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.Taxonomic significance of yeast urease was first pointed out by SAKAGUCHI and SHIZUME (1) in 1937, and of 60 yeast strains, three Torula strains, one Schizosaccharomyces strain, and one unidentified strain were found to be urease-positive. Later, SEELIGER (2) investigated urease in sporogenous and asporogenous yeasts, and mentioned its particular distribution in the genera Cryptococcus and Rhodotorula. TSUCHIYA et al. (3,4) confirmed its usefulness in yeast taxonomy in connection with serological characteristics. NAKASE and KOMAGATA (5-8) and NAKASE (9) pointed out that in general urease-positive strains showed higher values of DNA base composition (GC content in DNA), while urease-negative yeast strains demonstrated lower values of GC content in DNA. On the other

Rapid Diazonium Blue B Test to Detect Basidiomycetous Yeasts

“…Previous studies have shown that extracellular enzyme production is common in basidiomycetous yeasts (8,20). Our results support the observation by van der Walt et al (22) that some ascomycetous yeasts, such as Saccharomycopsis spp., also produce extracellular enzymes.…”

“…Therefore, the use of the DBB test is not widespread. This report describes an improved DBB test to detect basidiomycetous relationships of yeasts and yeastlike organisms and correlates the results of the DBB test with extracellular enzyme production.(DBB) (2,3,6,8,9,11,14,17,(20)(21)(22) 26; C. E. …”

“…Ascomycetous yeasts have two-layered cell walls that are attacked by (1,3)-P-glucanases to release protoplasts, have deoxyribonucleic acid guanineplus-cytosine contents of about 30 to 60%, frequently are fermentative, usually lack extracellular urease and deoxyribonuclease (DNase), and have respiratory enzymes of coenzyme Q types 6 through 9 (2,3,11,14,20,25). Basidiomycetous yeasts have laminar cell walls that resist (1,3)-P-glucanase activity, have deoxyribonucleic acid guanine-plus-cytosine contents of about 50 to 7056, with rare exception are strictly oxidative, generally have extracellular urease and DNase, have respiratory enzymes of coenzyme Q types 7 through 10, and give a red to violet color reaction with diazonium blue B Sonck and E. Tunnela, Antonie van Leeuwenhoek J. Microbiol.…”

A colorless variant derived from Rhodosporidium toruloides strain YK 212 (IAM 13509, IFO 1236) and its taxonomic implication.

“…The activity of extracellular deoxyribonuclease (DNase) was determined by the method of SEN and KoMAGATA (19). The Diazonium Blue B (DBB) color test was performed according to the methods of VAN DER WALT and HoPsu-HAVV (20) and HAGLER and AHEARN (21).…”

A New Yeast Species, Candida Acutus, Isolated From Sulfited Grape Must

“…This yeast named Candida acutus was characterized by the morphological properties of the formation of septated or short mycelical cells and budding cells from tapering base on lateral of cells in ring or pellicle on YM broth, and the biochemical properties of a high GC content (54.7 %), the positive activities of urease and DNase, and the Q9 of coenzyme Q system. In the phylogenetic relationship of Candida, Torulopsis, and other anasporogenous yeasts on the basis of biochemical characters, NAKASE and KOMAGATA (7) and SEN and KOMAGATA (8) pointed out that yeasts with high GC content (above 50%) and activities of urease and extracellular DNase would originate from heterobasidiomycetes. From this point of view, C. acutus is considered to be related to heterobasidiomycetes, though its perfect stage is not found yet.…”