Strain improvement of aspergillus flavus for enhanced production of alkaline protease enzyme

TL;DR: Results revealed that alkaline protease activity assay under submerged culture conditions was more accurate than the relative growth production (C/G) method because there is no correlation between zone diameter and the ability to produce the enzyme in submerged cultures.

Abstract: The purpose of the present investigation was to enhance the production of industrially important enzyme alkaline protease by subjecting the wild alkaline protease producing fungal strain i.e. Aspergillus flavus (KS2). This strain was used to examine the changes in alkaline protease production following UV irradiation. Induction of mutation in strain , Aspergillus flavus was carried out by 0, 3, 6, 9, 12, 15, 18 and 20 min with 30-W germicidal lamp that has radiation at 2540 - 2550A 0 at a distance of 15 cm in dark and irradiated. A total of 17 mutants were selected. They were designated as AS1 to AS9 and AS10 to AS17. Among these only three strains viz., AS2, AS11, and AS16 did exhibit high efficiency in production on the basis of relative growth production (C/G). Of the seventeen mutants of , Aspergillus flavus ten were chosen to assay their productivity. Mutants no AS2, AS3, AS1 were the most effective in enzyme production under submerged conditions being 2500,2400,2300U/mL respectively. Results revealed that alkaline protease activity assay under submerged culture conditions was more accurate than the relative growth production (C/G) method because there is no correlation between zone diameter and the ability to produce the enzyme in submerged cultures. High level of productivity increased with AS2 mutant of Aspergillus flavus, indicating that the enzyme is to be thermoalkaliphilic protease.