Author/Authors :
Muthulakshmi, Chinnasamy Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India , Gomathi, Duraisamy Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India , Kumar, Dugganaboyana Guru Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India , Ravikumar, Ganesan Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India , Kalaiselvi, Manokaran Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India , Uma, Chandrasekar Department of Biochemistry - Karpagam University, Coimbatore – 641 021, India
Abstract :
Protease production under solid state fermentation (SSF) was investigated using isolated Aspergillus flavus. Different agro- industrial waste products were evaluated to check the possibility of potential utilization of substrates in SSF for protease production by Aspergillus flavus using wheat bran as a substrate. The results showed that the optimum conditions for maximum protease production were found to be 7th day of incubation at pH 5.0, temperature 30oC; inoculum size 3%; substrate concentration 3% and 3% KNO3 as nitrogen source. The purified enzyme produced 5.8 fold with recovery of 3.2% by DEAE-column chromatography and the molecular weight was estimated to be 46kDa by SDS-PAGE. It has a Vmax value of 60.0 U/mg and Km value of 0.6 mg/ml at pH of 7. The enzyme activity was found to be stable at 500 C and it was stimulated by metal ions like Cu2+ and Zn2+ and inhibited by Ca2+ and Mg 2+ .
Keywords :
protease , Aspergillus flavus , purification , SDS , PAGE , wheat bran , metal ions , precipitation
