Wu Meng1,2, Ruiming Wang2, Dongguang Xiao3. 1. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China. 2. Key Laboratory of Shandong Microbial Engineering, Qilu University of Technology, Jinan, 250353, China. 3. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China. xiao99@tust.edu.cn.
Abstract
OBJECTIVE: Bacillus subtilis BS2, which can produce tetramethylpyrazine (TTMP) from glucose, was engineered by knockout of the 2,3-butanediol (2,3-BD) dehydrogenase gene (bdhA) and then regulated through the addition of 2,3-BD to enhance the TTMP yield. RESULTS: The bdhA of B. subtilis BS2 was disrupted to construct a TTMP-producing strain termed BSA. In microaerobic flask fermentation, the BSA strain produced 27.8 g TTMP/l. This was 6 g/l higher than that produced by the initial strain. Compared with that in BS2, the maximum yield of acetoin, which is a TTMP precursor, also increased from 11.3 to 16.4 g/l in BSA. The TTMP production by BS2 was enhanced by 2,3-BD supplemented to the fermentation medium. The maximum TTMP and acetoin yields were improved from 21.8 to 29.7 g/l and from 11.3 to 15.4 g/l, respectively, as the 2,3-BD concentration increased from 0 to 3 g/l. Conversely, the yields did not increase when the 2,3-BD concentration in the matrix was ≥4 g/l. CONCLUSIONS: This study provides valuable information to enhance the TTMP productivity of mutagenic strains through gene manipulation and fermentation optimization.
OBJECTIVE:Bacillus subtilis BS2, which can produce tetramethylpyrazine (TTMP) from glucose, was engineered by knockout of the 2,3-butanediol (2,3-BD) dehydrogenase gene (bdhA) and then regulated through the addition of 2,3-BD to enhance the TTMP yield. RESULTS: The bdhA of B. subtilis BS2 was disrupted to construct a TTMP-producing strain termed BSA. In microaerobic flask fermentation, the BSA strain produced 27.8 g TTMP/l. This was 6 g/l higher than that produced by the initial strain. Compared with that in BS2, the maximum yield of acetoin, which is a TTMP precursor, also increased from 11.3 to 16.4 g/l in BSA. The TTMP production by BS2 was enhanced by 2,3-BD supplemented to the fermentation medium. The maximum TTMP and acetoin yields were improved from 21.8 to 29.7 g/l and from 11.3 to 15.4 g/l, respectively, as the 2,3-BD concentration increased from 0 to 3 g/l. Conversely, the yields did not increase when the 2,3-BD concentration in the matrix was ≥4 g/l. CONCLUSIONS: This study provides valuable information to enhance the TTMP productivity of mutagenic strains through gene manipulation and fermentation optimization.