Effect of Salt and Inhibitoron the Isolation, Purification and Characterization of α -Amylase from Aspergillusniger Produced from Pigeon Pea

Abstract

α-Amylase an industrially used enzyme can be obtained from Aspergillusniger and can be produced from food sources such as pigeon pea. α-Amylase was produced from Aspergillusniger isolated from pigeon pea, purified and characterized. This process was achieved using ammonium sulphate, ion exchange DEAE column and gel filtration (Sephadex A-50 and sephadex G-100) chromatography. The effect of salt and inhibitor was determinedAmmonium sulphate precipitation results showed that the highest specific α-amylase activity was (1.01 U/ml. mg) obtained at 11.27% saturation level, with a purity of 1.81-fold of the crude extract and yielding 1.00%. Further purification using gel filtration increased the enzyme purity and yielding 8.94-fold relative to the crude extract 3.01% and yielding Specific activity after purification was 4.99 U/mg. The effect of salts on α-Amylase activity increased to 258.09% when in MgSO4, while decreased to 7.71% and 21.07% when in MnSO4 and CuCl2 respectively and yielded no result when in PbNO3.Its reaction with chemical inhibitors such as Bromosuccinimide was activated to 136.465% and was inhibited at Mercaptoethanol to 0%. All these were determined using a visible spectrophotometer with an absorbance of 540nm, against the control that contains 100µL of the enzyme and 100µL of 1% starch solution.Therefore α -amylase produced from Aspergillusniger can be exploited for potential usage for industrial applications of enzymes in a wide range of production and its application in food processing.