42, n.º 3 (4 de mayo de 2021): 636–43. http://dx.doi.org/10.22438/jeb/42/3/mrn-1604.
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Aim: To study the dynamics of enzymes involved in biochemical process of jute (Corchorus spp.) retting with and without microbial retting consortium. Methodology: Two large scale retting trials were conducted with and without microbial retting consortium in triplicate. The retting water samples were collected every day at 24 hrs interval from both the trials. Polygalcturonase (PG), pectin lyase (PNL) and xylanase activities along with the pH were measured from the collected retting water samples following standard procedure. Fibre quality parameters were also studied from the resultant fibre obtained from both the retting trials. Results: There was a sharp decrease in pH of retting liquor by 1.35 units and that of pectin lyase activity by 97.9 Uml-1 within 24 hrs of inoculation of microbial retting consortium. Thereafter, higher pectin lyase (123.1 Uml-1), polygalacturonase (3.56 Iuml-1) and xylanase (0.818 IUml-1) activities were recorded during middle stage of retting. The enzyme activities were lower and non-significant at last stage of retting (11-14 days). The completion of retting without microbial consortium took longer time due to lower enzymatic activities as compared to microbial consortium mediated retting. Interpretation: The PG, PNL and xylanase enzymes released by the microbial consortium during retting of jute helped in faster biodegradation of pectin and xylan compared to control retting. Hence, the pre retting treatment of jute with microbial consortium is suggested for quick retting.
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Tran, Thi Ngoc, Chien Thang Doan y San-Lang Wang. "Conversion of Wheat Bran to Xylanases and Dye Adsorbent by Streptomyces thermocarboxydus". Polymers 13, n.º 2 (17 de enero de 2021): 287. http://dx.doi.org/10.3390/polym13020287.
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Agro-byproducts can be utilized as effective and low-cost nutrient sources for microbial fermentation to produce a variety of usable products. In this study, wheat bran powder (WBP) was found to be the most effective carbon source for xylanase production by Streptomyces thermocarboxydus TKU045. The optimal media for xylanase production was 2% (w/v) WBP, 1.50% (w/v) KNO3, 0.05% (w/v) MgSO4, and 0.10% (w/v) K2HPO4, and the optimal culture conditions were 50 mL (in a 250 mL-volume Erlenmeyer flask), initial pH 9.0, 37 °C, 125 rpm, and 48 h. Accordingly, the highest xylanase activity was 6.393 ± 0.130 U/mL, 6.9-fold higher than that from un-optimized conditions. S. thermocarboxydus TKU045 secreted at least four xylanases with the molecular weights of >180, 36, 29, and 27 kDa when cultured on the WBP-containing medium. The enzyme cocktail produced by S. thermocarboxydus TKU045 was optimally active over a broad range of temperature and pH (40–70 °C and pH 5–8, respectively) and could hydrolyze birchwood xylan to produce xylobiose as the major product. The obtained xylose oligosaccharide (XOS) were investigated for 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and the growth effect of lactic acid bacteria. Finally, the solid waste from the WBP fermentation using S. thermocarboxydus TKU045 revealed the high adsorption of Congo red, Red 7, and Methyl blue. Thus, S. thermocarboxydus TKU045 could be a potential strain to utilize wheat bran to produce xylanases for XOS preparation and dye adsorbent.
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Phuyal, Milan, Uttam Budhathoki, Durga Bista, Shailendra Shakya, Rajan Shrestha y Ashwinee Kumar Shrestha. "Xylanase-Producing Microbes and Their Real-World Application". International Journal of Chemical Engineering 2023 (1 de noviembre de 2023): 1–14. http://dx.doi.org/10.1155/2023/3593035.
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The present study is focused on the availability of microbial sources capable of producing xylanase, a hemicelluloses-degrading enzyme with multiple modes of action along with specificity, and their real-world applications. For the accumulation of suitable data, article surfing was carried out using multiple search engines viz. Hinari and PubMed; irrelevant and duplicate articles were discarded and articles were summarized in a narrative way herein. This review article was written aiming to bridge the recent research activities with the commercial activities of xylanase going on around the globe. The readers would be able to acknowledge themselves with the basic idea of the hydrolytic enzyme xylanase, their classification representing their different families, presenting the affinity of different families at the structural level, the sources, and the commercial implications that have been going on alone and in combination. The major hemicellulose, Xylan is digested with the help of combination other enzymes such as alpha-amylase, subtilisin, protease, and endo-1,3(4)-β-glucanase along with xylanase. Xylanase has a diverse applications such as pharmaceutical, food and feed, bakery, paper and pulp, textile, and bio-refinery industries. The objective of this review article is to compile microbial sources of this enzyme and its application for betterment of human kind.
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Aftab, Maham, Uroosa Ejaz, Rami Adel Pashameah, Aimen Fatima, Jaweria Syed, Immad Ansari, Muhammad Sohail, Samah A. AlSubhi, Eman Alzahrani y Zeinhom M. El-Bahy. "Utilization of Corncob as an Immobilization Matrix for a Xylanolytic Yeast Strain". Polymers 15, n.º 3 (29 de enero de 2023): 683. http://dx.doi.org/10.3390/polym15030683.
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Immobilization of microbial cells for the production of industrially important enzymes has been reported to offer the advantages of recyclability, higher yields and cost effectiveness. The search for an appropriate matrix that is affordable and easy to prepare is a significant topic in microbial biotechnology. Here, an abundant type of agro-industrial waste—corncob—was utilized as an immobilization matrix for the production of xylanase from an indigenous yeast strain, Saccharomyces cerevisiae MK-157. This is the first report describing xylanase production from immobilized S. cerevisiae. To render the corncob matrix more porous, alkaline pretreatment was undertaken and yeast cells were immobilized on the matrix by cultivating at 30 °C for 48 h in Sabouraud dextrose broth. After incubation, the immobilized matrix was transferred to mineral salt medium containing 1% xylan and incubated at 30 °C for 24 h. Xylanase production was determined in cell-free culture supernatant and the matrix was recycled for up to seven cycles. Moreover, xylanase-mediated saccharification was carried out using sugarcane bagasse as a substrate and the release of reducing sugars was monitored. The results showed that the immobilized yeast produced 4.97 IU mL−1 xylanase in the first production cycle, indicating a >tenfold increase compared to the free cells. Xylanase production further increased to its maximum levels (9.23 IU mL−1) in the fourth production cycle. Nonetheless, the cells retained 100% productivity for up to seven cycles. The volumetric and specific productivity of xylanase were also the highest in the fourth cycle. Scanning electron microscopy images revealed the rough surface of the untreated corncob, which became more porous after alkaline pretreatment. Immobilized yeast cells were also visible on the corncob pieces. The saccharification of a natural resource—sugarcane bagasse—using xylanase preparation yielded 26 mg L−1 of reducing sugars. Therefore, it can be concluded that yeast strains can yield sufficient quantities of xylanase, allowing possible biotechnological applications. Moreover, corncob can serve as a cost-effective matrix for industrially important yeast strains.
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Sadeghi, A. A., P. Shawrang y K. Karimi. "Sites of phytase and xylanase activities in the gastrointestinal tract of broiler chickens". Proceedings of the British Society of Animal Science 2007 (abril de 2007): 28. http://dx.doi.org/10.1017/s1752756200019311.
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Because digesta vary in pH in different gastrointestinal segments of poultry, exogenous phytase or xylanase may exhibit differences in activity along the gastrointestinal tract. Previous reports indicated that the stomach is the major site of exogenous microbial phytase activity, with no further activity found in the small intestine of piglets. Information regarding exogenous phytase or xylanase activity in the gastrointestinal tract of poultry is largely unavailable. Because exogenous phytase or xylanase activity in the digesta is extremely low, normal phytase or xylanase activity measurements are prone to errors resulting from background interference contributed by the exogenous inorganic phosphate or xylose in the digesta (Walsh et al., 1995). The aim of this study was to utilize electrophoresis activity stain to detect the activity of phytase or xylanase in different gastrointestinal segments of broiler chickens fed diets containing exogenous enzymes.
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Kaur, Ajit y Urmila Gupta Phutela. "Optimization of cultural conditions for submerged state fermentation of di-gested biogas slurry for production of lignocellulolytic enzymes using Phanaerochaete chrysosporium MTCC 787". Journal of Applied and Natural Science 9, n.º 3 (1 de septiembre de 2017): 1729–34. http://dx.doi.org/10.31018/jans.v9i3.1429.
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Growing environmental concerns and increasing demands from end-use sectors have increased the glob-al market for microbial products. Optimizations of production parameters hold great importance for the industry. The present study was aimed at optimization of submerged state fermentation conditions for production of lignocelluloly-tic enzymes from digested biogas slurry by Phanaerochaete chrysosporium MTCC 787. Enzyme activities for differ-ent enzymes i.e. endoglucanase, exoglucanase, β-glucosidase; xylanase and mannanase; laccase, lignin peroxidase and manganese peroxidise, using P. chrysosporium MTCC 787 were maximum at 50% concentration of digested slur-ry and showed maximum value of xylanase i.e. 187.41U/ml. Effect of temperature (25°C, 30°C and 35°C) on lignocellu-losic bioconversion showed that at 30°C, maximum value of manganese peroxidise (167.5 U/ml) was obtained. High-est enzyme activites were obtained at selected inoculum size i.e. 10⁷spores/ml, e.g. 85.29 U/ml xylanase was ob-tained. Incubation period of 8 days and pH of 7.0 came out to be best conditions for P. chrysosporium MTCC787 to produce maximum enzyme activity e.g. xylanase 95.47U/ml at pH 7.0 and xylanase 144.96U/ml at 8 day incu-bation.This work presents a novel concept in optimization of fermentation process to produce lignocellulolytic en-zymes as this work is focussed on utilization of digested biogas slurry as a substrate for enzyme production and enhancement of the production with microbial source, which is environment friendly.
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Weiss, E., M. Eklund, A. Semaskaite, R. Urbaityte, B. Metzler-Zebeli, N. Sauer, A. Ratriyanto, R. Gruzauskas y R. Mosenthin. "Combinations of feed additives affect ileal fibre digestibility and bacterial numbers in ileal digesta of piglets". Czech Journal of Animal Science 58, No. 8 (30 de julio de 2013): 351–59. http://dx.doi.org/10.17221/6901-cjas.
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The study was performed to investigate the effect of combinations of feed additives consisting of either a combination of a probiotic and a prebiotic (synbiotic), or a combination of a probiotic and xylanase on ileal nutrient digestibility, ileal microbial metabolite concentrations, and microbial composition in ileal digesta of weaned piglets. In total, 12 six-week old barrows with an average initial body weight of 7.5 kg, fitted with an ileal T-cannula, were assigned to 3 dietary treatments. The basal diet was supplemented with a combination of 1 g probiotics (Pediococcus acidilactici, Bactocell<sup>®</sup>)and 20 g prebiotics (oligofructose) (Pro/Pre) or 1 g probiotics (Pediococcus acidilactici, Bactocell<sup>®</sup>) and 0.5 g xylanase (Pro/Xyl) per kg diet. The supplementation of Pro/Xyl increased ileal digestibility of neutral detergent fibre (NDF) by 41.6% (P < 0.05). The microbial metabolite concentrations, pH of ileal digesta as well as ileal lactobacilli populations were not affected (P > 0.05) by any of the treatments. Enterobacteriaceae were reduced (P < 0.05) upon supplementation of Pro/Pre, resulting in an increased (P < 0.05) ileal lactobacilli to Enterobacteriaceae ratio compared with piglets fed the control diet. In conclusion, NDF digestibility was increased following xylanase supplementation, while microbial activity and composition in the ileum were not affected. The synbiotic approach was effective in reducing ileal Enterobacteriaceae numbers.
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MAZIDAH, INAYAH NOER, LAKSMI AMBARSARI y ANJA MERYANDINI. "Karakterisasi Xilanase dari Bakteri Xilanolitik XJ20 asal Tanah Hutan Taman Nasional Bukit Duabelas Jambi Indonesia". Jurnal Sumberdaya Hayati 2, n.º 1 (14 de noviembre de 2016): 25–30. http://dx.doi.org/10.29244/jsdh.2.1.25-30.
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Xylanase is an extracellular enzymes that can be produced by microbes which capable to degrade xylan into xilo-oligosaccharides (XOS) and xylose. Application of xylanase is still not optimal due to the lack of availability of superior microbial cultures producing xylanase. The purpose of this study was to determine the characteristics of xylanase produced by bacteria isolated from Forest land Bukit Duabelas National Park, Jambi, Indonesia. Xylanase produced by bacterial isolate XJ20 was selected for further enzymatic activity and characteritics assays. Xylanolytic activity was measured by using the 3.5-dinitrosalicylic acid (DNS) assay. High activity of xylanase was recorded at three times of incubation, which were 6 (0.015 U/mL), 14 (0.012 U/mL) and 20 (0.007 U/mL). The first peak and the second peak reached the highest activity at a temperature of 70 °C, however, the first peak reached the highest activity at pH 4.0 and a second peak at pH 7.0. pH 4.0 xylanase were incubated at room temperature and 70 °C has a half time consecutive 9 hours and 6 hours, whereas at pH 7.0, has a half time consecutive 4 hours and 3 hours. Stability of enzyme better at pH 4.0 and at room temperature.
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Van Hoeck, Veerle, Ingrid Somers, Anas Abdelqader, Alexandra L. Wealleans, Sandy Van de Craen y Dany Morisset. "Xylanase impact beyond performance: A microbiome approach in laying hens". PLOS ONE 16, n.º 9 (20 de septiembre de 2021): e0257681. http://dx.doi.org/10.1371/journal.pone.0257681.
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Anti-nutritional compounds such as non-starch polysaccharides (NSP) are present in viscous cereals used in feed for poultry. Therefore, exogenous carbohydrases are commonly added to monogastric feed to degrade these NSP. Our hypothesis is that xylanase not only improves laying hen performance and digestibility, but also induces a significant shift in microbial composition within the intestinal tract and thereby might exert a prebiotic effect. In this context, a better understanding on whether and how the chicken gut microbial population can be modulated by xylanase is required. To do so, the effects of dietary supplementation of xylanase on performance, apparent total tract digestibility (ATTD) and cecal microbiome in laying hens were evaluated in the present study. A total of 96 HiSex laying hens were used in this experiment (3 diets and 16 replicates of 2 hens). Xylanase was added to the diets at concentrations of 0, 45,000 (15 g/t XygestTM HT) and 90,000 U/kg (30 g/t Xygest HT). The diets were based on wheat (~55%), soybean and sunflower meal. The lowest dosage, 45,000 U/kg, significantly increased average egg weight and improved feed efficiency compared to the control treatment (P<0.05). Egg quality parameters were significantly improved in the experiment in response to the xylanase addition. For example, during the last 28 days of the trial, birds receiving the 45,000 U/kg and the 90,000 U/kg treatments exhibited an increase in Haugh units and albumin heights (P<0.05). Compared with the control, the ATTD of organic matter and crude protein were drastically improved in the 45,000 U/kg treatment group (P<0.05). Furthermore, gross energy and the ATTD of crude fat were improved significantly for birds fed 90,000 U/kg group compared to the control. Importantly, 16S rRNA gene analysis revealed that xylanase at 45,000 U/kg dosage can exert a change in the cecal microbiome. A significant increase in beneficial bacteria (Bacilli class; Enterococcaceae and Lactobacillales orders; Merdibacter, Enterococcus and Nocardiopsis genera; Enterococcus casseliflavus species) was documented when adding 45,000 U/kg xylanase to the diet of laying hens. In conclusion, dietary supplementation of xylanase 45,000 U/kg significantly improved laying hen performance and digestibility. Furthermore, microbiome data suggest that xylanase modulates the laying hen bacterial population beneficially, thus potentially exerting a prebiotic effect.
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Lin, Yanhuan, Changle Li, Chenxin Wei, Hui Lin y Liaoyuan Zhang. "Mining, Identification, and Characterization of Three Xylanases from the Microbiota of T. fuciformis with Its Companion Strains". Catalysts 14, n.º 1 (24 de diciembre de 2023): 15. http://dx.doi.org/10.3390/catal14010015.
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Microbial xylanase has wide application in bioenergy, animal feed, environmental protection, the pulp and paper industry, and agricultural development. In this study, three xylanases from the microbiota of T. fuciformis with its companion strains were identified by metagenomics sequencing. The three enzymes were subjected to cloning and expression in E. coli or P. pastoris, purification, and characterization for their properties. The results showed that AsXyn1, from Annulohypoxylon stygium, among the three enzymes possessed high thermostability at 40 °C and broad pH tolerance in the range of 2.0–10.0, exhibiting its application potential. Furthermore, it was found that post-translational modification (such as glycosylation) of AsXyn1 enzyme modulated its activity, kinetic parameters, and thermostability. These results and findings provided a hint for enzyme modification and design in future.
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Ellatif, Sawsan Abd, Elsayed S. Abdel Razik, Ameena A. AL-surhanee, Faisal Al-Sarraj, Ghadir E. Daigham y Amira Y. Mahfouz. "Enhanced Production, Cloning, and Expression of a Xylanase Gene from Endophytic Fungal Strain Trichoderma harzianum kj831197.1: Unveiling the In Vitro Anti-Fungal Activity against Phytopathogenic Fungi". Journal of Fungi 8, n.º 5 (25 de abril de 2022): 447. http://dx.doi.org/10.3390/jof8050447.
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Trichoderma sp. is extensively applied as a beneficial fungus for the management of plant diseases, plant growth promotion, induced resistance, and plays an important role in global sustainable agriculture. This study aimed to enhance the production of microbial xylanase in high titer from the endophytic fungus Trichoderma harzianum kj831197.1, and the cloning of xylanase genes in E. coli DH5α using a pUC19 vector. A combination of glucose, 0.1 mM, Tween 80 with lactose, and 2 mM galactose combined with malt extract boostedthe enzyme production. Xylanase production was maximized at a pH of 5.0, temp. of 30 °C, and agitation of 150 rpm in the presence of malt extract and bagasse as the best nitrogen source and waste, respectively, using submerged fermentation. The molecular weight of highly purified xylanase was 32 KDa, identified using SDS-PAGE. The xylanase gene of T. harzianum kj831197.1 was screened in fungal DNA using definite primers specified in the gene bank database. The identified region was excised using restriction enzymes HindIII and EcoRI and cloned into a pUC19 plasmid vector. Optimization of fermentation conditions improved xylanase production about 23.9-fold.The antifungal efficacy of xylanase toward different phytopathogenic fungi was determined. The highest inhibition was against Corynespora cassiicola, Alternaria sp., Fusarium oxysporum, and Botrytis fabae. This study offered an economical, simple, and efficient method using Trichoderma harzianum kj831197.1 for the production of the xylanase enzyme via the submerged fermentation method.
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Ellatif, Sawsan Abd, Elsayed S. Abdel Razik, Ameena A. AL-surhanee, Faisal Al-Sarraj, Ghadir E. Daigham y Amira Y. Mahfouz. "Enhanced Production, Cloning, and Expression of a Xylanase Gene from Endophytic Fungal Strain Trichoderma harzianum kj831197.1: Unveiling the In Vitro Anti-Fungal Activity against Phytopathogenic Fungi". Journal of Fungi 8, n.º 5 (25 de abril de 2022): 447. http://dx.doi.org/10.3390/jof8050447.
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Trichoderma sp. is extensively applied as a beneficial fungus for the management of plant diseases, plant growth promotion, induced resistance, and plays an important role in global sustainable agriculture. This study aimed to enhance the production of microbial xylanase in high titer from the endophytic fungus Trichoderma harzianum kj831197.1, and the cloning of xylanase genes in E. coli DH5α using a pUC19 vector. A combination of glucose, 0.1 mM, Tween 80 with lactose, and 2 mM galactose combined with malt extract boostedthe enzyme production. Xylanase production was maximized at a pH of 5.0, temp. of 30 °C, and agitation of 150 rpm in the presence of malt extract and bagasse as the best nitrogen source and waste, respectively, using submerged fermentation. The molecular weight of highly purified xylanase was 32 KDa, identified using SDS-PAGE. The xylanase gene of T. harzianum kj831197.1 was screened in fungal DNA using definite primers specified in the gene bank database. The identified region was excised using restriction enzymes HindIII and EcoRI and cloned into a pUC19 plasmid vector. Optimization of fermentation conditions improved xylanase production about 23.9-fold.The antifungal efficacy of xylanase toward different phytopathogenic fungi was determined. The highest inhibition was against Corynespora cassiicola, Alternaria sp., Fusarium oxysporum, and Botrytis fabae. This study offered an economical, simple, and efficient method using Trichoderma harzianum kj831197.1 for the production of the xylanase enzyme via the submerged fermentation method.
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Melo-Durán, Diego, José Francisco Pérez, Gemma González-Ortiz, Roser Sala, Sandra Villagómez-Estrada, Michael R. Bedford, Hadden Graham y David Solà-Oriol. "Influence of Particle Size and Xylanase in Corn-Soybean Pelleted Diets on Performance, Nutrient Utilization, Microbiota and Short-Chain Fatty Acid Production in Young Broilers". Animals 10, n.º 10 (17 de octubre de 2020): 1904. http://dx.doi.org/10.3390/ani10101904.
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The objective of this study was to investigate the effects of particle size and xylanase supplementation in corn-based pellet diets on the performance and digestive traits in young broilers. A total of 512 male Ross 308 broilers were used in a 21-day study. The treatments were designed in a 4 × 2 factorial arrangement with four levels of geometric mean diameter (Dgw) of corn (540, 660, 1390, and 1700 µm), and two levels of xylanase (0 or 16,000 BXU/kg diet). Feeding coarse corn diets (1390 and 1700 µm Dgw) and xylanase supplementation showed an inferior coefficient of variation of body weight. Higher gizzard weight, microbiome alpha-diversity, and clustered separately beta-diversity (p < 0.05) were observed in birds fed coarse diets. The addition of xylanase promoted changes in relative bacteria abundance, increasing Lachnospiraceae, Defluviitaleaceae, Bacteroidaceae, Bacillaceae, Eggerthellaceae, and Streptococcaceae families in the 1700 µm group, and Christensenellaceae and Lachnospiraceae families in the 540 µm Dgw group. In conclusion, xylanase supplementation and particle size of corn interact in the intestinal environment, showing changes in microbial composition. Coarse diets and xylanase supplementation showed improved body weight homogeneity, which might be related to a better gut development and microbiota modulation.
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Kiribayeva, A., D. Silayev, A. Abdullayeva, Yu Shamsiyeva, Ye Ramankulov y B. Khassenov. "HYDROLYSIS OF PLANT BIOMASS USING RECOMBINANT ALPHA-AMYLASE FROM BACILLUS LICHENIFORMIS AND XYLANASE FROM BACILLUS SONORENSIS". Eurasian Journal of Applied Biotechnology, n.º 4 (29 de septiembre de 2022): 31–39. http://dx.doi.org/10.11134/btp.4.2022.4.
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With the reduction of fossil hydrocarbon sources and the increasing need for energy, chemical resources and food, the use of biomass as a renewable source is of great importance. This, in turn, necessitates efficient enzymes for bioconversion of biomass. Enzymes are important in industry because they are biocatalysts for complex chemical processes. The conversion of plant biomass into sugars requires a complex of enzymes whose composition must be adapted to the type of biomass and а pretreatment method. The efficiency of enzymatic hydrolysis can be increased by optimizing the composition of the enzymatic complex, increasing the catalytic activity and stability of the enzymes included in it. A large number of microbial amylases are now commercially available, and they have almost completely replaced chemical starch hydrolysis in the processing industry. The use of bacterial xylanases is a key step in the conversion of lignocellulosic polysaccharides into fermentable sugars for the production of biofuels and value-added products. Enzyme complexes containing both α-amylases and xylanases have found applications in the pulp and paper industry and feed production.
Recombinant α-amylase and xylanase from Bacillus licheniformis and Bacillus sonorensis, respectively, were obtained using recombinant DNA technology. These enzymes were purified by metal affinity chromatography from the lysate of induced cultures of recombinant strains. Enzymatic hydrolysis of potato starch and birch xylan with these recombinant enzymes was performed. The hydrolysis products of these polysaccharides were studied by thin-layer chromatography. It was found that the products of hydrolysis of potato starch using recombinant α-amylase were maltose and maltooligosaccharides and a small amount of glucose. Xylan was isolated from birch sawdust and hydrolyzed by recombinant xylanase. Detection of the hydrolysis products of xylan showed that xylan is hydrolyzed to oligoxylans with a degree of polymerization of at least 2 monomers. No xylose was detected among the hydrolysis products. The results indicate that α-amylase from Bacillus licheniformis and xylanase from Bacillus sonorensis are endoenzymes.
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Yudina, Anna, Olga Ovchinnikova, Vladimir Cheptsov y Dmitry Fomin. "Localization of C Cycle Enzymes in Arable and Forest Phaeozems within Levels of Soil Microstructure". Microorganisms 11, n.º 5 (19 de mayo de 2023): 1343. http://dx.doi.org/10.3390/microorganisms11051343.
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Soil microbial and enzyme activities are closely related to the spatial variability of soil environmental conditions at the microscale (μm-mm). The origin and localization of the enzymes are somewhat neglected when the measured activity is used to evaluate specific soil functions. The activity of four hydrolytic enzymes (β-glucosidase, Cellobiohydrolase, Chitinase, Xylanase) and microbial diversity based on community-level physiological profiling were determined in samples of arable and native Phaeozems with increasing physical impact to soil solids. The level of impact on the soil solids had a significant effect on enzyme activity and depended on both the enzyme type and soil land use. The highest proportion of the activity of Xylanase and Cellobiohydrolase of arable Phaeozem was determined at the dispersion energy in the range of 450–650 J·mL−1 and was associated with the primary soil particles’ hierarchy level. The highest proportions of β-glucosidase and Chitinase activities were determined for forest Phaeozem after applying energies lower than 150 J·mL−1 and characterizing the level of soil microaggregates. The increased activity of Xylanase and Cellobiohydrolase in primary soil particles of arable soil compared to those in forest soil might be a reflection of the substrates being unavailable to decomposition, leading to enzyme accumulation on the solid surface. For the Phaeozems, the lower the level of soil microstructure organization, the greater the differences observed between soils of different land use type, i.e., microbial communities, associated with lower microstructure levels, were more specific to land use type.
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Zerva, Ioanna, Nikolaos Remmas y Spyridon Ntougias. "Diversity and Biotechnological Potential of Xylan-Degrading Microorganisms from Orange Juice Processing Waste". Water 11, n.º 2 (5 de febrero de 2019): 274. http://dx.doi.org/10.3390/w11020274.
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The orange juice processing sector produces worldwide massive amounts of waste, which is characterized by high lignin, cellulose and hemicellulose content, and which exceeds 40% of the fruit’s dry weight (d.w.). In this work, the diversity and the biotechnological potential of xylan-degrading microbiota in orange juice processing waste were investigated through the implementation of an enrichment isolation strategy followed by enzyme assays for the determination of xylanolytic activities, and via next generation sequencing for microbial diversity identification. Intracellular rather than extracellular endo-1,4-β-xylanase activities were detected, indicating that peripheral cell-bound (surface) xylanases are involved in xylan hydrolysis by the examined microbial strains. Among the isolated microbial strains, bacterial isolates belonging to Pseudomonas psychrotolerans/P. oryzihabitans spectrum (99.9%/99.8% similarity, respectively) exhibited activities of 280 U/mg protein. In contrast, almost all microbial strains isolated exerted low extracellular 1,4-β-xylosidase activities (<5 U/mg protein), whereas no intracellular 1,4-β-xylosidase activities were detected for any of them. Illumina data showed the dominance of lactic and acetic acid bacteria and of the yeasts Hanseniaspora and Zygosaccharomyces. This is the first report on indigenous xylanolytic microbiota isolated from orange juice processing waste, possessing the biotechnological potential to serve as biocatalysts for citrus biomass valorization through the production of high-added value products and energy recovery.
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Hatano, Kazunori, Douglas J. Frederick y James A. Moore. "Microbial Ecology of Constructed Wetlands Used for Treating Pulp Mill Wastewater". Water Science and Technology 29, n.º 4 (1 de febrero de 1994): 233–39. http://dx.doi.org/10.2166/wst.1994.0199.
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Objectives were to evaluate microbial populations in two free-water surface (FWS) constructed wetland cells receiving secondary treated pulp-mill wastewater, identify the microorganisms having decomposition activity of selected organic substances and discuss diversity of actinomycetes isolated from soil, plant and wastewater samples. The populations of microorganisms in soil samples in the two wetland cells showed similar size in both cells; 6–7 × 106 cfu/g, 0.7–1.0 × 106 cfu/g, and 0.8–1.0 × 104 cfu/g, respectively, for total bacteria, actinomycetes and fungi. The population of bacteria in wastewater was similar in size to bacteria isolated from soil, but those of actinomycetes and fungi exhibited a very small size: 2–3 × 103 cfu/ml and only about 10 cfu/ml, respectively. In the populations on the surface of bulrush stems, the number of bacteria, actinomycetes and fungi found on the top portion of the stems was 4 × 105 cfu/cm2, 1.4 × 103 cfu/cm2 and 0.5 × 102 cfu/cm2, respectively. Actinomycetes and fungi occurred in very low numbers on the bottom of stems. More than 90% of actinomycetes isolated from the wetland cells had amylase activity, and 60 and 25% of them had chitinase and xylanase activity, respectively. Approximately 70 and 50% of fungi had protease and amylase activities, respectively. Fungi also had xylanase activity in about 40% of isolates. On the other hand, about 40% of bacteria exhibited protease activity, but a very low proportion of them had chitinase and xylanase activities. The number of actinomycete species isolated from wastewater and the surface of plant stems was restricted in comparison to that of actinomycetes isolated from soil.
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Aguiar, Milena Santos, Andrea Limoeiro Carvalho y Elizama Aguiar Oliveira. "Characterization of amylase, lipase and xylanase produced by actinobacteria cultivated in licuri [Syagrus coronata - (Martius) Beccari] residues". Revista de Biotecnologia & Ciência (ISSN 2238-6629) 12 (11 de abril de 2023): e13183. http://dx.doi.org/10.31668/rbc.v12i0.13183.
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In order to seach for different microbial sources of enzymes, Arthrobacter polychromogenes CDPI-30 and Streptomyces violaceoruber CDPA-32 were individually cultivated in licuri [Syagrus coronata - (Martius) Beccari] residues. It was possible to detect some enzymes but amylase, lipase and xylanase were selected for a basic characterization. The optimum conditions were observed at pH 6 and 7 and 40 – 70 °C for amylases, pH 4 – 6 and 50 – 90 °C for lipases and pH 8 and 10 and 20 – 50 °C for xylanases. The best stabilities, evaluated under different conditions were, in a way, a result from the optimal conditions. Additionally, substrate saturation was not observed for soluble starch and xylan until 15 mg/mL and p-nitrophenyl palmitate until 9.95 µmol/mL. These results indicate that both, actinobacteria and the agroindustrial residues, are good choices to produce basic industrial enzymes.
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Cowieson, A. J., W. Schliffka, I. Knap, F. F. Roos, R. Schoop y J. W. Wilson. "Meta-analysis of effect of a mono-component xylanase on the nutritional value of wheat supplemented with exogenous phytase for broiler chickens". Animal Production Science 56, n.º 12 (2016): 2014. http://dx.doi.org/10.1071/an15199.
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A total of 1600 Ross broiler chicks were used in six separate balance studies (with equivalent protocols) to investigate the effect of an exogenous xylanase on the nutritional value of wheat (supplemented with a background of exogenous phytase) sourced from Asia, North America and Europe. The mean apparent metabolisable energy of the 10 batches of wheat per se was 13.4 MJ/kg DM and the addition of xylanase increased (P < 0.001) this by an average of 0.43 MJ/kg DM (~3.2%). Apparent ileal digestibility of nitrogen in the 10 batches of wheat per se was 69.8% and xylanase addition increased (P < 0.001) this by 2%. The apparent ileal disappearance of soluble and insoluble non-starch polysaccharides (NSP) was –53% and +5%, respectively and xylanase addition increased these by 28% and 15%, respectively. The apparent ileal disappearance of total arabinose + xylose was –10% and xylanase increased this by 21%. The apparent ileal flow of fucose was 0.38 g/kg DM intake and xylanase addition reduced (P < 0.05) this by 0.03 g/kg DM intake. There was a significant negative correlation between the apparent ileal flow of fucose and the digestibility of nitrogen and energy in the wheat and the wheat plus xylanase. These results demonstrate the continued effectiveness of exogenous xylanase to enhance the nutritional value of wheat for broiler chickens. Furthermore, the degradation of NSP fractions is confirmatory of both soluble and insoluble fibre hydrolysis in the intestine of the birds. Finally, although de-caging, viscosity amelioration and microbial changes are likely to be involved, the reduced flow of fucose in the intestine of birds fed wheat with supplemental xylanase is indicative of reduced endogenous (mucin) loss with net energy and enteric health implications. The effect of wheat pentosans and xylanase on intestinal secretion and endogenous protein and energy loss is an area for future study. Finally, the results presented herein suggest a reduction in soluble NSP concentrations in wheat over the past 2–3 decades, which is a trend that may explain anecdotal observations that the incidence of so-called sticky wheats is in decline. Systematic assessment of the implications of changing substrate concentrations and characteristics for new xylanase development is warranted.
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Dujkovic, Tatjana, Ivana Pajcin, Vanja Vlajkov y Jovana Grahovac. "Bacillus spp. enzymatic activity to support circular economy". Acta Periodica Technologica, n.º 54 (2023): 325–35. http://dx.doi.org/10.2298/apt2354325d.
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Agricultural and industrial waste represents the most abundant renewable resource in the biosphere and is readily available in substantial quantities. Recently, there has been a growing focus on harnessing the potential of these types of waste as raw materials for producing value-added products, such as microbial enzymes, using solid-state or submerged fermentation systems. Among all the bacterial genera utilized in the production of industrially important enzymes, the Bacillus genus stands out as the most extensively employed for this purpose. In this study, the production of various enzymes such as protease, pectinase, cellulase, xylanase, lipase, and gelatinase was evaluated using the different Bacillus strains isolated from vegetables? rhizosphere. The growth zones and halos were observed to determine production of the following enzymes: cellulases, proteases, pectinases, xylanases, gelatinases and lipases, confirming the breakdown of complex substrates in the medium. Bacillus Pap 3 exhibited the highest EAI (enzymatic activity index) value (4.00) for pectinase activity, indicating its remarkable extracellular level of pectinase performance. The highest enzymatic activity in terms of halo zone diameters was achieved in the case of cellulases and xylanases production by the isolates Mah 1a and Mah 1b. Further research would be directed towards the production of the tested enzymes by Bacillus spp. on the waste streams of food and agroindustry, but also towards the utilization of the proven enzymatic activity to obtain other microbial value-added products to develop viable bioprocess solutions usable in the circular economy context.
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Dmitrieva, Anastasia, Elizaveta Faskhutdinova, Timothy Larichev, Natalia Velichkovich, Veronika Boger y Larisa Aksenova. "Environmentally friendly energy, extremophilic microorganisms, enzymatic activity, microbial fuel cell, hard-to-decompose substrates". Food Processing: Techniques and Technology 54, n.º 1 (28 de marzo de 2024): 27–36. http://dx.doi.org/10.21603/2074-9414-2024-1-2486.
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Traditional energy sources pollute the environment. Microbial fuel cells are an alternative energy source that can reduce the environmental burden. Microbial fuel cells also remove recalcitrant wastes from wastewater. This research featured the enzymatic potential of microbial isolates obtained from the Abakan Arzhan thermal spring.
The study involved isolates of the genera Geobacter, Thermomonas, and Rhodopseudomonas. The keratinolytic analysis was in line with State Standard R 55987-2014. The chitinolytic activity was determined by injecting a bacterial suspension on Petri dishes with a chitin-containing medium. The lipolytic analysis involved cultivating the isolates in Stern’s glycerol fuchsin broth. The xylan hydrolysis depended on the reducing sugars. The cellulase activity was measured according to the standard method recom mended by the International Union of Pure and Applied Chemistry (IUPAC). The catalase potential was evaluated by the gasometric method on 1% gasoline media. The optimal parameters of consortium cultivation were determined by the voltage generated.
The Geobacter isolate had the maximal keratinolytic activity while the Thermomonas isolate demonstrated the maximal protein hydrolysis (80.1 ± 1.5%). Both Geobacter and Rhodopseudomonas showed good lytic activity against chitin with the lysis zone of ≥ 3 mm. The Geobacter isolate demonstrated as many as 350 units of xylanase activity and 365 units of cellulase activity; Ther momonas had 350 units of xylanase activity and 360 units of cellulase activity; Rhodopseudomonas showed 310 units of xylanase activity and 304 units of cellulase activity. The maximal catalase properties belonged to Geobacter (1.40 units) and Thermomonas (1.38 units). The maximal energy generation by bacterial consortia occurred at pH 8 and 45°C after 48 h of cultivation.
In this research, isolates of the genera Geobacter, Thermomonas, and Rhodopseudomonas from the Abakan Arzhan thermal spring were able to remove recalcitrant components, thus demonstrating good prospects for biological treatment of industrial wastewater.
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Mejias, Laura, Alejandra Cerda, Raquel Barrena, Teresa Gea y Antoni Sánchez. "Microbial Strategies for Cellulase and Xylanase Production through Solid-State Fermentation of Digestate from Biowaste". Sustainability 10, n.º 7 (12 de julio de 2018): 2433. http://dx.doi.org/10.3390/su10072433.
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Solid-state fermentation (SSF) is a promising technology for producing bioproducts from organic wastes. The objective of this study is to assess the feasibility of using digestate as substrate to produce hydrolytic enzymes, mainly cellulase and xylanase, by exploring three different inoculation strategies: (i) SSF with autochthonous microbiota; (ii) non-sterile SSF inoculated with Trichoderma reesei and (iii) sequential batch operation to select a specialized inoculum, testing two different residence times. Native microbial population did not show a significant cellulase production, suggesting the need for a specialized inoculum. The inoculation of Trichoderma reesei did not improve the enzymatic activity. On the other hand, inconsistent operation was achieved during sequential batch reactor in terms of specific oxygen uptake rate, temperature and enzymatic activity profile. Low cellulase and xylanase activities were attained and the main hypotheses are non-appropriate biomass selection and some degree of hydrolysis by non-targeted proteases produced during fermentation.
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Nawawi, Muhammad Hariadi, Rosfarizan Mohamad, Paridah Md Tahir y Wan Zuhainis Saad. "Extracellular Xylanopectinolytic Enzymes by Bacillus subtilis ADI1 from EFB’s Compost". International Scholarly Research Notices 2017 (24 de abril de 2017): 1–7. http://dx.doi.org/10.1155/2017/7831954.
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Microbial xylanase and pectinase are two extremely valuable enzymes, which have captivated much attention. This can be seen from the increased demand for these enzymes by many industrial sectors. This study investigates the isolation and screening of extracellular xylanopectinolytic enzymes-producing bacteria in a submerged fermentation (SmF). Samples are collected from the compost of empty fruit bunch (EFB) at Biocompost Pilot Plant, located at Biorefinery Plant, Universiti Putra Malaysia. From the experiment, out of 20 isolates, 11 isolates show xylanase or/and pectinase activity, and only one isolate (EFB-11) shows the concurrent activities of xylanase and pectinase. These activities are selected for enzyme production under submerged fermentation (quantitative screening). At the 72nd hour of incubation, xylanase and pectinase show the highest production, which ranges about 42.33 U/mL and 62.17 U/mL (with low amount of cellulase present), supplemented with 2% (w/v) of rice bran as carbon source at incubation temperature level, which is 30°C. Meanwhile, the pH of media is shifted to 8.42, which indicates that EFB-11 isolate is alkalotolerant bacteria and identified as Bacillus subtilis ADI1. This strain proves to have potential in agroindustrial bioconversion and has a promising ability to scale up to an industrial scale.
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Nusairat, Basheer, Nasser Odetallah y Jeng-Jie Wang. "Live Performance and Microbial Load Modulation of Broilers Fed a Direct-Fed Microbials (DFM) and Xylanase Combination". Veterinary Sciences 9, n.º 3 (18 de marzo de 2022): 142. http://dx.doi.org/10.3390/vetsci9030142.
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The animal industry, which focuses on producing protein for human consumption, is continuously seeking solutions that can enhance both animal performance and health at a low cost. Several feed additives are currently being used to improve the nutritive value of feed as well as replacing the subtherapeutic levels of antibiotic growth promoters (AGP). This study was designed to investigate the effect of a feed additive that is a blend of multi-strain Bacillus spp. probiotics and a xylanase in a 2 × 2 factorial dietary treatments design, testing two levels of the feed additive blend (0 and 100 g/MT) and two cereal grain types (corn and wheat) on live performance, gut lesions, environmental Clostridium perfringens load, and pathogen load in the digesta of broiler chickens (E. tenella, total aerobic count cells (APC), E. coli, and C. perfringens). Day-old chicks were randomly placed in 10 replicate pens per treatment with 52 birds per replicate and grown to 42 d of age. Data were analyzed by two-way ANOVA. At 42 d, birds fed EnzaPro were heavier (p < 0.0004) than unsupplemented birds. An improvement in FCR (p = 0.03) was observed from 1 to 42 d by approximately two points in both corn- and wheat-based diets supplemented with EnzaPro. In wheat-based diets, supplementing EnzaPro reduced (p < 0.0001) a 21 d lesion score of intestines with a further reduction (p < 0.02) at 42 d. EnzaPro reduced (p < 0.03) litter moisture by approximately 1% compared to non-supplemented EnzaPro in both corn- and wheat-based diets. Pathogen load in digesta (C. perfringens, E. tenella, APC, and E. coli) was reduced (p < 0.0002) when EnzaPro was supplemented in diets. It can be concluded that EnzaPro (a blend of DFM Bacillus spp (1 × 105 CFU/g feed) and xylanase (10 XU/g feed)) may be used in both corn- and wheat-based diets to improve the performance and gut health of broilers.
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Liu, Wei, Qiang Si, Lin Sun, Zhijun Wang, Mingjian Liu, Shuai Du, Gentu Ge y Yushan Jia. "Effects of Cellulase and Xylanase Addition on Fermentation Quality, Aerobic Stability, and Bacteria Composition of Low Water-Soluble Carbohydrates Oat Silage". Fermentation 9, n.º 7 (7 de julio de 2023): 638. http://dx.doi.org/10.3390/fermentation9070638.
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Most oat forage has low water-soluble carbohydrates (WSC), which may be the main limited factor for silage fermentation safely, but oat is rich in cellulose and hemicellulose; therefore, we assume that xylanase and cellulase as additives can reduce the content of cellulose and xylan in oat silage, increase the microbial fermentable sugar content, and improve the fermentation quality of the silage. After wilting, oats were treated as follows: (i) distributed water (CK); (ii) silages inoculated with xylanase (X); (iii) silages inoculated with cellulase (C), ensiling for 3 days (early stage of silage) and 60 days (late stage of silage), respectively, after ensiling 60 days for a 5-day aerobic exposure study. The pH, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were significantly reduced by xylanase and cellulase treatment during the late stage of silage, and the concentration of lactic acid, acetic acid, and ammonia nitrogen increased remarkably. The WSC content reached its peak with xylanase treatment during the late stage of silage. The content of crude protein (CP) was not affected by additives but by the silage period; CP and ether extract (EE) significantly increased during the late stage of silage compared to the early stage. After ensiling, the bacterial community showed that xylanase and cellulase treatment increased the relative abundance of lactic acid bacteria. Lactobacillus has a higher relative abundance with cellulase treatment after 60 days of ensiling; this can effectively reduce the pH of silage and ensure long-term, stable storage of silage. Cellulase and xylanase increased bacterial diversity during aerobic exposure and improved the aerobic stability of silage significantly. This study indicated that different additives and silage periods had significant effects on chemical compositions, fermentation quality, and bacterial community; meanwhile, both additives improved the aerobic stability of silage. In summary, when the WSC of oat is low, cellulase and xylanase have good effects as silage additives, and the comprehensive effect of cellulase is more prominent.
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Alves-Prado, Heloiza Ferreira, Fabiana Carina Pavezzi, Rodrigo Simões Ribeiro Leite, Valéria Maia de Oliveira, Lara Durães Sette y Roberto DaSilva. "Screening and Production Study of Microbial Xylanase Producers from Brazilian Cerrado". Applied Biochemistry and Biotechnology 161, n.º 1-8 (8 de noviembre de 2009): 333–46. http://dx.doi.org/10.1007/s12010-009-8823-5.
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FarkaÅ¡, V., Mária LiÅ¡ková y P. Biely. "Novel media for detection of microbial producers of cellulase and xylanase". FEMS Microbiology Letters 28, n.º 2 (junio de 1985): 137–40. http://dx.doi.org/10.1111/j.1574-6968.1985.tb00779.x.
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Zhou, Hanchang, Lan Di, Xiaoju Hua, Tao Deng y Xiaodong Wang. "Bacterial Community Drives the Carbon Source Degradation during the Composting of Cinnamomum camphora Leaf Industrial Extracted Residues". Microbiology Research 14, n.º 1 (9 de febrero de 2023): 229–42. http://dx.doi.org/10.3390/microbiolres14010019.
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The increasing production of industrial aromatic plant residues (IAPRs) are potentially environmental risky, and composting is a promising solution to resolve the coming IAPR problems. Carbon source degradation is a basic but important field in compost research; however, we still lack a clear understanding of carbon source degradation and the corresponding relationship to microbial community variation during IAPR composting, which hampers the improvement of IAPR composting efficiency and the promotion of this technology. In this study, samples were chosen on the first day, the 10th day, the 20th day, and the last day during the composting of Cinnamomum camphora leaf IAPRs, and the microbial community composition, main carbon source composition, and several enzyme activities were measured accordingly. The results showed that during composting, the hemicellulose had the highest reduction (200 g kg−1), followed by cellulose (143 g kg−1), lignin (15.5 g kg−1), starch (5.48 g kg−1), and soluble sugar (0.56 g kg−1), which supported that hemicellulose and cellulose were the main carbon source to microbes during composting. The relative abundance of the main bacterial phylum Firmicute decreased from 85.1% to 40.3% while Actinobactreia increased from 14.4% to 36.7%, and the relative abundance of main fungal class Eurotiomycetes decreased from 60.9% to 19.6% while Sordariomycetes increased from 16.9% to 69.7%. Though principal coordinates analysis found that both bacterial and fungal community composition significantly varied during composting (p < 0.05), structure equation modeling (SEM) supported that bacterial composition rather than fungal counterpart was more responsible for the change in carbon source composition, as the standard total effects offered by bacterial composition (−0.768) was about five times the fungal composition (−0.144). Enzyme2 (comprised of xylanase, laccase, cellulase and manganese peroxidase) provided −0.801 standard total effects to carbon source composition, while Enzyme1 (comprised of lignin peroxidase and polyphenol oxidase) had only 0.172. Furthermore, xylanase and laccase were the only two enzymes appeared in co-occurrence network, clustered with nearly all the carbon sources concerned (except starch) in module-II. Xylanase, hemicellulose, and cellulose were linked to higher numbers of OTUs, more than laccase and other carbon sources. In addition, there were 11 BOTUs but only 1 FOTUs directly interacted to xylanase, hemicellulose, and cellulose simultaneously, three of them were Limnochordaceae and two were Savagea, which highlighted the potential core function in lignocellulose degradation provided by bacterial members, especially Limnochordaceae and Savagea. Thus, the results supported that during composting of Cinnamomum camphora leaf IAPRs, the degradation of dominate carbon sources, hemicellulose and cellulose, was mainly driven by bacterial community rather than fungal community. In addition, the bacterial originated xylanase and laccase played potentially core roles in the functional modules. This research clearly investigated the microbial dynamics of carbon source degradation during the composting of Cinnamomum camphora leaf IAPRs, and offers valuable information about and new insight into future IAPRs waste treatment.
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PAYAN, Françoise, Ruth FLATMAN, Sophie PORCIERO, Gary WILLIAMSON, Nathalie JUGE y Alain ROUSSEL. "Structural analysis of xylanase inhibitor protein I (XIP-I), a proteinaceous xylanase inhibitor from wheat (Triticum aestivum, var. Soisson)". Biochemical Journal 372, n.º 2 (1 de junio de 2003): 399–405. http://dx.doi.org/10.1042/bj20021802.
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A novel class of proteinaceous inhibitors exhibiting specificity towards microbial xylanases has recently been discovered in cereals. The three-dimensional structure of xylanase inhibitor protein I (XIP-I) from wheat (Triticum aestivum, var. Soisson) was determined by X-ray crystallography at 1.8 Å (1 Å=0.1 nm) resolution. The inhibitor possesses a (β/α)8 barrel fold and has structural features typical of glycoside hydrolase family 18, namely two consensus regions, approximately corresponding to the third and fourth barrel strands, and two non-proline cis-peptide bonds, Ser36–Phe and Trp256–Asp (in XIP-I numbering). However, detailed structural analysis of XIP-I revealed several differences in the region homologous with the active site of chitinases. The catalytic glutamic acid residue of family 18 chitinases [Glu127 in hevamine, a chitinase/lysozyme from the rubber tree (Hevea brasiliensis)] is conserved in the structure of the inhibitor (Glu128), but its side chain is fully engaged in salt bridges with two neighbouring arginine residues. Gly81, located in subsite −1 of hevamine, where the reaction intermediate is formed, is replaced by Tyr80 in XIP-I. The tyrosine side chain fills the subsite area and makes a strong hydrogen bond with the side chain of Glu190 located at the opposite side of the cleft, preventing access of the substrate to the catalytic glutamic acid. The structural differences in the inhibitor cleft structure probably account for the lack of activity of XIP-I towards chitin.
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Kaczmarek, S. A., A. J. Cowieson, D. Józefiak y A. Rutkowski. "Effect of maize endosperm hardness, drying temperature and microbial enzyme supplementation on the performance of broiler chickens". Animal Production Science 54, n.º 7 (2014): 956. http://dx.doi.org/10.1071/an13113.
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This study was conducted to determine the influence of maize endosperm type (soft or vitreous), drying temperature (60, 100, 140°C), and enzyme addition (no enzyme or phytase + xylanase) on broiler chicken growth, amino acid availability, and phytate phosphorus hydrolysis. One-day-old Ross-308 broiler chicks (total 1200) were allotted to floor pens with a randomised complete block design (2 × 3 × 2). Diets were formulated to be marginally deficient in Lys, total sulfur amino acids, calcium, and nonphytate phosphorus. A positive effect (P < 0.05) of enzyme addition on chicken bodyweight gain to day 35 was observed (1884 vs 1940 g). Bodyweight gains and feed conversion ratios (FCR) were linearly depressed when drying temperature was increased. Chickens fed vitreous maize were characterised by lower bodyweight gain (1932 vs 1893 g; P < 0.05) and higher FCR (1.796 vs 1.840g : g; P < 0.05). There were no interactions between any of the main effects for overall performance metrics. The use of phytase improved phytic acid digestibility (0.302 vs 0.389; P < 0.05) but phytic acid digestibility was unaffected (P > 0.05) by drying temperature or hardness. The highest drying temperature had a negative effect on amino acids digestibility (P < 0.05). The use of phytase and xylanase improved amino acid apparent ileal digestibility (P < 0.05), except for Cys, Met, and Phe. Results from this study show that drying temperature and vitreousness of maize influence the nutritional value of this grain for broilers. Part of the beneficial effect of the addition of phytase + xylanase to diets with overheated maize for poultry appears to be mediated through an improvement in amino acid availability.
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Wang, Y., T. A. McAllister, L. M. Rode, K. A. Beauchemin, D. P. Morgavi, V. L. Nsereko, A. D. Iwaasa y W. Yang. "Effects of an exogenous enzyme preparation on microbial protein synthesis, enzyme activity and attachment to feed in the Rumen Simulation Technique (Rusitec)". British Journal of Nutrition 85, n.º 3 (marzo de 2001): 325–32. http://dx.doi.org/10.1079/bjn2000277.
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The effects of an exogenous enzyme preparation, the application method and feed type on ruminal fermentation and microbial protein synthesis were investigated using the rumen simulation technique (Rusitec). Steam-rolled barley grain and chopped alfalfa hay were sprayed with water (control, C), an enzyme preparation with a predominant xylanase activity (EF), or autoclaved enzyme (AEF) 24 h prior to feeding, or the enzyme was supplied in the buffer infused into the Rusitec (EI). Microbial N incorporation was measured using (15NH4)2SO4in the buffer. Spent feed bags were pummelled mechanically in buffer to segregate the feed particle-associated (FPA) and feed particle-bound (FPB) bacterial fractions. Enzymes applied to feed reduced neutral-detergent fibre content, and increased the concentration of reducing sugars in barley grain, but not alfalfa hay. Ruminal cellulolytic bacteria were more numerous with EF than with C. Disappearance of DM from barley grain was higher with EF than with C, but alfalfa was unaffected by EF. Treatment EF increased incorporation of15N into FPA and FPB fractions at 24 and 48 h. In contrast, AEF reduced the 24 h values, relative to C; AEF and C were similar at 48 h. Infused enzyme (EI) did not affect15N incorporation. Xylanase activity in effluent was increased by EF and EI, compared to C, but not by AEF. Xylanase activity in FPA was higher at 48 h than at 24 h with all treatments; it was higher with EF than C at 24 and 48 h, but was not altered by AEF or EI. Applying enzymes onto feeds before feeding was more effective than dosing directly into the artificial rumen for increasing ruminal fibrolytic activity.
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Truchado, P., P. Van den Abbeele, A. Rivière, S. Possemiers, L. De Vuyst y T. Van de Wiele. "Bifidobacterium longum D2 enhances microbial degradation of long-chain arabinoxylans in an in vitro model of the proximal colon". Beneficial Microbes 6, n.º 6 (1 de diciembre de 2015): 849–60. http://dx.doi.org/10.3920/bm2015.0023.
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Long-chain arabinoxylans (LC-AX) are degraded in the colon by intestinal bacteria possessing AX-degrading enzymes, such as bifidobacteria. Enzymatic activity of intestinal bacterial might vary depending on the composition of the gut microbiota. To compare the enzymatic activities of the bacterial gut communities of two healthy individuals (donors D1 and D2), these bacterial communities were inoculated into in vitro model M-SHIME®. Differences in xylanase activities and denaturing gradient gel electrophoresis profiles, in particular a DNA-band corresponding with Bifidobacterium longum, were found in the proximal colon vessel. 16S rRNA gene sequencing analysis demonstrated the presence of two different B. longum species in these bacterial communities, showing 99% gene sequence similarity with B. longum NCC2705 and B. longum. subsp. longum KACC 91563, respectively, further referred to as B. longum D1 and B. longum D2. When grown on LC-AX as the sole added energy source, B. longum D2 displayed significantly higher activities of β-xylanase (5.3-fold), β-xylosidase (2.9-fold), and α-arabinofuranosidase (1.5-fold), respectively, compared to B. longum D1. When B. longum D2 was inoculated in the M-SHIME, inoculated with the bacterial gut communities of the individual with low AX-degrading enzyme activities, the β-xylanase activity increased (1.5-fold) in the proximal vessel. We demonstrated the presence of differences in LC-AX degrading enzyme activities of the bacterial gut communities of two individuals in the in vitro M-SHIME model, which could be linked to the presence of a potent AX-degrading B. longum (D2) strain.
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Yu, Qiang, Mengxin Li, Yu Zhang, Jinyi Xu, Ping Li, Hong Sun, Yixiao Xie, Rui Dong, Yulong Zheng y Chao Chen. "Effects of Different Cutting Stages and Additives on the Fermentation Quality and Microbial Community of Sudangrass (Sorghum sudanense Stapf.) Silages". Fermentation 9, n.º 8 (21 de agosto de 2023): 777. http://dx.doi.org/10.3390/fermentation9080777.
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(1) Background: Previous studies have indicated that ferulic acid esterase (FAE), cellulase and xylanase have synergistic effects in lignocellulose degradation, and the cutting stage has a major impact on silages. Whether these additives affect the silages at different cutting stages is unclear. (2) Methods: Sudangrass height at the tested cutting stages was 1.8 m (S1) and 2.0 m (S2). The silage from the two cutting stages was treated with FAE-producing Lactobacillus plantarum (LP), cellulase and xylanase (CX) and a combination of LP and CX (LP+CX) for 30 and 60 days. (3) Results: Compared with CK, adding LP+CX significantly decreased the pH and the content of neutral detergent fiber (NDF) and acidic detergent fiber (ADF) (p < 0.05) and increased the lactic acid (LA) concentration (p < 0.05), dry matter (DM) content and crude protein content. Adding LP+CX effectively degraded lignocellulose in sudangrass, and the NDF and ADF degradation rates at the two stages were all more than 30%. In comparison, cutting at the S2 stage led to a lower pH and higher LA and DM contents (p < 0.05). Additives and the cutting stage exerted a strong effect on the silage microbial community, and Firmicutes and Lactiplantibacillus became the most dominant bacterial phyla and genera, especially at the S2 stage. (4) Conclusions: The results suggest that FAE-producing L. plantarum, cellulase and xylanase had synergistic effects on sudangrass silages, especially at the S2 stage, and their use can thus serve as an efficient method for ensiling.
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Zhang, Bi-zhou, Qinggeer Borjigin, Ju-lin Gao, Xiao-fang Yu, Shu-ping Hu, Fu-gui Wang, Xin Zhang y Sheng-cai Han. "METAGENOMIC ANALYSIS OF MICROBIAL CONSORTIUM GF-20 IN CORN STOVER DEGRADATION AT LOW TEMPERATURE". Journal of Environmental Engineering and Landscape Management 31, n.º 1 (15 de marzo de 2023): 92–102. http://dx.doi.org/10.3846/jeelm.2023.18489.
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In our previous work, a microbial consortium GF-20 (Qinggeer et al., 2016) was enriched from compost habitats and adapted to efficiently and stably degrade corn stover under low temperatures. While the main microorganism and degradation-related functions and degradation-related coding enzyme genes of GF-20 were not clear. Therefore, the current study used the metagenomic to decipher the systematic and functional contexts within such microbial consortium under low temperatures. The results showed that the dominant functional microbials in GF-20 consortium were bacteria. The dominant phylums in GF-20 consortium were Proteobacteria (62.84%) and Bacteroidetes (10.24%). The dominant genus was Pseudomonas (50.84%), followed by Dysgonomonas (5.86%), Achromobacter (4.94%), Stenotrophomonas (3.67%) and Flavobacterium (2.04%). The metabolism was mainly composed of carbohydrate metabolism and amino acid metabolism, and included signal transduction, cell transport and other metabolic modes. The functional genes encoded were mainly distributed in glycosidolytic enzyme genes, and the functional enzymes were β-glucosidase, acetyl-CoA, pyruvate dehydrogenase and galactosidase. The GF-20 microbial consortium degraded the cellulose in corn stover primarily by β-glucosidase and endoglucanase, which were produced by 12 genera of microorganisms. The hemicellulose synergistic effect was produced by 15 genera of microorganisms including xylanase, xyloglucanase, mannolanase and branching enzyme.