2 research outputs found
Sequential cellulase production, saccharification and ethanol fermentation using rice straw
616-620This study presents alkali pretreated rice straw for
cellulase production using Aspergillus niger CP1 by solid state
fermentation (SSF). On 8th day, 140±2.4 IU g/l dry substrate (ds) carboxy
methyl cellulose CMCase), 15±1.2 IU g/l ds filter paper activity (FPA) and
24±1.1 IU g/l ds â-glucosidase activities were noted. On extraction of 120 g
material with 1 l of 0.1 mol/l citrate buffer, 5.9±0.12 IU ml/l CMCase,
0.62±0.001 IU ml/l FPA and 1.11±0.002 IU/ml â-glucosidase were obtained. When
extracted enzyme was used for saccharification of 120 g fresh pretreated rice
straw containing 100 g holocellulose, 45±0.2 g, sugars (50 g/l) were released
in 900 ml hydrolysate to give 45% hydrolysis. Hydrolysate after yeast
fermentation gave 15.6±0.05 g/l ethanol with a yield of 0.4±0.011 g/l/h and 78%
fermentation efficiency. In sequential enzyme production, saccharification and
fermentation studies, on 8thday of cellulase production by SSF, temperature was
shifted from 28±1°C to 55°C for 36 h, and 76% hydrolysis
was achieved. When A. niger in hydrolysate was
inactivated and used, 68±0.83 g/l ethanol and 92% fermentation efficiency were
obtained. Hydrolysate used without inactivation of A. niger gave 61.65±0.78 g/l
ethanol and 85% fermentation efficiency