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Thi Huyen Do, Ngoc Giang Le, Trong Khoa Dao, Thi Mai Phuong Nguyen, Tung Lam Le, Han Ly Luu, Khanh Hoang Viet Nguyen, Van Lam Nguyen, Lan Anh Le, Thu Nguyet Phung, Nico M van Straalen, Dick Roelofs, Nam Hai Truong
The scarcity of enzymes having an optimal activity in lignocellulose deconstruction is an obstacle for industrial-scale conversion of cellulosic biomass into biofuels. With the aim of mining novel lignocellulolytic enzymes, a ~9 Gb metagenome of bacteria in Vietnamese native goats' rumen was sequenced by Illumina platform. From the data, 821 ORFs encoding carbohydrate esterases (CEs) and polysaccharide lyases (PLs) serving for lignocellulose pre-treatment, 816 ORFs encoding 11 glycoside hydrolase families (GHs) of cellulases, and 2252 ORFs encoding 22 GHs of hemicellulases, were mined...
March 12, 2018: Journal of General and Applied Microbiology
Xing Qin, Xiaoyun Su, Huiying Luo, Rui Ma, Bin Yao, Fuying Ma
Background: Irpex lacteus is one of the most potent white rot fungi for biological pretreatment of lignocellulose for second biofuel production. To elucidate the underlying molecular mechanism involved in lignocellulose deconstruction, genomic and transcriptomic analyses were carried out for I. lacteus CD2 grown in submerged fermentation using ball-milled corn stover as the carbon source. Results: Irpex lacteus CD2 efficiently decomposed 74.9% lignin, 86.3% cellulose, and 83...
2018: Biotechnology for Biofuels
Chao Fan, Xinxin Xu, Liya Song, Weishi Guan, Jinyang Li, Bo Liu, Pengjun Shi, Wei Zhang
A transfer DNA (T-DNA)-tagged mutant library of Humicola insolens was screened for mutants with altered cellulase production using the plate-clearing zone assay. Three selected mutants (5-A7, 5-C6, and 13-B7) exhibited significantly depressed FPase, CMCase and xylanase activities compared with the wild-type strain upon shake-flask fermentation, while the pNPCase and pNPGase activities of the three mutants were relatively higher than those of the parental strain. Combined with the results of SDS-PAGE and mass spectrometry, we suggest that expression of the CMCases Cel6B, Cel7B, CMC3, and XynA/B/C was reduced in the mutant strains...
March 2018: 3 Biotech
Yi Yang, Jinshui Yang, Jiawen Liu, Ruonan Wang, Liang Liu, Fengqin Wang, Hongli Yuan
Herein, we report the secretome of Penicillium chrysogenum P33 under induction of lignocellulose for the first time. A total of 356 proteins were identified, including complete cellulases and numerous hemicellulases. Supplementing a commercial cellulase with increasing dosage of P33 enzyme cocktail from 1 to 5 mg/g substrate increased the release of reducing sugars from delignified corn stover by 21.4% to 106.8%. When 50% cellulase was replaced by P33 enzyme cocktail, release of reducing sugars was 78.6% higher than with cellulase alone...
February 6, 2018: Bioresource Technology
Xia Zou, Zhenxing Ren, Na Wang, Yin Cheng, Yuanyuan Jiang, Yan Wang, Chenggang Xu
Background: Anaerobic, mesophilic, and cellulolytic Clostridium papyrosolvens produces an efficient cellulolytic extracellular complex named cellulosome that hydrolyzes plant cell wall polysaccharides into simple sugars. Its genome harbors two long cellulosomal clusters: cip - cel operon encoding major cellulosome components (including scaffolding) and xyl - doc gene cluster encoding hemicellulases. Compared with works on cip - cel operon, there are much fewer studies on xyl - doc mainly due to its rare location in cellulolytic clostridia...
2018: Biotechnology for Biofuels
Grzegorz Janusz, Andrzej Mazur, Jerzy Wielbo, Piotr Koper, Kamil Żebracki, Anna Pawlik, Beata Ciołek, Andrzej Paszczyński, Agnieszka Kubik-Komar
To explore the number of enzymes engaged by Cerrena unicolor FCL139 for wood degradation, the transcriptomes of the fungus growing on birch, ash, maple sawdust and the control liquid medium were analyzed. Among 12,966 gene models predicted for the C. unicolor genome, 10,396 all-unigenes were detected, of which 9567 were found to be expressed in each of the tested growth media. The highest number (107) of unique transcripts was detected during fungus growth in the control liquid medium, while the lowest number (11) - in the fungal culture comprising maple saw dust...
March 2018: Microbiological Research
Jinguang Hu, Dong Tian, Scott Renneckar, Jack N Saddler
Physiochemical methods have generally been used to "open-up" biomass substrates/pulps and have been the main method used to fibrillate cellulose. However, recent work has shown that canonical cellulase enzymes such as endoglucanases, in combination with "amorphogenesis inducing" proteins such as lytic polysaccharide monooxygenases (LPMO), swollenin and hemicellulases, are able to increase cellulose accessibility. In the work reported here different combinations of endoglucanase, LPMO and xylanase were applied to Kraft pulps to assess their potential to induce fibrillation at low enzyme loading over a short time period...
February 16, 2018: Scientific Reports
Wenping Zhang, Wenbin Liu, Rong Hou, Liang Zhang, Stephan Schmitz-Esser, Huaibo Sun, Junjin Xie, Yunfei Zhang, Chengdong Wang, Lifeng Li, Bisong Yue, He Huang, Hairui Wang, Fujun Shen, Zhihe Zhang
The giant panda feeds almost exclusively on bamboo, a diet highly enriched in lignin and cellulose, but is characterized by a digestive tract similar to carnivores. It is still large unknown if and how the giant panda gut microbiota contributes to lignin and cellulose degradation. Here we show the giant pandas' gut microbiota does not significantly contribute to cellulose and lignin degradation. We found that no operational taxonomic unit had a nearest neighbor identified as a cellulolytic species or strain with a significant higher abundance in juvenile than cubs, a very low abundance of putative lignin and cellulose genes existed in part of analyzing samples but a significant higher abundance of genes involved in starch and hemicellulose degradation in juveniles than cubs...
February 1, 2018: ISME Journal
Chin-Chung Chen, Guo-Jhan Gao, Ai-Ling Kao, Zheng-Chia Tsai
In this study, the gene fusion of endoglucanase (EG, one of cellulases) from Teleogryllus emma and xylanase (Xyn, one of hemicellulases) from Thermomyces lanuginosus was constructed to generate a fusion enzyme (EG-M-Xyn). Through the expression and purification by ultrafiltration and size-exclusion chromatography, the purified EG-M-Xyn had a molecular weight of 75.5 kDa and exhibited the specific activity of CMCase and xylanase as 306.8 U/mg and 1227.3 U/mg, respectively. The Km values (CMC and beechwood xylan) were 6...
January 18, 2018: International Journal of Biological Macromolecules
Hanjun He, Mei Bai, Panpan Tong, Yanting Hu, Ming Yang, Hong Wu
Cellulases, hemicellulases and pectinases play important roles in fruit development and maturation, but mutants with defects in the fruit have not been reported for cellulase or hemicellulase genes. Here we report the functional characterization of cellulase gene CEL6 and hemicellulase gene MAN7 in silique development and dehiscence in Arabidopsis. These genes were found to be expressed in vegetative and reproductive organs, and their expression in the silique partially depended on the IND and ALC transcriptional factors...
January 18, 2018: Plant Physiology
Veeresh Juturu, Jin Chuan Wu
Pichia pastoris is a well-known platform strain for heterologous protein expression. Over the past five years, different strategies to improve the efficiency of recombinant protein expression by this yeast strain have been developed; these include a patent-free protein expression kit, construction of the P. pastoris CBS7435Ku70 platform strain with its high efficiency in site-specific recombination of plasmid DNA into the genomic DNA, the design of synthetic promoters and their variants by combining different core promoters with multiple putative transcription factors, the generation of mutant GAP promoter variants with various promoter strengths, codon optimization, engineering the α-factor signal sequence by replacing the native glutamic acid at the Kex2 cleavage site with the other 19 natural amino acids and the addition of mammalian signal sequence to the yeast signal sequence, and the co-expression of single chaperones, multiple chaperones or helper proteins that aid in recombinant protein folding...
January 4, 2018: Chembiochem: a European Journal of Chemical Biology
Rafaela I S Ladeira Ázar, Túlio Morgan, Antonio Carlos Freitas Dos Santos, Eduardo de Aquino Ximenes, Michael R Ladisch, Valéria M Guimarães
Cellulase and hemicellulase activities in a 1:1 ratio of enzymes extracted from Chrysoporthe cubensis and Penicillium pinophilum were evaluated in the presence of known monocomponent phenolic inhibitors and also with phenol mixtures derived from alkali pretreated sugarcane bagasse. The cellulolytic activities from C. cubensis:P. pinophilum displayed a much higher tolerance to phenolic inhibitors than equivalent enzyme activities obtained from Trichoderma reesei and Aspergillus niger. Enzymes from T. reesei and A...
February 2018: Enzyme and Microbial Technology
Chuannan Long, Yijin Cheng, Jingjing Cui, Jian Liu, Lihui Gan, Bin Zeng, Minnan Long
The role of the transcription factor creA-mediating carbon catabolite repression in Trichoderma orientalis EU7-22 was investigated for cellulase and hemicellulase production. The binary vector pUR5750G/creA::hph was constructed to knock out creA by homologous integration, generating the ΔcreA mutant Trichoderma orientalis CF1D. For strain CF1D, the filter paper activities (FPA), endoglucanase activities (CMC), cellobiohydrolase activity(CBH), β-glucosidase activity (BG), xylanase activity (XYN), and extracellular protein concentration were 1...
January 2018: Molecular Biotechnology
Tomoko Maehara, Haruka Yagi, Tomoko Sato, Mayumi Ohnishi-Kameyama, Zui Fujimoto, Kei Kamino, Yoshiaki Kitamura, Franz St John, Katsuro Yaoi, Satoshi Kaneko
Endoxylanases are important enzymes in bioenergy research because they specifically hydrolyze xylan, the predominant polysaccharide in the hemicellulose fraction of lignocellulosic biomass. For effective biomass utilization, it is important to understand the mechanism of substrate recognition by these enzymes. Recent studies have shown that the substrate specificities of bacterial and fungal endoxylanases classified into glycoside hydrolase family 30 (GH30) were quite different. While the functional differences have been described, the mechanism of substrate recognition is still unknown...
February 15, 2018: Applied and Environmental Microbiology
Yanfen Cheng, Ying Wang, Yuanfei Li, Yipeng Zhang, Tianyi Liu, Yu Wang, Thomas J Sharpton, Weiyun Zhu
The aim of this study was to improve the utilization of rice straw as forage in ruminants by investigating the degradation pattern of rice straw in the dairy cow rumen. Ground up rice straw was incubated in situ in the rumens of three Holstein cows over a period of 72 h. The rumen fluid at 0 h and the rice straw at 0.5, 1, 2, 4, 6, 12, 24, 48, and 72 h were collected for analysis of the bacterial community and the degradation of the rice straw. The bacterial community and the carbohydrate-active enzymes in the rumen fluid were analyzed by metagenomics...
2017: Frontiers in Microbiology
Silvia Hüttner, Thanh Thuy Nguyen, Zoraide Granchi, Thomas Chin-A-Woeng, Dag Ahrén, Johan Larsbrink, Vu Nguyen Thanh, Lisbeth Olsson
Background: Genome and transcriptome sequencing has greatly facilitated the understanding of biomass-degrading mechanisms in a number of fungal species. The information obtained enables the investigation and discovery of genes encoding proteins involved in plant cell wall degradation, which are crucial for saccharification of lignocellulosic biomass in second-generation biorefinery applications. The thermophilic fungus Malbranchea cinnamomea is an efficient producer of many industrially relevant enzymes and a detailed analysis of its genomic content will considerably enhance our understanding of its lignocellulolytic system and promote the discovery of novel proteins...
2017: Biotechnology for Biofuels
Bareket Dassa, Ilya Borovok, Vincent Lombard, Bernard Henrissat, Raphael Lamed, Edward A Bayer, Sarah Moraïs
The bacterial cellulosome is an extracellular, multi-enzyme machinery, which efficiently depolymerizes plant biomass by degrading plant cell wall polysaccharides. Several cellulolytic bacteria have evolved various elaborate modular architectures of active cellulosomes. We present here a genome-wide analysis of a dozen mesophilic clostridia species, including both well-studied and yet-undescribed cellulosome-producing bacteria. We first report here, the presence of cellulosomal elements, thus expanding our knowledge regarding the prevalence of the cellulosomal paradigm in nature...
November 18, 2017: Microorganisms
Lara Hassan, Manfred J Reppke, Nils Thieme, Steffen A Schweizer, Carsten W Mueller, J Philipp Benz
Background: The industrial applications of cellulases are mostly limited by the costs associated with their production. Optimized production pathways are therefore desirable. Based on their enzyme inducing capacity, celluloses are commonly used in fermentation media. However, the influence of their physiochemical characteristics on the production process is not well understood. In this study, we examined how physical, structural and chemical properties of celluloses influence cellulase and hemicellulase production in an industrially-optimized and a non-engineered filamentous fungus: Trichoderma reesei RUT-C30 and Neurospora crassa...
2017: Fungal Biology and Biotechnology
Daniel P Kiesenhofer, Robert L Mach, Astrid R Mach-Aigner
Trichoderma reesei can produce up to 100 g/l of extracellular proteins. The major and industrially relevant products are the cellobiohydrolase CBHI and the hemicellulase XYNI. Both encoding genes are transcriptionally activated by the regulatory protein Xyr1. The first 850 nucleotides of the cbh1 promoter contain fourteen Xyr1-binding sites (XBS), in the xyn1 promoter are eight XBS present. Some of these XBS are arranged in tandem, others as inverted repeats. One such cis element, an inverted repeat, plays a crucial role for the inducibility of the xyn1 promoter...
October 27, 2017: Applied and Environmental Microbiology
Yujia Jiang, Tianpeng Chen, Weiliang Dong, Min Zhang, Wenming Zhang, Hao Wu, Jiangfeng Ma, Min Jiang, Fengxue Xin
A wild type solventogenic Clostridium beijerinckii NJP7 capable of converting polysaccharides, such as hemicellulose, into butanol and isopropanol via a unique acetone-isopropanol-butanol (AIB) pathway was isolated and characterized. This represents the first wild type isopropanol-butanol generating bacterium which could achieve butanol production directly from lignocellulose through consolidated bioprocessing (CBP). Strain NJP7 was isolated from decomposite soil from Laoshan Nature Park, China, and its genome shows 98...
October 24, 2017: Current Microbiology
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