Efficient production of lysine from genetically modified Corynebacterium glutamicum by feedback inhibition resistant strain

Abstract

Lysine is an essential amino acid required for the synthesis of proteins. Lysine deficiency leads to numerous irreversible damages to the brain and other body organs. It plays a vital role in the treatment of osteoporosis and Herpes Simplex Virus (HSV). Lysine is commonly produced through fermentation. However, its efficient production is still a bottle neck. The wild strains of microorganisms are unable to produce sufficient amino acid. The current study was designed to enhance the lysine production through feedback inhibition resistant strains. N-methyl-N-nitro-N-nitrosoguanidine (NTG) was utilized to mutate the Corynebacterium glutamicum strain B391 to increase the production of Lysine. C. glutamicum was used as fermenting agent and cultivated in molasses-based media. S-β-aminoethyl-L-cysteine (AEC) lysine analogue resistant mutants were selected. It was observed that 30 g/L and 55 g/L of lysine were produced by the parent and mutant strains, respectively. The increase in lysine production was observed with 10% of sugar concentration in 100 mL of molasses media (6.5 pH, and temperature 30°C) with inoculum size of 8%. Furthermore, two different molasses media with different ingredients (termed M1 and M2) were used for the lysine production. The lysine production M-2 was observed more prominent.