Biotechnologie et biomatériaux

Abstrait

Properties of Alkaline Protease C₄₅ Produced by Alkaliphilic Bacillus Sp. Isolated from Chitu, Ethiopian Soda Lake

Gizachew Haile and Amare Gessesse

A total of 240 alkaliphilic bacteria were isolated from samples collected from alkaline soda lakes of Ethiopia and were screened for the production of alkaline proteases. Of these, 30% were protease positive indicating the abundance of protease producing microorganisms in these habitats. The Bacillus sp. designated as C45 that grow in solid state medium was selected based on the property of the enzyme for further study. The protease produced by the Bacillus sp. was active in the pH range of 6.5-11.5, with optimum activity at pH 8-9; and stable at alkaline pH. The optimum temperature for activity was 40°C and 50°C in absence and presence of 5 mM of Ca+2, respectively. The enzyme displayed appreciable activity and stability at low temperature. These properties suggest that protease C45 could find potential application for dehairing and detergent at moderate temperature. When protease C45 was added to raw hide it enabled dehairing, suggesting the potential usefulness of the enzyme in the leather industry.