Efficient production of L-lactic acid from corn straw hydrolysate

Abstract

In this study, L-lactic acid was produced from corn straw hydrolysate by the strain Lactobacillus sp. L47, the fermentation conditions such as nitrogen sources, mineral salts, metal ions, incubation periods, pH values and temperatures were investigated, and the optimal incubation conditions were obtained: corn straw hydrolysate of 243.1 ml/l, (NH4)2SO4 10 g/l, yeast extract 10 g/l, KH2PO4 0.5 g/l, ZnSO4 • 7H2O 0.3 g/l, MgSO4• 7H2O 0.1 g/l, MnSO4• H2O 0.01 g/l, CaCO3 60 g/l, initial medium pH 6.0, controlled fermentation pH 6.0, 20 ml of seed, incubation temperatrure 46 °C. Under the optimal fermentation conditions, the highest L-lactic acid production was 99.8 g/l in 40 h.