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Xylanase
About: Xylanase is a research topic. Over the lifetime, 7099 publications have been published within this topic receiving 163793 citations.
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TL;DR: A thermostable xylanase (XynB) with a thermostables self-splicing bacterial intein to control the xylan enzyme activity is engineered and processed dried ixynB maize stover by temperature-regulated xylanases activation and hydrolysis in a cocktail of commercial CWD enzymes produced >90% theoretical glucose and >63% theoretical xylose yields.
Abstract: Plant cellulosic biomass is an abundant, low-cost feedstock for producing biofuels and chemicals. Expressing cell wall-degrading (CWD) enzymes (e.g. xylanases) in plant feedstocks could reduce the amount of enzymes required for feedstock pretreatment and hydrolysis during bioprocessing to release soluble sugars. However, in planta expression of xylanases can reduce biomass yield and plant fertility. To overcome this problem, we engineered a thermostable xylanase (XynB) with a thermostable self-splicing bacterial intein to control the xylanase activity. Intein-modified XynB (iXynB) variants were selected that have 60% enzymatic activity upon intein self-splicing at temperatures >59 °C. Greenhouse-grown xynB maize expressing XynB has shriveled seeds and low fertility, but ixynB maize had normal seeds and fertility. Processing dried ixynB maize stover by temperature-regulated xylanase activation and hydrolysis in a cocktail of commercial CWD enzymes produced >90% theoretical glucose and >63% theoretical xylose yields.
85 citations
TL;DR: Higher expression of soluble xylanases in a scalable semi-synthetic medium showed potential of the process for soluble enzyme production.
85 citations
TL;DR: The use of crude xylanase of Bacillus subtilis devoid of β-xylosidase to produce high-pure XOS from ammonia pretreated sugarcane bagasse is described to be useful for further development of low-cost process for production of high- Pure prebiotics from lignocellulosic materials.
Abstract: Xylooligosaccharides (XOS) are used as prebiotics in food industries. XOS with high purity is required for effective prebiotic function. All crude xylanases exhibit β-xylosidase, which forms significant amount of xylose and reduces the yield and purity of XOS. Here, we describe the use of crude xylanase of Bacillus subtilis devoid of β-xylosidase to produce high-pure XOS from ammonia pretreated sugarcane bagasse. MALDI-TOF-MS and HPLC analysis of XOS showed the formation of xylobiose, xylotriose and xylotetraose with xylobiose as the major product. The conversion of bagasse to XOS was >99% with negligible amount of xylose (0.4%). NMR analysis of XOS mixture indicated the presence of arabinosyl and glucuronyl substituted XOS. The relative content of substituted XOS in the mixture was 32%. The XOS mixture supported growth of probiotic bifidobacterial strains under anaerobic conditions. The bifidobacterial strains completely utilized XOS with production of short chain fatty acids indicating their prebiotic function. The concentration of fatty acids formed was in the order of acetate, formate and lactate. Hence, the present method would be useful for further development of low-cost process for production of high-pure prebiotic XOS from lignocellulosic materials.
85 citations
TL;DR: Out of the three agro-wastes used in this study, wheat bran holds greatest promise for low cost production of the xylanase enzyme, with Wheat bran giving the highest value of 1.14 mg/mL at 96 h.
Abstract: Xylanase production by wild-type Aspergillus niger ANL301, newly isolated from wood-waste, was monitored at 24 h intervals for a period 168 h in media containing different carbon sources. The carbon sources were oat-spelt xylan (Fluka) and three agro-wastes (sawdust, sugarcane pulp and wheat bran). Highest xylanase activity of 6.47 units/mL was obtained at 96 h in media containing wheat bran as sole carbon source. Maximum activity value for the media containing sugarcane pulp was 0.95 units/mL obtained also at 96 h. Sawdust and oat spelt xylan gave the peak enzyme activities of 0.65 and 0.80 units/mL respectively at 120 h. High protein yield was obtained in media containing the agro-wastes, with wheat bran giving the highest value of 1.14 mg/mL at 96 h. The maximum specific xylanase activities were 3.86, 3.37, 5.69, and 9.36 units/ mg protein for sawdust, sugarcane pulp, wheat bran and oat spelt xylan, respectively. Out of the three agro-wastes used in this study, wheat bran holds greatest promise for low cost production of the xylanase enzyme.
85 citations
TL;DR: Trichoderma reesei was co-cultured with either Aspergillus niger or A. phoenicis in solid substrate fermentation on sugar cane bagasse for xylanase production and optimal activities of cellulase and xylan enzyme were attained.
Abstract: Trichoderma reesei was co-cultured with either Aspergillus niger or A. phoenicis in solid substrate fermentation on sugar cane bagasse for xylanase production. When soymeal was used as nitrogen supplement, optimal activities of cellulase (14-15 IU/g dry wt) and xylanase (2,600-2,800 IU/g dry wt) were attained by both mixed culture systems in 72 h of fermentation, corresponding to xylanase volumetric productivities of 5,500-5,900 lU/L.h.
85 citations