Abstract

OPTIMIZATION STUDIES ON ALKALINE PROTEASE OF ASPERGILLUS NIGER ISOLATED FROM SEASHORE SOIL OF BAY OF BENGAL

Yepuru Suman Kumar, Sujatha Gundeboina, Lingamgunta Lakshman Kumar and Kedam T. Raju*

ABSTRACT

Due to the importance alkaline proteases in biotechnological applications, a number of microorganisms explored. Therefore, this study, we isolated Aspergillus niger from soil biome and various parameter such incubation, temperature, pH, substrate and some metal ions, chelators and inhibitors on enzyme activity were determined. The study reveals that the strain was identified by morphological and screened on skim milk agar plates at 37o C for 72 h and confirmed through protease assay. The optimum yield of this enzyme was obtained from the appropriate fermentation conditions like pH ranging from 6.0-8.5, temperature at 20-40oC and incubation for 24, 48, and 72 h respectively was studied. In addition, the maximum enzyme production obtained from solid state fermentation under 10% wheat bran substrate compared to other agro-waste solid substrates such as sesame oil cake (SOC) and cotton seed oil cake (COC). Furthermore, protease was significantly activated by metal ions such as Fe 2+, Zn2+, Ca 2+ while it was inhibited by the metal ion chelator phenylmethylsulphonyl fluoride (PMSF), ethylenediaminetetraacetic (EDTA) and SDS. Our findings suggest the potential of this isolate for protease production and that this enzyme may be suitable for biotechnological purpose.

Keywords: Alkaline proteases; Aspergillus niger; Sesame oil cake; Cotton seed oil cake; Biotechnology.