Efficient biosynthesis of (R)-mandelic acid from styrene oxide by an adaptive evolutionary Gluconobacter oxydans STA

Biotechnology for Biofuels and Bioproducts

Research

Jiajia You¹  Jin Han¹  Minglong Shao¹  Meijuan Xu¹  Xian Zhang¹  Mengkai Hu¹  Fei Liu¹  Yan Chen¹  Xuewei Pan¹  Taowei Yang¹  Zhiming Rao¹  Junping Zhou² 

[1] Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, 214122, Wuxi, China;School of Biotechnology, Zhejiang University of Technology, 310014, Hangzhou, China;

关键词: R;    Gluconobacter oxydans;    Adaptive laboratory evolution;    Promoters;    Styrene oxide;    Biotransformation;   

DOI  :  10.1186/s13068-023-02258-7

 received in 2022-09-15, accepted in 2023-01-01,  发布年份 2023

来源: Springer

【 摘 要 】

Background(R)-mandelic acid (R-MA) is a highly valuable hydroxyl acid in the pharmaceutical industry. However, biosynthesis of optically pure R-MA remains significant challenges, including the lack of suitable catalysts and high toxicity to host strains. Adaptive laboratory evolution (ALE) was a promising and powerful strategy to obtain specially evolved strains.ResultsHerein, we report a new cell factory of the Gluconobacter oxydans to biocatalytic styrene oxide into R-MA by utilizing the G. oxydans endogenous efficiently incomplete oxidization and the epoxide hydrolase (SpEH) heterologous expressed in G. oxydans. With a new screened strong endogenous promoter P12780, the production of R-MA was improved to 10.26 g/L compared to 7.36 g/L of using Plac. As R-MA showed great inhibition for the reaction and toxicity to cell growth, adaptive laboratory evolution (ALE) strategy was introduced to improve the cellular R-MA tolerance. The adapted strain that can tolerate 6 g/L R-MA was isolated (named G. oxydans STA), while the wild-type strain cannot grow under this stress. The conversion rate was increased from 0.366 g/L/h of wild type to 0.703 g/L/h by the recombinant STA, and the final R-MA titer reached 14.06 g/L. Whole-genome sequencing revealed multiple gene-mutations in STA, in combination with transcriptome analysis under R-MA stress condition, we identified five critical genes that were associated with R-MA tolerance, among which AcrA overexpression could further improve R-MA titer to 15.70 g/L, the highest titer reported from bulk styrene oxide substrate.ConclusionsThe microbial engineering with systematic combination of static regulation, ALE, and transcriptome analysis strategy provides valuable solutions for high-efficient chemical biosynthesis, and our evolved G. oxydans would be better to serve as a chassis cell for hydroxyl acid production.

【 授权许可】

CC BY   
© The Author(s) 2023

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