Systematic of the genera Saccharomyces, Schizosaccharomyces, Endomycopsis, Kluyveromyces, Schwanniomyces and Brettanomyces: proton magnetic resonance spectra of the mannans and mannose-containing polysaccharides as an aid in classification

Evaluation of phylogenetic relationships among fission yeast by nDNA/nDNA reassociation and conventional taxonomic criteria

The genus Schizosaccharomyces comprises a small, somewhat heterogeneous group of yeast species which have in common a unique mode of vegetative reproduction by cross-wall formation without constriction as well as a certain degree of osmophilia, most strains having been isolated from habitats of high sugar concentration. This study evaluated inter- and intraspecific relationships utilizing nDNA/nDNA optical reassociation and by the analysis of physiological profiles of several strains of each species. Results demonstrate that the genus should be divided into three species: Schiz. japonicus, Schiz. octosporus and Schiz. pombe.

Coenzyme Q system in the classification of some ascosporogenous yeast genera in the families Saccharomycetaceae and Spermophthoraceae

The Co-Q systems of 11 strains representing the genera Schwanniomyces, Lodderomyces, Lipomyces, Nematospora and Metschnikowia were determined. All the genera were characterized by the Q-9 system except for the genus Nematospora with needle-shaped ascospores. The only species, Nem. coryli, was found to have the Q-6 system. These results are discussed from the taxonomic point of view.

Three new asporogenous yeasts found in industrial waste water

Representatives of three new asporogenous species, Candida flavificans, Candida inositophila, and Torulopsis sorbophila were isolated from washings of ion-exchange resin in a guanosine monophosphate manufacturing plant. The DNA base composition, proton-magnetic-resonance spectrum of extracted polysaccharides, and serological characteristics of the yeasts were investigated in addition to the characteristics commonly employed. Descriptions of the new species are given.

Discrimination between Sporothrix schenckii and Ceratocystis stenoceras rhamnomannans by proton and carbon-13 magnetic resonance spectroscopy

The proton and (13)C magnetic resonance (CMR) spectra of 10 Sporothrix schenckii and three Ceratocystis stenoceras rhamnomannans were studied. On the basis of their CMR spectra, the rhamnomannans from S. schenckii strains could be classified into two major types, I and II, readily distinguishable from the polysaccharides formed at the same temperature (25 C) by C. stenoceras. Rhamnomannans from S. schenckii synthesized at 37 C gave CMR spectra (type III) differing from those of polysaccharides of types I and II and from those of C. stenoceras polysaccharides. The contention that C. stenoceras might be the perfect form of S. schenckii is not supported by the present data. A presumptive pathogenic mutant of C. stenoceras synthesized a type I rhamnomannan characteristic of S. schenckii, clearly differing from the rhamnomannans from C. stenoceras synthesized in the same conditions. Nuclear magnetic resonance spectroscopy revealed differences in the structures of the polysaccharides from these species not previously recognized by methylation analysis.

Scanning electron microscopy of ascospores of Schwanniomyces

Ascospores of the four recognized species of Schwanniomyces were examined by scanning electron microscopy. Spores of S. alluvius, S. castellii, and S. occidentalis, which were essentially identical, had abundant, long protuberances and wide, thin equatorial rings. The two known strains of S. persoonii differed from the other species as well as from each other. One strain had spores with a wide ring but only a few short protuberances; spores from the second strain were covered with craterlike depressions and had a narrow ring. Also examined were spores of Schwanniomyces hominis (=Saccharomyces rosei) which lacked a ring and were covered with short irregularly shaped protuberances, a finding consistent with the morphology of spores from other strains of S. rosei.