文献类型：期刊文献

英文题名：Engineering Pichia pastoris to improve S-adenosyl- l-methionine production using systems metabolic strategies

作者：Qin, Xiulin[1,2];Lu, Junjie[1];Zhang, Yin[1];Wu, Xiaole[1];Qiao, Xuefeng[1];Wang, Zhipeng[1];Chu, Ju[1];Qian, Jiangchao[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Guangxi Univ, Coll Life Sci & Technol, State Key Lab Conservat & Utilizat Subtrop Agrobi, Nanning 530004, Peoples R China

年份：2020

卷号：117

期号：5

起止页码：1436

外文期刊名：BIOTECHNOLOGY AND BIOENGINEERING

收录：;EI(收录号：20200708179103);WOS:【SCI-EXPANDED(收录号:WOS:000513292800001)】；

基金：National Natural Science Foundation of China, Grant/Award Number: 20976050; Fundamental Research Funds for the Central Universities, Grant/Award Number: 22221818014; National Basic Research Program of China, Grant/Award Number: 2013CB733600

语种：英文

外文关键词：metabolic engineering; Pichia pastoris; promoter library; S-adenosyl-L-methionine; transcriptome profiling

摘要：S-adenosyl-l-methionine (SAM) is a highly valued chemical that can be used as a dietary supplement and has been used to treat depression, osteoarthritis, and liver problems as well. We adopted systems metabolic engineering strategies to improve SAM production in a high-producing strain (GS115/DS56). First, the cystathionine beta-synthase gene CYS4 was downregulated using a weak promoter P-G12 to reduce the removal of homocysteine from SAM cycle, thus leading to a 48.8% increase in the SAM titer (1.68 g/L) from the strain G12-CBS, while preventing cysteine auxotrophy induced by deletion of this essential gene. Subsequently, the SAM titer of G12-CBS was improved to 13.01 g/L in 15-L fed-batch fermentation using the optimal l-methionine feeding strategy. Finally, based on comparative transcriptomics, five genes were chosen and overexpressed for further enhancement of SAM production. Among them, GDH2 and ACS2 exhibited positive effects, and the additional overexpression of GDH2 led to a 52.3% increase of titer (2.71 g/L) in shake flask culture. Therefore, the engineered Pichia pastoris strains can be utilized in industrial production of SAM using a simple and cost-effective process, and these approaches could be employed for improving the production of other chemicals by P. pastoris.