Activity of Thermostable Proteases of some Actinomycetes and Fungi PDF

Keywords

soil, enzymes, Saudi Arabia

Abstract

The activities of thermostable proteolytic enzymes produced from the most potent. Streptomyces sp., T. vulgaris, Aspergillus fumigatus and Penicillium sp., isolated from soils of the Eastern Region of Saudi Arabia were investigated. The enzymes were most active toward gelatin at pH 5-7, 6-7, and 5- 5.6, and the optimum temperatures were 50, 50, 40 and 50- 55°C, respectively. The proteases exhibited extreme thermostability. The enzymes from T. vulgaris and Penicillium sp. retained 100% activity after 30 minutes at 70°C, and those from Streptomyces sp. and A. fumigatus after up to 20 min. After 2 hr at 70°C they lost 22, 45, 33 and 45% of activities, respectively. The protease of Streptomyces sp. was a specific enzyme for gelatin, but the proteases of the other species could hydrolyze casein and albumin also. The enzymes exhibited fair stability at 4°C during 3 months.