Leucosporidium fellii sp. nov., a basidiomycetous yeast that degrades L(+)-tartaric acid

A new species of basidiomycetous yeast Leucosporidium fellii was isolated from soil in Portugal on a selective L(+)-tartaric acid medium. This yeast is self-sporulating but forms dikaryotic hyphae with clamp connections and is presumably homothallic. It differs from the type strain of Leucosporidium scottii in its life cycle, assimilation pattern and guanine-cytosine content and from the other described Leucosporidium species by additional characteristics.     

Sterigmatosporidium gen. n., a new heterothallic basidiomycetous yeast,the perfect state of a new species of Sterigmatomyces Fell

Sterigmatosporidium gen. n. is described as a new basidiomycetous yeast-like fungus with the single species Sterigmatosporidium polymorphum sp. n. for which a Latin diagnosis and a preliminary life cycle are presented. The mean character distinguishing the new genus from the imperfect genus Sterigmatomyces is the development of a dikaryotic mycelium with clamp connections producing sexual spores in ramified whorls and lateral chlamydospores as well as blastospores. The dikaryotic phase could be induced by crossing compatible haploid clones of the heterothallic fungus, which are similar to Sterigmatomyces but not identical with any known species.     

The perfect and imperfect states ofSporobolomyces salmonicolor

A strain ofSporobolomyces salmonicolor from which both the haplophase and diplophase had been recovered was found to form teliospores which germinated usually by the formation of a non-septate promycelium bearing 2–4 sporidia. The strain has consequently been transferred to the new basidiomycetous yeast genusAessosporon, for which a diagnosis and type are given, and which has been assigned to the Tilletiaceae.     

Nucleotide sequence analysis of a variable region of the large subunit rRNA for identification of marine-occurring yeasts

A 230-nucleotide region of the large subunit (LSU) ribosomal RNA was examined to determine whether signature nucleotide sequences could be used for species identifications of basidiomycetous yeasts. Multiple strains of genetically defined heterothallic species ofRhodosporidium, Leucosporidium, Cystofilobasidium, andSporidiobolus demonstrated that nucleotide sequences within these species are homologous and that differences between species range from 1 to 20 or more bases. Also included in this study were several homothallic species of these teleomorphic genera and some anamorphs assigned toRhodotorula andCandida. Those results indicated close relationships among certain homothallic species, particularly in the genusMrakia, and potential relationships of homothallic and anamorphic strains to several teleomorphs. The data suggest that LSU sequences can be used for yeast identifications with the possible exception of closely related homothallic species.     

Morphological and Mutational Analysis of Mating in Ustilago hordei

Martinez-Espinoza, A. D., Gerhardt, S. A., and Sherwood, J. E. 1993. Morphological and mutational analysis of mating in Ustilago hordei. Experimental Mycology 17, 200-214. Ustilago hordei is a basidiomycete that causes covered smut on barley. Mating in U. hordei, which is controlled by a single locus with two alleles, results in the conversion of haploid, nonpathogenic yeast-like sporidia to dikaryotic, pathogenic mycelia. When sporidia of the opposite mating type were mixed and placed on water agar, both cell types produced conjugation tubes within 2 h at 21°C. Growth of conjugation tubes was directed toward the tip of tubes arising from cells of the opposite mating type. These tubes fused and the dikaryotic mycelium emerged from the conjugation bridge. Sporidia separated by a dialysis membrane were still capable of inducing conjugation tube formation by cells of the opposite mating type, indicating the involvement of diffusible small-molecular-weight mating factors (pheromones). Numerous nutritional and environmental variables were examined in order to optimize conjugation tube induction. Twenty-six mutants that fail to form dikaryotic mycelium have been isolated and characterized. These mutants were arranged into classes based on their ability to form conjugation tubes, the ability to induce conjugation tube formation by opposite mating-type cells, and cell morphology. These mutants provide an indication of the genetic complexity involved in this critical phase of the U. hordei life cycle.     

Comparative study of cultures of four species of the genusOudemansiella

Thirty stationary and submerged cultures of species of the genusOudemansiella Speg.,viz. two narrow-region species (O. brunneomarginata, O. canarii) and two primarily wideregion species (O.mucida, O. radicata) were compared. Stationary cultures have identical macroscopic and microscopic features (they produce crust, teleomorph, large thick-walled basidiospores with an apiculum and an uneven surface, dikaryotic hyphae have clamp connections). “Coils” were detected in the mycelium of two species by SEM. Submerged cultures produce antibacterial and particularly antifungal antibiotics, although with various intensity.O. brunneomarginata was first studied in pure culture and its microstructures were first studied by SEM. It could be demonstrated that this species is related with other representatives of the genusOudemansiella. In the present taxonomy of basidiomycetes it is advisable to extend and deepen data concerning a single genusOudemansiella with a series of interspecies taxons, without impairing “borders” of the genus.     

Heterothallism in the basidiomycetous yeast genusSporidiobolus Nyland

The sexual speciesSporidiobolus salmonicolor andSporidiobolus pararoseus spp. nov. are described as heterothallic species in the genusSporidiobolus, a genus consisting of two homothallic species,Sporidiobolus johnsonii andSporidiobolus ruinenii. The four species are compared and a key to the genus is presented. As a taxonomic correctionSporobolomyces pararoseus nom. nud. is reported as a synonym ofSporobolomyces shibatanus.     

The origin of some species of the genus Candida in non-pseudomycelium-producing anascosporogenous yeasts

Summary One hundred thirty-one cultures of anascosporogenous yeasts isolated from the human body late in 1947 were all typical members of the genusCryptococcus when examined in 1947 and early in 1948. No mycelium was produced in repeated tests in corn meal agar scratch plates or in beef peptone gelatin stabs. By 1950, 17 of the 131 cultures had definitely become morphologically identical with members of the genusCandida, showing typical pseudomycelial growth with blastospores sprouting from the mycelium on the above mentioned media. It is concluded that some species ofCandida can be morphological dissociates ofCryptococcus. The status and the varied phylogeny of the genusCandida is discussed.

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Sumario Todos los 131 cultivos de una colección de levaduras imperfectas recientemente aisladas de la piel de seres humanos eran miembras típicas del géneroCryptococcus en 1947. No producían ningún micelio, aunque lo buscabamos repeditas veces en gelosa de harina de maíz y en gelatina de carne y peptona. Ahora en 1950, 17 de los 131 cultivos se han convertido en formas identicas morfológicamente con miembras del generoCandida. En estas medias las 17 levaduras ya poseen un seudomicelio conspicuo de que muchas blastoesporas brotan. Se deduce que unas especies deCandida pueden ser formas deCryptococcus producidas por disociación microbiana. Se trata del estado y de la filogenia multiple del géneroCandida.

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El origen de unas especies del géneroCandida en levaduras imperfectas que no formaban seudomicelio

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This investigation was supported in part by funds provided for biological and medical research by the State of Washington Initiative Measure No. 171.     

LOLA ZRREGULARIS (CHLOROPHYTA-CLADOPHORACEAE): A NEW SPECIES FROM THE ROSS SEA,ANTARCTICA1

A small, loose lying, unbranched, filamentous alga from the Ross Sea, Antarctica, is described as a new species, Lola irregularis. The genus Lola is closely related to the genera Hormiscia, Rhizoclonium, and Chaetomorpha in the family Cladophoraceae. A key to all known species of Lola is included. This is the first record of a species of Lola south of the Antarctic convergence.     

Filobasidium capsuligenum nov. comb.

Leucosporidium capsuligenum Fell et al. is classified in the genusFilobasidium Olive sinceTilletia-like basidia were discovered growing out from a dicaryotic mycelium with clamp connections. The speciesFilobasidium floriforme andFilobasidium capsuligenum are compared morphologically and physiologically. The author is indebted to Dr. G. Kraepelin who place the original culture, isolated from soil with dead leaves, to the disposal of the Centraalbureau voor Schimmelcultures, and to Dr. J. A. von Arx who provided him with the singlespore isolates.     

Reversion of protoplasts from dikaryotic mycelium ofSchizophyllum commune

Summary Morphological observations on the reversion of homokaryotic protoplasts obtained from dikaryotic mycelium ofSchizophyllum commune reveal that part of the morphogenetic processes operative in clamp formation are transiently expressed in the absence of heterokaryotic conditions. Often the homokaryotic revertants start off to produce simple septa and then 21form pseudoclamps for some time before they revert permanently to the normal monokaryotic morphology with simple septa. Heterokaryotic revertants often form pseudoclamps before reverting to the normal dikaryotic morphology with true clamps.     

LOLA IRREGULARIS (CHLOROPHYTA-CLADOPHORACEAE) : A NEW SPECIES FROM THE ROSS SEA,ANTARCTICA1

A small, loose lying, unbranched, filamentous alga from the Ross Sea, Antarctica, is described as a new species, Lola irregularis. The genus Lola is closely related to the genera Hormiscia, Rhizoclonium, and Chaetomorpha in the family Cladophoraceae. A key to all known species of Lola is included. This is the first record of a species of Lola south of the Antarctic convergence.     

The taxonomy of yeasts isolated fromDrosophila in the Yosemite region of California

Summary A survey was made of the yeasts occurring in the intestinal tract of wild species ofDrosophila occurring in the Yosemite Region of California. Two hundred and forty one yeasts, representing 42 species and varieties, were identified. Each isolate was obtained from a different fly. Almost half of the isolates belong toSaccharomyces. The most common species in this genus wereS. montanus (36 isolates),S. veronae (30 isolates),S. cerevisiae var.tetrasporus (22 isolates) andS. drosophilarum (13 isolates). Further species are listed in Table 1.Zygosaccharomyces fermentati Naganishi was shown to be a distinct species and not a synonym ofS. cerevisiae. In order to avoid confusion with another yeast of the same name, it has been proposed to change the nameZ. fermentati toS. montanus Naganishi. Two new species ofSaccharomyces were described,S. wickerhamii andS. kluyveri. S. mangini var.tetrasporus has been renamedS. cerevisiae var.tetrasporus. A non-cellobiose attacking strain ofS. drosophilarum has been designated tentativelyS. drosophilarum var.acellobiosa. A new species of the genusPichia was described asP. xylosa. Saccharomyces pastori andSaccharomyces pini were transferred to the genusPichia on the basis of arguments given in the preceding paper. A new species ofTrichosporon was described asTr. aculeatum on the basis of the presence of characteristic needlelike cells. Common species besides those mentioned inSaccharomyces wereHansenula angusta (19),Kloeckera apiculata (15),Kl. magna (13), andTorulopsis stellata (10). Other genera represented wereHanseniaspora, Cryptococus, Rhodotorula, Candida andOospora. Evidence was obtained that many species of imperfect genera consist of distinctly different physiological types.     

Ustilago maydisMating Hyphae Orient Their Growth toward Pheromone Sources

Snetselaar, K. M., Bölker, M., and Kahmann, R. 1996.Ustilago maydismating hyphae orient their growth toward pheromone sources.Fungal Genetics and Biology20,299–312. When small drops ofUstilago maydissporidia were placed 100–200 μm apart on agar surfaces and covered with paraffin oil, sporidia from one drop formed thin hyphae that grew in a zig-zag fashion toward the other drop if it contained sporidia making the appropriate pheromone. For example,a2b2mating hyphae grew towarda1b1anda1b2mating hyphae, and the filaments eventually fused tip to tip. Time-lapse photography indicated that the mating hyphae can rapidly change orientation in response to nearby compatible sporidia. When exposed to pheromone produced by cells in an adjacent drop, haploid sporidia with thea2allele began elongating before sporidia with thea1allele. Sporidia without functional pheromone genes responded to pheromone although they did not induce a response, and sporidia without pheromone receptors induced formation of mating hyphae although they did not form mating hyphae. Diploid sporidia heterozygous atbbut not ataformed straight, rigid, aerial filaments when exposed to pheromone produced by the appropriate haploid sporidia. Again, thea2a2b1b2strain formed filaments more quickly than thea1a1b1b2strain. Taken together, these results suggest that thea2pheromone diffuses less readily or is degraded more quickly than thea1pheromone.     

The taxonomy of yeasts found in exudates of certain trees and other natural breeding sites of some species ofDrosophila

Summary A survey was made of the yeasts occurring in slime fluxes ofQuercus kellogii (black oak),Abies concolor (red fir) and in certain mushrooms and dead logs in the mountains of the Yosemite region of California. Most of the 134 isolates identified were found to be non-fermentative or poorly fermentative (fermenting glucose only and usually weakly). The isolates were placed in the following genera:Pichia (34),Debaryomyces (35), imperfect forms ofHansenula (39),Endomyces (3),Saccharomyces (2),Candida (11),Trichosporon (7),Torulopsis (1),Cryptococcus (1) andSporobolomyces (1). Four new species have been described,Pichia silvestris, Pichia quercibus, Pichia carsonii andDebaryomyces fluxorum. P. quercibus andP. carsonii are unusual representatives of the genusPichia in that they form a very primitive pseudomycelium and lack pellicles on malt extract. To accommodate such species an amended diagnosis of the genusPichia has been proposed byPhaff in an accompanying paper.Saccharomyces pastori, of which 12 isolates were obtained, has been transferred to the amended genusPichia asP. pastori (Guilliermond) nov. comb.     

Mating types inPichia membranaefaciens

Mating types have been found in a strain ofPichia membranaefaciens. The implication of this finding for the classification of some heterothallic species provisionally placed in the genusEndomycopsis is considered.     

Fusarium nisikadoi, a new species from Japan

A new species ofFusarium, F. nisikadoi, isolated fromPhyllostachys nigra var.henonis (bamboo) andTriticum aestivum (wheat) in Japan, is described, illustrated and discussed. This species is differentiated from other known species of the genus by the following characteristics: whitish colony color, long zigzag-like chains of 0–3(-5)-septate clavate conidia, intermixed with pyriform conidia, produced mostly from monophialides and rarely from polyphialides in the aerial mycelium, very long and slender sporodochial conidia, and no chlamydospores. The long chains of septate conidia are known only in this species of the genusFusarium. The conidiophores on the aerial mycelium sometimes proliferate sympodially. The species is tentatively placed in the form-sectionLiseola.     

Fungal diseases of the respiratory tract

The proportion ofCandida and non-Candida species in the clinical material from patients. with respiratory-tract diseases was determined.C. albicans was isolated in 102 cases. An additional 89 strains of yeasts, isolated in association with respiratory diseases, belonged to 10 non-albicans Candida spp. andCryptococcus spp. The prevailing species, which occurred in 47 cases, wasC. parapsilosis. C. tropicalis, C. glabrata, andC. guilliermondii were isolated in 12, 10, and 9 cases, respectively. Four strains ofC. krusei and three strains ofC. lusitaniae and one strain each ofC. freyschussii, C. robusta, C. zeylanoides, andCryptococcus neoformans were also isolated.     

Teliospore germination and compatibility groups in Sphacelotheca tanglinensis

Teliospores ofS. tanglinensis germinate readily in tap water, each producing a 4-celled promycelium bearing 4 sporidia. Sporidia become 2 or more celled after detaching from the promycelium. Fusion between compatible sporidia occurs in a number of ways resulting in hyphae formation. Teliospores form in 3-month old compatibly mated sporidial cultures. Compatibility inS. tanglinensis is a bipolar type.

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Zusammenfassung Sphacelotheca tanglinensis (Tracy &Earle)Zundel (syn.S. ischaemicola Ling) infiziert die Infloreszenzen vonIschaemum indicum (Houtt.)Merr. undI. timorense Kunth. in Singapore und Malaya. Die Keimung von Teliosporen, die nachfolgenden Wachstumphasen und die Kompatibilitätsgruppen sind bisher nicht untersucht worden, außer einigen Beobachtungen der Keimung der Teliosporen. Diese Phasen sind deshalb untersucht worden.

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Adapted from thesis submitted by the junior author to the University of Singapore for the M. Sc. degree.     

Ecology of yeasts in polluted water

The general size and composition of the extant yeast populations in 13 polluted freshwater habitats were surveyed. Subsequently the yeast populations in three of the 13 locations were quantitatively determined and compared. The three locations had (A) low pollution levels, (B) heavy industrial waste pollution, and (C) heavy domestic waste pollution.The yeast population at location A was dominated byRhodotorula andCryptococcus isolates. At station BRhodotorula andCandida were predominant.Candida isolates were in the majority at location C andRhodotorula strains were second in frequency, but were much lower in proportion of the population than at the other two habitats.These polluted waters in general had large yeast populations, ranging as high as 27,000 yeasts per 100 ml, and averaging approximately 3000 yeasts per 100 ml.The presence of human wastes was especially associated with large increases in the proportion ofCandida yeasts in the environment. The genusRhodotorula was consistently present at all locations, but the genusCryptococcus was a major component of the yeast population only in non-polluted or lightly polluted fresh water.We appreciate the assistance of the Calumet Area Surveillance Program, Federal Water Pollution Control Administration, Chicago, in the collection of water samples. This investigation was supported by U.S. Public Health Service Research Grant No. AI 04642 from the National Institute of Allergy and Infectious Diseases.