Title
Kinetic characterization and industrial applicability of novel protease produced from Aspergillus ornatus using agro-industrial materials
Authors
IRFAN ALI MUDDASSAR ZAFAR MUHAMMAD IJAZ ANWAR MUHAMMAD IRSHAD ZAHID ANWAR AFTAB AHMAD and HAQ NAWAZ

Received May, 21, 2015
Published Volume 51 Issue 1-2 January-February
Keywords Aspergillus ornatus, protease, purification, characterization, detergent compatibility

Abstract
In this study, we used various lignocellulosic materials to find out their elicitation potential for induced protease production under solid state fermentation (SSF). A significant difference was recorded in the specific substrate uptake rate, biomass and protease excretion during the exponential phase of A. ornatus in the culture medium supplemented with mango peel as a growth supporting substrate. Maximum protease activity of 150 U/mL was recorded after 48 h of controlled fermentation. A purification fold of 11.3 with 269.1 U/mg specific activity and 20.7% yield was achieved after purification in comparison with the crude protease. The characterization profile revealed that purified protease was optimally active at pH 10 and 40 °C. Moreover, the activity of the protease was stimulated up to variable extents by Mn2+, Cd2+, Mg2+, whereas an inhibitory effect was shown by Ethylenediaminetetraacetic acid (EDTA) and Sodium dodecyl sulfate (SDS). A considerable level of compatibility was also recorded against various tested detergents, in addition with up to 48 days of shelf life at room temperature. In conclusion, the maximal production of protease in the presence of a cheaper substrate at low concentration and its potential as a detergent additive for improved washing makes the strain and its enzymes potentially useful for industrial purposes, especially for the detergent and laundry industry.