Premium
Cysteine synthase A overexpression in Corynebacterium glutamicum enhances l ‐isoleucine production
Author(s) -
Ma Wenjian,
Wang Jianli,
Li Ye,
Wang Xiaoyuan
Publication year - 2018
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1002/bab.1698
Subject(s) - corynebacterium glutamicum , isoleucine , biochemistry , cysteine , fermentation , biology , biosynthesis , bacteria , amino acid , chemistry , leucine , enzyme , gene , genetics
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.