Engineered

Corynebacterium glutamicum

was constructed for L-ornithine production by disrupting genes of

argF

and

proB

to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogenase complex(ODHC) on L-ornithine production was also investigated.It was found that the inactivation of ODHC by knockout of the

kgd

gene enhanced L-ornithine production.The engineered

C.glutamicum

ATCC13032(

ΔargF

ΔproB

Δkgd

) produced L-ornithine up to 4.78 g·L

-1

from 0.24 g·L

-1

of the wild-type strain.In order to understand the mechanism of L-ornithine production in

C.glutamicum

ATCC13032(

ΔargF

ΔproB

Δkgd

) and find out new strategies for further enhancing L-ornithine production

the comparative proteome between the wild-type and the engineered strain was analyzed.L-Ornithine overproduction in the engineered strain was related to the up-regulation of the expression levels of enzymes involved in L-ornithine biosynthesis pathway and down-regulation of the expression levels of proteins involved in pentose phosphate pathway.The overexpression of genes in the upstream pathway of glutamate to increase the availability of endogenous glutamate may further in-crease ornithine production in the engineered

C.glutamicum

and the ornithine synthesis enzymes(ArgCJBD) may not be the limiting enzymes in the engineered

C.glutamicum

.