UNASSIGNED: Although the existence of Candida species in the respiratory tract is often considered commensal, it is crucial to recognize the significance of Candida colonization in immunocompromised or COVID-19 patients. The emergence of Candida auris as an emerging pathogen further emphasizes the importance of monitoring yeast infection/colonization, particularly in COVID-19 patients.
UNASSIGNED: In this study, respiratory samples mainly from COVID-19 patients, primarily those suspected of having a fungal infection, were cultured on Sabouraud dextrose agar plates and the yeast colonies were identified using a two-step multiplex PCR method. The samples suspected of C. auris underwent specific nested PCR followed by sequence analysis.
UNASSIGNED: A total of 199 respiratory samples were collected from 73 women and 126 men, ranging in age from 1.6 to 88 years. Among the patients, 141 had COVID-19, 32 had cancer, 5 were hospitalized in ICU, 2 had chronic obstructive pulmonary disease)COPD(, and others were patients with combination diseases. From these samples, a total of 334 yeast strains were identified. C. albicans (n=132, 39.52%) was the most common species, followed by C. tropicalis (n=67, 20%), C. glabrata (n=56, 16.76%), C. krusei (n=18, 5.4%), C. parapsilosis (n=17, 5.08%), Saccharomyces cerevisiae (n=10, 3%), C. kefyr (n=9, 2.6%), C. dubliniensis (n=7, 2.1%), C. lusitaniae (n=5, 1.5%), C. auris (n=3, 0.9%), C. guilliermondii (n=2, 0.6%), C. rugosa (n=1, 0.3%), C. intermedia (n=1, 0.3%), and Trichosporon spp. (n=1, 0.3%). C. auris was detected in a patient in ICU and two COVID-19 patients. While its presence was confirmed through sequence analysis, our extensive efforts to isolate C. auris were unsuccessful.
UNASSIGNED: While C. albicans colonization remains prevalent, our study found no evidence of Candida lung infection. Since the role of Candida colonization in airway secretions remains ambiguous due to limited research, further studies are imperative to shed light on this matter.

Yeasts are single-celled fungi that are widespread around the globe. They are part of a community of microorganisms that use a wide variety of habitats, including fruit surfaces. This study aimed to characterise the culturable epiphytic yeasts associated with apple fruits. The isolated yeast strains were identified by sequencing the 5.8S-ITS region and D1/D2 region of the large subunit ribosomal RNA gene and maintained for long-term storage. A total of 230 yeast isolates belonging to 33 species were recovered. Most of the collected isolates belonged to the phylum Basidiomycota. Members of genera Vishniacozyma, Filobasidium, and Rhodotorula were most frequently isolated. Over half of the species were isolated on only one to three occasions. In seven of the species obtained, the isolates were considerably divergent from their closest relatives and may therefore represent new distinct species. The results of this study demonstrate a high diversity of yeast species associated with apple fruits.

Two yeast strains (NYNU 211162 and NYNU 211275) were isolated from rotting wood collected in the Baotianman Nature Reserve, Henan Province, central China. Phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region revealed that the strains represent a phylogenetically distinct species within the genus Spencermartinsiella. The name Spencermartinsiella henanensis fa., sp. nov. is proposed for this species with holotype CICC 33543T (Mycobank MB 851142). S. henanensis sp. nov. differed by only 3 nt (~0.5 %) substitutions from the closest known species S. europaea NCAIM Y.01817T in the D1/D2 domain, but by 33 nt (~6 %) substitutions, 34 nt (~3.8 %) substitutions, 30 nt (~5.6 %) substitutions and 75 nt (~9.9 %) substitutions in the ITS region and the partial TEF1, COXII and RPB2 genes. Additionally, S. henanensis sp. nov. can be physiologically distinguished from S. europaea by its ability to assimilate inulin, inability to assimilate ethylamine and cadaverine, and incapability of growth at 30 °C.

Two strains (NYNU 218101 and NYNU 218104) of an asexual yeast species were isolated from insect frass collected in insect tunnels of red leaf plum trees in the Henan Province, central China. Molecular phylogenetic analysis of the D1/D2 domain of the large subunit rRNA gene and the internal transcribed spacer (ITS) region showed that these two strains belonged to the genus Danielozyma, with Danielozyma litseae as the closest known species. They differed from the type strain of D. litseae by 0.6 % substitutions (three substitutions and one gap) in the D1/D2 domain and by 5.1 % substitutions (19 substitutions and six gaps) in the ITS region, respectively. When compared with the partial ACT1, TEF1 and RPB1 gene sequences, they differed by 3 % (26 substitutions), 2.7 % (25 substitutions) and 9 %(54 substitutions) from D. litseae NRRL YB-3246T in these regions. Physiologically, they also differed from its closest known species D. litseae based on the ability to assimilate inulin and galactitol, as well as to grow in 0.1 % cycloheximide and its inability to ferment maltose and raffinose. In order to classify the two new isolates based on morphological and molecular evidence, we proposed the description of a novel species Danielozyma pruni sp. nov. with strain JCM 35735T as holotype (Mycobank MB 849101).

Two apiculate strains (NYNU 181072 and NYNU 181083) of a bipolar budding yeast species were isolated from rotting wood samples collected in Xishuangbanna Tropical Rainforest in Yunnan Province, southwest PR China. On the basis of phenotypic characteristics and the results of phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA, internal transcribed spacer (ITS) region and the actin (ACT1) gene, the two strains were found to represent a single novel species of the genus Hanseniaspora, for which the name Hanseniaspora menglaensis f.a., sp. nov. (holotype CICC 33364T; MycoBank MB 847437) is proposed. In the phylogenetic tree, H. menglaensis sp. nov. showed a close relationship with Hanseniaspora lindneri, Hanseniaspora mollemarum, Hanseniaspora smithiae and Hanseniaspora valbyensis. H. menglaensis sp. nov. differed from H. lindneri, the most closely related known species, by 1.2 % substitutions in the D1/D2 domain, 2.5 % substitutions in the ITS region and 5.4 % substitutions in the ACT1 gene, respectively. Physiologically, H. menglaensis sp. nov. can also be distinguished from H. lindneri by its ability to assimilate d-gluconate.

Two strains of a novel ascomycetous yeast species were isolated from rotting wood samples collected in Jiuxi Mountain Forest Park in Yunnan Province, southwest China. Both strains formed one or two spherical ascospores in persistent asci. Phylogenetic analysis of the concatenated sequences of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) and the D1/D2 domain of the large subunit rRNA gene revealed that the novel strains represented a phylogenetically distinct species belonging to the genus Torulaspora. This novel species differed from the type strains of the closest known species, Torulaspora nypae and Torulaspora maleeae, by 0.9 and 1.2 % nucleotide substitutions in the D1/D2 domain and 5.3 and 6 % nucleotide substitutions in the ITS region, respectively. The novel species can also be distinguished from T. nypae and T. maleeae in terms of the ability to assimilate ribitol, succinate and citrate, and its ability to grow at 37 °C. The species name of Torulaspora jiuxiensis sp. nov. is proposed with holotype CBS 16004T (Mycobank MB 844535).

In this review, we describe the genomic and physiological features of the yeast species predominantly isolated from Nuruk, a starter for traditional Korean rice wines, and Jang, a traditional Korean fermented soy product. Nuruk and Jang have several prevalent yeast species, including Saccharomycopsis fibuligera, Hyphopichia burtonii, and Debaryomyces hansenii complex, which belong to the CUG clade showing high osmotic tolerance. Comparative genomics revealed that the interspecies hybridization within yeast species for generating heterozygous diploid genomes occurs frequently as an evolutional strategy in the fermentation environment of Nuruk and Jang. Through gene inventory analysis based on the high-quality reference genome of S. fibuligera, new genes involved in cellulose degradation and volatile aroma biosynthesis and applicable to the production of novel valuable enzymes and chemicals can be discovered. The integrated genomic and transcriptomic analysis of Hyphopichia yeasts, which exhibit strong halotolerance, provides insights into the novel mechanisms of salt and osmo-stress tolerance for survival in fermentation environments with a low-water activity and high-concentration salts. In addition, Jang yeast isolates, such as D. hansenii, show probiotic potential for the industrial application of yeast species beyond fermentation starters to diverse human health sectors.

The olive oil microbiota mainly consists of yeasts, which may positively or negatively affect the physicochemical and sensory features of product. In this study, 17 yeast strains belonging to Candida boidinii, Lachancea fermentati, Nakazawaea molendinolei, N. wickerhamii and Schwanniomyces polymorphus species were collected during olive oil production, identified and tested for the ability to ferment sugars, to grow at low temperatures, for the occurrence of different enzymatic activities, for the tolerance and degradation of phenolic compounds, radical scavenging activities, biofilm formation, survival to simulated gastro-intestinal (GIT) tract. Yeasts were also inoculated in extra virgin olive oils (EVOO; from Leccino and Coratina cultivar) to evaluate their survival and their effect on EVOO quality (changes in analytical indices) during 6-months of storage. Most of strains were able to grow at 15°C, while the ability to ferment different sugars was strain-specific. All strains had β-glucosidase activity, while none exhibited lipolytic activity; peroxidase was widespread among the strains, while protease activity was strain-dependent. Esterase and the ability to hydrolyse oleuropein and form hydroxytyrosol was present only in N. wickerhamii strains. All strains were able to survive in olive mill wastewater, used as a model of phenolic compounds-rich matrix. A potential biofilm formation was observed only in N. wickerhamii, while the ability to scavenge radical and to cope with GIT-associated stresses were strain-dependent. High levels of survival were observed for almost strains (except S. polymorphus), in both Leccino and Coratina samples. Yeasts limited the acidity rise in olive oils, but overtime they contributed to increase the parameters related to oxidative phenomena (i.e. peroxides, K232, K270), resulting in a declassification of EVOOs. The total phenolic content (TPC) was correlated to the presence of yeasts and, at the end of storage period (6 months) inoculated samples had significantly lower concentrations compared to the control oils. This study confirms that yeasts are able to survive in olive oils and, therefore, the control of their occurrence during extraction process and storage conditions is needed to obtain high-quality products and to maintain the standards of EVOO classification.

Yeasts are increasingly employed in synthetic biology as chassis strains, including conventional and non-conventional species. It is still unclear how genomic evolution determines metabolic diversity among various yeast species and strains. In this study, we constructed draft GEMs for 332 yeast species using two alternative procedures from the toolbox RAVEN v 2.0. We found that draft GEMs could reflect the difference in yeast metabolic potentials, and therefore, could be utilized to probe the evolutionary trend of metabolism among 332 yeast species. We created a pan-draft metabolic model to account for the metabolic capacity of every sequenced yeast species by merging all draft GEMs. Further analysis showed that the pan-reactome of yeast has a \"closed\" property, which confirmed the great conservatism that exists in yeast metabolic evolution. Lastly, the quantitative correlations among trait similarity, evolutionary distances, genotype, and model similarity were thoroughly investigated. The results suggest that the evolutionary distance and genotype, to some extent, determine model similarity, but not trait similarity, indicating that multiple mechanisms shape yeast trait evolution. A large-scale reconstruction and integrative analysis of yeast draft GEMs would be a valuable resource to probe the evolutionary mechanism behind yeast trait variety and to further refine the existing yeast species-specific GEMs for the community.

During an investigation of the diversity of airborne yeasts in a famous Chinese baijiu fermentation workshop, two yeast strains were isolated from the air of the Wuliangye 501# baijiu-making workshop in Yibin, Sichuan Province, PR China and subjected to taxonomic analysis. The results of phylogenetic analysis of two regions of the rRNA gene cluster, the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, indicated that these strains represented a novel species of the genus Moniliella distinct from closely related species. The similarity between the novel species and the most closely related known species, Moniliella dehoogii, was 94.1 % for the D1/D2 LSU rRNA gene (30 substitutions and 12 indels out of 556 bp) and 95.6 % for the ITS region (9 substitutions and 6 indels out of 475 bp). In contrast with M. dehoogii, this novel species was able to assimilate d-ribose, l-arabinose, d-arabinose, cellobiose, d-glucono-1,5-lactone, dl-lactate, citrate, 1,2-propanediol, 2,3-butanediol and ethanol but was unable to ferment raffinose or assimilate inulin. On the basis of the results of phylogenetic analysis and the physiological characteristics, these investigated strains represent a novel species of the genus Moniliella, for which the name Moniliella aeria sp. nov. is proposed. Its holotype is CGMCC 20235T, and the MycoBank number is MB840188.