Xiwei Tian, Xuehua Liu, Yifan Zhang, Yang Chen, Haifeng Hang, Ju Chu, Yingping Zhuang
Bioresource technology 2021 MarThe 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 high-performance strain (NCBIO01-M2-ldhL1-HT) that could efficiently produce L-lactic acid at a high temperature of 45℃. 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. Copyright © 2020 Elsevier Ltd. All rights reserved.
Xiwei Tian, Xuehua Liu, Yifan Zhang, Yang Chen, Haifeng Hang, Ju Chu, Yingping Zhuang. Metabolic engineering coupled with adaptive evolution strategies for the efficient production of high-quality L-lactic acid by Lactobacillus paracasei. Bioresource technology. 2021 Mar;323:124549
PMID: 33406469
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