Alkaline protease production, extraction and characterization from alkaliphilic Bacillus licheniformis KBDL4: a Lonar...

A bacterium producing an alkaline protease was isolated from the Lonar soda lake, Buldhana district (19 degrees 58' N; 76 degrees 31' E), Maharashtra, India. The most appropriate medium for the growth and protease production was composed of (g/L): casein 10; yeast extract 4; KH2PO4 0.5, K2HPO4 0.5 and CaCl2 0.5. The enzyme showed maximum activity with and without 5 mM Ca2+ at 70 and 60 degrees C, respectively. The enzyme retained 40 and 82% of its initial activity after heating for 60 min at 60 degrees C, in absence and presence of 5 mM CaCl2 respectively. The enzyme remained active and stable at pH 8-12, with an optimum at pH 10. The enzyme showed stability towards non-ionic and anionic surfactants, and oxidizing agents. It also showed excellent stability and compatibility with commonly used laundry detergents. Wash performance analysis revealed that enzyme could effectively remove blood stains. It also showed decomposition of gelatinous coating on X- ray film.