Savitreea pentosicarens gen. nov., sp. nov., a yeast species in the family Saccharomycetaceae isolated from a grease trap.

Two strains (DMKU-GTCP10-8 and CLIB 1740) representing a novel anamorphic yeast species were isolated from a grease sample collected from a grease trap in Thailand and from an unidentified fungus collected in French Guiana, respectively. On the basis of phylogenetic analysis based on the combined D1/D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, Lachancea fermentati CBS 707T was the closely related species with 12.8 % sequence divergence (70 nucleotide substitutions and three gaps in 571 nucleotides) and 28.1 % sequence divergence (93 nucleotide substitutions and 90 gaps in 651 nucleotides) in the D1/D2 domain of the LSU rRNA gene and the ITS region, respectively. Phylogenetic analysis based on the concatenated sequences of the five genes including the small subunit rRNA gene, the D1/D2 domain of the LSU rRNA gene, the ITS region, translation elongation factor-1 alpha (TEF1) and RNA polymerase II subunit 2 (RPB2) genes confirmed that the two strains (DMKU-GTCP10-8 and CLIB 1740) were well-separated from other described yeast genera in Saccharomycetaceae. Hence, Savitreea pentosicarens gen. nov., sp. nov. is proposed to accommodate these two strains as members of the family Saccharomycetaceae. The holotype is S. pentosicarens DMKU-GTCP10-8T (ex-type strain TBRC 12159=PYCC 8490; MycoBank number 835044).

Large biodiversity of yeasts in French Guiana and the description of Suhomyces coccinellae f.a. sp. nov. and Suhomyces faveliae f.a. sp. nov.

The extent of the diversity of yeasts in tropical rain forest and different environments from French Guiana was investigated. A total of 365 samples were collected from various substrates, such as plants, fruits and insects, at 13 locations, yielding 276 pure yeast isolates. Sequence analysis of the D1/D2 domains of the large subunit rRNA gene indicated that 210 isolates out of 276 belonged to 82 described species (67 Saccharomycotina, 14 Basidiomycota and 1 Pezizomycotina). In addition to these, a total of 54 Saccharomycotina isolates could not be assigned to a known species. These belonged to 14 genera and should be studied further from a taxonomic point of view. In addition, among the 43 Basidiomycotina isolates found, 12 could not be assigned to a known species. This report shows an unexpected biodiversity and indicates that oversea territories, such as French Guiana, constitute a largely unexplored reservoir for yeast diversity. Two Saccharomycotina strains, CLIB 1706 and CLIB 1725, isolated from an insect and from a fern respectively, were characterized further and were shown to belong to the Suhomyces clade on the basis of the rDNA sequence comparison. CLIB 1706TrDNA sequences showed nine substitutions and three indels out of 556 bp (D1/D2 domains) and 32 substitutions and 12 indels out of 380 bp [internal transcribed spacer (ITS)] with that of the most closely related species Suhomyces guaymorum CBS 9823T. CLIB 1725T rDNA sequences presented 18 substitutions and one indel out of 549 bp (D1/D2 domains) and 48 substitutions and 11 indels out of 398 bp (ITS) with that of its closest relative Suhomyces vadensis CBS 9454T. Two novel species of the genus Suhomyces were described to accommodate these two strains: Suhomyces coccinellae f.a. sp. nov. (CLIB 1706T=CBS 14298T) and Suhomyces faveliae f.a. sp. nov. (CLIB 1725T=CBS 14299T).

Kurtzmaniella hittingeri f.a., sp. nov., isolated from rotting wood and fruits, and transfer of three Candida species to the genus Kurtzmaniella as new combinations.

Twelve strains of a novel yeast species were isolated from rotting wood, mushrooms and fruit samples in Brazil and French Guiana. Analysis of the sequences of the internal transcribed spacer region and the D1/D2 domains of the large subunit rRNA gene showed that the novel species belongs to the Kurtzmaniella clade. The novel species differed from its closest relative, Candida natalensis, by 12 substitutions in the D1/D2 sequences. The novel species could be distinguished from C. natalensis by its inability to assimilate cellobiose and salicin, and growth at 50 % (w/w) glucose. The name Kurtzmaniella hittingeri f.a., sp. nov. is proposed for the novel species. The type strain of K. hittingeri sp. nov. is CBS 13469T (=UFMG CM-Y272T). The MycoBank number is 827183. We also propose the transfer of Candida fragi, Candida quercitrusa and Candida natalensis to the genus Kurtzmaniella as new combinations.

Wickerhamiella dianesei f.a., sp. nov. and Wickerhamiella kurtzmanii f.a., sp. nov., two yeast species isolated from plants and insects.

Six yeast strains representing two novel Wickerhamiella species were isolated from plants and insects collected in Costa Rica, Brazil, and French Guiana. They belong to a subclade containing Wickerhamiella domercqiae and Wickerhamiella bombiphila, and differ by approximately 12 % in the D1/D2 sequences of the large subunit rRNA gene from these species. The intergenic spacer (ITS) regions of the two novel species differ by around 19 and 27 %, respectively, from those of W. domercqiae. The novel species exhibit 5 % divergence in the D1/D2 sequences among them (around 4 % in the ITS). The names Wickerhamiella dianesei f.a., sp. nov. and Wickerhamiella kurtzmanii f.a., sp. nov. are proposed to accommodate these species, for which a sexual cycle has not been observed. Wickerhamiella dianesei was isolated from the stingless bee, Trigona fulviventris, collected in an Asteraceae flower in Costa Rica, and from leaves of Sabicea brasiliensis (Rubiaceae) and a flower of Byrsonima crassifolia (Malpighiaceae) in Brazil. Wickerhamiellsa kurtzmanii was isolated from a flower of Ipomoea batatoides (Convolvulaceae) in Costa Rica, the surface of a fruit of B. crassifolia in Brazil, and flowers in French Guiana. The type strains are Wickerhamiella dianesei UWOPS 00-107.1T (=CBS 14185=NRRL Y-63789; Mycobank number MB 827008) and Wickerhamiella kurtzmanii UWOPS 00-192.1T (=CBS 15383=NRRL Y-63979; MB 827011).

Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov., isolated from flowers in French Guiana.

Analysis of yeasts isolated from various biotopes in French Guiana led to the identification of two strains isolated from flowers and designated CLIB 1634T and CLIB 1707T. Comparison of the D1/D2 domain of the large subunit (LSU D1/D2) rRNA gene sequences of CLIB 1634T and CLIB 1707T to those in the GenBank database revealed that these strains belong to the Starmerella clade. Strain CLIB 1634T was shown to diverge from the closely related Starmerella apicola type strain CBS 2868T with a sequence divergence of 1.34 and 1.30 %, in the LSU D1/D2 rRNA gene and internal transcribed spacer (ITS) sequences respectively. Strain CLIB 1634T and Candida apicola CBS 2868T diverged by 3.81 and 14.96 % at the level of the protein-coding gene partial sequences EF-1α and RPB2, respectively. CLIB 1707T was found to have sequence divergence of 3.88 and 9.16 % in the LSU D1/D2 rRNA gene and ITS, respectively, from that of the most closely related species Starmerella ratchasimensis type strain CBS 10611T. The species Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov. are proposed to accommodate strains CLIB 1634T (=CBS 15247T) and CLIB 1707T (=CBS 15257T), respectively.

Papiliotrema plantarum sp. nov., a novel tremellaceous sexual yeast species.

During a survey of the yeast community associated with the phylloplane of corn in Thailand, a basidiomycetous yeast strain belonging to the genus Papiliotrema was isolated. Analyses of the D1/D2 domains of the 26S (LSU) rRNA gene and complete ITS region supported the recognition of a novel species, for which the name Papiliotrema plantarum sp. nov. is proposed (type strain DMKU-CP801T=CBS 15220T=PYCC 7257T). Another strain of P. plantarum sp. nov., isolated in French Guiana, was found to be sexually compatible with the Thai isolate and mycelium with clamp connections, basidia and basidiospores were observed in culture. The basidial morphology of P. plantarum combined features previously observed for Papiliotrema bandonii and Papiliotrema fuscus, which represent the only sexual species hitherto known in the genus, i.e. transversely septate basidia, with sexual structures of the Tremella type.

Description of Hyphopichia buzzinii f.a., sp. nov. and Hyphopichia homilentoma comb. nov., the teleomorph of Candida homilentoma.

During studies of the yeast diversity associated with rotting wood in Brazil and fruits, plants and insects in French Guiana, three strains of a new species were isolated. Analysis of the sequences of the internal transcribed spacer (ITS)-5.8S and D1/D2 domains of the large subunit of the rRNA gene showed that this species belongs to the genus Hyphopichia and its closest relative is Candida homilentoma. These species differ by 44 nucleotide substitutions in D1/D2 sequences. A new species Hyphopichia buzzinii f. a., sp. nov., is proposed to accommodate these isolates. The type strain of Hyphopichia buzzinii sp. nov. is CLIB 1739T (=CBS 14300T = UFMG-CM-Y6121T; MycoBank number is MB 815609). In addition, we isolated 11 strains of C. homilentoma from rotting wood, leaf surfaces, and water bodies in Brazil, and these strains when crossed among one another and with the type strain (CBS 6312T) of this species, produced hat-shaped ascospores typical of the genus Hyphopichia. We describe the teleomorph of C. homilentoma as a new combination, Hyphopichia homilentoma comb. nov. (type strain CBS 6312T; MycoBank number is MB 820009). We also propose to transfer the other six Candida species of the Hyphopichia clade to this genus as new combinations. Hyphopichia homilentoma produced ethanol and xylitol from D-xylose whereas H. buzzinii was only able to convert this pentose to xylitol.

Three novel ascomycetous yeast species of the Kazachstania clade, Kazachstania saulgeensis sp. nov., Kazachstaniaserrabonitensis sp. nov. and Kazachstania australis sp. nov. Reassignment of Candida humilis to Kazachstania humilis f.a. comb. nov. and Candida pseudohumilis to Kazachstania pseudohumilis f.a. comb. nov.

Five ascosporogenous yeast strains related to the genus Kazachstania were isolated. Two strains (CLIB 1764T and CLIB 1780) were isolated from French sourdoughs; three others (UFMG-CM-Y273T, UFMG-CM-Y451 and UFMG-CM-Y452) were from rotting wood in Brazil. The sequences of the French and Brazilian strains differed by one and three substitutions, respectively, in the D1/D2 large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS). The D1/D2 LSU rRNA sequence of these strains differed by 0.5 and 0.7 % from Kazachstania exigua, but their ITS sequences diverged by 8.1 and 8.3 %, respectively, from that of the closest described species Kazachstania barnettii. Analysis of protein coding sequences of RPB1, RPB2 and EF-1α distinguished the French from the Brazilian strains, with respectively 3.3, 6 and 11.7 % substitutions. Two novel species are described to accommodate these newly isolated strains: Kazachstania saulgeensis sp. nov. (type strain CLIB 1764T=CBS 14374T) and Kazachstania serrabonitensis sp. nov. (type strain UFMG-CM-Y273T=CLIB 1783T=CBS 14236T). Further analysis of culture collections revealed a strain previously assigned to the K. exigua species, but having 3.8 % difference (22 substitutions and 2 indels) in its ITS with respect to K. exigua. Hence, we describe a new taxon, Kazachstania australis sp. nov. (type strain CLIB 162T=CBS 2141T), to accommodate this strain. Finally, Candida humilis and Candida pseudohumilis are reassigned to the genus Kazachstania as new combinations. On the basis of sequence analysis, we also propose that Candida milleri and Kazachstania humilis comb. nov. are conspecific.

Yamadazyma barbieri f.a. sp. nov., an ascomycetous anamorphic yeast isolated from a Mid-Atlantic Ridge hydrothermal site (-2300 m) and marine coastal waters.

Two yeast strains that are members of the same species were isolated from different marine habitats, i.e. one from Mid-Atlantic Ridge ocean water samples located in the direct vicinity of black smokers near the Rainbow deep-sea hydrothermal vent and one from Brazilian marine water samples off the Ipanema beach. Strains CLIB 1964T and CLIB 1965 are anamorphic ascomycetous yeasts affiliated to the Yamadazyma clade of Saccharomycetales. Interestingly, these strains were phylogenetically and distinctly positioned into a group of species comprising all species of the genus Yamadazyma isolated from marine habitats including deep-sea hydrothermal vents, i.e.Candida atmosphaerica,C. spencermartinsiae,C. atlantica,C. oceani and C. taylorii. These strains differed significantly in their D1/D2 domain sequences of the LSU rRNA gene from the closely related species mentioned above, by 2.6, 3.0, 3.4, 3.8 and 6.0 %, respectively. Internal transcribed spacer region sequence divergence was also significant and corresponded to 4.6, 4.7, 4.7, 12.0 and 24.7 % with C. atlantica,C. atmosphaerica, C. spencermartinsiae,C. oceani and C. taylorii, respectively. Phenotypically, strains CLIB 1964T and CLIB 1965 could be distinguished from closely related species by their inability to assimilate l-sorbose. CLIB 1964T (=CBS 14301T=UBOCC-A-214001T) is the designated type strain for Yamadazyma barbieri sp. nov. The MycoBank number is MB 815884.

Two novel Saccharomycopsis species isolated from black olive brines and a tropical plant. Description of Saccharomycopsis olivae f. a., sp. nov. and Saccharomycopsis guyanensis f. a., sp. nov. Reassignment of Candida amapae to Saccharomycopsis amapae f. a., comb. nov., Candida lassenensis to Saccharomycopsis lassenensis f. a., comb. nov. and Arthroascus babjevae to Saccharomycopsis babjevae f. a., comb. nov.

Three yeast strains related to members of the genus Saccharomycopsis were isolated. One strain (CLIB 1310) was isolated from olive brines of fermented black olives in France and two strains (CLIB 1454 and CLIB 1455) were isolated from a plant in French Guiana. Sequence analyses based on the D1/D2 domains of the nuclear large subunit rRNA gene, small-subunit rRNA gene and partial EF-1α gene revealed that the strains represented two novel taxa exhibiting extensive sequence divergence from the previously described species of the genus Saccharomycopsis. Two novel species are described to accommodate these newly isolated strains: Saccharomycopsis olivae sp. nov. (type strain CLIB 1310(T) = CBS 12701(T)) and Saccharomycopsis guyanensis sp. nov. (type strain CLIB 1455(T) = CBS 12914(T) and strain CLIB 1454). Both strains CLIB 1454 and CLIB 1455(T) displayed identical sequences but differed in their ability to metabolize sorbitol and in their morphology on agar medium. Candida amapae, Candida lassensensis and Arthroascus babjevae belonging to the Saccharomycopsis clade, are reassigned to Saccharomycopsis as novel combinations.