文献类型：期刊文献

英文题名：Metabolic engineering coupled with adaptive evolution strategies for the efficient production of high-quality L-lactic acid by Lactobacillus paracasei

作者：Tian, Xiwei[1];Liu, Xuehua[1];Zhang, Yifan[1];Chen, Yang[1];Hang, Haifeng[1];Chu, Ju[1];Zhuang, Yingping[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, POB 329,130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2021

卷号：323

外文期刊名：BIORESOURCE TECHNOLOGY

收录：;EI(收录号：20210209751738);WOS:【SCI-EXPANDED(收录号:WOS:000614252400017)】；

基金：This work was financially supported by the National Key Research and Development Program of China (2017YFB0309302, 2018YFA0900300), the National Science Foundation for Young Scientists of China (31700038).

语种：英文

外文关键词：Lactobacillus paracasei; Lactic acid; CRISPR Cas9; Adaptive evolution; Open fermentation

摘要：The main indicators for industrial production of high-quality lactic acid at elevated temperatures are high titer, productivity, yield, and optical purity. However, no such strains have been reported to meet all these requirements simultaneously. In this study, a high optical purity L-lactic acid producing strain is developed through the CRISPR-Cas9 gene editing platform. Further, adaptive evolution was used to breed and select a highperformance strain (NCBIO01-M2-ldhL1-HT) that could efficiently produce L-lactic acid at a high temperature of 45celcius. This strain produced 221.0 g/L of L-lactic acid in open fermentation with high initial glucose concentration. Also, L-lactic acid productivity and yield was above 7.5 g/L/h and 0.96 g/g respectively, as well as the optical purity of L-lactic acid in the fermentation broth exceeded 99.1%. In short, this breeding strain possess high potential to be considered for the commercial production of polymer-grade L-lactic acid.