Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10395486 | Bioresource Technology | 2011 | 7 Pages |
Abstract
Zwf (code for glucose-6-phosphate dehydrogenase) and gnd (code for 6-phosphogluconate dehydrogenase) genes from Corynebacterium glutamicum were firstly cloned, and then site-directed mutagenesis was successfully introduced to remove allosteric inhibition by intracellular metabolites. Expression of the mutant zwf and gnd in Bacillus subtilis RH33 resulted in significant enhancement of riboflavin productivity, while the specific growth rate decreased slightly and the specific glucose uptake rate was unchanged. Introduction of the mutant zwf and gnd led to approximately 18% and 22% increased riboflavin production, respectively. An improvement by 31% and 39% of the riboflavin production was obtained by co-expression of the mutated dehydrogenases in shaker flask and fed-batch cultivation. Intracellular metabolites analysis indicated that metabolites detected in pentose phosphate pathway or riboflavin synthesis pathway of engineered strains showed higher concentration, while TCA cycle and glycolysis metabolites detected were lower abundance than that of parent strain.
Keywords
CDWRU5PPRPPd-Glyceraldehyde 3-phosphateL-PheDPDPEPFBPTCAPPPL-phenylalanineflavin adenine dinucleotideFMNG6PD6-phosphogluconate dehydrogenaseLC–MS/MStricarboxylic acidFADdihydropyrimidine dehydrogenaseRiboflavinfructose 1,6-bisphosphatephosphoribosyl pyrophosphatephosphoenolpyruvateflavin mononucleotideLuria–Bertaniminimal mediumpentose phosphate pathwaycell dry weightglucose-6-phosphate dehydrogenase
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Zhiwen Wang, Tao Chen, Xianghui Ma, Zhuo Shen, Xueming Zhao,