M.Th. Smith

Arxula gen. nov. (Candidaceae), a new anamorphic, arthroconidial yeast genus

The new genus Arxula is proposed for the classification of xerotolerant, ascomycetous, anamorphic, arthroconidial yeasts. The genus is considered to be of endomycetaceous affinity.

Physiological and DNA Characterization of Candida maltosa, a Hydrocarbon-Utilizing Yeast

Selected yeasts classified as Candida sake van Uden et Buckley were examined for their physiological, morphological and immunological properties and their DNA relatedness. Candida maltosa Komagata, Nakase et Katsuya is herein recognized as a species separate from C. sake. Candida maltosa was distinguished from C. sake and from C. tropicalis by insignificant DNA reassociation. In addition, C. maltosa was distinguished from C. sake by its higher maximal growth temperature and lower guanine plus cytosine content of its DNA and from C. tropicalis by its failure to utilize soluble starch for growth and its resistance to cycloheximide. The species C. cloacae and C. subtropicalis are placed in synonymy with C. maltosa.

Fungal Planet description sheets: 400–468

Novel species of fungi described in the present study include the following from Australia: Vermiculariopsiella eucalypti, Mulderomyces natalis (incl. Mulderomyces gen. nov.), Fusicladium paraamoenum, Neotrimmatostroma paraexcentricum, and Pseudophloeospora eucalyptorum on leaves of Eucalyptus spp., Anungitea grevilleae (on leaves of Grevillea sp.), Pyrenochaeta acaciae (on leaves of Acacia sp.), and Brunneocarpos banksiae (incl. Brunneocarpos gen. nov.) on cones of Banksia attenuata. Novel foliicolous taxa from South Africa include Neosulcatispora strelitziae (on Strelitzia nicolai), Colletotrichum ledebouriae (on Ledebouria floridunda), Cylindrosympodioides brabejum (incl. Cylindrosympodioides gen. nov.) on Brabejum stellatifolium, Sclerostagonospora ericae (on Erica sp.), Setophoma cyperi (on Cyperus sphaerocephala), and Phaeosphaeria breonadiae (on Breonadia microcephala). Novelties described from Robben Island (South Africa) include Wojnowiciella cissampeli and Diaporthe cissampeli (both on Cissampelos capensis), Phaeotheca salicorniae (on Salicornia meyeriana), Paracylindrocarpon aloicola (incl. Paracylindrocarpon gen. nov.) on Aloe sp., and Libertasomyces myopori (incl. Libertasomyces gen. nov.) on Myoporum serratum. Several novelties are recorded from La Réunion (France), namely Phaeosphaeriopsis agapanthi (on Agapanthus sp.), Roussoella solani (on Solanum mauritianum), Vermiculariopsiella acaciae (on Acacia heterophylla), Dothiorella acacicola (on Acacia mearnsii), Chalara clidemiae (on Clidemia hirta), Cytospora tibouchinae (on Tibouchina semidecandra), Diaporthe ocoteae (on Ocotea obtusata), Castanediella eucalypticola, Phaeophleospora eucalypticola and Fusicladium eucalypticola (on Eucalyptus robusta), Lareunionomyces syzygii (incl. Lareunionomyces gen. nov.) and Parawiesneriomyces syzygii (incl. Parawiesneriomyces gen. nov.) on leaves of Syzygium jambos. Novel taxa from the USA include Meristemomyces arctostaphylos (on Arctostaphylos patula), Ochroconis dracaenae (on Dracaena reflexa), Rasamsonia columbiensis (air of a hotel conference room), Paecilomyces tabacinus (on Nicotiana tabacum), Toxicocladosporium hominis (from human broncoalveolar lavage fluid), Nothophoma macrospora (from respiratory secretion of a patient with pneumonia), and Penidiellopsis radicularis (incl. Penidiellopsis gen. nov.) from a human nail. Novel taxa described from Malaysia include Prosopidicola albizziae (on Albizzia falcataria), Proxipyricularia asari (on Asarum sp.), Diaporthe passifloricola (on Passiflora foetida), Paramycoleptodiscus albizziae (incl. Paramycoleptodiscus gen. nov.) on Albizzia falcataria, and Malaysiasca phaii (incl. Malaysiasca gen. nov.) on Phaius reflexipetalus. Two species are newly described from human patients in the Czech Republic, namely Microascus longicollis (from toenails of patient with suspected onychomycosis), and Chrysosporium echinulatum (from sole skin of patient). Furthermore, Alternaria quercicola is described on leaves of Quercus brantii (Iran), Stemphylium beticola on leaves of Beta vulgaris (The Netherlands), Scleroderma capeverdeanum on soil (Cape Verde Islands), Scleroderma dunensis on soil, and Blastobotrys meliponae from bee honey (Brazil), Ganoderma mbrekobenum on angiosperms (Ghana), Geoglossum raitviirii and Entoloma kruticianum on soil (Russia), Priceomyces vitoshaensis on Pterostichus melas (Carabidae) (Bulgaria) is the only one for which the family is listed, Ganoderma ecuadoriense on decaying wood (Ecuador), Thyrostroma cornicola on Cornus officinalis (Korea), Cercophora vinosa on decorticated branch of Salix sp. (France), Coprinus pinetorum, Coprinus littoralis and Xerocomellus poederi on soil (Spain). Two new genera from Colombia include Helminthosporiella and Uwemyces on leaves of Elaeis oleifera. Two species are described from India, namely Russula intervenosa (ectomycorrhizal with Shorea robusta), and Crinipellis odorata (on bark of Mytragyna parviflora). Novelties from Thailand include Cyphellophora gamsii (on leaf litter), Pisolithus aureosericeus and Corynascus citrinus (on soil). Two species are newly described from Citrus in Italy, namely Dendryphiella paravinosa on Citrus sinensis, and Ramularia citricola on Citrus floridana. Morphological and culture characteristics along with ITS nrDNA barcodes are provided for all taxa.

Polyphasic re-examination of Debaryomyces hansenii strains and reinstatement of D. hansenii, D. fabryi and D. subglobosus

The type species of the genus Debaryomyces, Debaryomyces hansenii, is a highly heterogeneous species. It has been isolated from a large diversity of natural sources including fruit, air, water, soil, but most frequently from processed food products. The species delineation of this yeast species urgently needs clarification. The heterogeneity in taxonomic characteristics has resulted in the description of varieties linked to D. hansenii. The aim of this study was to re-examine and classify D. hansenii using a polyphasic approach. A total of 65 D. hansenii isolates were examined, 57 representing the variety hansenii and nine the variety fabryi. The selection of strains for DNA reassociation and phylogenetic analysis was based on polymerase chain reaction mediated fingerprints using four mini- and microsatellite-specific primers. The discriminating power of growth at 35 °C and 37 °C was re-examined and ascospore production was observed. DNA reassociations and phylogenetic analyses were performed on selected isolates from each of the clusters obtained from the DNA fingerprint analyses. The data indicated the presence of three distinct species within the D. hansenii group, which were represented by type strains of former species and that are proposed to be reinstated: D. hansenii (CBS 767T = MUCL 49680T), D. fabryi (CBS 789T = MUCL 49731T) and D. subglobosus (CBS 792T = MUCL 49732T).

The value of the D1/D2 and internal transcribed spacers (ITS) domains for the identification of yeast species belonging to the genus Yamadazyma

In a taxonomic study of yeasts that have been isolated in French Guiana and Thailand, five yeast strains isolated from plants were found to belong to the Yamadazyma clade of Saccharomycotina. On the basis of morphology, physiology and the nucleotide divergence in the D1/D2 domain of the 26S nuclear ribosomal RNA (nrRNA) gene, as well as the internal transcribed spacers (ITS) domain of the nrRNA gene operon, these strains were identified to represent three novel species in this teleomorphic clade. An additional isolate, that is publicly available from the CBS yeast collection and isolated from Taiwan, was found to be similar to one of the novel species described from Thailand. Yeast species belonging to the Yamadazyma clade have previously been described as members of the Candida membranifaciens clade. These species are widely distributed and were isolated from diverse habitats, including water, plants, animals and guts of insects and termites. In the present study the ITS region is shown to be a valuable region for species identification within this clade, and the novel species proposed are Candida vaughaniae (ex-type strain CBS 8583), Candida khao-thaluensis (ex-type strain CBS 8535) and Candida tallmaniae (ex-type strain CBS 8575).

Dipodascus de Lagerheim

Publisher Summary This chapter focuses on Dipodascus genus and its constituent species. The colonies of this genus are white or cream-colored, farinose or hairy, and are usually dry. Its hyphae are hyaline, mostly disarticulating into rectangular arthroconidia and the asci are acicular, cylindrical, ellipsoidal or subglobose, formed after fusion of gametangia located laterally on hyphae. The asci have persistent walls and open by rupture at the apex. The ascospores are 4–128 per ascus, hyaline, ellipsoidal, with smooth walls and surrounded by regular slime sheaths. Fermentation is mostly absent and extracellular starch is not produced. The constituent species of this genus include Dipodascus aggregatus, Dipodascus albidus, Dipodascus ambrosiae, and Dipodascus armillariae. Hyphae in Dipodascus aggregatus locally becomedensely septate and form clusters of isogamic gametangia. Asci are aggregated in small groups, cylindrical with rounded apex, mostly with 10–30 ascospores, which are liberated by apical rupture of the ascus. In Dipodascus albidus, gametangia are mostly identical, and mostly formed on opposite sides of a septum. The ascospores of this species are up to 128 per ascus, and are hyaline or subhyaline and broadly ellipsoidal.

Molecular differentiation of sibling species in the Galactomyces geotrichum complex

PCR-analysis, multilocus enzyme electrophoresis and molecular karyotyping were used to characterize 52 strains belonging to the genus Galactomyces. The resultant data revealed that a PCR method employing the universal primer N21 and microsatellite primer (CAC)5 is appropriate for the distinction of four Ga. geotrichum sibling species, Ga. citri-aurantii and Ga. reessii. Better separation was achieved with the UP primer N21; each species displayed a specific pattern with very low intraspecific variation. We propose to use the primer N21 for the differentiation of the six taxa composing the genus Galactomyces. Multilocus enzyme electrophoresis revealed genetic homogeneity of each sibling species within the Ga. geotrichum complex. On the other hand, the four sibling species, having from 41 to 59% of nDNA homology and similar phenotypic characteristics, are clearly distinguished based on their electrophoretic profiles using two enzymes: mannose-6-phosphate isomerase (MPI) and phosphoglucomutase (PGM). Despite the same number of chromosomal bands, different karyotype patterns were found in Ga. geotrichum sensu stricto and its two sibling species A and B. Within each sibling species, chromosome length polymorphism was observed, in particular for small bands, allowing discrimination to the strain level.

Galactomyces Redhead & Malloch

Publisher Summary This chapter focuses on Galactomyce genus and its constituent species. The colonies of this genus are white, farinose or hairy, and dry; and its hyphae are hyaline and disarticulate into rectangular arthroconidia. Its septa have micropores, and gametangia are formed laterally on profusely septate parts of hyphae on opposite sides of septa. The asci are subspherical, containing 1 ascospore, which is liberated by disintegration of the entire ascus wall. The ascospores are round, pale brownish, with a rough outer wall layer and with an exosporium and an equatorial furrow. The constituent species of this genus include Galactomyces citri-aurantii, Galactomyces geotrichum, and Galactomyces reessii. In case of Galactomyces citri-aurantii, gametangia are formed in dense clusters laterally on fertile hyphae and gametangia are located on opposite sides of septa or on separate hyphae. The ascospores are broadly ellipsoidal and hyaline, with a smooth or verruculose inner wall and an irregular exosporium, often with a hyaline equatorial furrow and a central lipid droplet. In case of Galactomyces geotrichum, gametangia are formed laterally on densely septate parts of fertile hyphae, which arise after mating. The gametangia are located on opposite sides of the septa, and the asci are subspherical and contain one ascospore.

Hyphozyma, a new genus of yeast-like Hyphomycetes

Hyphozyma gen. nov. is characterized by pink, slimy colonies, showing initial-or late-stage budding and hyphae which produce conidia in basipetal succession through inconspicuous lateral openings. The cell walls contain rhamnose. Two species and a variety are described and their relation to some genera of yeasts and Hyphomycetes is discussed.

Lipomyces Lodder & Kreger-van Rij

Publisher Summary This chapter focuses on Lipomyces genus and its member species. Cells are ellipsoidal or globose, and reproduction takes place through multilateral budding. Oval to cylindrical giant cells may occur in this genus, and pseudomycelium is absent. The cells of most strains are surrounded by a thick mucoid capsule and most strains form starch-like polysaccharides in this capsule. Asci develop in various ways where an “active bud” is mostly involved in formation of the ascus. When the asci develop from active buds only, they often enlarge to an elongate pear shape. The entire ascus may liberate itself from the cell when they mature and the number of spores may reach up to 16 or more for each ascus. When the ascus results from the conjugation of an active bud and a protuberance of a cell, the ascus wall is thicker. The ascospores are globose, ellipsoidal to oblong-ellipsoidal, and generally liberated at maturity. The pigmented walls are of a light amber to brown color and the ascospore wall may be warty, smooth, or it bears ridges running longitudinally on the surface. The member species of this genus include Lipomyces japonicus, Lipomyces kononenkoae, Lipomyces lipofer, and Lipomyces starkeyi.