ISOLATION, CULTIVATION AND CHARACTERIZATION OF A FUNGAL ISOLATE FROM AGRO-SOIL WASTE FOR PRODUCTION AMYLASE ENZYME

Abstract

Amylase enzymes are industrially important enzymes used in food, sugar, textile, pharmaceutical, paper and detergent industries. The main objective of this study is to characterize and produce amylase enzyme from fungal strains isolated from soil. Soil samples were collected from three places and a total of 89 fungal isolates were screened for their potential to produce amylase. Of which Aspergillus niger FAB-211 showed the maximum potential to produce amylase and considered for further study. Maximum amylase pro duction using the strain was obtained by an optimum condition of pH 6.0 (0.483 U/ml) at 45 o c (1.241 U/ml) and 3 days of incubation (0.281 U/ml). Maltose (0.684 U/ml) and yeast extract (0.501 U/ml) were found to be the best carbon and nitrogen sources and resulted in maximum activity respectively. It was observed that 6 disc spore inoculum size of A. niger FAB-211(1.081 U/ml) resulted maximum activity. Solid state fermentation processes was examined using banana, mango and potato peels. Banana peel was promising and showed maximum (0.481 U/ml) result and 2:1 initial diluents to substrate ratio resulted in maximum production (0.881 U/ml). The optimum enzyme activity was reached at pH 6.0 and 45 o c. The enzyme was stable at 45 o c and 50 o c retained more than 90% and 84% of its activity. The enzyme was active and stable at broad pH range of 4.0-8.0 and 5.0-7.0 respectively . Highly activated by Ca 2+ ion and moderately activated by K + and Fe 3+ ions. More than 69% its activity was retained in 20% v/v of H2O2 concentration. These properties make it a very promising candidate for their application in industries.