Evaluation of sweet sorghum juice for the production of lysine using Corynebacterium glutamicum

Abstract

Sweet sorghum juice is a liquid sugar feedstock that can be produced in non-tropical climates. Utilization of sweet sorghum juice as a feedstock for the production of lysine was investigated utilizing the auxotrophic mutant Corynebacterium glutamicum ATCC 21513 in stirred tank bioreactors. The juice was found to have inadequate nutrients for growth of the auxotroph alone and was supplemented with two levels of yeast extract and peptone. The supplemented juice could support growth and produce lysine from the available sugars. No inhibitory effects of the juice were found on the growth of the organism. The lysine concentrations reach 28.8 g/L in the batch fermentations with complete utilization of the available sugars and a conversion efficiency of 0.23 g/g.