Abstract:

In order to improve the yield of glutamic acid, we deleted the ATP synthase gene and inserted Vitreoscilla
hemoglobin (VHb) gene into Corynebacterium crenatum genome by homologous recombination to acquire two recombinant
Corynebacterium crenatum, T6-13-△atp and T6-13-△atp-tac-VHb. The yield of glutamic acid and growth of recombinant
Corynebacterium crenatum were determined. The yield of glutamic acid produced by T6-13-△atp strain after 32 h of
fermentation was 27.76% higher than that obtained from the original strain, although the recombinant strain grew more
slowly and could not reach the concentration of the original strain at the stationary stage. Meanwhile, the yield of glutamic
acid produced by T6-13-△atp-tac-VHb strain was 36.91% higher than that of the original strain during 32 h fermentation, and its
growth rate and the glutamic acid concentration at the stable stage were the same as those observed for the original strain. These
results may lay the foundation for constructing high-yield and stable industrial glutamic acid-producing strains.

Key words: Corynebacterium crenatum, glutamic acid, ATP synthase, Vitreoscilla hemoglobin