Isolation and characterization of a bacterial thermostable Protease from poultry dung

Abstract

Thermophilic bacteria identified as Klebsiella species was isolated from poultry dung using nutrient broth inoculated with pure colonies. The species were grown between temperatures of 45^oC to 65^oC and was found to be most thermotolerant at 62^oC. Protease enzyme was isolated from Klebsiella species and was further purified and characterized through ammonium sulphate precipitation and gel filtration on Sephadex G-100 column chromatography. The specific activity obtained for the partially purified enzyme was 0.1 units/mg protein with 4.2 % protein recovery. The apparent molecular weight as estimated by gel filtration on Sephadex G-100 column was 21.5kDa. The enzyme has optimum activity at pH 9.0 and at temperature of 35 C. An apparent k for the m hydrolysis of casein was found to be approximately 0.75 mg/ml with 0.6 % (w/v) casein.

Key words: Poultry dungs, Bacteria, Thermostable protease, Thermophiles, Klebsiella species