Gelatinised and hydrolysed corn starch is a cost-effective carbon source with higher production of L-lactic acid by Bacillus coagulans compared with glucose

L-lactic acid is an important organic acid widely used in pharmaceutical, food and textile industries. Bacillus coagulans BCS13002 can efficiently produce L-lactic acid with two kinds of carbon sources. BCS13002 produced L-lactic acid at a content of 10.23 +/- 0.16 g/L and 11.67 +/- 0.22 g/L, when glucose and gelatinised and hydrolysed corn starch (GHCS) were used, respectively. GHCS exhibits several advantages, including high yield of L-lactic acid and low cost. Proteomics analyses identified several key enzymes, which contributed to the higher production of L-lactic acid when GHCS was used as the carbon source. Those key enzymes were involved in the two-component system (SpoOF), pantothenate and CoA biosynthesis (pantothenate synthetase, 1.584-fold; dihydroxy-acid dehydratase, 1.517-fold), beta-alanine metabolism (1.605-fold) and valine, leucine and isoleucine biosynthesis (1.517-fold) pathways. This study provides a biological basis for using GHCS as a substitute of glucose in the production of L-lactic acid.

Automated summary

L-lactic acid is an important organic acid widely used in pharmaceutical, food and textile industries, and Bacillus coagulans BCS13002 can efficiently produce L-lactic acid with GHCS as the carbon source. Key enzymes identified in proteomics analyses contribute to the higher production of L-lactic acid, providing a biological basis for using GHCS as a substitute for glucose.