Kangsadan Boonprab, Natcha Duangchuen, Worakan Krundawloy and Panupong Tangjitpanich
Department of Fishery Products, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand, 10900
The effect of freeze-drying cellulase from Trichoderma viridae on acceleration of Cladophora glomerata hydrolysis for saccharification in bioethanol production was provided. C. glomerata gave cellulose, hemicellulose, lignin, and ash content [Mean (%) ± SD; n=3], with 35.28 ± 3.36, 20.00 ± 1.20, 3.45 ± 1.57 and 15.07 ± 9.09, respectively. Among 4 crude cellulase preparation methods as ethanol 95%, acetone, ethanol 95% + acetone, and ammonium sulphate, it was found that acetone precipitation was selected with the highest enzyme activity [Mean (FPU/g solid substrate) ± SD; n=3] as 139.05 ± 10.35 from total enzymatic protein amount [Mean (mg/g solid substrate) ± SD; n=3] as 485.23 ± 48.81. After freeze dryer technique was applied to crude enzyme, cellulase activity [Mean (FPU/g solid substrate) ± SD; n=3] /protein [Mean (mg/g solid substrate) ± SD; n=3] was equivalent to crude enzyme without freeze-drying with no significant differences (p ≤ 0.05). Saccharification of algae using freeze-dried cellulase at 4, 25, 35 and 50 °C using 5 mL [enzyme powder 0.021 g (6.59 mg protein content)], 10 mL [enzyme powder 0.0424 g (13.18 mg protein content)] and 15 mL [enzyme powder 0.065 g (19.77 mg protein content)] was determined to obtain the appropriate condition. It showed that at 4 °C, the freeze-drying enzyme 0.065 g (19.77 mg protein content) yielded the highest reducing sugar [Mean (mg/g dry weight algae) ± SD; n= 3] as 119.81 ± 11.33, which had higher efficiency of reducing sugar release than crude enzyme without freeze-drying (control) in all treatments.