Rice flour showed an almost increase in protease activity followed by wheat flour, which showed a increase over the basal media. However, supplementation of potato starch, corn starch, and ragi exerted an inhibitory effect on alkaline protease production. | Turk J Biol 35 (2011) 177-182 © TÜBİTAK doi: Influence of process parameters on the production of detergent compatible alkaline protease by a newly isolated Bacillus sp. Y. Shivakumar SRIVIDYA1, Majumdar MALA2 1Department of Microbiology, Centre for PG Studies, Jain University, Bangalore, Karnataka - INDIA 2Department of Biotechnology, Centre for PG Studies, Jain University, Bangalore, Karnataka - INDIA Received: Abstract: Detergent compatible alkaline protease production by a newly isolated Bacillus from laundry soil was studied under shake flask conditions in growth medium comprised (g/L): peptone, 1; NaCl, 5; skim milk, 100; Na2CO3, 4. Different environmental process parameters such as fermentation period, initial pH, incubation temperature, and nutritional parameters such as supplementation of different starch sources and nitrogen sources were standardized for the maximum yield of alkaline protease. Rice flour showed an almost increase in protease activity followed by wheat flour, which showed a increase over the basal media. However, supplementation of potato starch, corn starch, and ragi exerted an inhibitory effect on alkaline protease production. Protease production by Bacillus sp. Y was suppressed up to 80% in the presence of most of the organic and inorganic nitrogen sources tested in comparison to rice flour:peptone supplementation. Hence, based on the optimization studies, we achieved a yield of 88 PU/mL ( increase) with the Bacillus sp. Y when cultivated for 72 h at pH , 37 °C in a medium containing: rice flour (1%, w/v), NaCl (, w/v), and skim milk (10%, v/v) with Na2CO3 (, w/v). Key words: Alkaline protease, Bacillus sp. Y, optimization, cheap substrates Introduction Proteases are essential constituents of all forms of life on earth including prokaryotes, fungi, plants, and animals. They are highly exploited enzymes in food, leather, detergent, pharmaceutical, diagnostics,