Zahra jafari - Graduate student, Babol Noshhirvani University Of Technology
Ghasem najafpour - Faculty member, Babol Noshhirvani University Of Technology
Fatemeh ayub meiguni - Graduate student,Babol Noshhirvani University Of Technology

Alkaline proteases are used in number of industries due to their high pH tolerance and thermastability. In present work, Bacillus strains (Bacillus subtilis PTCC 1254, B. subtilis PTCC 1156 and Bsubtils PTCC 1715) were supplied by Persian Type Culture Collection. All strains were screened forproteolytic activity using alkaline casein agar plate, all of them showed desired alkaline proteolyticactivity. Among three stains, one strain was selected for further study. The production of mosbacterial proteases has always been with expensive refined substrates which tend to increase theproduction cost. Hence, a low-cost substrate such as starchy waste and culture conditions werecapable of optimizing protease production by B. subtilis 1254. Under optimized culture conditions apH 9, temperature 37 °C and 5% inoculum size with starchy waste (25% v/v), sugarcane bagasse (2g/l) and corn bran (4 g/l) as carbon and nitrogen sources of the fermentation medium, maximumalkaline protease activity (83.46 U/ml) was achieved. Also the results showed that the obtainedprotease activity from low cost substrates was significantly higher than that from expensivesubstrates.