Zhenhua Su1, Zhenjian Zhang1, Jian Yu1, Congcong Yuan1, Yanbing Shen2, Jianxin Wang3, Liqiu Su1, Min Wang4. 1. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China. 2. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China. shenyb@tust.edu.cn. 3. Frontage Laboratories, Inc, Exton, PA, 19341, USA. 4. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China. minw@tust.edu.cn.
Abstract
BACKGROUND: The production of androstenedione (AD) from phytosterols by Mycolicibacterium neoaurum is a multi-step biotransformation process, which requires degradation of sterol side chains, accompanied by the production of propionyl-CoA. However, the transient production of large amounts of propionyl-CoA can accumulate intracellularly to produce toxic effects and severely inhibit AD production. RESULTS: In the present study, the intracellular propionyl-CoA concentration was effectively reduced and the productivity of the strain was improved by enhancing the cytosolic methyl-branched lipid synthesis pathway and increasing the expression level of nat operator gene, respectively. Subsequently, the application of a pathway combination strategy, combined and the inducible regulation strategy, further improved AD productivity with a maximum AD conversion rate of 96.88%, an increase of 13.93% over the original strain. CONCLUSIONS: Overall, we provide a new strategy for reducing propionyl-CoA stress during biotransformation for the production of AD and other steroidal drugs using phytosterols.
BACKGROUND: The production of androstenedione (AD) from phytosterols by Mycolicibacterium neoaurum is a multi-step biotransformation process, which requires degradation of sterol side chains, accompanied by the production of propionyl-CoA. However, the transient production of large amounts of propionyl-CoA can accumulate intracellularly to produce toxic effects and severely inhibit AD production. RESULTS: In the present study, the intracellular propionyl-CoA concentration was effectively reduced and the productivity of the strain was improved by enhancing the cytosolic methyl-branched lipid synthesis pathway and increasing the expression level of nat operator gene, respectively. Subsequently, the application of a pathway combination strategy, combined and the inducible regulation strategy, further improved AD productivity with a maximum AD conversion rate of 96.88%, an increase of 13.93% over the original strain. CONCLUSIONS: Overall, we provide a new strategy for reducing propionyl-CoA stress during biotransformation for the production of AD and other steroidal drugs using phytosterols.
Authors: Srinivasan Vijay; Hoang T Hai; Do D A Thu; Errin Johnson; Anna Pielach; Nguyen H Phu; Guy E Thwaites; Nguyen T T Thuong Journal: Front Microbiol Date: 2018-01-11 Impact factor: 5.640