Production of protease and elastase by Pseudomonas aeruginosa strains isolated from patients

Using 20 strains of Pseudomonas aeruginosa isolated from patients, production of protease, elastase, and collagenase was determined by shaking culture in either complex or semisynthetic medium. No collagenase was produced by any strain of P. aeruginosa. According to their production of protease and elastase in different media, the P. aeruginosa strains were divided into three groups: the first group can produce elastase in complex medium and both protease and elastase in semisynthetic medium; the second group cannot produce any proteolytic enzymes in complex medium but can produce any proteolytic enzymes in either medium; and the third group cannot produce any proteolytic enzymes in either medium. In spite of the differences in the ability of the strains to produce the enzymes, depending upon the origin of the strains, the protease or elastases produced in different broths were regarded as identical.