Open AccessAltered Metabolic Flux due to Deletion of odhA causes l -Glutamate Overproduction in Corynebacterium glutamicum
Author(s) -
Yoko Asakura,
Eiichiro Kimura,
Yoshihiro Usuda,
Yoshio Kawahara,
Kunihiko Matsui,
Tsuyoshi Osumi,
Tsuyoshi Nakamatsu
Publication year - 2007
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.01867-06
Subject(s) - corynebacterium glutamicum , overproduction , biochemistry , auxotrophy , glutamate receptor , flux (metallurgy) , biology , glutamate dehydrogenase , strain (injury) , chemistry , enzyme , escherichia coli , gene , receptor , organic chemistry , anatomy
l -Glutamate overproduction inCorynebacterium glutamicum , a biotin auxotroph, is induced by biotin limitation or by treatment with certain fatty acid ester surfactants or with penicillin. We have analyzed the relationship between the inductions, 2-oxoglutarate dehydrogenase complex (ODHC) activity, andl -glutamate production. Here we show that a strain deleted forodhA and completely lacking ODHC activity producesl -glutamate as efficiently as the induced wild type (27.8 mmol/g [dry weight] of cells for theohdA deletion strain compared with only 1.0 mmol/g [dry weight] of cells for the uninduced wild type). This level of production is achieved without any induction or alteration in the fatty acid composition of the cells, showing thatl -glutamate overproduction can be caused by the change in metabolic flux alone. Interestingly, thel -glutamate productivity of theodhA -deleted strain is increased about 10% by each of thel -glutamate-producing inductions, showing that the change in metabolic flux resulting from theodhA deletion and the inductions have additive effects onl -glutamate overproduction. Tween 40 was indicated to induce drastic metabolic change leading tol -glutamate overproduction in theodhA -deleted strain. Furthermore, optimizing the metabolic flux from 2-oxoglutarate tol -glutamate by tuning glutamate dehydrogenase activity increased thel -glutamate production of theodhA -deleted strain.