Comparative analysis on immobilized cells of Aspergillus oryzae and Bacillus cereus in production of amylase by solid state and submerged fermentation

Alpha amylase (α-amylase) enzyme is used as a thinning agent in the starch hydrolysis and it is widely used in the food processing, paper and textile industries. The intention of the present study was to analyse the α-amylase activity in solid state fermentation and submerged fermentation using immobilized cells of Aspergillus oryzae (A. oryzae) and Bacillus cereus (B. cereus), respectively. The enzyme activity was measured at different time intervals. Substrates used in fermentation were rice bran, paddy husk, raw rice and brown rice. Rice bran was noted to be the best substrate marking an average of 49.4 ppm/g for 120 h in solid state fermentation by A. oryzae followed by raw rice showing 43.5, brown rice 40.2 ppm/g and paddy husk 7.1 ppm/g correspondingly. Similarly, rice bran was found to be a superior substrate giving an average amylase activity of 132.6 ppm/g followed by brown rice with 105.9 ppm/g, raw rice with 98.0 ppm/g and paddy husk with 15.0 ppm/g among all substrates after immobilization of the enzyme. The present findings that amylase production is higher in solid state fermentation by A. oryzae with rice bran as the substrate.