Ragi Husk as Substrate for Cellulase Production Under Temperature Mediated Solid State Fermentation by Streptomyces Sp

Abstract

Cellulases have diversity of industrial applications and their cost effective production using agroindustrial wastes by solid state fermentation poses an efficient method. Actinomycetes are considered highly valuable due to their secondary metabolites production and in this study, an attempt was made to optimize the use of ragi husk and refine the process of cellulase production by temperature mediated solid state fermentation. Actinomycetes were isolated from paper mill industry soil and cellulase producing Streptomyces sp was selected for the experiments. Ragi husk was used as substrate for solid state fermentation of cellulase and varying incubation temperatures (20°C, 25°C, 30°C, 35°C and 40°C) was considered to determine its effect on enzyme activity after 6th, 9th and 12th day of fermentation. The carboxymethyl cellualse (CMC-ase) activity was measured and the observations obtained were compared with the standard glucose curve to determine the amount of reducing sugar (µg ml-1) released. Enzyme activity was highest at 35°C and was recorded as 35.14, 45.90 and 59.56 IU ml-1 at the end of 6th, 9th and 12th day of fermentation. Highest amount of reducing sugars at a concentration of 322 µg ml-1 was released at the end of 12th day at 35°C. The results indicated that the enzyme activity was temperature dependent while using ragi husk as growth substrate under solid state fermentation.