Production of extracellular amylase from agricultural residues by a newly isolated Aspergillus species in solid state fermentation

Abstract

The production of extracellular amylases by solid state fermentation (SSF) was investigated employing our laboratory isolate Aspergillus sp.MK07. Various agricultural residual substrates like wheat bran, rice bran and green gram husk were studied for enzyme production. Highest enzyme production was obtained with wheat bran as a substrate. Effects of process variables, namely: incubation period, temperature, initial moisture content, pH, supplementary carbon, nitrogen source and inoculum level on production of amylase have been studied and accordingly, optimum conditions have been determined. It was found that amylase production was highest at 120 h of incubation period at 30°C, 70% initial moisture content, 5.0 pH and 5% inoculum level. Supplementation of carbon (starch) and nitrogen source (peptone) showed an increase in amylase production and the highest amount of amylase production obtained under all optimized conditions was 164 U/g.

Key words: Solid state fermentation, optimization, Aspergillus, fermentation, amylase