Improvingglutarate production inEscherichia coli by enhancing the CoA precursors
Mei Zhao1,2, Yu
Zhou1,2, Xue Sui1,2, Guohui
Li1,2 and Yu Deng1,2*
1 National Engineering Laboratory for Cereal Fermentation Technology
(NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122,
China
2 Jiangsu Provincial Research Center for Bioactive Product Processing
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122,
China
* Correspondence to:
Yu Deng: National Engineering
Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan
University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
Phone: +86-510-85329031, Fax: +86-510-85918309
E-mail:dengyu@jiangnan.edu.cn
Abstract:Glutarate
is an attractive C5 platform chemical having wide application in nylon
and plasticizer. However, microbial glutarate is mainly accumulated in
the degradation of lysine and other methods were rarely explored for
producing the glutarate from glucose directly. Here, we utilized a
reversed adipic acid degradation pathway (RADP) and improved the
glutarate production by increasing the precursors (malonyl-CoA and
acetyl-CoA) based on the previously studied strain Bgl4146.
Specifically, the conversion system of intracellular acetyl-CoA to
malonyl-CoA was firstly constructed and optimized to balance acetyl-CoA
synthase and acetyl-CoA carboxylase under different dissolved oxygen,
enhancing the glutarate production from 0.09 g/L to 0.49 g/L. Then,
modulating CoA balance by monitoring the expression of acetate kinase
and pyruvate dehydrogenase resulting in a rise in glutarate titer up to
0.70 g/L. Finally, the optimized strain Bgl51464 was able to produce
7.97 g/L glutarate in a 5-L bioreactor. This strategy was described
here, which could lay a certain foundation for the development of
effective CoA balance to produce industrially high value-added
chemicals.
Key words: Glutarate; The reverse adipate degradation pathway;
Malonate; Acetate; Malonyl-CoA; Acetyl-CoA