Affiliation:
1. School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education Jiangnan University Wuxi 214122
2. School of Life Sciences and Health Engineering Jiangnan University Wuxi 214122 China
Abstract
AbstractThe widespread attention towards 1,4‐butanediol (BDO) as a key chemical raw material stems from its potential in producing biodegradable plastics. However, the efficiency of its biosynthesis via current bioprocesses is limited. In this study, a dual‐pathway approach for 1,4‐BDO production from succinic acid was developed. Specifically, a double‐enzyme catalytic pathway involving carboxylic acid reductase and ethanol dehydrogenase was proposed. Optimization of the expression levels of the pathway enzymes led to a significant 318 % increase in 1,4‐BDO titer. Additionally, the rate‐limiting enzyme MmCAR was engineered to enhance the kcat/KM values by 50 % and increase 1,4‐BDO titer by 46.7 %. To address cofactor supply limitations, an NADPH and ATP cycling system was established, resulting in a 48.9 % increase in 1,4‐BDO production. Ultimately, after 48 hours, 1,4‐BDO titers reached 201 mg/L and 1555 mg/L in shake flask and 5 L fermenter, respectively. This work represents a significant advancement in 1,4‐BDO synthesis from succinic acid, with potential applications in the organic chemical and food industries.