Redirection of the central metabolism of Klebsiella pneumoniae towards dihydroxyacetone production

Microbial Cell Factories

Frank Baganz¹  Gary J. Lye¹  Xiyang Lu²  Qinghui Wang²  Lin Shu²  Jian Hao²  Jiping Shi²  Shaoqi Sun²  Yike Wang²  Chenguang Zhu³ 

[1] Department of Biochemical Engineering, University College London;Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences;School of Life Science, Shanghai University;

关键词: Dihydroxyacetone;    Glycerol;    tpiA;    hdpA;    Klebsiella pneumoniae;   

DOI  :  10.1186/s12934-021-01608-0

来源: DOAJ

【 摘 要 】

Abstract Background Klebsiella pneumoniae is a bacterium that can be used as producer for numerous chemicals. Glycerol can be catabolised by K. pneumoniae and dihydroxyacetone is an intermediate of this catabolism pathway. Here dihydroxyacetone and glycerol were produced from glucose by this bacterium based a redirected glycerol catabolism pathway. Results tpiA, encoding triosephosphate isomerase, was knocked out to block the further catabolism of dihydroxyacetone phosphate in the glycolysis. After overexpression of a Corynebacterium glutamicum dihydroxyacetone phosphate dephosphorylase (hdpA), the engineered strain produced remarkable levels of dihydroxyacetone (7.0 g/L) and glycerol (2.5 g/L) from glucose. Further increase in product formation were obtained by knocking out gapA encoding an iosenzyme of glyceraldehyde 3-phosphate dehydrogenase. There are two dihydroxyacetone kinases in K. pneumoniae. They were both disrupted to prevent an inefficient reaction cycle between dihydroxyacetone phosphate and dihydroxyacetone, and the resulting strains had a distinct improvement in dihydroxyacetone and glycerol production. pH 6.0 and low air supplement were identified as the optimal conditions for dihydroxyacetone and glycerol production by K, pneumoniae ΔtpiA-ΔDHAK-hdpA. In fed batch fermentation 23.9 g/L of dihydroxyacetone and 10.8 g/L of glycerol were produced after 91 h of cultivation, with the total conversion ratio of 0.97 mol/mol glucose. Conclusions This study provides a novel and highly efficient way of dihydroxyacetone and glycerol production from glucose.

【 授权许可】

Unknown