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

Cheng, Yi, Liu, Zhengchu, Zeng, Jie, Cheng, Lifeng, Yan, Zhun, Duan, Shengwen, Feng, Xiangyuan, Zheng, Ke, Zheng, Xia, Wang, Ruijun
Biotechnology letters 2016 v.38 no.12 pp. 2089-2096
Escherichia coli, chemical oxygen demand, degumming, enzyme activity, genes, pectate lyase, plasmids, ramie, reducing sugars, synergism, weight loss, xylanases
OBJECTIVES: To research the inherent properties of the co-expression of three types degumming-related enzymes and breed more powerful degumming strains. RESULTS: 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. CONCLUSIONS: The co-expression of degumming-related enzyme genes may be applied in industrial tests and represents a novel direction for bio-degumming research.