Enhanced production of bacitracin via energy metabolism engineering in Bacillus licheniformis DW2.

Qing Zhang; Shan Zhu; Naixiang Cui; Bowen Zhang; Zhi Wang; Xiaobin Chen; Jun Liu; Junhui LI; Dongbo Cai; Zhifan Yang; Shouwen Chen; Xin MA

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Enhanced production of bacitracin via energy metabolism engineering in Bacillus licheniformis DW2.

Author: Qing ZHANG ¹ ; Shan ZHU ¹ ; Naixiang CUI ¹ ; Bowen ZHANG ¹ ; Zhi WANG ² ; Xiaobin CHEN ³ ; Jun LIU ³ ; Junhui LI ³ ; Dongbo CAI ¹ ; Zhifan YANG ¹ ; Shouwen CHEN ¹ ; Xin MA ¹
Author Information

1. Environmental Microbial Technology Center of Hubei Province, State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan 430062, Hubei, China.
2. Hubei Provincial Key Laboratory of Industrial Microbiology, Key Laboratory of Fermentation Engineering (Ministry of Education), School of Food and Biological Engineering, Hubei University of Technology, Wuhan 430068, Hubei, China.
3. Lifecome Biochemistry Co. Ltd, Pucheng 353400, Fujian, China.
Publication Type:Journal Article
Keywords: ATP supply; Bacillus licheniformis; bacitracin; metabolic engineering
MeSH: Bacillus licheniformis; metabolism; Bacitracin; biosynthesis; Energy Metabolism; genetics; Industrial Microbiology; methods
From: Chinese Journal of Biotechnology 2020;36(6):1126-1137
CountryChina
Language:Chinese
Abstract: Bacitracin is a broad-spectrum cyclic peptide antibiotic, and mainly produced by Bacillus. Energy metabolism plays as a critical role in high-level production of target metabolites. In this study, Bacillus licheniformis DW2, an industrial strain for bacitracin production, was served as the original strain. First, our results confirmed that elimination of cytochrome bd oxidase branch via deleting gene cydB benefited bacitracin synthesis. Bacitracin titer and ATP content were increased by 10.97% and 22.96%, compared with those of original strain, respectively. Then, strengthening cytochrome aa3 oxidase branch via overexpressing gene qoxA was conducive to bacitracin production. Bacitracin titer and ATP content were increased by 18.97% and 34.00%, respectively. In addition, strengthening ADP synthesis supply is also proven as an effective strategy to promote intracellular ATP accumulation, overexpression of adenosine kinase DcK and adenylate kinase AdK could all improve bacitracin titers, among which, dck overexpression strain showed the better performance, and bacitracin titer was increased by 16.78%. Based on the above individual methods, a method of combining the deletion of gene cydB and overexpression of genes qoxA, dck were used to enhance ATP content of cells to 39.54 nmol/L, increased by 49.32% compared to original strain, and bacitracin titer produced by the final strain DW2-CQD (DW2ΔcydB::qoxA::dck) was 954.25 U/mL, increased by 21.66%. The bacitracin titer produced per cell was 2.11 U/CFU, increased by 11.05%. Collectively, this study demonstrates that improving ATP content was an efficient strategy to improve bacitracin production, and a promising strain B. licheniformis DW2-CQD was attained for industrial production of bacitracin.