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Yuanyuan Zhang, Caiyun Wang, Lulu Wang, Ruoxin Yang, Peilei Hou, Junhong Liu
To achieve a cost-effective bioconversion of lignocellulosic materials, a novel xylose/glucose co-fermentation process by co-culture of cellulose-utilizing recombinant Saccharomyces cerevisiae (S. cerevisiae) and xylan-utilizing recombinant Pichia pastoris (P. pastoris) was developed, in which ethanol was produced directly from wheat straw without additional hydrolytic enzymes. Recombinant S. cerevisiae coexpressing three types of cellulase and recombinant P. pastoris coexpressing two types of xylanase were constructed, respectively...
January 18, 2017: Journal of Industrial Microbiology & Biotechnology
Vandan Shah, Brennal Pierre, Tamari Kirtadze, Seung Shin, Jin Ryoun Kim
High thermostability of an enzyme is critical for its industrial application. While many engineering approaches such as mutagenesis have enhanced enzyme thermostability, they often suffer from reduced enzymatic activity. A thermally stabilized enzyme with unchanged amino acids is preferable for subsequent functional evolution necessary to address other important industrial needs. In the research presented here, we applied insertional fusion to a thermophilic maltodextrin-binding protein from Pyrococcus furiosus (PfMBP) in order to improve the thermal stability of Bacillus circulans xylanase (BCX)...
January 17, 2017: Protein Engineering, Design & Selection: PEDS
Deborah Senf, Colin Ruprecht, Goswinus de Kruijff, Sebastian Simonetti, Frank Schuhmacher, Peter Seeberger, Fabian Pfrengle
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as biofuel production. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides...
January 16, 2017: Chemistry: a European Journal
Christian Derntl, Bernhard Kluger, Christoph Bueschl, Rainer Schuhmacher, Robert L Mach, Astrid R Mach-Aigner
Fungi can produce a wide range of chemical compounds via secondary metabolism. These compounds are of major interest because of their (potential) application in medicine and biotechnology and as a potential source for new therapeutic agents and drug leads. However, under laboratory conditions, most secondary metabolism genes remain silent. This circumstance is an obstacle for the production of known metabolites and the discovery of new secondary metabolites. In this study, we describe the dual role of the transcription factor Xylanase promoter binding protein 1 (Xpp1) in the regulation of both primary and secondary metabolism of Trichoderma reesei Xpp1 was previously described as a repressor of xylanases...
January 10, 2017: Proceedings of the National Academy of Sciences of the United States of America
Rui Ma, Yingguo Bai, Huoqing Huang, Huiying Luo, Sanfeng Chen, Yunliu Fan, Lei Cai, Bin Yao
Xylooligosaccharides as emerging prebiotics are able to promote the growth of probiotic bacteria. In the present study, four neutral, thermostable xylanases (MtXyn11A, MtXyn11At, MtXyn11B and MtXyn11C) from compost fungus Mycothermus thermophilus CGMCC3.18119 were overexpressed in Pichia pastoris GS115 and used to produce xylooligosaccharides from beechwood xylan. The enzymes showed similar enzymatic properties (maximal activities at pH 6.06.5 and 65 C) but varied in catalytic efficiency and cleaving actions...
January 9, 2017: Journal of Agricultural and Food Chemistry
Franciane Cristina de Figueiredo, Ana Flavia Azevedo Carvalho, Michel Brienzo, Tania Sila Campioni, Pedro de Oliva-Neto
Lignocellulosic material breakdown by hydrolysis is an important step to open new perspectives for bioenergy and special foods production like prebiotic xylooligosaccharides. Improvement of lignocellulose and arabinoxylan alkaline extraction from sugarcane bagasse and enzymatic hydrolysis were performed. Treatments 1 (10% KOH at 70°C), 3 (5% KOH at 121°C) and ZD method (24% KOH at 35°C) showed solid lignocellulose recovery of respectively 75.2%, 74.2% and 73%. A range of 24.8-27% extracted material with high arabinoxylan content (72...
December 26, 2016: Bioresource Technology
Aicha Asma Houfani, Tomáš Větrovský, Petr Baldrian, Said Benallaoua
Identification of bacteria that produce carbohydrolytic enzymes is extremely important given the increased demand for these enzymes in many industries. Twenty lignocellulose-degrading bacterial isolates from Algerian compost and different soils were screened for their potential to produce different enzymes involved in biomass deconstruction. Based on 16S rRNA gene sequencing, the isolates belonged to Proteobacteria and Actinobacteria. Differences among species were reflected both as the presence/absence of enzymes or at the level of enzyme activity...
February 2017: World Journal of Microbiology & Biotechnology
Alexander V Lisov, Oksana V Belova, Zoya A Lisova, Nataliy G Vinokurova, Alexey S Nagel, Zhanna I Andreeva-Kovalevskaya, Zhanna I Budarina, Maxim O Nagornykh, Marina V Zakharova, Andrey M Shadrin, Alexander S Solonin, Alexey A Leontievsky
Four xylanases of Cellulomonas flavigena were cloned, expressed in Escherichia coli and purified. Three enzymes (CFXyl1, CFXyl2, and CFXyl4) were from the GH10 family, while CFXyl3 was from the GH11 family. The enzymes possessed moderate temperature stability and a neutral pH optimum. The enzymes were more stable at alkaline pH values. CFXyl1 and CFXyl2 hydrolyzed xylan to form xylobiose, xylotriose, xylohexaose, xylopentaose, and xylose, which is typical for GH10. CFXyl3 (GH11) and CFXyl4 (GH10) formed the same xylooligosaccharides, but xylose was formed in small amounts...
December 2017: AMB Express
T A Woyengo, R Patterson, C L Levesque
The objectives were to determine the standardized ileal digestibility (SID) of AA and NE value of cold-pressed soybean cake (CP-SBC), and the effect of extrusion or adding multi-enzyme to CP-SBC diet for growing pigs. Eight ileal-cannulated pigs (initial BW = 79.7 ± 3.97 kg) were fed 4 diets in a replicated 4 × 4 Latin square design to give 8 replicates per diet. Diets included a cornstarch-based diet with CP-SBC, extruded CP-SBC, and SBC plus multi-enzyme (1,200 U of xylanase, 150 U of glucanase, 500 U of cellulase, 60 U of mannanase, 700 U of invertase, 5,000 U of protease, and 12,000 U of amylase/kilogram of diet; Superzyme-CS, 0...
December 2016: Journal of Animal Science
Lili Xiong, Ayyappa Kumar Sista Kameshwar, Xi Chen, Zhiyun Guo, Canquan Mao, Sanfeng Chen, Wensheng Qin
BACKGROUND: ACEII transcription factor plays a significant role in regulating the expression of cellulase and hemicellulase encoding genes. Apart from ACEII, transcription factors such as XYR1, CRE1, HAP2/3/5 complex and ACEI function in a coordinated pattern for regulating the gene expression of cellulases and hemicellulases. Studies have demonstrated that ACEII gene deletion results in decreased total cellulase and xylanase activities with reduced transcript levels of lignocellulolytic enzymes...
December 28, 2016: Microbial Cell Factories
Kamila de Sousa Gomes, Gabriela P Maitan-Alfenas, Lorena G A de Andrade, Daniel Luciano Falkoski, Valéria Monteze Guimarães, Acelino C Alfenas, Sebastião Tavares de Rezende
Xylanases from the pathogen fungus Chrysoporthe cubensis were produced under solid state fermentation (SSF) using wheat bran as carbon source. The enzymatic extracts were submitted to ion exchange (Q Sepharose) and gel filtration chromatography methods (Sephadex S-200) for purification. The xylanases were divided into three groups: P1 showed better performance at 60 °C and pH 4.0, P2 at 55 °C and pH 3.0, and P3 at 80 °C and pH 3.0. Oat spelt xylan was the best substrate hydrolyzed by P1 and P3, while beechwood xylan was better degraded by P2...
December 24, 2016: Applied Biochemistry and Biotechnology
Qin Li, Baoguo Sun, Ke Xiong, Chao Teng, Youqiang Xu, Liangjun Li, Xiuting Li
The purpose of this study was to gain insights into the hydrolysis characteristics of xylanase in producing xylo-oligosaccharides and to improve these by protein engineering. In this study, a hybrid enzyme (T-XynFM) was created from Talaromyces thermophilus F1208 xylanase (T-Xyn) by replacement of the N-terminal extension Phe1-Pro16 with Ala1-Gln8 and substitution of amino acid Phe193 (185) with Ser in the C-terminal. The enzyme showed optimum activity at 55°C and pH 6.5. Its residual activity was more than 55% after treatment at 50°C, pH 6...
December 21, 2016: International Journal of Biological Macromolecules
Silai Zhang, Akihiko Ban, Naoki Ebara, Osamu Mizutani, Mizuki Tanaka, Takahiro Shintani, Katsuya Gomi
In this study, we developed a self-excising Cre/loxP-mediated marker recycling system with mutated lox sequences to introduce a number of biosynthetic genes into Aspergillus oryzae. To construct the self-excising marker cassette, both the selectable marker, the Aspergillus nidulans adeA gene, and the Cre recombinase gene (cre), conditionally expressed by the xylanase-encoding gene promoter, were designed to be located between the mutant lox sequences, lox66 and lox71. However, construction of the plasmid failed, possibly owing to a slight expression of cre downstream of the fungal gene promoter in Escherichia coli...
December 20, 2016: Journal of Bioscience and Bioengineering
Taku Orita, Makiko Sakka, Tetsuya Kimura, Kazuo Sakka
Three cellulosomal subunits of Ruminiclostridium josui, the full-length scaffolding protein CipA (RjCipA), a cellulase Cel5B (RjCel5B) and a xylanase Xyn10C (RjXyn10C), were successfully produced by Escherichia coli recombinant clones. RjCel5B and RjXyn10C were characterized as an endoglucanase and an endoxylanase, respectively. RjCipA, RjCel5B and Xyn10C adsorbed to microcrystalline cellulose (Funacel) and rice straw powder. Interaction between RjCel5B and RjCipA, and RjXyn10C and RjCipA were confirmed by qualitative assays...
February 2017: Enzyme and Microbial Technology
Jae Yoon Kim, Guang Nong, John D Rice, Maria Gallo, James F Preston, Fredy Altpeter
Sugarcane (Saccharum sp. hybrids) is one of the most efficient and sustainable feedstocks for commercial production of fuel ethanol. Recent efforts focus on the integration of first and second generation bioethanol conversion technologies for sugarcane to increase biofuel yields. This integrated process will utilize both the cell wall bound sugars of the abundant lignocellulosic sugarcane residues in addition to the sucrose from stem internodes. Enzymatic hydrolysis of lignocellulosic biomass into its component sugars requires significant amounts of cell wall degrading enzymes...
December 22, 2016: Plant Molecular Biology
Bipasha Bhattacharjee, Neeta Pathaw, Nikhil K Chrungoo, Atanu Bhattacharjee
Chitinases are varied sized proteins which have the ability to degrade chitin and are present in a huge range of organisms like fungi, yeasts, arthropods, humans etc. and have been getting increased attention due to their biocontrol properties. In silico analysis sheds light on the extensive properties of this plant protein. In this paper, a particular antifungal protein Chitinase sourced from Sechium edule from East Khasi Hills, Meghalaya was characterized using an array of bioinformatics tools. The modelled protein showed conserved domains characteristic to glycosyl hydrolase, family 18 superfamily...
December 17, 2016: Gene
Hoon Kim, Hee-Do Hong, Kwang-Soon Shin
We recently isolated an immunostimulating polysaccharide (BLE-P-I), which possesses a large proportion of arabinoxylan, from young barley leaves. In the present study, to elucidate the structural details of BLE-P-I, it was fractionated into enzyme-resistant fraction (BLE-P-I-X1) and arabinoxylan-rich oligosaccharide fraction (BLE-P-I-X2) after endo-xylanase hydrolysis. Commercial wheat arabinoxylan was also fractionated into WAX-XI and WAX-X2 after the same treatment. BLE-P-I-X2 consisted of arabinose and xylose, including 11 types of neutral glycosidic linkages, whereas WAX-X2 had less, with 6 types of linkages...
February 10, 2017: Carbohydrate Polymers
Samarthya Bhagia, Rajeev Kumar, Charles E Wyman
To help understand factors controlling the recalcitrance of lignocellulosic biomass to deconstruction to sugars, poplar was pretreated with liquid hot water (LHW) and extremely dilute acid (EDA) at 140°C and 180°C in batch and flowthrough reactors. The resulting solids were then subjected to enzymatic hydrolysis by eight combinations of cellulase, xylanase, and bovine serum albumin (BSA). Co-addition of xylanase to cellulase resulted in up to 11 percentage points higher overall sugar yield than their sequential addition...
February 10, 2017: Carbohydrate Polymers
Justyna Bohacz
Environmentally friendly strategies of waste management are both part of legal solutions currently in place and a focus of interest worldwide. Large-scale composting plants are set up across various regions while home composting is becoming increasingly popular. A variety of microbial groups are successively at work during composting and enzymatic activities detected in the composting mass fluctuate accordingly. Changes in the activities of oxidoreductases and hydrolases, i.e. glucose oxidase, horseradish peroxidase, lignin peroxidase, laccase, xylanase, superoxide dismutase and keratinase, low-molecular weight compounds, i...
December 13, 2016: Science of the Total Environment
Yu-Wei Wu, Brendan Higgins, Chaowei Yu, Amitha P Reddy, Shannon Ceballos, Lawrence D Joh, Blake A Simmons, Steven W Singer, Jean S VanderGheynst
Ionic liquid (IL) pretreatment is a promising approach for the conversion of lignocellulose to biofuels. The toxicity of residual IL, however, negatively impacts the performance of industrial enzymes and microorganisms in hydrolysis and fermentation. In this study, a thermophilic microbial community was cultured on switchgrass amended with various levels of the ionic liquid 1-ethyl-3-methylimidazolium acetate. Changes in the microbial community composition and transcription of genes relevant to IL tolerance and lignocellulose hydrolysis were quantified...
November 2016: MSystems
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