Metabolic engineering of Corynebacterium glutamicum ATCC13032 to produce S-adenosyl-L-methionine

As an important biological methyl group donor, S-adenosyl-L-methionine is used as nutritional supplement or drug for various diseases, but bacterial strains that can efficiently produce S-adenosyl-L-methionine are not available. In this study, Corynebacterium glutamicum strain HW104 which can accumulate S-adenosyl-L-methionine was constructed from C. glutamicum ATCC13032 by deleting four genes thrB, metB, mcbR and Ncgl2640, and six genes metK, vgb, lysC(m), hom(m), metX and metY were overexpressed in HW104 in different combinations, forming strains HW104/pJYW-4-metK-vgb, HW104/pJYW-4-SAM2C-vgb, HW104/pJYW-4-metK-vgb-metYX, and HW104/pJYW-4-metK-vgb-metYX-hom(m)-lysC(m). Fermentation experiments showed that HW104/pJYW-4-metK-vgb produced more S-adenosyl-L-methionine than other strains, and the yield achieved 196.7 mg/L (12.15 mg/g DCW) after 48h. The results demonstrate the potential application of C. glutamicum for production of S-adenosyl-L-methionine without addition of L-methionine.