Date of Publication


Document Type


Degree Name

Master of Science (M.S.) in Biology






Pseudomonas aeruginosa, Protease



Physical Description

1 online resource (ix, 70 leaves)


Pseudomonas aeruginosa Ps-1C produces an extracellular proteolytic enzyme which from preliminary studies appears to be inducible, and responsible for corneal destruction in injured dyes. In the present study the nutritional requirements for this bacterium to produce the proteolytic enzyme(s) were investigated. Preliminary studies indicated that proteose peptone offered the required nutrients for good enzyme production. The separation of the components of proteose peptone by Sephadex C-10 and Sephadex G-75 descending column chromatography was undertaken to illucidate the nutritional requirements. It was also noted that casamino acids hydrolysate served as a good substrate for Pseudomonas aeruginosa to produce this enzyme. The separation of amino acid groups was undertaken using paper and Ceon electrophoresis and various types of thin layer chromatography. The three amino acids found to be required for good protease production were, phenylalanine, isoleucine, and valine in their respective concentrations of 0.5 mg/ml, 1.0 mg/ml, and 2.0 mg/ml. Isoleucine was found to be inhibiting at higher concentrations. Dextrose also inhibited protease production, but not growth, at concentrations greater than 0.05%. Divalent metal ions in varying concentrations were tested as nutritional requirements for enzyme production. Magnesium ion provided very good enzymatic activity at a concentration of 0.01 M, whereas cobalt, copper, calcium and zinc ions did not allow appreciable enzyme activity and even in some cases were inhibitive.


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Portland State University. Dept. of Biology

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