文献类型：期刊文献

英文题名：Characterization and engineering control of the effects of reactive oxygen species on the conversion of sterols to steroid synthons in Mycobacterium neoaurum

作者：Sun, Wan-Ju[1];Wang, Li[1];Liu, Hao-Hao[1];Liu, Yong-Jun[1];Ren, Yu-Hong[1];Wang, Feng-Qing[1];Wei, Dong-Zhi[1]

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

年份：2019

卷号：56

起止页码：97

外文期刊名：METABOLIC ENGINEERING

收录：;EI(收录号：20193807444615);WOS:【SCI-EXPANDED(收录号:WOS:000491860400010)】；

基金：We sincerely thank T. Parish (Department of Infectious and Tropical Diseases, United Kingdom) for providing the vectors, p2NIL and pGOAL19, and W. R. Jacobs Jr. (Howard Hughes Medical Institute) for plasmid pMV261. This work was financially supported by the National Natural Science Foundation of China (Grant No. 21776075) and the Fundamental Research Funds for the Central Universities (No. 22221818014).

语种：英文

外文关键词：Sterol catabolism; Reactive oxygen species; Catalase; Mycothiol; Ergothioneine; Mycobacteria

摘要：The conversion of sterols to steroid synthons by engineered mycobacteria comprises one of the basic ways for the production of steroid medications in the pharmaceutical industry. Here, we revealed that high amounts of reactive oxygen species (ROS) generate during the conversion process of sterols, which impairs the cell viability of mycobacterial cells and thus hinders the conversion of sterols to steroid synthons. Accordingly, the endogenous antioxidants for detoxifying ROS in mycobacteria, ROS scavenging enzymes and low molecular weight thiols, were examined. The results revealed that three antioxidants, catalase (CAT), mycothiol (MSH), and ergothioneine (EGT), demonstrated efficacy toward neutralizing the excessive ROS produced during sterol metabolism. CAT overexpression or MSH or EGT augmentation enhanced the conversion of phytosterols to 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) by 18.9%, 23.8%, and 32.1%, respectively, and also enhanced the cell viability, indicating the benefits of these antioxidants in reducing ROS-induced stress. Further combinatorial augmentation of CAT, MSH, and EGT demonstrated enhanced effects toward intracellular ROS scavenging, resulting in 54.2% greater cell viability and 47.5% enhancement in 4-HBC production. These findings indicated that the excessive ROS induces cell stress, in turn limiting the conversion of sterols, whereas neutralization of the excessive ROS by combined control of CAT, MSH, and EGT serves as an effective strategy to boost the conversion productivity of sterols to steroid synthons.