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Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry
Published on: July 20, 2016
Cysteine synthase A overexpression in Corynebacterium glutamicum enhances l-isoleucine production
Wenjian Ma1,2, Jianli Wang1,2, Ye Li1,3
1State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, People's Republic of China.
Abstract:
Cysteine synthase A (CysK) catalyzes the last reaction of l-cysteine synthesis in bacteria, but its moonlighting functions have been revealed recently. In this study, CysK was overexpressed in Corynebacterium glutamicum IWJ001, an l-isoleucine producer. Compared with the control IWJ001/pDXW-8, IWJ001/pDXW-8-cysK cells grew fast during log phase, and produced 26.5% more l-isoleucine in flask fermentation and 23.5% more l-isoleucine in fed-batch fermentation. The key genes aspC, lysC, hom, thrB, ilvA, and ilvBN involved in l-isoleucine biosynthesis were all upregulated in IWJ001/pDXW-8-cysK, compared with IWJ001/pDXW-8. In addition, IWJ001/pDXW-8-cysK cells were longer and thicker than IWJ001/pDXW-8 cells. Compared with IWJ001/pDXW-8, the membrane permeability increased 15.8% and biofilm formation ability decreased 71.3% for IWJ001/pDXW-8-cysK cells. The results demonstrate that CysK overexpression in C. glutamicum is a good approach to enhance l-isoleucine production.
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