文献类型：期刊文献

英文题名：Characterization and engineering of 3-ketosteroid-Δ1-dehydrogenase and 3-ketosteroid-9α-hydroxylase in Mycobacterium neoaurum ATCC 25795 to produce 9α-hydroxy-4-androstene-3,17-dione through the catabolism of sterols

作者：Yao, Kang[1];Xu, Li-Qin[1];Wang, Feng-Qing[1];Wei, Dong-Zhi[1]

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

年份：2014

卷号：24

起止页码：181

外文期刊名：METABOLIC ENGINEERING

收录：;EI(收录号：20142617863497);WOS:【SCI-EXPANDED(收录号:WOS:000338934300018)】；

基金：We thank T. Parish (Department of Infectious and Tropical Diseases, United Kingdom) for providing the plasmids, p2NIL and pGOAL19, and W. R. Jacobs, Jr. (Howard Hughes Medical Institute) for providing plasmid pMV261. This research was financially supported by the Fundamental Research Funds for the Central Universities of China (No. WF1114017), the National Special Fund for State Key Laboratory of Bioreactor Engineering (No. 2060204), and the National Natural Science Foundation of China (No. 21206039).

语种：英文

外文关键词：3-Ketosteroid-Delta(1)-dehydrogenase; Mycobacteria; Sterols; 9 alpha-Hydroxy-4-androstene-3,17-dione

摘要：3-Ketosteroid-Delta(1)-dehydrogenase (KstD) is a key enzyme involved in the microbial catabolism of sterols. Here, three homologues of KstD were characterized from Mycobacterium neoaurum ATCC 25795, showing distinct substrate preferences and transcriptional responses to steroids. Single deletion of any MN-kstD failed to result in a stable and maximum accumulation of 9-OHAD due to residual KstD activities. To develop stable 9-OHAD producers, all of these MN-KstDs were inactivated, which led to about 6.02 g l(-1) of 9-OHAD from 15 g l(-1) of phytosterols. However, the product was mixed with 1.55 g l(-1) of AD as a major by-product. To transform AD, the oxygenase component of 3-ketosteroid-9 alpha-hydroxylase (KSH), encoded by kshA, was overexpressed. As a result, the yield of 9-OHAD increased to 7.33 g l(-1) with less than 0.31 g l(-1) of AD and the selectivity of 9-OHAD production was improved to 95-97% among metabolites. (C) 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.