Enhanced production of bacitracin by knocking out of amino acid permease gene yhdG in Bacillus licheniformis DW2.

Yang LI; Fei WU; Dongbo Cai; Yangyang Zhan; Junhui LI; Xiaobin Chen; Huichao Chen; Shouwen Chen; Xin MA

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Enhanced production of bacitracin by knocking out of amino acid permease gene yhdG in Bacillus licheniformis DW2.

Author: Yang LI ¹ ; Fei WU ¹ ; Dongbo CAI ¹ ; Yangyang ZHAN ¹ ; Junhui LI ² ; Xiaobin CHEN ² ; Huichao CHEN ² ; Shouwen CHEN ¹ ; Xin MA ¹
Author Information

1. Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, Hubei, China.
2. Lifecome Biochemistry Co. Ltd, Pucheng 353400, Fujian, China.
Publication Type:Journal Article
Keywords: Bacillus licheniformis; amino acid permease YhdG; bacitracin; branched chain amino acids
From: Chinese Journal of Biotechnology 2018;34(6):916-927
CountryChina
Language:Chinese
Abstract: Bacitracin is a broad-spectrum polypeptide antibiotic, which is formed by 11 amino acids residues. Precursor amino acids supply might be the limit factor during bacitracin fermentation. First, our results demonstrated that increasing Ile and Leu supplies were regarded as the efficient strategies for the enhanced titer of bacitracin. Then, the amino acid permease YhdG, which was identified as the BCAA permease, was deleted and overexpressed in DW2, respectively. Our results showed that knocking out of permease YhdG could improve bacitracin production remarkablely. The bacitracin titer of the yhdG deficient strain DW2ΔyhdG reached 917.35 U/mL by flask fermentation, increased by 11% compared with that of DW2. In addition, the bacitracin titer was decreased by 25% in the YhdG overexpressed strain. Meanwhile, the intracellular concentrations of BCAA were higher than DW2 during the biosynthesis of bacitracin. The above results suggested that the permease YhdG might act as an exporter for branched chain amino acids in B. licheniformis DW2. Taken together, the increasing intracellular concentrations of branched chain amino acids by deleting amino acid permease YhdG could improve bacitracin titer. This study provided a new strategy for high-level production of bacitracin.