scispace - formally typeset
Search or ask a question

Showing papers on "Xylanase published in 2021"


Journal ArticleDOI
TL;DR: The main objective of the present study was to assess the impact on Nile tilapia (Oreochromis niloticus) of enzymes and probiotics, as well as their synergistic effect.

35 citations


Journal ArticleDOI
TL;DR: This investigation showed the feasibility to obtain an enzymatic extract with xylanase and cellulase activity using low-cost substrates such as SCB and BSG.

29 citations


Journal ArticleDOI
TL;DR: The results showed that a cooperative action of the set of hydrolytic and oxidative enzymes can be used as a "green" treatment prior to the sonication step to produce nanofibrillated cellulose with advanced properties.

29 citations


Journal ArticleDOI
03 Apr 2021-Mycology
TL;DR: Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy analyses confirmed the efficient structural alteration of sugarcane bagasse caused by enzymatic actions during A. flavus KUB2 cultivation as an efficient hydrolytic enzymes producer and an effective lignocellulose degrader.
Abstract: Lignocellulosic wastes, rice straw, sugarcane bagasse, rice bran and sawdust, and pure commercial carboxymethyl cellulose (CMC) and xylan were used as substrates to cultivate cellulolytic fungus, Aspergillus flavus KUB2, in submerged fermentation at 30°C Of all the substrates, sugarcane bagasse was a good source for the production of cellulolytic and also hemicellulolytic enzymes The maximum activities of endoglucanase (CMCase), total cellulase (FPase) and xylanase using sugarcane bagasse as substrate were 8%, 75% and 165%, respectively, higher than those of the commercial substrates The time course determination of enzyme production revealed that the highest CMCase (127 U/ml), FPase (072 U/ml) and xylanase (37681 U/ml) activities were observed at 14 days of fermentation Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses confirmed the efficient structural alteration of sugarcane bagasse caused by enzymatic actions during A flavus KUB2 cultivation Based on the results of the hydrolytic enzyme activities, FTIR and SEM, A flavus KUB2 is suggested as an efficient hydrolytic enzymes producer and an effective lignocellulose degrader, while sugarcane bagasse can be applied as a low-cost carbon source for the economical production of lignocellulose hydrolytic enzymes by A flavus KUB2

28 citations


Journal ArticleDOI
TL;DR: In this paper, the surface residues of xylanase from Chaetomium globosum (XylCg) were modified to lysine residues by site-directed mutagenesis.

27 citations


Journal ArticleDOI
TL;DR: The structural difference and role of xylan, procedures involved in the production of xylooligosaccharides (XOS), and their implementation into animal feeds are discussed in this article.
Abstract: This paper discusses the structural difference and role of xylan, procedures involved in the production of xylooligosaccharides (XOS), and their implementation into animal feeds. Xylan is non-starch polysaccharides that share a β-(1-4)-linked xylopyranose backbone as a common feature. Due to the myriad of residues that can be substituted on the polymers within the xylan family, more anti-nutritional factors are associated with certain types of xylan than others. XOS are sugar oligomers extracted from xylan-containing lignocellulosic materials, such as crop residues, wood, and herbaceous biomass, that possess prebiotic effects. XOS can also be produced in the intestine of monogastric animals to some extent when exogenous enzymes, such as xylanase, are added to the feed. Xylanase supplementation is a common practice within both swine and poultry production to reduce intestinal viscosity and improve digestive utilization of nutrients. The efficacy of xylanase supplementation varies widely due a number of factors, one of which being the presence of xylanase inhibitors present in common feedstuffs. The use of prebiotics in animal feeding is gaining popularity as producers look to accelerate growth rate, enhance intestinal health, and improve other production parameters in an attempt to provide a safe and sustainable food product. Available research on the impact of xylan, XOS, as well as xylanase on the growth and health of swine and poultry, is also summarized. The response to xylanase supplementation in swine and poultry feeds is highly variable and whether the benefits are a result of nutrient release from NSP, reduction in digesta viscosity, production of short chain xylooligosaccharides or a combination of these is still in question. XOS supplementation seems to benefit both swine and poultry at various stages of production, as well as varying levels of XOS purity and degree of polymerization; however, further research is needed to elucidate the ideal dosage, purity, and degree of polymerization needed to confer benefits on intestinal health and performance in each respective species.

26 citations


Journal ArticleDOI
12 Jul 2021
TL;DR: In this paper, the diversity of expressed genes encoding GH11 xylanases was investigated under Avicenia marina and Rhizophora stylosa trees during the wet and dry seasons and at two different sediment depths.
Abstract: Mangrove sediments from New Caledonia were screened for xylanase sequences. One enzyme was selected and characterized both biochemically and for its industrial potential. Using a specific cDNA amplification method coupled with a MiSeq sequencing approach, the diversity of expressed genes encoding GH11 xylanases was investigated beneath Avicenia marina and Rhizophora stylosa trees during the wet and dry seasons and at two different sediment depths. GH11 xylanase diversity varied more according to tree species and season, than with respect to depth. One complete cDNA was selected (OFU29) and expressed in Pichia pastoris. The corresponding enzyme (called Xyn11-29) was biochemically characterized, revealing an optimal activity at 40–50 °C and at a pH of 5.5. Xyn11-29 was stable for 48 h at 35 °C, with a half-life of 1 h at 40 °C and in the pH range of 5.5–6. Xyn11-29 exhibited a high hydrolysis capacity on destarched wheat bran, with 40% and 16% of xylose and arabinose released after 24 h hydrolysis. Its activity on wheat straw was lower, with a release of 2.8% and 6.9% of xylose and arabinose, respectively. As the protein was isolated from mangrove sediments, the effect of sea salt on its activity was studied and discussed.

25 citations


Journal ArticleDOI
TL;DR: In this article, Sugarcane bagasse and soybean meal are employed for optimised xylanase production with the concomitant synthesis of proteases, leading to a 2.16-fold increase in enzymatic activity.

25 citations


Journal ArticleDOI
TL;DR: It is demonstrated that hydrolyzed DDGS can be an alternative economical substrate for A. niger strains to produce cellulase and xylanase, respectively, and the next phases of the study should further optimize the production of cellulase-xylanase in terms of growth parameters and medium components by using bench-top bioreactors.
Abstract: Bioenergy is one of the most promising solutions for the environmental problems of using non-renewable energy resources. Bioethanol is a form of bioenergy produced from food crops, such as corn, wheat, and sugarcane. Distillers’ dried grains with solubles (DDGS) is the by-product of corn and wheat ethanol production in the dry mill process and has a high nutritional profile. The undigested carbohydrate components in DDGS and proteins can be utilized as the feedstock to produce microbial cellulases and xylanases as the value-added products. Currently, several bacterial and fungal strains are used to produce such enzymes by using expensive feedstocks for commercial preparations. In this study, several bacterial and fungal strains have been evaluated to explore the potential of hydrolyzed DDGS as the main feedstock for these hydrolytic enzymes production. Maximum cellulase production of 0.592 IU/ml was observed for Aspergillus niger (NRRL 1956) on the eighteenth day and stable high production of xylanase of 34.8 IU/ml was obtained for Aspergillus niger (NRRL 567) on day twelfth during shake-flask fermentation. Hydrolytic enzyme production by Bacillus subtilis (NRRL NSR352, DSM 17766, and NF1) was relatively lower (0–0.261 IU/ml for cellulase and 1.2–5.2 IU/ml for xylanase) than the fungal enzyme production. In conclusion, this study demonstrated that hydrolyzed DDGS can be an alternative economical substrate for A. niger strains to produce cellulase and xylanase, respectively. The next phases of the study should further optimize the production of cellulase and xylanase in terms of growth parameters and medium components by using bench-top bioreactors.

24 citations


Journal ArticleDOI
TL;DR: The results show that the immobilization of the enzymes did not extensively alter their functionality and increased enzyme stability compared to that of the free enzyme upon storage at 4 and 20 °C, and suggest the great potential of these nanoassemblies in bioindustry applications.
Abstract: Immobilization of enzymes has been extensively required in a wide variety of industrial applications as a way to ensure functionality and the potential of enzyme recycling after use. In particular,...

23 citations


Journal ArticleDOI
TL;DR: In this article, the authors explored the release of bound polyphenols (BP) from insoluble dietary fiber (IDF) and its mechanism by solid-state fermentation (SSF) via Trichoderma viride.
Abstract: This study is aimed at exploring the release of bound polyphenols (BP) from insoluble dietary fiber (IDF) and its mechanism by solid-state fermentation (SSF) via Trichoderma viride. The results indicated that BP released by SSF (5.55 mg GAE/g DW) was significantly higher than by alkaline hydrolysis. In addition, 39 polyphenols and catabolites were detected, and the related biotransformation pathways were speculated. Quantitative analysis showed that SSF released more ferulic acid, p-coumaric acid, and organic acids, which led to advances in antioxidant, α-amylase, and α-glucosidase inhibitory activities. Furthermore, structural characteristics (scanning electron microscopy, X-ray diffraction, thermos gravimetric analysis, and Fourier transform infrared spectroscopy) and dynamic changes of carbohydrate-hydrolyzing enzymes indicated that the destruction of hemicellulose and the secretion of xylanase were vital for releasing BP. Overall, this study demonstrated that SSF was beneficial to release BP from IDF, which could provide insight into utilizing agricultural byproducts in a more natural and economical way.

Journal ArticleDOI
TL;DR: A targeted review of 487 examples of quantified enzyme production from 209 studies reported on Science Direct was presented in this paper, which enabled the identification of the key substrates and enzymes for potential production pathways.

Journal ArticleDOI
TL;DR: Reducing sugar yields following the cellulase-hemicellulase co-treatment of untreated, alkaline- pretreated, and ionic liquid-pretreated bamboo were higher than those associated with separate cellulase and hemicelluase treatments, thus confirming the synergistic activity of cellulases-hemICEllulases co- treatment in the context of bamboo saccharification.

Journal ArticleDOI
N. E. Ward1
TL;DR: A broad scope of enzymatic activity in customized mixes can more effectively target the resilient NSP construct of cereal grains in commercial poultry diets, particularly those in corn-based feeds.

Journal ArticleDOI
TL;DR: Interestingly, their co-cultivation in sequential SoSF-SmF significantly improved overall enzyme production possibly due to synergism of the enzymes produced by both strains and combined advantages of SoSF and SmF.

Journal ArticleDOI
TL;DR: Although selective enzyme treatments have been used to successfully fibrillate chemical pulps, high lignin-containing mechanical pulps have proven to be more recalcitrant.
Abstract: Although selective enzyme treatments have been used to successfully fibrillate chemical pulps, high lignin-containing mechanical pulps have proven to be more recalcitrant. When a bleached chemi-thermomechanical pulp (BCTMP) was sulfonated prior to enzymatic treatment, relatively good fibrillation was achieved, although some pulp hydrolysis occurred after 6 h hydrolysis when using a commercial cellulase enzyme preparation (Cellic CTec 3). To try to minimize pulp losses, various enzyme cocktails, including endoglucanase (EG), xylanase, mannanase, and lytic polysaccharide monooxygenase (LPMO), were assessed for their ability to enhance fibrillation while minimizing cellulose hydrolysis. It was apparent that the yield as well as the zeta potential of the lignin-containing cellulose nanofibrils increased with enzyme treatment. This was likely due to an increase in surface charge and a decrease in particle size after LPMO and hemicellulase treatments, respectively. When carbohydrate-binding modules (CBMs) were used to quantify fiber changes, it was apparent that sulfonation had increased the accessibility of enzymes, while the combined action of the hemicellulases and LPMO increased EG accessibility to the less-ordered regions of the mechanical pulp, resulting in enhanced fibrillation. This work described, for the first time, the synergistic action of EG and various accessory enzymes enhancing mechanical pulp nanofibrillation.

Journal ArticleDOI
TL;DR: In this paper, a two-step acetic acid/sodium acetate (AC/SA) conjugate system was used for co-production of XOS and monosaccharides from corncob without xylan isolation and purification.

Journal ArticleDOI
TL;DR: The significant activities of the hydrolytic enzymes recorded with B. bassiana in this study present promising avenues for the use of the entomopathogen as a new source of industrial enzymes and by extension, other biotechnological applications.

Journal ArticleDOI
TL;DR: In this paper, the effects of supplemental xylanase and xylooligosaccharides (XOS) in a corn-soybean meal (SBM)-based diet on growth performance and intestinal health of broilers were evaluated.
Abstract: BACKGROUND This study evaluated the effects of supplemental xylanase and xylooligosaccharides (XOS) in a corn-soybean meal (SBM)-based diet on growth performance and intestinal health of broilers. A total of 288 day-old chicks (Cobb 500) were allocated to 36 floor pens (8 birds/pen) equally in 9 dietary treatments in a 3 × 3 factorial arrangement. The treatments were combinations of 3 levels of xylanase (0, 0.005% and 0.01% Econase XT) and 3 levels of prebiotics (0, 0.005% and 0.01% XOS) added to basal mash diets formulated in three phases (starter, d 0-14; grower, d 15-28; finisher, d 29-42). The feed intake and body weights were recorded weekly. On d 42, ileal sections were collected for histomorphometric and gene expression analysis, and cecal content was collected for determining short-chain fatty acids (SCFA) and microbiota. RESULTS Xylanase linearly (P 0.05). Supplemental xylanase and XOS did not affect average daily feed intake and feed conversion ratio (P > 0.05). Xylanase and XOS did not change villus height (VH) or crypt depth (CD) ratio (P > 0.05). However, xylanase exhibited a trend (P = 0.097) on VH:CD ratio. The inclusion of 0.01% XOS without xylanase increased the level of IL-10 (a marker of anti-inflammatory cytokine) and IL-4 (a T-cell differentiation cytokine) genes compared with control (P 0.05). However, the mean proportion of family Ruminococcaceae was increased by the supplemental 0.01% xylanase (P < 0.01). CONCLUSION It can be concluded that XOS can enhance cecal fermentation, while xylanase can increase the body weight gain along with the fermentation metabolites in the ceca of broilers fed the corn-SBM-based diet but the effects may not always translate into an improved mucosal absorptive capacity and a better feed efficiency.

Journal ArticleDOI
TL;DR: The cellulose component selectivity of the polymer-acting β-glucosidase and xylanase of T. asperellum UC1 was successfully identified by an in silico approach of molecular docking, molecular dynamics simulation and Molecular-mechanics Poisson-Boltzmann surface area analysis.
Abstract: Literature has shown that oil palm leaves (OPL) can be transformed into nanocellulose (NC) by fungal lignocellulosic enzymes, particularly those produced by the Trichoderma species. However, mechan...

Journal ArticleDOI
TL;DR: Light is shed on the understanding of xylan degradation and plant cell wall deconstruction, which can be applied to several applications in food, feed, and bioeconomy.
Abstract: The functional screening of a Pseudacanthotermes militaris termite gut metagenomic library revealed an array of xylan-degrading enzymes, including P. militaris 25 (Pm25), a multimodular glycoside hydrolase family 10 (GH10). Sequence analysis showed details of the unusual domain organization of this enzyme. It consists of one catalytic domain, which is intercalated by two carbohydrate binding modules (CBMs) from family 4. The genes upstream of the genes encoding Pm25 are susC-susD-unk, suggesting Pm25 is a Xyn10C-like enzyme belonging to a polysaccharide utilization locus. The majority of Xyn10C-like enzymes shared the same interrupted domain architecture and were vastly distributed in different xylan utilization loci found in gut Bacteroidetes, indicating the importance of this enzyme in glycan acquisition for gut microbiota. To understand its unusual multimodularity and the possible role of the CBMs, a detailed characterization of the full-length Pm25 and truncated variants was performed. Results revealed that the GH10 catalytic module is specific toward the hydrolysis of xylan. Ligand binding results indicate that the GH10 module and the CBMs act independently, whereas the tandem CBM4s act synergistically with each other and improve enzymatic activity when assayed on insoluble polysaccharides. In addition, we show that the UNK protein upstream of Pm25 is able to bind arabinoxylan. Altogether, these findings contribute to a better understanding of the potential role of Xyn10C-like proteins in xylan utilization systems of gut bacteria. IMPORTANCE Xylan is the major hemicellulosic polysaccharide in cereals and contributes to the recalcitrance of the plant cell wall toward degradation. Members of the Bacteroidetes, one of the main phyla in rumen and human gut microbiota, have been shown to encode polysaccharide utilization loci dedicated to the degradation of xylan. Here, we present the biochemical characterization of a xylanase encoded by a Bacteroidetes strain isolated from the termite gut metagenome. This xylanase is a multimodular enzyme, the sequence of which is interrupted by the insertion of two CBMs from family 4. Our results show that this enzyme resembles homologues that were shown to be important for xylan degradation in rumen or human diet and show that the CBM insertion in the middle of the sequence seems to be a common feature in xylan utilization systems. This study shed light on our understanding of xylan degradation and plant cell wall deconstruction, which can be applied to several applications in food, feed, and bioeconomy.

Journal ArticleDOI
TL;DR: The utility of this novel bacterial strain in industries as high-temperature catalysts is revealed using the caver analysis, Molecular Dynamics simulation, and Density Functional Theory (DFT) studies.

Journal ArticleDOI
TL;DR: In this paper, a stable bifunctional cellulase/xylanase, PersiCelXyn1, was identified from the rumen microbiota by the multi-stage in-silico screening pipeline and computationally assisted methodology.

Journal ArticleDOI
TL;DR: The central MS XOS, exerted the highest cholesterol reduction and antioxidant activities 74.7 and 92%, respectively, showed remarkable in vivo protective role against the hepatic toxicity of lithium carbonate evaluated by changes in body weight, liver function markers and tissue makers.

Journal ArticleDOI
TL;DR: Results clearly demonstrated that the B. pumilus SV-85S xylanase was effective as a pulp bio-bleaching agent and the decrease in chlorine consumption by pre-treatment of pulp with x Dylanase apparently made the bio- bleaching process not only economical but also eco-friendly.
Abstract: Hyper production of an extra cellular, alkali stable, cellulase free and thermostable xylanase have been produced from Bacillus pumilus SV-205 using wheat bran as a substrate under solid state fermentation. Enzyme production under optimized conditions enhanced the production level from 4510 to 65,130 ± 1000 IU/g dry substrate, which was 14.4 fold as compared to production under un-optimized conditions. The application of crude xylanase was investigated in pulp bio bleaching. The bio-bleaching of kraft pulp with xylanase was the most effective at an enzyme dose of 12.5 IU/g oven dried pulp, pH 10.0 and 120 min incubation at 60 °C. Under the optimized conditions, xylanase pre-treatment reduced Kappa number by 0.8 points and increased brightness by 1.08 points as compared with the control. The pre-treatment of pulp with xylanase resulted in 19.01% reduction in chlorine consumption by maintaining the same brightness as in control. These results clearly demonstrated that the B. pumilus SV-85S xylanase was effective as a pulp bio-bleaching agent. The decrease in chlorine consumption by pre-treatment of pulp with xylanase apparently made the bio-bleaching process not only economical but also eco-friendly. The xylanase from B. pumilus SV-205 exhibit remarkable properties which are suitable for application in paper pulp bleaching and an elevated production of xylanase by B. pumilus SV-205 under solid state fermentation over wheat bran, a cheap and easily available agro-residue would apparently reduce the enzyme cost substantially.

Journal ArticleDOI
TL;DR: The present review provides evidence that narrates xylanase's presence in the production of biofuels such as bioethanol and biobutanol and discusses the major aspects of biofuel conversion efficiency.
Abstract: Strengthening green alternative energy sources has been enforced due to hydrocarbon fuels’ consequential harmful impacts. Climate change, economic enhancement, and energy security are motivating reasons behind the idea of expansion of biofuel production worldwide. Raw materials like lignocellulose have wide range of complex sugars in the form of cellulose (60–70%) and xylan (30–40%) which further by its hydrolysis and fermentation can be used to produce biofuels. Presently, naturally occurring xylanase enzyme is widely used as a natural resource for biofuel diligence to break down the second abundant β-1,4 xylan sugar into xylooligosaccharide, xylobiose, and xylose subunits. For larger scale, numerous approaches are required to improve or modify its thermostability, specificity, and enzyme activity along with its broad range of substrate to shorten the cost in biofuel production. Therefore, the present review provides a synopsis of present scenario of xylanase as a major participant in biofuel production, along with its various applications and factors affecting xylanase production. This present review provides evidence that narrates its presence in the production of biofuels such as bioethanol and biobutanol. Lastly, the present works discuss the major aspects of biofuel conversion efficiency.

Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the performance of β-glucosidase by solid state cultivation of the fungus Thermoascus crustaceus in a low-cost cultivation medium (comprising agroindustrial residues).
Abstract: Microbial β-glucosidases can be used in several industrial processes, including production of biofuels, functional foods, juices, and beverages. In the present work, production of β-glucosidase by solid state cultivation of the fungus Thermoascus crustaceus in a low-cost cultivation medium (comprising agroindustrial residues) was evaluated. The highest production of β-glucosidase, about 415.1 U/g substrate (or 41.51 U/mL), was obtained by cultivating the fungus in wheat bran with 70% humidity, during 96 h at 40°C. The enzymatic activity was optimum at pH 4.5 and 65°C. β-Glucosidase maintained its catalytic activity when incubated at a pH range of 4.0-8.0 and temperature of 30-55°C. The enzyme was strongly inhibited by glucose; even when the substrate and glucose concentrations were equal, the inhibition was not reversed, suggesting a non-competitive inhibition. In the presence of up to 10% ethanol, β-glucosidase maintained its catalytic activity. In addition to β-glucosidase, the enzymatic extract showed activity of 36 U/g for endoglucanase, 256.2 U/g for xylanase, and 18.2 U/g for β-xylosidase. The results allow to conclude that the fungus T. crustaceus has considerable potential for production of β-glucosidase and xylanase when cultivated in agroindustrial residues, thereby reducing the cost of these biocatalysts.

Journal ArticleDOI
TL;DR: The quantitative assay for pECTinase activity of the four isolates provided proof that they are pectinase producers and can be considered potential candidates for industrial uses.
Abstract: Pectinases are a group of enzymes with broad application, including in plant fiber processing, pectic wastewater treatment, paper pulping, fruit juice extraction, and clarification. With an increasing industrial demand for these enzymes, it is useful to isolate organisms that produce large amounts of pectinase and possess wide ranges of stability factors like temperature and pH. In this study, 17 out of 29 bacteria (58.62%) from forest soil samples were pectinolytic. However, only four bacteria (S-5, S-10, S-14, and S-17) showed high pectin hydrolysis zones (ranging from 0.2 cm to 1.7 cm). These four bacteria were identified based on colony morphology, microscopic characterization, biochemical characteristics, and 16S rDNA sequencing. They were designated as Streptomyces sp. (S-5, S-14), Cellulomonas sp. (S-10), and Bacillus sp. (S-17). Interestingly, bacteria showed cellulase and xylanase activity in addition to pectinase. The quantitative assay for pectinase activity of the four isolates provided proof that they are pectinase producers and can be considered potential candidates for industrial uses. The crude enzyme extracts of these bacteria are applicable in oil and juice extraction from sesame seeds and apples, respectively.

Journal ArticleDOI
TL;DR: In this article, a method for cost-and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate was described, which possessed xylan enzyme activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis and ROS burst.
Abstract: Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.

Journal ArticleDOI
TL;DR: In this article, a xylanase hyper-producing system was established by tailoring two transcription factors, XYR1 and ACE1, and homologous overexpression of the major endo-xylanase XYNII.
Abstract: Filamentous fungus Trichoderma reesei has been widely used as a workhorse for cellulase and xylanase productions Xylanase has been reported as the crucial accessory enzyme in the degradation of lignocellulose for higher accessibility of cellulase In addition, the efficient hydrolysis of xylan needs the co-work of multiple xylanolytic enzymes, which rise an increasing demand for the high yield of xylanase for efficient biomass degradation In this study, a xylanase hyper-producing system in T reesei was established by tailoring two transcription factors, XYR1 and ACE1, and homologous overexpression of the major endo-xylanase XYNII The expressed xylanase cocktail contained 5256 U/mL xylanase activity and 925 U/mL β-xylosidase (pNPXase) activity Meanwhile, the transcription level of the xylanolytic genes in the strain with XYR1 overexpressed was upregulated, which was well correlated with the amount of XYR1-binding sites In addition, the higher expression of associated xylanolytic enzymes would result in more efficient xylan hydrolysis Besides, 2310–3085 U/mL of xylanase activities were achieved using soluble carbon source, which was more efficient and economical than the traditional strategy of xylan induction Unexpectedly, deletion of ace1 in C30OExyr1 did not give any improvement, which might be the result of the disturbed function of the complex formed between ACE1 and XYR1 The enzymatic hydrolysis of alkali pretreated corn stover using the crude xylanase cocktails as accessory enzymes resulted in a 3664% increase in saccharification efficiency with the ratio of xylanase activity vs FPase activity at 500, compared to that using cellulase alone An efficient and economical xylanase hyper-producing platform was developed in T reesei RUT-C30 The novel platform with outstanding ability for crude xylanase cocktail production would greatly fit in biomass degradation and give a new perspective of further engineering in T reesei for industrial purposes