文献类型：期刊文献

英文题名：Role Identification and Application of SigD in the Transformation of Soybean Phytosterol to 9α-Hydroxy-4-androstene-3,17-dione in Mycobacterium neoaurum

作者：Xiong, Liang-Bin[1];Liu, Hao-Hao[1];Xu, Li-Qin[1];Wei, Dong-Zhi[1];Wang, Feng-Qing[1]

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

年份：2017

卷号：65

期号：3

起止页码：626

外文期刊名：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

收录：;EI(收录号：20170503308483);WOS:【SCI-EXPANDED(收录号:WOS:000392910700011)】；

基金：This research was financially supported by the National Natural Science Foundation of China (No. 31370080) and the National Special Fund for State Key Laboratory of Bioreactor Engineering.

语种：英文

外文关键词：mycobacteria; 9a-hydroxy-4-androstene-3,17-dione (9-OHAD); soybean phytosterol; transcription factor; sigD; choM2

摘要：9 alpha-Hydroxy-4-androstene-3,17-dione (9-OHAD) is a valuable steroid pharmaceutical intermediate which can be produced by the conversion of soybean phytosterols in mycobacteria. However, the unsatisfactory productivity and conversion efficiency of engineered mycobacterial strains hinder their industrial applications. Here, a sigma factor D (sigD) was investigated due to its dramatic downregulation during the conversion of phytosterols to 9-OHAD. It was determined as a negative regulator in the metabolism of phytosterols, and the deletion of sigD in a 9-OHAD-producing strain significantly enhanced the titer of 9-OHAD by 18.9%. Furthermore, a high yielding strain was constructed by the combined modifications of sigD and choM2, a key gene in the phytosterol metabolism pathway. After the modifications, the productivity of 9-OHAD reached 0.071 g/L/h (10.27 g/L from 20 g/L phytosterol), which was 22.5% higher than the original productivity of 0.058 g/L/h (8.37 g/L from 20 g/L phytosterol) in the industrial resting cell biotransformation system.