Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China.
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China.
J Biotechnol. 2021 Sep 20;339:65-72. doi: 10.1016/j.jbiotec.2021.07.014. Epub 2021 Aug 2.
D-pantothenic acid (D-PA) is an essential vitamin that has been widely used in medicine, food, and animal feed. Microbial production of D-PA from natural renewable resources is attractive and challenging. In this study, both strain improvements and fermentation process strategies were applied to achieve high-level D-PA production in Escherichia coli. First, a D-PA-producing strain was developed through deletion of the aceF and mdh genes combined with the overexpression of the gene ppnk. The obtained engineered E. coli DPA02/pT-ppnk accumulated 6.89 ± 0.11 g/L of D-PA in shake flask fermentation, which was 79.9 % higher than the control strain. Moreover, the cultivation process contributed greatly to D-PA production with respect to titer and productivity by betaine supplementation and dissolved oxygen (DO)-feedback feeding framework. Under optimal conditions, 68.3 g/L of D-PA, the specific productivity of 0.794 g/L h and the yield of 0.36 g/g glucose in 5 L fermenter were achieved. Overall, this research successfully exploited advanced strategies to lay the foundation for bio-based D-PA production in industrial applications.
D-泛酸钙（D-PA）是一种重要的维生素，已广泛应用于医学、食品和动物饲料领域。利用天然可再生资源微生物生产 D-PA 具有吸引力和挑战性。在这项研究中，我们同时应用了菌株改良和发酵过程策略，以在大肠杆菌中实现高水平的 D-PA 生产。首先，通过缺失 aceF 和 mdh 基因并过表达 ppnk 基因，开发了一种生产 D-PA 的菌株。所得工程大肠杆菌 DPA02/pT-ppnk 在摇瓶发酵中积累了 6.89 ± 0.11 g/L 的 D-PA，比对照菌株提高了 79.9%。此外，通过添加甜菜碱和溶氧（DO）反馈补料策略，对培养过程进行了优化，大大提高了 D-PA 的产量和生产效率。在最优条件下，在 5 L 发酵罐中实现了 68.3 g/L 的 D-PA、0.794 g/L h 的比生产率和 0.36 g/g 葡萄糖的产率。总的来说，这项研究成功地利用了先进的策略，为工业应用中基于生物的 D-PA 生产奠定了基础。
