DISTRIBUTION OF UREASE AND EXTRACELLULAR DNASE IN YEAST SPECIES

Abstract

Urease and extracellular DNase activities were tested in 292 strains belonging to 125 species of 33 genera. Basidiomycetous yeasts and related species had both urease and extracellular DNase. Species belonging to the genera Rhodotorula and Cryptococcus, and four species of Candida (Candida curvata, Candida humicola, Candida bogoriensis, and Candida diffluens) which are considered to be closely related to basidiomycetous yeasts, showed both activities. In general, ascosporogenous yeasts and their imperfect forms did not have either urease or extracellular DNase. Hansenula bimundalis and Saccharomycopsis lipolytica showed both enzymes, but the activities were weaker than those of basidiomycetous yeasts. Schizosaccharomyces pombe, Schizosaccharomyces octosporus, Citeromyces matritensis, Lipomyces starkeyi, and Nadsonia elongata had urease but not extracellular DNase. Saccharomycopsis fibuligera, Hansenula jadinii, Hansenula minuta, Pichia pinus, Pichia rhodanensis, and Candida pseudotropicalis showed extracellular DNase but not urease. Taxonomic significance of urease and extracellular DNase is discussed.