Cellulases are group extremely important enzymes which plays a crucial role in global carbon cycle by degrading insoluble cellulosic material. Cellulases can be used industrially in the economical and eco-friendly production of fermentation products. However, high cost of cellulases acting as a barrier for industrial scale usage of these enzymes. Cost-effective production of cellulases can be achieved by optimizing the media conditions and by choosing cheaper alternative lignocellulosic material as primary carbon and energy sources. In this study, we focused on production and purification of extracellular fungal cellulases using rice husk powder as primary carbon source in submerged fermentation. We performed optimization studies on cellulase production by varying inoculum size, initial substrate concentration, pH and supplementary carbon source. We observed a linear increase in cellulase production by increasing the inoculum size, initial substrate concentration and supplementary carbon concentration from 1% to 10%. However, increase in initial substrate i.e., rice husk powder concentration above 10% we observed decrease in cellulase production probably due to the inhibitory effect of high initial substrate concentrations. We were able to optimize the fungal cellulase production up to a concentration of 134 IU/ ml of broth using submerged fermentation.
Key words: Cellulases, Cost-effective production, Rice husk powder, Media optimization, submerged fermentation
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