Optimization of Nutritional Parameters by One-Factor-At-A-Time Method for the Biosynthesis of Alkaline Protease from the Isolated Strain Alternaria alternata TUSGF1

Alkaline proteases are essential enzymes that have several applications in our industry. The aim was optimization of nutritional parameters by one-factor-at-a-time (OFAT) method in solid-state fermentation. Production of protease by employing our laboratory's new isolate, Alternaria alternata TUSG1 (strain accession number- MF401426) under solid-state fermentation was optimized. The nutritional factors were investigated, and only one agricultural residue (cauliflower leaves) with different particle sizes was checked. Highest enzyme production was obtained with a medium particle size of cauliflower leaves (610 U/gds) followed by coarse waste (603U/gds) and fine waste (596 U/gds) using 106 spores/ml as inoculum at 30° C for 7 days. The organism utilized carbon sources 0.5% (w/w) dextrose, fructose, maltose, sucrose, lactose, and starch. Among them, maltose was found to be the best carbon source. A variety of inorganic and organic media components were investigated for nitrogen sources of 0.3% (w/w), and skim milk was turned out to the best. The maximum enzyme activity was obtained with 1% maltose, 0.5% skim milk and 0.05% MgSO4. With optimized media 1.53 fold increase in the protease production at agricultural residue cauliflower leaves was obtained.