Five yeast strains, phenotypically indistinguishable fromYarrowia lipolyticaandYarrowia deformans, were recovered from different animal-related samples. One strain was isolated from a bacon processing plant in Denmark, two strains from chicken liver in the USA, one strain from chicken breast in Hungary and one from minced beef in Hungary. Comparisons of the sequences of their large subunit rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) regions revealed that, despite their phenotypic similarity, they represent a novel yeast species of theYarrowiaclade withY. deformansbeing the genotypically closest relative (LSU rRNA gene D1/D2 and ITS region similarity of 97.0 and 93.7 %, respectively).Yarrowia divulgataf.a., sp. nov. is proposed to accommodate these strains with F6-17^T( = CBS 11013^T = CCUG 56725^T) as the type strain. Some D1/D2 sequences of yeasts from marine habitats were found in the GenBank database that were identical to those of the strains ofY. divulgataf.a., sp. nov. Unfortunately, these strains were not available for our study.

Taphrinomycotina is the smallest subphylum of the phylum Ascomycota. It is an assemblage of distantly related early diverging lineages of the phylum, comprising organisms with divergent morphology and ecology; however, phylogenomic analyses support its monophyly. In this study, we report the isolation of a yeast strain, which could not be assigned to any of the currently recognised five classes of Taphrinomycotina. The strain of the novel budding species was recovered from extra virgin olive oil and characterised phenotypically by standard methods. The ultrastructure of the cell wall was investigated by transmission electron microscopy. Comparisons of barcoding DNA sequences indicated that the investigated strain is not closely related to any known organism. Tentative phylogenetic placement was achieved by maximum-likelihood analysis of the D1/D2 domain of the nuclear LSU rRNA gene. The genome of the investigated strain was sequenced, assembled, and annotated. Phylogenomic analyses placed it next to the fission Schizosaccharomyces species. To accommodate the novel species, Novakomyces olei, a novel genus Novakomyces, a novel family Novakomycetaceae, a novel order Novakomycetales, and a novel class Novakomycetes is proposed as well. Functional analysis of genes missing in N. olei in comparison to Schizosaccharomyces pombe revealed that they are biased towards biosynthesis of complex organic molecules, regulation of mRNA, and the electron transport chain. Correlating the genome content and physiology among species of Taphrinomycotina revealed some discordance between pheno- and genotype. N. olei produced ascospores in axenic culture preceded by conjugation between two cells. We confirmed that N. olei is a primary homothallic species lacking genes for different mating types.

The systematic position of 16 yeast strains isolated from Thailand, Hungary, The Netherlands, and the Republic of Poland were evaluated using morphological, physiological, and phylogenetic analyses. Based on the similarity of the D1/D2 domain of the LSU rRNA gene, the strains were assigned to two distinct species, Trichosporiella flavificans and representatives of a new yeast species. Phylogenetic analyses revealed that Candida ghanaensis CBS 8798^T showed a strong relationship with the aforementioned two species. The more fascinating issue is that Candida and Trichosporiella genera have been placed in different subphyla, Saccharomycotina and Pezizomycotina, respectively. The close relationship between Trichosporiella flavificans, Candida ghanaensis and the undescribed species was unexpected and needed to be clarified. As for morphological and physiological characteristics, the three yeast species shared a hairy colony appearance and an ability to assimilate 18 carbon sources. Based on phylogenetic analyses carried out in the present study, Crinitomyces gen. nov. was proposed to accommodate the new yeast species, Crinitomyces reliqui sp. nov. (Holotype: TBRC 15054, Isotypes: DMKU-FW23-23 and PYCC 9001). In addition, the two species Trichosporiella flavificans and Candida ghanaensis were reassigned to the genus Crinitomyces as, Crinitomyces flavificans (Type: CBS 760.79) comb. nov. and Crinitomyces ghanaensis (Type: CBS 8798) comb. nov., respectively.

A previously undescribed cis-clerodane diterpenoid, diangelate solidagoic acid J (1), along with two known cis-clerodane diterpenoids, solidagoic acid C (2) and solidagoic acid D (3), as well as two known unsaturated monoacylglycerols, 1-linoleoyl glycerol (4) and 1-α-linolenoyl glycerol (5), were isolated and characterized from the n-hexane leaf extract of Solidago gigantea (giant goldenrod). Compounds 2–5 were identified first in this species, and compounds 4 and 5 are reported here for the first time in the Solidago genus. The bioassay-guided isolation procedure included thin-layer chromatography (TLC) coupled with a Bacillus subtilis antibacterial assay, preparative flash column chromatography, and TLC–mass spectrometry (MS). Their structures were elucidated via extensive spectroscopic and spectrometric techniques such as one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution tandem mass spectrometry (HRMS/MS). The antimicrobial activities of the isolated compounds were evaluated by a microdilution assay. All compounds exhibited weak to moderate antibacterial activity against the Gram-positive plant pathogen Clavibacter michiganensis, with MIC values ranging from 17 to 133 µg/mL, with compound 5 being the most potent. Only compound 1 was active against Curtobacterium flaccumfaciens pv. flaccumfaciens, while compound 3 demonstrated a weak antibacterial effect against B. subtilis and Rhodococcus fascians. Additionally, the growth of B. subtilis and R. fascians was moderately inhibited by compounds 1 and 5, respectively. None of the tested compounds showed antibacterial activity against Gram-negative Pseudomonas syringae pv. tomato and Xanthomonas arboricola pv. pruni. No bactericidal activity was observed against the tested microorganisms. Compounds 2 and 3 displayed weak antifungal activity against the crop pathogens Bipolaris sorokiniana and Fusarium graminearum. Our results demonstrate the efficacy of bioassay-guided strategies in facilitating the discovery of novel bioactive compounds.

Six conspecific yeast strains, representing an undescribed species, were isolated from rotten wood collected in different locations in Hungary and Germany and an additional one from fungal fruiting body in Taiwan. The seven strains share identical nucleotide sequences in the D1/D2 domain of the nuclear large subunit (LSU) rRNA gene. The Hungarian and Taiwanese isolates share identical internal transcribed spacer (ITS) sequences as well, while the two German isolates differ from them merely by three substitutions and four indels in this region. The investigated strains are very closely related to Diddensiella santjacobensis. Along their LSU D1/D2 domain they differ only by one substitution from the type strain of D. santjacobensis. However, in the ITS region of Hungarian and Taiwanese strains we detected 3.5 % divergence (nine substitutions and nine indels) between the undescribed species and D. santjacobensis, while the German strains differed by 13 substitutions and nine indels from D. santjacobensis. This ITS sequence divergence has raised the possibility that the strains investigated in this study may represent a different species from D. santjacobensis. This hypothesis was supported by comparisons of partial translation elongation factor 1-α (EF-1α) and cytochrome oxidase II (COX II) gene sequences. While no difference and 1–2 substitutions among the partial EF-1α and COX II gene sequences of the strains of the undescribed species, respectively, were detected; the undescribed species differ by about 4 % (36 substitutions) and 10 % (50–51 substitutions) from D. santjacobensis in these regions. Parsimony network analysis of the partial COX II gene sequences also separated the investigated strains from the type strain of D. santjacobensis. In this paper we propose Diddensiella parasantjacobensis f.a., sp. nov. (holotype: NCAIM Y.02121; isotypes: CBS 17819, DSM 114156) to accommodate the above-noted strains.

Yeasts and yeast-like fungi represent an understudied component of indoor mycobiota, despite including numerous opportunistic human pathogens. This study investigated the diversity, habitats, and potential dispersal mechanisms of yeasts in non-clinical indoor environments. A review of previous studies was combined with new field and laboratory observations. Overall, 1977 yeast occurrence records, including 106 records generated during this study, were analyzed. In total, 83 genera comprising 170 species were identified from 1320 habitat records. Most frequently reported species were Candida parapsilosis (13.8%), Rhodotorula mucilaginosa (7.7%), and Exophiala dermatitidis (7.1%). Habitat records were dominated by wet-cell environments (90.9%), particularly dishwashers, sinks, plumbing systems, tap water and washing machines. Additional habitats included indoor plants, potting soils and wooden materials, the latter representing a previously unreported indoor habitat. Multiple correspondence analysis identified moisture availability as the principal factor structuring habitat associations. Among 89 isolates, ballistospore production, long filamentous thread formation, and dry aerial structures were observed in 3.3%, 2.2%, and 16.9%, respectively. In E. dermatitidis, long filamentous threads were observed to facilitate dispersal by both air currents and contact with surfaces, as confirmed experimentally in one of the investigated strains. These findings expand knowledge of indoor yeast ecology and suggest broader dispersal strategies than previously recognized, while highlighting the need for further ecological and epidemiological studies.