Purification and Properties of a Collagenolytic Protease Produced by Bacillus cereus MBL13 Strain

A novel collagenase-producing bacterium has been isolated and identified as Bacillus cereus MBL13. From the culture supernatant of B. cereus MBL13 grown on bone collagen as the sole carbon and nitrogen source, an extracellular protease with novel property of hydrolyzing waste animal bones was purified. The molecular mass of the purified collagenolytic protease was estimated to be (38.0±1.5) kDa. As determined by amino acid analysis, it had high contents of asparagine, lysine and serine. The optimum temperature and pH for the collagenase activity were 40 °C and pH=8.0, respectively. The results of the effects of some metal ions, inhibitors and protein substrates suggested that the purified collagenolytic protease is a member of the metalloproteases. Type I collagen (the typical collagen in animal bone) was used as the substrate for determination of Michaelis-Menten kinetics. The obtained Km value was (1.31±0.05) g/L and the corresponding vmax value was (12.54±2.5) μmol/min. The study assumes that the collagenolytic protease purified from B. cereus MBL13 strain could be applied in the hydrolysis of waste animal bones