Oxidant and solvent stable alkaline protease from Aspergillus flavus and its characterization

Abstract

Proteases are commercially important enzymes (Ferrero et al., 1996; Kumar et al. 1999) accounting for approximately 60% of global industrial enzyme sales (Rao et al. 1998). Proteases occur widely in plants and animals, but commercial proteases are produced exclusively from microorganism (Chutmanop et al, 2008). Aspergillus, Penicillium and Rhizopus are widely used for protease production since, several species of these genera are regarded as safe (GRAS) strains (Pandey 1992). Aspergillus, has ideally been an organism of choice for bulk production of industrial enzymes, as the fungi can grow on relatively inexpensive agricultural wastes (Bergquist et al. 2002). Enzyme production can be carried out by both submerged fermentation (SmF) and solid-state fermentation (SSF), the latter being a technique of choice (Pandey et al. 2001; Sandhya et al. 2005). Alkaline serine proteases (EC 3.4.21) are active and stable at neutral to alkaline pH (7-12), and find extensive applications in protein chemistry and protein engineering as well as in industries such as detergents, leather, protein recovery, meat tenderization etc (Lauer et al. 2000; Johnvesly and Naik, 2001). Alkaline proteases with novel properties, such as stability in the presence of organic solvents, are in great demand for their increasing application in organic synthesis (Gupta and Khare, 2006). In the view of above we report here the production of alkaline protease by A. flavus MTCC 9952, with an aim to find a set of culture conditions using agro industrial wastes and characterize the properties of partially purified enzyme leading to the development of detergent formulations and for peptide synthesis in non aqueous media. © 2011 Academic Journals.