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Foods (Basel, Switzerland) Nov 2022On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of...
On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of lactic acid. In contrast, the species Metschnikowia pulcherrima is renowned for its high enzymatic activity capable of producing aromatic esters during fermentation. By enhancing acidity and boosting the concentration of aromatic compounds, both species are currently used to enhance the organoleptic profile of wines. In this regard, ternary fermentations with M. pulcherrima and L. thermotolerans were carried out and the wines produced were further analysed with GC-FID, FTIR, and UV-Vis spectrophotometry. The outcomes showed that the species M. pulcherrima favored an increase in ethyl lactate (between 37 and 41 mg/L) along with an increased concentration of 2-phenylethyl alcohol (between 30 and 35 mg/L), whereas the species L. thermotolerans was able to produce 1 g/L of lactic acid in ternary fermentations. Additionally, pH levels were slightly lower in these fermentations and the color of the white wines produced showed less chemical oxidation as hue values were lower than the control. Finally, the ternary fermentations of L. thermotolerans and M. pulcherrima had higher overall rating in the tasting. In conclusion, ternary fermentations involving these two non-Saccharomyces species are suggested as a substitute for spontaneous fermentations in the production of wines from neutral varieties to express freshness more vividly. This biotechnology may be further favored by the possibility of applying emerging technologies for the removal of microorganisms in grapes and musts.
PubMed: 36429326
DOI: 10.3390/foods11223734 -
Genes Jan 2019Yeasts belonging to the genus are particularly interesting for the unusual formation of only two needle-shaped ascospores during their mating cycle. Presently, the...
Yeasts belonging to the genus are particularly interesting for the unusual formation of only two needle-shaped ascospores during their mating cycle. Presently, the meiotic process that can lead to only two spores from a diploid zygote is poorly understood. The expression of fluorescent nuclear proteins should allow the meiotic process to be visualized in vivo; however, no large-spored species of has ever been transformed. Accordingly, we aimed to develop a transformation method for , a particularly large-spored species of , with the goal of enabling the genetic manipulations required to study biological processes in detail. Genetic analyses confirmed that , and many other species, are CUG-Ser yeasts. Codon-optimized selectable markers lacking CUG codons were used to successfully transform by electroporation and lithium acetate, and transformants appeared to be the result of random integration. Mating experiments confirmed that transformed-strains were capable of generating large asci and undergoing recombination. Finally, random integration was used to transform an additional 21 yeast strains, and all attempts successfully generated transformants. The results provide a simple method to transform many yeasts from an array of different clades and can be used to study or develop many species for various applications.
Topics: Codon; Electroporation; Fungal Proteins; Gene Transfer Techniques; Transformation, Genetic; Yeasts
PubMed: 30678093
DOI: 10.3390/genes10020078 -
International Journal of Systematic and... Sep 2006Eight yeast strains were isolated from jujube fruit surfaces collected in Shanxi and Shandong Provinces, China. All eight strains produced needle-shaped ascospores under...
Eight yeast strains were isolated from jujube fruit surfaces collected in Shanxi and Shandong Provinces, China. All eight strains produced needle-shaped ascospores under suitable conditions. Three separate groups, representing three novel species in the genus Metschnikowia, were recognized by sequence comparisons of the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region. The names Metschnikowia sinensis sp. nov. (type strain XY103(T)=AS 2.3110(T)=CBS 10357(T)), Metschnikowia zizyphicola sp. nov. (type strain XY201(T)=AS 2.3111(T)=CBS 10358(T)) and Metschnikowia shanxiensis sp. nov. (type strain XY801(T)=AS 2.3112(T)=CBS 10359(T)) are proposed for the three novel species. Phylogenetic analysis of the 26S rDNA D1/D2 domain sequence showed that these three novel species are clustered in a clade together with the previously described species Metschnikowia fructicola, Metschnikowia andauensis, Metschnikowia pulcherrima and Metschnikowia chrysoperlae.
Topics: China; DNA, Fungal; DNA, Ribosomal Spacer; Molecular Sequence Data; RNA, Ribosomal; Saccharomycetales; Ziziphus
PubMed: 16957129
DOI: 10.1099/ijs.0.64391-0 -
Archives of Microbiology May 2022Yeasts can produce toxins in protein or glycoprotein structures that can act as an inhibitor on some bacteria and yeast species. The effects of those toxins on the...
Yeasts can produce toxins in protein or glycoprotein structures that can act as an inhibitor on some bacteria and yeast species. The effects of those toxins on the growth of pathogenic and food spoilage microorganisms are subject to various studies. Metschnikowia pulcherrima was determined to be a killer toxin-producing yeast that was tested against three selected microorganisms, namely Escherichia coli Type-I, Micrococcus luteus and Candida albicans. The killer toxin only showed inhibitory activity against M. luteus. Different pH (5-6-7-8), temperature (20-25-30-35 °C) and carbon source (glucose-glycerol-ethanol-acetate) combinations were applied to stimulate the growth and toxin production of the killer yeast. The greatest increase among the different combinations was obtained at 20 °C and pH 7 when glycerol was used as the main carbon source. It was then also tested against other pathogen indicators or pathogens under these conditions. The killer toxin was partially purified by ethanol precipitation and showed inhibitory activity against M. luteus (36 mm). According to the protein profile obtained by SDS-PAGE, the molecular weight of the inhibitor toxin was measured about 7.4 kDa. The molecular weight with amino acid sequence of the killer toxin was 10.3 kDa and determined by MALDI-TOF mass spectrometry.
Topics: Carbon; Escherichia coli; Ethanol; Glycerol; Metschnikowia; Yeasts
PubMed: 35587835
DOI: 10.1007/s00203-022-02940-8 -
International Journal of Systematic and... Jun 2014Eight strains with identical sequences of the D1/D2 domains of the large subunit rRNA genes were isolated from fallen fruits in two distant localities in Laos. These...
Eight strains with identical sequences of the D1/D2 domains of the large subunit rRNA genes were isolated from fallen fruits in two distant localities in Laos. These strains represent a novel dimorphic budding yeast species producing invasive pseudohyphae and a brown pigment when growing on media containing quinic acid as the sole carbon source or tryptophan as the sole nitrogen source. Phylogenetic analysis of the sequences of the D1/D2 domains, the internal transcribed spacer (ITS) regions and the 18S rRNA genes placed the novel species in the Metschnikowia clade close to Candida torresii, Metschnikowia drosophilae and Candida danieliae. The taxonomic name Metschnikowia laotica f.a., sp. nov., reflecting the geographical origin of the isolates, is proposed for the novel species. The type strain is 11-524(T) ( = CBS 12961(T) = NCAIM Y.02124(T) = CCY 64-4-1(T)). The Mycobank number is MB 807383.
Topics: DNA, Fungal; DNA, Ribosomal Spacer; Fruit; Laos; Metschnikowia; Molecular Sequence Data; Mycological Typing Techniques; Phylogeny; Pigmentation; Quinic Acid; RNA, Ribosomal; RNA, Ribosomal, 18S; Sequence Analysis, DNA
PubMed: 24573162
DOI: 10.1099/ijs.0.061796-0 -
FEMS Yeast Research May 2002Two new haplontic heterothallic species of Metschnikowia were discovered in flowers and associated beetles. Metschnikowia arizonensis was recovered from flowers of...
Two new haplontic heterothallic species of Metschnikowia were discovered in flowers and associated beetles. Metschnikowia arizonensis was recovered from flowers of cholla cactus (Opuntia echinocarpa) and a specimen of Carpophilus sp. (Coleoptera: Nitidulidae) found in these flowers, in Arizona. Metschnikowia dekortorum was isolated in specimens of the nitidulid beetle Conotelus sp. captured in flowers of two species of Ipomoea in northwestern Guanacaste Province, Costa Rica. The sexual cycle of these yeasts is typical of the large-spored Metschnikowia species, but the asci and spores are intermediate in size between these and other members of the genus. The physiology is consistent with that of most Metschnikowia species except that both species fail to utilize lysine as sole nitrogen source. Also, M. arizonensis utilizes fewer carbon compounds than most species and exhibits considerable variability among strains at this level. Partial ribosomal DNA large-subunit (D1/D2) sequences suggest that M. arizonensis and M. dekortorum are moderately related sister species whose positions are intermediate between the large-spored species Metschnikowia and Metschnikowia hibisci. The type cultures are: M. arizonensis, strains UWO(PS)99-103.3.1=CBS 9064=NRRL Y-27427 (h(+), holotype) and UWO(PS)99-103.4=CBS 9065=NRRL Y-27428 (h(-), isotype); and M. dekortorum, strains UWO(PS)01-142b3=CBS 9063=NRRL Y-27429 (h(+), holotype) and UWO(PS)01-138a3=CBS 9062=NRRL Y-27430 (h(-), isotype).
Topics: Animals; Coleoptera; DNA, Ribosomal; Flowers; Phylogeny; Saccharomycetales
PubMed: 12702295
DOI: 10.1111/j.1567-1364.2002.tb00072.x -
International Journal of Systematic and... Oct 2012A collection of yeasts isolated from nectar of flowers of Protea caffra (Proteaceae) and associated scarab beetles (Atrichelaphinis tigrina, Cyrtothyrea marginalis,...
A collection of yeasts isolated from nectar of flowers of Protea caffra (Proteaceae) and associated scarab beetles (Atrichelaphinis tigrina, Cyrtothyrea marginalis, Trichostetha fascicularis and Heterochelus sp.) and drosophilid flies in South Africa, contained 28 isolates that could not be assigned to known species. Comparisons of the D1/D2 domains of the large subunit rRNA gene demonstrated the existence of three separate phylotypes with an affinity to the genus Metschnikowia and more specifically to the beetle-associated large-spored Metschnikowia clade. Twenty-six strains that had similar D1/D2 sequences were mixed in all pairwise combinations. They were found to mate and give rise to large asci typical of those in the clade. The name Metschnikowia proteae sp. nov. (type strain EBDT1Y1(T) = CBS 12522(T) = NRRL Y-48784(T); allotype strain EBDC2Y2 = CBS 12521 = NRRL Y-48785) is proposed to accommodate this novel species. The ecology of this novel yeast species is discussed in relation to its potential plant and insect host species. The additional two single strains isolated from Heterochelus sp. represent two novel undescribed species (Candida sp. 1 EBDM2Y3 and Candida sp. 2 EBDM8Y1). As these single strains are probably haploid mating types of Metschnikowia species, their description is deferred until the species are sufficiently well sampled to permit meaningful descriptions.
Topics: Animals; Candida; Coleoptera; DNA, Fungal; Drosophilidae; Flowers; Genes, rRNA; Metschnikowia; Molecular Sequence Data; Phylogeny; Plant Nectar; Sequence Analysis, DNA; South Africa
PubMed: 22407789
DOI: 10.1099/ijs.0.040790-0 -
Annual Review of Microbiology Sep 2017The fungal phylum Ascomycota comprises three subphyla: Saccharomycotina, Pezizomycotina, and Taphrinomycotina. In many Saccharomycotina species, cell identity is... (Review)
Review
The fungal phylum Ascomycota comprises three subphyla: Saccharomycotina, Pezizomycotina, and Taphrinomycotina. In many Saccharomycotina species, cell identity is determined by genes at the MAT (mating-type) locus; mating occurs between MATa and MATα cells. Some species can switch between MATa and MATα mating types. Switching in the Saccharomycotina originated in the common ancestor of the Saccharomycetaceae, Pichiaceae, and Metschnikowiaceae families, as a flip/flop mechanism that inverted a section of chromosome. Switching was subsequently lost in the Metschnikowiaceae, including Candida albicans, but became more complex in the Saccharomycetaceae when the mechanism changed from inversion to copy-and-paste between HML/HMR and MAT. Based on their phylogenetic closeness and the similarity of their MTL (mating-type like) loci, some Metschnikowia species may provide useful models for the sexual cycles of Candida species. Conservation of synteny demonstrates that, despite changes in its gene content, a single orthologous locus (MAT/MTL) has controlled cell type throughout ascomycete evolution.
Topics: Ascomycota; Evolution, Molecular; Genes, Mating Type, Fungal; Genetic Loci; Heredity
PubMed: 28657889
DOI: 10.1146/annurev-micro-090816-093403 -
Journal of Invertebrate Pathology Feb 2017Ips sexdentatus (six-spined engraver beetle) from Austria and Poland were dissected and examined for the presence of pathogens. Specimens collected in Austria were found...
Metschnikowia cf. typographi and other pathogens from the bark beetle Ips sexdentatus - Prevalence, histological and ultrastructural evidence, and molecular characterization.
Ips sexdentatus (six-spined engraver beetle) from Austria and Poland were dissected and examined for the presence of pathogens. Specimens collected in Austria were found to contain the ascomycetous fungus Metschnikowia cf. typographi. Infection rates ranged from 3.6% to 26.8% at different collection sites. M. cf. typographi infected midguts were investigated by histological, ultrastructural and molecular techniques. Extraordinary ultrastructural details are shown, such as ascospores with bilateral flattened flanks resembling alar rims at both sides of their attenuating tube-like ends. These have not yet been described in other yeast species. Molecular investigations showed a close phylogenetic relationship to the fungi Metschnikowia agaves and Candida wancherniae. Presence of the entomopathogenic fungus Beauveria bassiana found in Austria was confirmed both morphologically and molecularly. The eugregarine Gregarina typographi was diagnosed most frequently. Infection rates of all I. sexdentatus specimens ranged from 21.4% to 71.9% in Austria and 54.1% to 68.8% in Poland. Other entomopathogenic protists, bacteria, or viruses were not detected.
Topics: Animals; Austria; Coleoptera; Genes, Fungal; Metschnikowia; Microscopy, Electron, Transmission; Poland; Polymerase Chain Reaction
PubMed: 27914926
DOI: 10.1016/j.jip.2016.11.015 -
Canadian Journal of Microbiology Feb 2001Two new haplontic heterothallic species of Metschnikowia were isolated from floricolous insects and flowers. Metschnikowia lochheadii was recovered from insects found in...
Two new haplontic heterothallic species of Metschnikowia were isolated from floricolous insects and flowers. Metschnikowia lochheadii was recovered from insects found in various flowers on the Hawaiian Islands of Kauai and Maui, and from Conotelus sp. (Coleoptera: Nitidulidae) in northwestern Guanacaste Province, Costa Rica. The morphology, physiology, and sexual cycle are typical of the large-spored Metschnikowia species, and the partial ribosomal DNA large subunit (D1D2) sequences suggest that the new species is most closely related to Candida ipomoeae. Metschnikowia lochheadii is nearly indistinguishable from its ascogenous relatives and conjugates freely with Metschnikowia continentalis, forming sterile asci. It also exhibits asymmetric mating with Metschnikowia hawaiiensis. Metschnikowia drosophilae was found in morning glory (Ipomoea sp.) flowers and associated Drosophila bromeliae on Grand Cayman Island. Its nutritional profile is atypical of the genus, being the only species that does not utilize sucrose or maltose as carbon sources, and one of the few that does not utilize melezitose. D1D2 sequences show that Metschnikowia drosophilae is a sister species to Candida torresii, to which it bears considerable similarity in nutritional profile. The type cultures are: Metschnikowia lochheadii, strains UWO(PS)00-133.2 = CBS 8807 (h+, holotype) UWO(PS)99-661.1 = CBS 8808 (h-, isotype); and Metschnikowia drosophilae, strains UWO(PS)83-1135.3 = CBS 8809 (h+, holotype) and UWO(PS)83-1143.1 = CBS 8810 (h-, isotype).
Topics: Animals; Costa Rica; Genome, Fungal; Hawaii; Insecta; Molecular Sequence Data; Phylogeny; Plants; Yeasts
PubMed: 11261488
DOI: 10.1139/w00-130