초록
In this study, the lignocellulosic residue coffee pulp was used as carbon source in fermentative l(+)-lactic acid production using Bacillus coagulans. After thermo-chemical treatment at 121<SUP>o</SUP>C for 30min in presence of 0.18molL<SUP>-1</SUP> H<SUB>2</SUB>SO<SUB>4</SUB> and following an enzymatic digestion using Accellerase 1500 carbon-rich hydrolysates were obtained. Two different coffee pulp materials with comparable biomass composition were used, but sugar concentrations in hydrolysates showed variations. The primary sugars were (gL<SUP>-1</SUP>) glucose (20-30), xylose (15-25), sucrose (5-11) and arabinose (0.7-10). Fermentations were carried out at laboratory (2L) and pilot (50L) scales in presence of 10gL<SUP>-1</SUP> yeast extract. At pilot scale carbon utilization and lactic acid yield per gram of sugar consumed were 94.65% and 0.78gg<SUP>-1</SUP>, respectively. The productivity was 4.02gL<SUP>-1</SUP>h<SUP>-1</SUP>. Downstream processing resulted in a pure formulation containing 937gL<SUP>-1</SUP>l(+)-lactic acid with an optical purity of 99.7%.