Extracellular proteinases of BacNus spp. isolated from fermented African locust bean, Iru

Extracellular proteinase production by seven strains of Bacillus subtilis group isolated from fermented African locust bean was compared. The seven strains, which were designated BSl, BS2, BS3, BLl, BL2, BL4 and BP2, showed signi- ficant differences (cx=O.OS) in extracellular proteinases production. The order of proteolytic activity (in descending order) of the strains in nutrient broth medium containing African locust bean was: BL2 > BP2 > BS2 > BL4 > BS3 > BLl > BSl. The proteinases of strains BL2 were purified and characterized by ammonium sulphate precipitation, ion-exchange chromatography. Three proteinases (serine proteinase, neutral proteinase and an esterase) were identified with MW of 18.2-19.7, 226 and 33.5 kDa, respectively. The serine proteinase was highly hydrophobic while the esterase was characterized by low specific activity