European Journal of Biotechnology and Bioscience

Authors
D.E.El-Hadedy, Eman W. El-Gammal and Moataza M. Saad

Abstract
The present study target is alkaline protease production by Streptomyces flavogriseus which isolated and identified by 16S rRNA and was deposited in the genebank sequence database under accessions number AB723783.1. Alkaline protease was produced by free and immobilized cells. Entrapment method of immobilization was used with agar, gelatin and polyacrylamide matrices. Data showed that gelatin entrapped cells gave the maximum specific activity (1042.0 U/mg protein); followed by agar (930.8 U/mg protein) and polyacrylamide (690.7 U/ mg protein) after 48 h of incubation. The reusability test proved that the gelatin entrapped cells can be reused for 4 cycles with retention of about 75% of enzyme specific activity followed by polyacrylamide and agar; the reusability was for 2 and 4 cycles, respectively. After gamma radiation exposure of gelatin entrapped cells, the maximum value of protease specific activity reached 19152 U/mg protein at dose 12 kGy. On the other hand, studies on submerged fermentation using free cells revealed that the maximum level of enzyme production (10358.9 U/me protein) was during the stationary phase at day 6 with carbon source 1.0 g% molase, 0.172 N % of NH4 HPO4, pH 7, at 30 °C. The optimum time for exposure to UV was 20 min increased the specific activity to 17448.2 U/mg protein.