Toxigenic and Nontoxigenic Strains of Aspergilli and Penicillia Grown in the Presence of Sodium Chloride Cause Enzyme-Catalyzed Hydrolysis of Protein, Fat and Hydrogen Peroxide

Abstract

Eight strains of Aspergillus flavus, three of Aspergillus parasiticus, one of Aspergillus ochraceus and ten of Penicillum spp. were evaluated for their ability to hydrolyze protein, fat and hydrogen peroxide when the molds were grown in the presence of different amounts (0–10%) of sodium chloride. Proteolytic and lipolytic activities of strains of A. flavus generally increased with an increase in the amount of sodium chloride in the medium. This was true for proteolytic and less so for lipolytic activity of A. parasiticus and A. ochraceus. Of the penicillia tested, five exhibited a marked increase and five a smaller increase in proteolytic and lipolytic activity at 2, 4 and 6% sodium chloride, but such activity either remained constant or decreased at 8 and 10% sodium chloride. Peroxidase activity in mycelia of all strains of aspergilli increased with an increase of sodium chloride in the medium. Most strains of Penicillium spp. exhibited maximum peroxidase activity at 2% sodium chloride, and some reduction in activity when the amount of sodium chloride in the medium exceeded 2%.