文献类型：期刊文献

英文题名：Enhanced Low Molecular Weight Poly-γ-Glutamic Acid Production in Recombinant Bacillus subtilis 1A751 with Zinc Ion

作者：Jiang, Sijing[1];Fan, Liqiang[1];Zhao, Mengyao[1];Qiu, Yongjun[1,2];Zhao, Liming[1,2]

机构：[1]East China Univ Sci & Technol, R&D Ctr Separat & Extract Technol Fermentat Ind, State Key Lab Bioreactor Engn, Sch Biotechnol, Shanghai 200237, Peoples R China;[2]SCICBT, Shanghai 200237, Peoples R China

年份：2019

卷号：189

期号：2

起止页码：411

外文期刊名：APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY

收录：;EI(收录号：20191906896480);WOS:【SCI-EXPANDED(收录号:WOS:000487133300006)】；

基金：This work is financially supported by the National Key Research and Development Program of China (2017YFB0309302), the National High Technology Research and Development Program of China (863 Program) (No. SS2014AA021202), and "Shu Guang" project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation (15SG28).

语种：英文

外文关键词：Recombinant Bacillus subtilis; Low molecular weight; Poly-gamma-glutamic acid (gamma-PGA); Poly-gamma-glutamic acid synthase; pgsBCAE center dot Zn2+

摘要：Poly-gamma-glutamic acid (gamma-PGA) is a novel biodegradable polyamide material. Microbial fermentation is the only way to produce gamma-PGA, but the molecular weight of gamma-PGA varied depending on different strains and culture conditions used. The molecular weight of gamma-PGA is a main factor affecting the utilization of gamma-PGA. It is urgent to find an efficient way to prepare gamma-PGA with specific molecular weight, especially low molecular weight. Bacillus subtilis ECUST is a glutamate-dependent strain that produces gamma-PGA. In this study, a recombinant B. subtilis harboring the gamma-PGA synthase gene cluster pgsBCAE of our preciously identified gamma-PGA-producing B. subtilis ECUST was constructed. Assay of gamma-PGA contents and properties showed that recombinant B. subtilis 1A751-pBNS2-pgsBCAE obtained the ability to synthesize gamma-PGA with low molecular weight (about 10 kDa). The excessive addition of glutamate inhibited the gamma-PGA synthesis, while the addition of Zn2+ could promote the synthesis of gamma-PGA by increasing the transcription of pgsB but had no effect on the molecular weight of synthesized gamma-PGA. Under optimized conditions, gamma-PGA produced by recombinant B. subtilis 1A751-pBNS2-pgsBCAE increased from initial 0.54 g/L to 3.9 g/L, and the glutamate conversion rate reached 78%. Recombinant B. subtilis 1A751-pBNS2-pgsBCAE has the potential for efficient preparation of low molecular weight gamma-PGA.