Co-production of S-adenosyl-L-methionine and L-isoleucine in Corynebacterium glutamicum

• Production of SAM in Corynebacteriumglutamicum ATCC13032 and IWJ001was investigated.
• Overexpression of metK and vgb in ATCC13032 increased SAM production 5.83 times.
• Overexpression of metK and vgb in IWJ001 increased SAM production 14.95 times.
• ATP was found to be the limiting factor for SAM production in IWJ001/pDXW-8-metk-vgb.
• IWJ001/pDXW-8-metk-vgb could produce 0.67 g/L SAM and 13.8 g/L L-isoleucine.

In this study, production of S-adenosyl-L-methionine in Corynebacterium glutamicum was investigated by overexpressing genes metK and vgb. Compared with vector control, overexpression of metK alone in C. glutamicum ATCC13032 and IWJ001 increased SAM production 5.11 and 11.65 times, respectively; while overexpression of metK and vgb in C. glutamicum ATCC13032 and IWJ001 increased SAM production 5.83 and 14.95 times, respectively. Further studies on IWJ001/pDXW-8-metk-vgb showed that the limiting factor for SAM production is intracellular ATP supply. Since IWJ001 is an L-isoleucine production strain, IWJ001/pDXW-8-metk-vgb could produce both SAM and L-isoleucine. After 72 h fermentation, SAM and L-isoleucine in IWJ001/pDXW-8-metk-vgb reached 0.67 g/L and 13.8 g/L, respectively. The results demonstrate the potential application of C. glutamicum for co-production of SAM and amino acids.