436-440Economic and sustainable production of bioethanol from biomass through enzymatic route depends on economics of cellulase availability, the key factor for the success of the technology. It has been realized that the bottleneck of the technology lies in obtaining highly efficient cellulase which could result in an economically feasible technology. In this study, we compared cellulase production by Penicillium janthinellum EMS UV-8 in shake flask in two different medium; modified Mandel and Weber (M & W) and the corn steep liquor (CSL) based medium. In CSL based medium, 3.02 FPU/mL was produced compared to 1.25 FPU/mL in modified r M & W medium. Hence, CSL based medium was employed in bioreactor for cellulase production. In cellulase production, Penicillium sp. is comparable to the widely acclaimed Trichoderma sp. Changing the production medium from modified M & W medium to CSL based medium, increased cellulase production by two fold. In the bioreactor, controlled monitoring of DO and pH resulted in increase in the cellulase activity upto 5.44±0.3 FPU/ml at 168 h