At present, utilization of groundnut shell is still very low. Hence, this study was carried out to valorize groundnut shell as a substrate for solid-state fermentation (SSF) using mixed culture of Trichoderma sp., tape yeast, and tempeh yeast to produce cellulase with a substrate to culture ratio of 10:1. The process was carried at 25°C for 5 days, and the fungal biomass as well as cellulase activity was determined daily. The groundnut shell contains approximately 12.24% cellulose, 50.15% cellulose, and 33% lignin, on a dry basis. After 5 days of fermentation, the fungal biomass and cellulase activity lies in the range of 0.07–0.34 g and cellulase activity of of 0.06–0.12 filter paper unit FPU/ ml, respectively. A maximum biomass of 0.34 g was obtained from a mixed culture of Trichoderma sp. and tempeh yeast whereas a maximum cellulase activity of 0.12 FPU/ml from a mixed culture of Trichoderma sp. and tape yeast. The results demonstrate that cellulase activity produced by mixed cultures was higher value than produced by single cultures. Mathematical models were also developed using secondary data to estimate kinetic parameters for producing cellulase using submerged and SSF. Both models can predict the kinetic parameters reasonably well.
Key words: Cellulase activity, Groundnut shell, Kinetic parameters, Solid state fermentation, Trichoderma sp