Characterization of the Protease Produced by Rhizophus Stolonifer Purified from Bread

Abstract

Rhizophus species are capable of producing diverse enzymes. Proteases are one of the enzyme types that are produced by large number of microbes and they break up the peptide bonds of proteins to release amino acids. The study was aimed to determine the types of enzymes produced by Rhizophus stolonifer strain purified from bread and to characterize the proteases produced by this fungal strain. A Rhizophus stolonifer strain was isolated and purified from 48 hours old moist bread and screened for the production of diverse group of enzymes. Selected Rhizophus stolonifer strain grew well and produced proteases, amylases and xylanases at room temperature and pH 7.0 and a pure form of this strain was used to study the kinetic properties of the crude protease. The protease was extracted with 0.1M phosphate buffer of pH 7.0 and at 25^oC and it showed zero order kinetics for 10 minutes. The crude protease activity was higher at pH 8.0 and 30^?C. Michaelis constant for the crude enzyme to soluble substrate was 624.9M and Vmax was 136.4 pmol/minat pH 8.0 and 30^oC.