Optimization of Food-Waste Based Culture Medium for Cellulase Production by Thermophilic Bacillus sp SMIA-2 and effect of Divalent Metal Ions on Activity and Stability of the Enzyme at Higher Temperatures

Abstract

In general, the costs for cellulases production are associated with the value of the carbon source used in the process. Waste from the food processing industry contains several reusable substances that can replace the expensive components used in culture media for the production of cellulases. In this work, it was studied the combined interactive effect of different concentrations of sugarcane bagasse treated with alkali, passion fruit rind flour and corn steep liquor for maximal avicel-hydrolyzing enzymes – avicelases by thermophilic Bacillus sp SMIA-2, using statistical methodology. The influence of metal ions on the activity and stability of the enzyme was also investigated in order to increase the industrial applicability of enzymes. A concentration of 0.3% (w /v) of these three components in the production medium can be used successfully to obtain high levels of avicellase activity. The avicelase displayed enhanced activity in the presence of 10 Mm CoCl2 after incubation at 90ºC for 1 h, indicating that this enzyme depended on the metal ions to promote its activity and stability at higher temperatures.