文献类型：期刊文献

英文题名：Identification and in situ removal of an inhibitory intermediate to develop an efficient phytosterol bioconversion process using a cyclodextrin-resting cell system

作者：Wang, Da[1];Zhang, Jian[1];Cao, Dan-Dan[1];Wang, Xuedong[1];Wei, Dongzhi[1]

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

年份：2021

卷号：11

期号：40

起止页码：24787

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20213010689079);WOS:【SCI-EXPANDED(收录号:WOS:000678299000033)】；

基金：This work was supported by the National Natural Science Foundation of China (31570079, 21706072).

语种：英文

外文关键词：Cyclodextrins - Metabolites - Production efficiency - Metabolism - Alcohols - Bioconversion

摘要：A classically versatile steroid intermediate, 9 alpha-hydroxyandrost-4-ene-3,17-dione (9 alpha-OH-AD), can be obtained by phytosterol (PS) bioconversion using Mycobacterium. In this study, a cyclodextrin-resting cell reaction system with a high concentration of PS (50 g L-1) was used to produce 9 alpha-OH-AD. However, the inhibitory effect of metabolic intermediates is a key factor limiting production efficiency. After the separation and identification of a series of metabolic intermediates, it was found that 4-ene-3-keto steroids, which are the first metabolites of sterol side-chain degradation, accumulated at the beginning of the bioprocess and had a remarkable inhibitory effect on bioconversion. The bioconversion rate was greatly improved when 5 g L-1 of macroporous adsorbent resin D101 was added to the reaction system in the initial phase. A certain amount of resin acted as a reservoir to remove the inhibitory intermediate in situ and facilitated the bioconversion process, and the 9 alpha-OH-AD space-time yield increased to 8.51 g L-1 d(-1), which was 23.15% higher than that without resin addition (6.91 g L-1 d(-1)) after 72 h bioconversion. In summary, we identified an inhibitory intermediate that limits the bioconversion rate and provided a solution based on resin adsorption for improving 9 alpha-OH-AD production efficiency in a commercial-scale process.