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Ascomycete yeasts are metabolically diverse, with great potential for biotechnology. Here, we report the comparative genome analysis of 29 taxonomically and biotechnologically important yeasts, including 16 newly sequenced. We identify a genetic code change, CUG-Ala, in Pachysolen tannophilus in the clade sister to the known CUG-Ser clade. Our well-resolved yeast phylogeny shows that some traits, such as methylotrophy, are restricted to single clades, whereas others, such as l-rhamnose utilization, have patchy phylogenetic distributions. Gene clusters, with variable organization and distribution, encode many pathways of interest. Genomics can predict some biochemical traits precisely, but the genomic basis of others, such as xylose utilization, remains unresolved. Our data also provide insight into early evolution of ascomycetes. We document the loss of H3K9me2/3 heterochromatin, the origin of ascomycete mating-type switching, and panascomycete synteny at the MAT locus. These data and analyses will facilitate the engineering of efficient biosynthetic and degradative pathways and gateways for genomic manipulation.

Nonsynaptic mechanism changes, particularly the enhancement of NKCC1 expression in the dentate gyrus (DG) after 4 weeks of ethanol consumption, motivate the present work, in which rats were submitted to a period of chronic consumption (12 weeks). Four groups of six animals (6-week-old male Wistar rats) were formed, including the control (C), ethanol 1 (E1), ethanol 2 (E2) and ethanol 3 (E3) groups. The rats in the E1, E2 and E3 groups were treated daily with a 30% v/v solution of ethanol, administered via oral gavage (1.0, 2.0 and 3.0 g/kg, respectively). Nonsynaptic epileptiform activities (NEA) were induced by means of the zero-Ca 2+ and high-K + model using hippocampal slices and were recorded in the DG. The presence of NKCC1, KCC2, α 1 -Na + /K + -ATPase and GFAP immunoreactivity was analyzed. The results demonstrate that alcohol consumption changes NEA, and these changes are more prominent at the lower dosage. An increase in the DC shifts associated with epileptiform discharges was present with the low dose. This increase was correlated with the increment of NKCC1 expression. Confocal microscopy images indicate the NKCC1 increase was pronounced in the initial axonal segment of granule cells. The blockage of these cotransporters during NEA induction with bumetanide suppressed the DC shift increase and diminished all parameters of NEA that were quantified for all groups treated with ethanol. Therefore, the increase in NKCC1 expression and the effective activity of this cotransporter, which were observed in the treated groups, suggest that drugs that act for block NKCC1 represent promising strategies for diminishing the effects of alcohol damage on the brain. [ABSTRACT FROM AUTHOR]

Nineteen isolates representing a candidate for a novel yeast species belonging to the genus Spencermartinsiella were recovered from rotting wood samples collected at different sites in Atlantic Rainforest and Amazonian Forest ecosystems in Brazil. Similarity search of the nucleotide sequence of the intergenic spacer (ITS)-5.8S and large subunit D1/D2 regions of the ribosomal gene cluster showed that this novel yeast is closely related to Spencermartinsiella cellulosicola . The isolates differ by four nucleotide substitutions in the D1/D2 domain and six substitutions and 31 indels in the ITS region from the holotype of S. cellulosicola . Phylogenomic analysis based on 1474 single-copy orthologues for a set of Spencermartinsiella species whose whole genome sequences are available confirmed that the novel species is phylogenetically close to S. cellulosicola . The low average nucleotide identity value of 83% observed between S. cellulosicola and the candidate species confirms that they are distinct. The novel species produced asci with hemispherical ascospores. The name Spencermartinsiella nicolii sp. nov. is proposed. The holotype is CBS 14238 T . The MycoBank number is MB855027. Interestingly, the D1/D2 sequence of the S. nicolii was identical to that of an uncultured strain of Spencermartinsiella causing systemic infection in a male adult crocodile ( Crocodylus niloticus ). The characterization of some virulence factors and antifungal susceptibility of S. nicolii isolates suggest that this yeast may be an opportunistic pathogen for animals, including humans; the isolates grow at 37 °C.

Four isolates of Spathaspora species were recovered from rotting wood collected in two Brazilian Amazonian biomes. The isolates produced unconjugated allantoid asci with a single elongated ascospore with curved ends. Sequence analysis of the ITS-5.8S region and the D1/D2 domains of the large subunit rRNA gene showed that the isolates represent two different novel Spathaspora species, phylogenetically related to Sp. boniae . Two isolates were obtained from rotting wood collected in two different sites of the Amazonian forest in the state of Pará. The name Spathaspora brunopereirae sp. nov. is proposed to accommodate these isolates. The holotype of Spathaspora brunopereirae sp. nov. is CBS 16119 T (MycoBank MB846672). The other two isolates were obtained from a region of transition between the Amazonian forest and the Cerrado ecosystem in the state of Tocantins. The name Spathaspora domphillipsii sp. nov. is proposed for this novel species. The holotype of Spathaspora domphillipsii sp. nov. is CBS 14229 T (MycoBank MB846697). Both species are able to convert d-xylose into ethanol and xylitol, a trait with biotechnological applications.

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.