Characterisation of a Neutral Protease Produced by Micrococcus Luteus

Abstract

A proteolytic enzyme produced by a cassava-fermenting strain of Micrococcus luteus was extracted and purified 50-fold by gel filtration and ion exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 25o C, the apparent molecular weight 42 kDa and the Km value, 0.45 mg ml-1 with casein as substrate. The enzyme was stimulated by Ca2+ and Mg2+ but inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, KCN, citric acid and L-cysteine indicating the enzyme to be a metalloprotease.