文献类型：期刊文献

英文题名：Engineering Pediococcus acidilactici with xylose assimilation pathway for high titer cellulosic L-lactic acid fermentation

作者：Qiu, Zhongyang[1];Gao, Qiuqiang[1];Bao, Jie[1]

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

年份：2018

卷号：249

起止页码：9

外文期刊名：BIORESOURCE TECHNOLOGY

收录：;EI(收录号：20174204275061);WOS:【SCI-EXPANDED(收录号:WOS:000425764100002)】；

语种：英文

外文关键词：Pediococcus acidilactici; L-Lactic acid; Xylose-assimilating pathway; Adaptive evolution; Lignocellulose

摘要：Xylose-assimilating pathways were constructed in the parental Pediococcus acidilactici strain and evolutionarily adapted to yield a highly stable co-fermentation strain for L-lactic acid production. The phosphoketolase pathway (PK) was blocked for reduction of acetic acid generation by disrupting phosphoketolase (pkt) gene. The pentose phosphate pathway (PPP) was reconstructed for xylose assimilation by integrating four heterologous genes encoding transketolase (tkt), transaldolase (tal), xylose isomerase (xylA) and xylulokinase (xylB) into the P. acidilactici chromosome. The xylose-assimilating ability of the constructed strain was significantly improved by long term adaptive evolution. The engineered strain was applied to the simultaneous saccharification and co-fermentation (SSCF) under high solids loading of wheat straw. The L-lactic acid titer, productivity and xylose conversion reached the record high at 130.8 +/- 1.6 g/L, 1.82 +/- 0.0 g/L/h, and 94.9 +/- 0.0%, respectively. This study provided an important strain and process prototype for production of high titer cellulosic L-lactic acid.