HUANG Xing, LIU Ming, GONG Bo, et al. Expression of site-directed mutant glutamine synthetase and enzymatic glutamine production[J]. CIESC Journal, 2008, (6): 1479-1484.
HUANG Xing, LIU Ming, GONG Bo, et al. Expression of site-directed mutant glutamine synthetase and enzymatic glutamine production[J]. CIESC Journal, 2008, (6): 1479-1484.DOI:
To solve putative adenylation of glutamine synthetase (GS) in the enzymatic production of glutamine at a high concentration of ammonium salt
glnA encoding GS was cloned from Corynebacterium glutamicum ATCC 14067 and mutated by overlapping primer to replace the putative adenylation site of GS
Tyr405 by Phe405.The mutant GS was expressed in E.coli and the conditions of GS production were optimized.In the process catalyzed by the mutant GS
glutamine production was increased by adding monosodium glutamate and ammonium chloride in shaking flasks and glutamine yield reached 16.8 g·L-1.By controlling the enzymatic conditions in 5 L bioreactor
glutamine yield reached 34.2 g·L-1 with a molar conversion of 96.3% to glutamate.