Four new yeasts in the Candida mesenterica clade associated with basidiocarp-feeding beetles

We isolated five yeasts related to Candida mesenterica from the digestive tract, frass, and habitat of beetles in six families inhabiting basidiocarps. Based on rDNA sequence comparisons and phenotypic characters, the yeasts were identified as Kodamaea ohmeri and four undescribed taxa. Phylogenetic analysis of combined small and large subunit ribosomal DNA sequences placed the five taxa in a statistically well supported clade with C. mesenterica, Candida suecica and other yeast species known from basidiocarps, including 'Endomyces scopularum' (CBS154.92 and 155.92), Candida fukazawae, Candida fungicola and Candida sagamina. Only one of the new taxa produced ascospores; the other three reproduced only asexually. The yeasts appear to be less closely associated with beetles than with the beetle habitat. The new species and their type strains are Kodamaea laetipori (type strain NRRL Y-27713 T), Candida derodonti (type strain NRRL Y-2771 1 T), Candida arcana (type strain NRRL Y-27712 T) and Candida plutei (type strain NRRL Y-27715 T).     

Candida alocasiicola sp. nov., Candida hainanensis sp. nov., Candida heveicola sp. nov. and Candida musiphila sp. nov., novel anamorphic, ascomycetous yeast species isolated from plants

In a taxonomic study on the ascomycetous yeasts isolated from plant materials collected in tropical forests in Yunnan and Hainan Provinces, southern China, four strains isolated from tree sap (YJ2E(T)) and flowers (YF9E(T), YWZH3C(T) and YYF2A(T)) were revealed to represent four undescribed yeast species. Molecular phylogenetic analysis based on the large subunit (26S) rRNA gene D1/D2 domain sequences showed that strain YJ2E(T) was located in a clade together with Candida haemulonii and C. pseudohaemulonii. Strain YF9E(T) was most closely related to C. azyma and strain YWZH3C(T) to C. sorbophila and C. spandovensis. Strain YYF2A(T) was clustered in a clade containing small-spored Metschnikowia species and related anamorphic Candida species. The new strains differed from their closely related described species by more than 10% mismatches in the D1/D2 domain. No sexual states were observed for the four strains on various sporulation media. The new species are therefore assigned to the genus Candida and described as Candida alocasiicola sp. nov. (type strain, YF9E(T) = AS 2.3484(T) = CBS 10702(T)), Candida hainanensis sp. nov. (type strain, YYF2A(T) = AS 2.3478(T) = CBS 10696(T)), Candida heveicola sp. nov. (type strain, YJ2E(T) = AS 2.3483(T) = CBS 10701(T)) and Candida musiphila sp. nov. (type strain, YWZH3C(T) = AS 2.3479(T) = CBS 10697(T)).     

Three new species of anamorphic yeasts phenotypically and phylogenetically related toCandida mesenterica: The description ofCandida fungicola sp. nov.,Candida sagamina sp. nov., andCandida fukazawae sp. nov. isolated from fruit bodies of mushrooms

Four strains of anamorphic yeasts isolated from fruit bodies of mushrooms collected in Japan were found to represent three new species of the genusCandida. These species resembleCandida mesenterica in characteristics commonly employed in the classification of yeasts. On the basis of DNA-DNA reassociation, however, they were clearly distinguished fromC. mesenterica and from one another. Three new species,Candida fungicola, Candida sagamina, andCandida fukazawae, are proposed for these yeasts. The analysis of SSU rDNA sequences suggested that these three species were closely related to each other and toC. mesenterica andC. suecica.     

Short Communication: Characterization and succession of yeast populations associated with spontaneous fermentations during the production of Brazilian sugar-cane aguardente

A succession of yeasts was observed during fermentation of aguardente with Saccharomyces cerevisiae being the predominant species. Candida sake, Kluyveromyces marxianus var. drosophilarum and apiculate yeasts were also frequent. Transient yeast species were found in variable numbers, probably due to the daily addition of sugar-cane juice. Killer yeasts were isolated and may have a role in the exclusion of some transient and contaminant species.     

Occurrence of human-associated yeasts in bivalve shellfish from Long Island Sound.

Candida parapsilosis, C. tropicalis, and Torulopsis glabrata were the human-associated yeasts most frequently isolated from quahogs, oysters, and mussels collected from four estuarine areas along the northern shore of Long Island Sound. Some inconsistency and seasonal variation in the occurrence of these and other yeast species were noted. In particular, C. albicans densities were greatest during colder months in the more heavily polluted waters. A total of 347 yeasts were isolated and cultured at 37 degrees C and, of these, 219 of 62% were human-associated forms. Generally, these yeasts in the animals sampled reflected the overall pollution status of the estuary from which they were taken. This study represents a clear demonstration of potentially pathogenic yeasts in a valuable marine resource.     

Occurrence of human-associated yeasts in bivalve shellfish from Long Island Sound.

Candida parapsilosis, C. tropicalis, and Torulopsis glabrata were the human-associated yeasts most frequently isolated from quahogs, oysters, and mussels collected from four estuarine areas along the northern shore of Long Island Sound. Some inconsistency and seasonal variation in the occurrence of these and other yeast species were noted. In particular, C. albicans densities were greatest during colder months in the more heavily polluted waters. A total of 347 yeasts were isolated and cultured at 37 degrees C and, of these, 219 of 62% were human-associated forms. Generally, these yeasts in the animals sampled reflected the overall pollution status of the estuary from which they were taken. This study represents a clear demonstration of potentially pathogenic yeasts in a valuable marine resource.     

Evaluation of a new chromogenic medium (Candida ID) for the isolation and presumptive identification of Candida albicans and other medically important yeasts

Candidiasis is a frequent human infection caused mainly by Candida albicans. However, other species are emerging as important pathogens, as Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei or Candida guilliermondii. Rapid identification of clinical isolates could facilitate diagnosis and treatment. Candida ID (bioMerieux, Spain) is a new medium for the isolation and presumptive identification of yeasts: C. albicans grows as blue colonies, and C. tropicalis, C. guilliermondii, Candida kefyr and Candida lusitaniae as pink ones. The utility of Candida ID was evaluated with more than 700 clinical isolates and type culture collection strains from different genera including Candida, Cryptococcus, Saccharomyces, and Rhodotorula. Presumptive identification was confirmed by germ tube test, microscopic morphology and chlamydoconidia production on corn meal agar and carbohydrate assimilation on API-ATB ID 32C or Vitek (bioMerieux). Growth on Candida ID was rapid (18-24 h) for most of the yeast strains tested. Sensitivity and specificity of identification of C. albicans was significantly high (>98%), since a very low number of isolates were found to be false negative or false positive. A better result was obtained for species growing as pink colonies (>99.5%). Detection of different species of medical important yeasts was easy with Candida ID, as perfectly distinct colors and textures of colonies were observed on this medium. Candida ID allowed the discrimination between C. glabrata (creamy and smooth) and C. krusei (rough and white) colonies. Other species showed different colony textures and colours, white being the predominant colour. Candida ID was very useful for the presumptive identification C. albicans isolates.     

Yeasts isolated from plant-associated beetles and other insects: seven novel Candida species near Candida albicans

Yeasts related to Candida albicans were isolated from the digestive tracts of beetles in eight families and various orders of insects such as earwigs, crickets, and roaches, most of which were caught at light traps or in a few cases directly from plant materials. Based on comparisons of DNA sequences and other taxonomic characteristics, a total of 41 isolates were identified as Candida orthopsilosis, Candida pseudorhagii, Candida maltosa, Candida parapsilosis, Candida tropicalis, Candida neerlandica, Lodderomyces elongisporus, and seven new Candida species. The new species and type strains are designated as Candida gigantensis NRRL Y-27736T, Candida bohiensis NRRL Y-27737T, Candida alai NRRL Y-27739T, Candida buenavistaensis NRRL Y-27734T, Candida frijolesensis NRRL Y-48060T, Candida labiduridarum NRRL Y-27940T, and Candida tetrigidarum NRRL Y-48142T. A phylogeny based on SSU and LSU rRNA gene sequences indicated that most of the new species were closely related to members of the C. albicans/L. elongisporus clade, such as C. albicans, Candida dulbliniensis, C. neerlandica, Candida chauliodes, and Candida corydali. Candida alai was placed near this clade, but no closely related sister taxon was identified. The ecology of the insect-associated yeasts is discussed and compared with the results from other studies.     

Rapid identification of Candida glabrata using a new commercial kit

Candida glabrata is an emergent pathogen with diminished susceptibility to azoles, thus a rapid identification of this yeast could be of help to choose the appropriate treatment. GLABRATA RTT (Fumouze Diagnostics, France) is a new C. glabrata identification test. To evaluate its utility in the clinical laboratory daily routine, we prospectively tested 168 yeasts isolated in our hospital. GLABRATA RTT results had a sensitivity of 98.4% and a specificity of 100%. The combination of CHROMagar Candida isolation medium and GLABRATA RTT test allowed the identification of the four most common species in the clinical practice (Candida albicans, Candida tropicalis, Candida krusei and C. glabrata).     

Three new ascomycetous yeasts from insect-associated arboreal habitats

A new species of Pichia and two new species of Candida are described and were determined to be genetically isolated from all other currently recognized ascomycetous yeasts from their sequence divergence in the species-variable D1/D2 domain of large subunit (26S) ribosomal DNA. The three species were primarily isolated from the frass of wood-boring insects living in pine and spruce trees. The new species and their type strains are the following: Pichia ramenticola NRRL YB-1985 (CBS 8699), mating type alpha (NRRL YB-3835, CBS 8700, mating type a), Candida piceae NRRL YB-2107 (CBS 8701), and Candida wyomingensis NRRL YB-2152 (CBS 8703). Pichia ramenticola and C. piceae assimilate methanol as a carbon source; P. ramenticola is the first known heterothallic ascomycetous yeast to utilize this compound.     

Isolation of proteolytic psychrotrophic yeasts from fresh raw seafoods

A total of 103 cultures of yeasts were isolated from seven kinds of fresh raw seafoods. The isolates comprised six genera, Candida, Cryptococcus, Debaryomyces, Rhodotorula, Sterigmatomyces and Trichosporon , and included 21 different species. All the isolates were psychrotrophic yeasts. Proteolytic activities of 50 psychrotrophic strains were studied by use of skim milk within the temperature range of 0–42°C. All the strains showed various degrees of proteolysis. In particular, Candida lipolytica. Trichosporon pullulans and Candida scottii were active species at low temperatures. Sensory spoilage due to the proteolytic yeasts were observed in mackerel homogenates stored at 10°C. C. lipolytica -inoculated homogenates caused spoilage with ammoniacal odours after 1 week of storage. Values of total volatile basic nitrogen at 10°C were highest with C. lipolytica among 35 strains tested, followed by Tr. pullans. Trichosporon cutaneum, C. scottii, Rhodotorula glutinis and Cryptococcus luteolus. Proteolytic psychrotrophic yeasts were widely distributed in raw seafoods.     

Characterisation of the diversity and physiology of cellobiose-fermenting yeasts isolated from rotting wood in Brazilian ecosystems

We investigated the yeast species associated with rotting wood samples obtained from Brazilian ecosystems, with a special focus on cellobiose-fermenting species. About 647 yeast strains were isolated from rotting wood samples collected from the areas of Atlantic rainforest, Cerrado, and Amazonian forest. Eighty-six known species and 47 novel species of yeasts were isolated. Candida boidinii, Cyberlindnera subsufficiens, Meyerozyma guilliermondii, Schwanniomyces polymorphus, Candida natalensis, and Debaryomyces hansenii were the most frequently isolated species. Among the cellobiose-fermenting yeasts, 14 known and three novel yeast species were identified. Scheffersomyces queiroziae, Sc. amazonensis, Yamadazyma sp.1, Hanseniaspora opuntiae, C. jaroonii, and Candida tammaniensis were the main ethanol-producing yeasts. These species also produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. In fermentation assays using a culture medium containing 50 g L^?1 cellobiose, ethanol production was observed in all cases; Sc. queiroziae and Sc. amazonensis showed the highest yield, efficiency, and productivity. Candida jaroonii and Yamadazyma sp.1 strains also showed high efficiency in cellobiose fermentation, while C. tammaniensis and H. opuntiae strains produced low amounts of ethanol. This study shows the potential of rotting wood samples from Brazilian ecosystems as a source of yeasts, including new species as well as those with promising biotechnological properties.     

<Emphasis Type="Italic">Candida kashinagacola</Emphasis> sp. nov., <Emphasis Type="Italic">C. pseudovanderkliftii</Emphasis> sp. nov. and <Emphasis Type="Italic">C. vanderkliftii</Emphasis> sp. nov., three new yeasts from ambrosia beetle-associated sources

Three new yeast species, Candida kashinagacola (JCM 15019(T) = CBS 10903(T)), C. pseudovanderkliftii (JCM 15025(T) = CBS 10904(T)), and C. vanderkliftii (JCM 15029(T) = CBS 10905(T)) are described on the basis of comparison of nucleotide sequences of large subunit ribosomal DNA D1/D2 region (LSU rDNA D1/D2). The nearest assigned species of the three new species was Candida llanquihuensis. Candida kashinagacola and C. pseudovanderkliftii differed from C. llanquihuensis by 3.8% nucleotide substitution of the region, while C. vanderkliftii did by 4.4%. Three new species differed in a number of physiological and growth characteristics from any previously assigned species and from one another. A phylogenetic tree based on the sequences of LSU rDNA D1/D2 showed that these new species together with Candida sp. ST-246, Candida sp. JW01-7-11-1-4-y2, Candida sp. BG02-7-20-001A-2-1 and C. llanquihuensis form a clade near Ambrosiozyma species. The new species did not assimilate methanol as a sole source of carbon, which supported the monophyly of these non methanol-assimilating species which are closely related to the methylotrophic yeasts. Candida kashinagacola was frequently isolated from the beetle galleries of Platypus quercivorus in three different host trees (Quercus serrata, Q. laurifolia and Castanopsis cuspidata) located in the sourthern part of Kyoto, Japan, thus indicating that this species may be a primary ambrosia fungus of P. quercivorus. On the other hand, C. pseudovanderkliftii and C. vanderkliftii were isolated only from beetle galleries in Q. laurifolia. Candida vanderkliftii was isolated from beetle gallery of Platypus lewisi as well as those of P. quercivorus. Candida pseudovanderkliftii and C. vanderkliftii are assumed to be auxiliary ambrosia fungi of P. quercivorus.     

Yeasts in Ensiled High-Moisture Corn

A total of 1,365 yeasts were selected from ensiled high-moisture corn at various stages in the ensiling process to determine the sequence and relative numbers of yeast species. The yeast species most frequently isolated from freshly harvested corn were Candida parapsilosis and C. intermedia; these two species were isolated infrequently after the third week of storage. Species of yeasts that predominate after the 12th day of storage were Hansenula anomala (66% of the isolates studied) and C. krusei (26% of the isolates studied). The preponderance of H. anomala and C. krusei in ensiled corn is believed to be associated with the ability of these two species to assimilate lactic acid.     

Taxonomic study of four yeast strains assimilating methanol

The new isolated yeasts were very good producers of biomass from methanol. Their taxonomic studies were based on classical classification, GC content of DNA, proton magnetic resonance spectrum of the cell wall mannans and mannan and glucan and chitin contents in the cell walls. The isolates could not be identified with any species described in literature. Considering their special features and some relation to the known species, the isolated yeasts were classified as follows: C-16 as Candida bimundalis var. chlamydospora, C-4 as Candida melinii var. melibiosica, D-3 as Candida silvicola var. melibiosica and M-1 as Torulopsis candida var. nitratophila.     

Candida arabinofermentans, a new L-arabinose fermenting yeast

Candida arabinofermentans (type strain NRRL YB-2248, CBS 8468), a new yeast that ferments the pentose L-arabinose, is described. The three known strains of this new species were isolated from insect frass of pine and larch trees in the U.S. Phylogenetic analysis of nucleotide sequences from the D1/D2 domain of large subunit (26S) ribosomal DNA places C. arabinofermentans among the methanol-assimilating yeasts and most closely related to Candida ovalis. Strains of the new species produce 0.7-1.9 g/l ethanol from L-arabinose.     

Candida kazuoi sp. nov. and Candida hasegawae sp. nov., two new species of ascomycetous anamorphic yeasts isolated from insect frass in Thailand

Two strains of anamorphic yeasts isolated from insect frass collected in southern Thailand were assigned to the genus Candida based on the conventional taxonomic criteria used for yeast classification. In the phylogenetic tree based on the D1/D2 domain of the 26S rDNA, these strains are distant from the known species of yeasts and considered to represent two different new species. They are named Candida kazuoi sp. nov. and Candida hasegawae sp. nov.     

Routine Identification of Yeasts with the Aid of Molybdate-Agar Medium

A large number of yeasts, including a variety of species other than Candida albicans, were isolated from clinical specimens. C. tropicalis and Torulopsis glabrata were each found one-third as frequently as C. albicans. A schema is presented which made possible, by simple procedures, the identification of the great majority of the isolated yeasts. Preliminary isolation and differentiation was aided by the use of molybdate-agar medium. The use of the schema by diagnostic bacteriological laboratories is discussed.     

The yeast flora of some decaying mushrooms on trunks of living trees

Several ascomycetous and basidiomycetous yeasts were isolated from rotten mushrooms on the trunks of beech and tamarisk trees. One strain, identified as the novel species Cryptococcus allantoinivorans, assimilated allantoin as the sole carbon source. Phylogenetically it belongs to the C. laurentii complex, Papiliotrema bandonii being the closest relative. Some ascomycetous strains could not be distinguished from Pichia guillermondii, but deviated considerably in rDNA sequences. In addition to these species, both decaying mushrooms were inhabited by more common species, viz. Candida albicans, C. saitoana, Rhodotorula mucilaginosa, Trichosporon asahii, T. multisporum and T. porosum. The basidiomycetous yeasts, except R. mucilaginosa, assimilated some polysaccharides of plant origin.