Effect of Molasses on L-Serine Production by Recombinant Corynobacterium glutamicum

Abstract:

The recombinant Corynebacterium glutamicum SYPS-062 33a?驻SSA-PS was an L-serine producing strain on sucrose. To study the effects of molasses，different pretreatment techniques and concentrations of molasses were tested on the growth of the strain and L-serine accumulation. For endogenous regulation，the effect of the transcription of genes in EMP pathway was studied. The result indicated that molasses as the sole carbon was not favorable to the synthesis of L-serine. While，with the addition of molasses with 0.24% sugar by the pretreatment with H2SO4，the strain showed a significant improvement in the cell growth（OD562=76.37） and L-serine（32.76 g/L） after 120 h of fermentation. Compared to the control，the cell growth and L-serine were improved by 23.82 % and 29.44%，respectively. The results of qRT-PCR showed that the addition of molasses could significantly improve the transcription of genes in the EMP pathway，which was one of the reason why molasses could improve the production of L-serine.