Abstract:
Production of extracellular amylase by Aspergillus niger was studied under submerged fermentation using jackfruit rag
as the carbon source. Different parameters, such as incubation period, pH of the culture broth and level of substrate were
changed to optimise the conditions for amylase production. Maximum enzyme production ~ 8400 units/g was obtained in 5
days old cultures, grown at pH, 6.5 and 30°C with substrate level 20 gL-1. As nitrogen sources NH4Cl, KNO3 casein,
peptone and beef extract were tested. Except NH4Cl all other sources enhanced the amylase production. Study on the
kinetics of extracellular and intracellular amylase production revealed that extracellular amylase production was always
higher than that in intracellular. Crude amylase obtained from culture broth was partially purified by ammonium sulphate
fractionation followed by DEAE Cellulose chromatography. Partially purified enzyme exhibited optimum pH and
incubation temperature at pH 6 and 60°C respectively and higher thermal and pH stability at 50-60°C and pH 5-7
respectively and enhanced activity with Ca2+. These unique features of the enzyme indicates its suitability for various
industrial applications. Shorter incubation period and lower substrate cost offer the potential for inexpensive production of
amylase, making the process industrially and economically feasible
