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Hao Wu, Xianbo Cheng, Yongfeng Zhu, Wei Zeng, Guiguang Chen, Zhiqun Liang
Xylanase is an important enzyme involved in degrading xylan. In this study, an extracellular cellulase-free, thermostable endo-xylanase which was produced by Streptomyces griseorubens LH-3 with bagasse semi-cellulose as a carbon source was purified and characterized. The xylanase was purified 4-fold with a recovery yield of 21.6% by precipitation with 25-55% (NH4)2SO4, Mono Q ion exchange chromatography and sephacryl S-200 HR gel filtration chromatography. It appeared as a monomeric protein on SDS-PAGE gel and had an apparent molecular weight of 45...
September 14, 2017: Journal of Bioscience and Bioengineering
Wichanee Bankeeree, Rinji Akada, Pongtharin Lotrakul, Hunsa Punnapayak, Sehanat Prasongsuk
From three cell-associated β-xylosidases produced by Aureobasidium pullulans CBS 135684, the principal enzyme was enriched to apparent homogeneity and found to be active at high temperatures (60-70 °C) over a pH range of 5-9 with a specific activity of 163.3 units (U) mg(-1). The enzyme was thermostable, retaining over 80% of its initial activity after a 12-h incubation at 60 °C, with half-lives of 38, 22, and 10 h at 60, 65, and 70 °C, respectively. Moreover, it was tolerant to xylose inhibition with a K i value of 18 mM...
September 16, 2017: Applied Biochemistry and Biotechnology
Sindhu Mathew, Eva Nordberg Karlsson, Patrick Adlercreutz
The enzymatic, ecofriendly pretreatment of wheat bran with α-amylase from Bacillus amyloliquifaciens or B. licheniformis at 90°C for 1.5h followed by Neutrase at 50°C for 4h, aqueous liquefaction at 121°C for 15h and ethanol precipitation enabled the production of soluble arabinoxylan (AX) with purity of 70.9% and 68.4% (w/w) respectively. Process alternatives tried, to simplify the process and curtail the cost resulted in AX products with different purities, yields and arabinose to xylose ratio (A/X). Among the two glycoside hydrolase (GH) family endoxylanases evaluated, GH10 family hydrolysed soluble AX more efficiently with xylanase from Geobacillus stearothermophilus T-6 (GsXyn10A) producing maximum amount of quantifiable short xylo-oligosaccharides (XOS) and arabinoxylo-oligosaccharides (AXOS) (53% w/w) followed by the catalytic module of Rhodothermus marinus Xyn10A (RmXyn10A-CM) with 37% (w/w) conversion...
September 14, 2017: Journal of Biotechnology
Hailong Li, Hongli Wu, Lian Xiong, Xuefang Chen, Can Wang, Gaoxiang Qi, Chao Huang, Haijun Guo, Mutan Luo, Jian Liu, Minnan Long, Xinde Chen
Understanding the interaction mechanisms between xylan and xylan-degrading enzymes is beneficial to the efficient hydrolysis of xylan. Xylan from sugarcane bagasse (SB) was extracted and characterized. The effects of heat treatment and removal of side chains of SB xylan on the hydrolytic efficiency and synergistic action of endo-β-1,4-xylanases (HoXyn11A and AnXyn10C), β-xylosidases (AnXln3D), and α-l-arabinofuranosidases (AnAxh62A) were investigated. Results indicated that heat treatment of xylan can improve the hydrolytic efficiency of xylan-degrading enzymes, and it is essential for the efficient hydrolysis of xylan by HoXyn11A...
November 1, 2017: Carbohydrate Polymers
Yanxin Ye, Xuezhi Li, Yuan Cao, Jian Du, Shicheng Chen, Jian Zhao
β-Xylosidase activity is deficient in most cellulase enzymes secreted by filamentous fungi, which limits effective enzymatic hydrolysis of hemicellulose in lignocellulose materials and resulted in accumulation of xylo-oligosaccharides that inhibit the cellulase and xylanase activitives. An endogenous β-xylosidase gene, xyl3A, was overexpressed using two types of promoters in cellulolytic P. oxalicum RE-10. The mutants RXyl, RGXyl-1 and RGXyl-2 displayed higher β-xylosidase production than native strain RE-10 besides higher cellulase and xylanase activities, especially RGXyl-1, showing the highest β-xylosidase activity of 15...
August 30, 2017: Bioresource Technology
Bilal Ahmad Mir, Alexander A Myburg, Eshchar Mizrachi, Don A Cowan
Conversion of lignocellulosic biomass to biofuels and biomaterials suffers from high production costs associated with biomass pretreatment and enzymatic hydrolysis. In-planta expression of lignocellulose-digesting enzymes is a promising approach to reduce these cost elements. However, this approach faces a number of challenges, including auto-hydrolysis of developing cell walls, plant growth and yield penalties, low expression levels and the limited stability of expressed enzymes at the high temperatures generally used for biomass processing to release fermentable sugars...
September 13, 2017: Scientific Reports
Cheng Li, Ying Lin, Xueyun Zheng, Qingyan Yuan, Nuo Pang, Xihao Liao, Yuanyuan Huang, Xinying Zhang, Shuli Liang
Pichia pastoris is a widely used heterologous protein production workhorse. However, with its multiple genetic modifications to solve bottlenecks for heterologous protein productivity, P. pastoris lacks selectable markers. Existing selectable marker recycling plasmids have drawbacks (e.g., slow growth and conditional lethality). Here, zeocin-resistance marker recycling vectors were constructed using the Cre/loxP recombination system. The vectors were used to (i) knock in heterologous phytase, xylanase and lipase expression cassettes, (ii) increase the phytase, xylanase and lipase gene copy number to 13, 5, and 5, respectively, with vector introduction and (iii) engineer the secretion pathway by co-overexpressing secretion helper factors (Sly1p and Sec1p) without introducing selectable markers, giving a phytase field of 0...
September 11, 2017: Scientific Reports
Simon Heinze, Matthias Mechelke, Petra Kornberger, Wolfgang Liebl, Wolfgang H Schwarz, Vladimir V Zverlov
Enzymes that cleave polysaccharides in lignocellulose, i. e., cellulases, xylanases, and accessory enzymes, play crucial roles in the natural decomposition of plant-derived biomass and its efficient and sustainable processing into biofuels or other bulk chemicals. The analysis of open reading frame cthe_2195 from the thermophilic, cellulolytic anaerobe Clostridium thermocellum (also known as 'Ruminiclostridium thermocellum') suggested that it encoded a cellulosomal protein comprising a dockerin-I module, a carbohydrate-binding module, and a module of previously unknown function...
September 11, 2017: Scientific Reports
Sharmili Jagtap, Rehan Ahmed Deshmukh, Shylaja Menon, Santanu Das
Aspergillus fumigatus R1, on submerged fermentation using agricultural residues as carbon source produced extracellular xylanase (152IU/ml after 96h of incubation at 37°C with constant shaking at 100rpm). A maximum yield of 1gm% Xylooligosaccharides (XOS) mixture was obtained after 12h by enzymatic hydrolysis of xylan rich wheat husk without any prior pretreatment using the crude enzyme without any purification. HP-TLC data confirmed the presence of an array of XOS for its prebiotic properties by carrying out studies on ten standard probiotic cultures...
September 1, 2017: Bioresource Technology
Vajihe Mehnati-Najafabadi, Asghar Taheri-Kafrani, Abdol-Khalegh Bordbar
In order to utilize the advantages of immobilization such as improvement of stability, increasing the catalytic activity, ability to recovery and reuse of enzyme from reaction medium, xylanase enzyme was immobilized on superparamagnetic garphene oxide nanosheets (GOMNP). Xylanase, as a hydrolytic enzyme of xylan has widely used in industry. Since the xylan is bulk, for enhance accessibility of active sites of the immobilized xylanase, polyethylene glycol bis amine (PEGA) was used as a spacer for functionalization of GOMNP...
September 6, 2017: International Journal of Biological Macromolecules
Raj Kumar Salar, Sukhvinder Singh Purewal, Kawaljit Singh Sandhu
In the present study, pearl millet cultivar PUSA-415 was fermented by solid state fermentation (SSF) process using Aspergillus sojae (MTCC-8779) as starter culture. The fermentation was carried out for the period of ten days. The effect of SSF on phenolic content, condensed tannin content, antioxidant potential and DNA damage protection of pearl millet during different fermentation period was determined. Results showed that SSF and thermal processing significantly affect the bioactive profile and antioxidant potential of bio-transformed pearl millet...
October 2017: Food Research International
Muhammad N Aftab, Asma Zafar, Irfana Iqbal, Afshan Kaleem, Khalid M Zia, Ali R Awan
Saccharification potential of xylanase enzyme cloned from Bacillus licheniformis into E. coli BL21 (DE3) was evaluated against plant biomass for the production of bioethanol. The expression of cloned gene was studied and conditions were optimized for its large scale production. The parameters effecting enzyme production were examined in a fermenter. Recombinant xylanase has the ability to breakdown birchwood xylan to release xylose as well as the potential to treat plant biomass, such as wheat straw, rice straw, and sugarcane bagass...
September 8, 2017: Bioengineered
Jonathan P Anderson, Jana Sperschneider, Joe Win, Brendan Kidd, Kentaro Yoshida, James Hane, Diane G O Saunders, Karam B Singh
Rhizoctonia solani is a fungal pathogen causing substantial damage to many of the worlds' largest food crops including wheat, rice, maize and soybean. Despite impacting global food security, little is known about the pathogenicity mechanisms employed by R. solani. To enable prediction of effectors possessing either broad efficacy or host specificity, a combined secretome was constructed from a monocot specific isolate, a dicot specific isolate and broad host range isolate infecting both monocot and dicot hosts...
September 5, 2017: Scientific Reports
Ming Yang, Jingfeng Wang, Xincun Hou, Juying Wu, Xifeng Fan, Fan Jiang, Pan Tao, Fan Wang, Pai Peng, Fangxia Yang, Junhua Zhang
The surface characterization and electrostatic property of Hybrid Pennisetum (HP) after alkaline sulfite pretreatment were explored for enhanced enzymatic hydrolysability. The O/C ratio in HP increased from 0.34 to 0.60, and C1 concentration decreased from 62.5% to 31.6%, indicating that alkaline sulfite pretreatment caused poorer lignin but richer carbohydrate on HP surface. Zeta potential and sulfur element analysis indicated that more enzymes would preferably adsorb on the carbohydrate surface of alkaline sulfite pretreated HP because the lignin was sulfonated, which facilitated the decrease of non-productive adsorption...
November 2017: Bioresource Technology
Pankaj Parab, Rakhee Khandeparker, Ujwala Amberkar, Vishwas Khodse
Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata, Padina tetrastromatica and Ulva lactuca, were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied...
October 2017: 3 Biotech
Aphisit Poonsrisawat, Atchara Paemanee, Sittichoke Wanlapatit, Kuakoon Piyachomkwan, Lily Eurwilaichitr, Verawat Champreda
In this study, an efficient ethanol production process using simultaneous saccharification and viscosity reduction of raw cassava pulp with no prior high temperature pre-gelatinization/liquefaction step was developed using a crude starch- and cell wall-degrading enzyme preparation from Aspergillus aculeatus BCC17849. Proteomic analysis revealed that the enzyme comprised a complex mixture of endo- and exo-acting amylases, cellulases, xylanases, and pectina ses belonging to various glycosyl hydrolase families...
October 2017: 3 Biotech
Rakhee Khandeparker, Pankaj Parab, Ujwala Amberkar
Bacterial strain Bacillus tequilensis BT21 isolated from marine sediments was found to produce extracellular xylanase. The xynBT21 gene encoding xylanase enzyme was cloned and expressed in Escherichia coli. The gene encoded a protein consisting of 213 amino acid residues with calculated molecular mass of 23.3 kDa. Purified recombinant xylanase had optimum activity at 60 °C and pH=6. The enzyme was highly stable in alkaline pH, at pH=7 it remained 100% active for 24 h, while its activity increased at pH=8 and 9 during incubation...
June 2017: Food Technology and Biotechnology
M M C Maroldi, V M Vasconcellos, P T Lacava, C S Farinas
The endophytic fungi represent a potential source of microorganisms for enzyme production. However, there have been only few studies exploiting their potential for the production of enzymes of industrial interest, such as the (hemi)cellulolytic enzymatic cocktail required in the hydrolysis of lignocellulosic biomass. Here, a collection of endophytic fungi isolated from mangrove tropical forests was evaluated for the production of carbohydrolases and performance on the hydrolysis of cellulose. For that, 41 endophytic strains were initially screened using a plate assay containing crystalline cellulose as the sole carbon source and the selected strains were cultivated under solid-state fermentation for endoglucanase, β-glucosidase, and xylanase enzyme quantification...
September 2, 2017: Applied Biochemistry and Biotechnology
Eun Gyeong Song, Ki Hyun Ryu
Plant-virus-based expression vectors have been used as an alternative to the creation of transgenic plants. Using a virus-based vector, we investigated the feasibility of producing the endoglucanase D (EngD) from Clostridium cellulovorans in Nicotiana benthamiana. This protein has endoglucanase, xylanase, and exoglucanase activities and may be of value for cellulose digestion in the generation of biofuels from plant biomass. The EngD gene was cloned between the nuclear inclusion b (NIb)- and coat protein (CP)-encoding sequences of pSP6PepMoV-Vb1...
September 1, 2017: Archives of Virology
Razia Tajwar, Saher Shahid, Rehan Zafar, Muhammad Waheed Akhtar
Xylanase XynB of the hyperthermophile Thermotoga maritima, which belongs to glycoside hydrolase family 10 (GH10), does not have an associated carbohydrate binding module (CBM) in the native state. CBM6 and CBM22 from a thermophile Clostridium thermocellum were fused to the catalytic domain of XynB (XynB-C) to determine the effects on activity and other properties. XynB-B22C and XynB-CB22, produced by fusing CBM22 to the N- and C-terminal of XynB-C, showed 1.7- and 3.24-fold increase in activity against the insoluble birchwood xylan, respectively...
November 2017: Enzyme and Microbial Technology
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