Study on the use of starch biomass as a carbon source in D-lactate fermentation

Wheat flour starch was bioconverted to D-lactic acid (D-LA) by simultaneous saccharification and fermentation (SSF) and sep. by hydrolysis and fermentation (SHF). Processes were carried out in a batch bioreactor in the presence of Sporolactobacillus laevolacticus DSM 442 strain for 120 h at 37 degrees C and 41 degrees C, at 150 rpm and 0.5 vvm N-2 flow. The content of D-LA and sugars (glucose and maltose) in the fermentation medium were detd. by HPLC and enzyme assays. In the SSF method, the process time was 24 h shorter compared to SHF, and the max. amts. of D-LA obtained by both methods were similar (102.3 and 89.2 g/L, resp.).