Waste Biogas residue from cassava dregs as carbon source to produce Galactomyces sp. Cczu11-1 cellulase and its enzymatic saccharification.

Abstract

In the conversion of cassava starch dregs to biogas by anaerobic fermentation, the biogas residue (BR) containing lignocellulosic materials still remained in the environment. In order to effectively utilize BR, the complexed 1-methyl-3-methylimidazolium dimethyl phosphate ([Mmim]DMP) media were used for pretreating cellulosic materials. After the optimization of pretreatment, the IL [Mmim]DMP-HCl-water (78.5:1.5:20, w/w/w) pretreament media were used for pretreating BR at 130°C for 30min. Furthermore, BR pretreated could be effectively saccharified by cellulase of Galactomyces sp. CCZU11-1. Moreover, BR could be used as a cheap carbon source for the production of Galactomyces sp. CCZU11-1 cellulase. After the culture optimization, the optimal culture conditions were obtained as follows: BR 5g/L, (NH4)2SO4 5g/L, K2HPO4 2g/L, MgSO4 0.2g/L, NaCl 1g/L, PEG6000 4g/L, pH5.5, and culture temperature 30°C. After the fermentation for 6days, the FPA and CMCase were 26.2 and 52.8U/mL, respectively. In conclusion, waste BR could be chosen as a promising feedstock for biofuels.