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Your search keyword '"Cheng, Lifeng"' showing total 4 results
Start Over Author "Cheng, Lifeng" Topic xylanase
4 results on '"Cheng, Lifeng"'

2. Construction and co-expression of polycistronic plasmids encoding bio-degumming-related enzymes to improve the degumming process of ramie fibres

Author

Xiangyuan Feng, Duan Shengwen, Xia Zheng, Ruijun Wang, Cheng Lifeng, Zhun Yan, Zheng Ke, Jie Zeng, Zhengchu Liu, and Yi Cheng

Subjects
0106 biological sciences, Bioengineering, 02 engineering and technology, medicine.disease_cause, 01 natural sciences, Applied Microbiology and Biotechnology, Ramie, Plasmid, 010608 biotechnology, Mannosidases, medicine, Escherichia coli, Gene, Polysaccharide-Lyases, chemistry.chemical_classification, business.industry, General Medicine, 021001 nanoscience & nanotechnology, Reducing sugar, Biotechnology, Enzyme, Biodegradation, Environmental, Xylosidases, chemistry, Biochemistry, Pectate lyase, Xylanase, 0210 nano-technology, business, Plasmids
Abstract

To research the inherent properties of the co-expression of three types degumming-related enzymes and breed more powerful degumming strains. Six tandem multimers of the pectate lyase gene, the xylanase gene, and the endo-1,4-β-mannanase gene, which are essential for degumming process, were co-expressed and evaluated in Escherichia coli BL21(DE3). The xyl91 gene had a synergistic effect with endo-1,4-β-mannanase and pectate lyase from DCE-01, when xyl gene was replaced with xyl91 in the multimer. The recombinant pET-pxm(91x) was selected and transformed into the original degumming strain DCE-01, which led to an enzymatic activity improvement. Furthermore, the weight loss, reducing sugar and COD value of the sample treated with the new engineered strain pET-pxm(91x)/DCE-01 increased to 22.5 %, 460 mg ml−1 and 4.9, respectively. The co-expression of degumming-related enzyme genes may be applied in industrial tests and represents a novel direction for bio-degumming research.

Published
2016

3. A novel endo-β-1,4-xylanase GH30 from Dickeya dadantii DCE-01: Clone, expression, characterization, and ramie biological degumming function.

Author

Wang, Ruijun, Liu, Zhengchu, Cheng, Lifeng, Duan, Shengwen, Feng, Xiangyuan, Zheng, Ke, Cheng, Yi, and Zeng, Jie

Subjects
XYLANASES, ERWINIA chrysanthemi, RAMIE, PLANT fibers, GLYCOSIDASES, HYDROLYSIS
Abstract

Xylanase plays an important role in the hydrolysis of hemicellulose and has gained much attention in the field of biological degumming. The research for xylanases with cellulase-free and high activity for biological degumming has intensified in recent years. In the present research, heterologous expression of a novel endo-β-1,4-xylanase (GH30) from Dickeya dadantii DCE-01 in Escherichia coli BL21 (DE3) was reported. Biochemical characterization of the enzyme and a potential application in ramie biological degumming was discussed. The results showed that the xylanase gene consists of 1251 nucleotides, belonging to glycoside hydrolase family 30 (GH30). The optimal activity of the xylanase was observed at 50℃ and a pH value of 6.4. The Km and Vmax values for beechwood xylan were 14.25 mg/mL and 296.6 μmol/mg, respectively. The catalytic activity was enhanced by addition of 1 mM Cu2+, Ca2+, Mg2+, and K+. The recombinant enzyme was specific for xylan substrates. The enzyme exhibited hydrolytic activity toward ramie hemicellulose. The recombinant xylanase could be effectively applied to ramie degumming. [ABSTRACT FROM AUTHOR]

Published
2019
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4. Purification and characterization of a xylanase from Bacillus subtilis isolated from the degumming line.

Author

Guo, Gang, Liu, Zhengchu, Xu, Junfei, Liu, Jianping, Dai, Xiaoyang, Xie, Daping, Peng, Keqing, Feng, Xiangyuan, Duan, Shengwen, Zheng, Ke, Cheng, Lifeng, and Fu, Yueguan

Subjects
XYLANASES, BACILLUS subtilis, MICROORGANISMS, MOLECULAR weights, CELLULOSE fibers
Abstract

Xylanases catalyze the hydrolysis of xylan, a major hemicellulose component of cell wall besides cellulose in most plant species. To extract cellulose fibers, it will be invaluable to screen for more effective xylanase-producing microorganisms. In this paper a new strategy for easy screening of xylanase-producing strains from the degumming line was presented. Using this strategy, a weak-acidic, cellulase-free xylanase from Bacillus subtilis has been isolated, purified and characterized. The xylanase showed high specific activity (36,633.4 U/mg), presented stable characteristics and can be separated and purified simply, with molecular weight 23.3 kD, pI 9.63. It reached its optimal activity at pH 5.8 and 60 °C, and retained over 80% of its maximal activity after pre-incubation at temperature 60 °C or pH 4.6 ∼ 6.4. Also, a two-step purification procedure based on the combination of ultrafiltration and gel filtration chromatography was introduced and described, achieving 17-fold purification with 68.11% yield. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Published
2012
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