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Antonie Van Leeuwenhoek Oct 2018Genes involved in mating type determination and recognition were examined in Metschnikowia and related species, to gather insights on factors affecting mating...
Genes involved in mating type determination and recognition were examined in Metschnikowia and related species, to gather insights on factors affecting mating compatibility patterns among haplontic, heterothallic yeast species of the genus. We confirmed the universality of the special mating locus organisation found in Clavispora lusitaniae across and exclusive to the family Metschnikowiaceae (i.e., Metschnikowia and Clavispora). Timing of the divergence between idiomorphs was confirmed to coincide with the origin of the larger (CUG-ser) clade comprising the Debaryomycetaceae and the Metschnikowiaceae, exclusive of Cephaloascus fragrans. The sequence of the a mating pheromone is highly conserved within the large-spored Metschnikowia species, including Metschnikowia orientalis and Metschnikowia hawaiiana, but not Metschnikowia drosophilae or Metschnikowia torresii, which have a pattern of their own, as do other clades in the genus. In contrast, variation in α pheromones shows a more continuous, although imperfect correlation with phylogenetic distance as well as with in vivo mating compatibility.
Topics: Amino Acid Sequence; Genes, Mating Type, Fungal; Genetic Variation; Genome, Fungal; Genomics; Mating Factor; Metschnikowia; Pheromones; Phylogeny; Quantitative Trait Loci; Quantitative Trait, Heritable; Sequence Analysis, DNA; Spores, Fungal
PubMed: 29651688
DOI: 10.1007/s10482-018-1084-y -
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 -
Microorganisms Jul 2020Over the last decade, several non- species have been used as an alternative yeast for producing wines with sensorial properties that are distinctive in comparison to... (Review)
Review
Over the last decade, several non- species have been used as an alternative yeast for producing wines with sensorial properties that are distinctive in comparison to those produced using only as the classical inoculum. Among the non- wine yeasts is one of the most investigated genera due to its widespread occurrence and its impact in winemaking, and it has been found in grapevine phyllospheres, fruit flies, grapes, and wine fermentations as being part of the resident microbiota of wineries and wine-making equipment. The versatility that allows some species to be used for winemaking relies on an ability to grow in combination with other yeast species, such as , during the first stages of wine fermentation, thereby modulating the synthesis of secondary metabolites during fermentation in order to improve the sensory profile of the wine. exerts a moderate fermentation power, some interesting enzymatic activities involving aromatic and color precursors, and potential antimicrobial activity against spoilage yeasts and fungi, resulting in this yeast being considered an interesting tool for use in the improvement of wine quality. The abovementioned properties have mostly been determined from studies on wine strains. However, and have also recently been studied for winemaking purposes.
PubMed: 32668690
DOI: 10.3390/microorganisms8071038 -
Yeast (Chichester, England) Mar 2017Wine is a complex beverage, comprising thousands of metabolites that are produced through the action of a plethora of yeasts and bacteria during fermentation of grape... (Review)
Review
Wine is a complex beverage, comprising thousands of metabolites that are produced through the action of a plethora of yeasts and bacteria during fermentation of grape must. These microbial communities originate in the vineyard and the winery and reflect the influence of several factors including grape variety, geographical location, climate, vineyard spraying, technological practices, processing stage and season (pre-harvest, harvest, post-harvest). Vineyard and winery microbial communities have the potential to participate during fermentation and influence wine flavour and aroma. Therefore, there is an enormous interest in isolating and characterising these communities, particularly non-Saccharomyces yeast species to increase wine flavour diversity, while also exploting regional signature microbial populations to enhance regionality. In this review we describe the role and relevance of the main non-Saccharomyces yeast species found in vineyards and wineries. This includes the latest reports covering the application of these species for winemaking; and the biotechnological characteristics and potential applications of non-Saccharomyces species in other areas. In particular, we focus attention on the species for which molecular and genomic tools and resources are available for study. Copyright © 2016 John Wiley & Sons, Ltd.
Topics: Brettanomyces; Farms; Fermentation; Hanseniaspora; Metschnikowia; Pichia; Rhodotorula; Torulaspora; Vitis; Wine; Yeasts; Zygosaccharomyces
PubMed: 27813152
DOI: 10.1002/yea.3219 -
World Journal of Microbiology &... Oct 2019Yeasts occur in all environments and have been described as potent antagonists of various plant pathogens. Due to their antagonistic ability, undemanding cultivation... (Review)
Review
Yeasts occur in all environments and have been described as potent antagonists of various plant pathogens. Due to their antagonistic ability, undemanding cultivation requirements, and limited biosafety concerns, many of these unicellular fungi have been considered for biocontrol applications. Here, we review the fundamental research on the mechanisms (e.g., competition, enzyme secretion, toxin production, volatiles, mycoparasitism, induction of resistance) by which biocontrol yeasts exert their activity as plant protection agents. In a second part, we focus on five yeast species (Candida oleophila, Aureobasidium pullulans, Metschnikowia fructicola, Cryptococcus albidus, Saccharomyces cerevisiae) that are or have been registered for the application as biocontrol products. These examples demonstrate the potential of yeasts for commercial biocontrol usage, but this review also highlights the scarcity of fundamental studies on yeast biocontrol mechanisms and of registered yeast-based biocontrol products. Yeast biocontrol mechanisms thus represent a largely unexplored field of research and plentiful opportunities for the development of commercial, yeast-based applications for plant protection exist.
Topics: Biological Control Agents; Plant Diseases; Yeasts
PubMed: 31576429
DOI: 10.1007/s11274-019-2728-4 -
Microorganisms Jul 2020Yeasts affiliated with the clade (subclade) of the large ascomycetous genus frequently turn out to produce the characteristic maroon-red pulcherrimin when tested for... (Review)
Review
Yeasts affiliated with the clade (subclade) of the large ascomycetous genus frequently turn out to produce the characteristic maroon-red pulcherrimin when tested for pigment production and prove to exert antagonistic effects on many types of microorganisms. The determination of the exact taxonomic position of the strains is hampered by the shortage of distinctive morphological and physiological properties of the species of the clade and the lack of rDNA barcode gaps. The rDNA repeats of the type strains of the species are not homogenized and are assumed to evolve by a birth-and-death mechanism combined with reticulation. The taxonomic division is further hampered by the incomplete biological (reproductive) isolation of the species: certain type strains can be hybridized and genome sequencing revealed chimeric genome structures in certain strains that might have evolved from interspecies hybrids (alloploid genome duplication). Various mechanisms have been proposed for the antimicrobial antagonism. One is related to pulcherrimin production. The diffusible precursor of pulcherrimin, the pulcherriminic acid is secreted by the cells into the environment where it forms the insoluble pulcherrimin with the ferric ions. The lack of free iron caused by the immobilization of ferric ions inhibits the growth of many microorganisms. Recent results of research into the complexity of the taxonomic division of the pulcherrimin-producing yeasts and the mechanism(s) underlying their antimicrobial antagonism are discussed in this review.
PubMed: 32664630
DOI: 10.3390/microorganisms8071029 -
Microorganisms Apr 2023Drinking wine is a processed beverage that offers high nutritional and health benefits. It is produced from grape must, which undergoes fermentation by yeasts (and... (Review)
Review
Drinking wine is a processed beverage that offers high nutritional and health benefits. It is produced from grape must, which undergoes fermentation by yeasts (and sometimes lactic acid bacteria) to create a product that is highly appreciated by consumers worldwide. However, if only one type of yeast, specifically , was used in the fermentation process, the resulting wine would lack aroma and flavor and may be rejected by consumers. To produce wine with a desirable taste and aroma, non- yeasts are necessary. These yeasts contribute volatile aromatic compounds that significantly impact the wine's final taste. They promote the release of primary aromatic compounds through a sequential hydrolysis mechanism involving several glycosidases unique to these yeasts. This review will discuss the unique characteristics of these yeasts (, , , , , , , , and others) and their impact on wine fermentations and co-fermentations. Their existence and the metabolites they produce enhance the complexity of wine flavor, resulting in a more enjoyable drinking experience.
PubMed: 37317152
DOI: 10.3390/microorganisms11051178 -
International Journal of Systematic and... Nov 2014In a taxonomic study of yeasts recovered from nectar of flowers and associated insects in South Africa, 11 strains were found to represent two novel species....
In a taxonomic study of yeasts recovered from nectar of flowers and associated insects in South Africa, 11 strains were found to represent two novel species. Morphological and physiological characteristics and sequence analyses of the large-subunit rRNA gene D1/D2 region, as well as the actin, RNA polymerase II and elongation factor 2 genes, showed that the two novel species belonged to the genus Metschnikowia. Metschnikowia drakensbergensis sp. nov. (type strain EBD-CdVSA09-2(T) =CBS 13649(T) =NRRL Y-63721(T); MycoBank no. MB809688; allotype EBD-CdVSA10-2(A) =CBS13650(A) =NRRL Y-63720(A)) was recovered from nectar of Protea roupelliae and the beetle Heterochelus sp. This species belongs to the large-spored Metschnikowia clade and is closely related to Metschnikowia proteae, with which mating reactions and single-spored asci were observed. Metschnikowia caudata sp. nov. (type strain EBD-CdVSA08-1(T) =CBS 13651(T) =NRRL Y-63722(T); MycoBank no. MB809689; allotype EBD-CdVSA57-2(A) =CBS 13729(A) =NRRL Y-63723(A)) was isolated from nectar of Protea dracomontana, P. roupelliae and P. subvestita and a honeybee, and is a sister species to Candida hainanensis and Metschnikowia lopburiensis. Analyses of the four sequences demonstrated the existence of three separate phylotypes. Intraspecies matings led to the production of mature asci of unprecedented morphology, with a long, flexuous tail. A single ascospore was produced in all compatible crosses, regardless of sequence phylotype. The two species appear to be endemic to South Africa. The ecology and habitat specificity of these novel species are discussed in terms of host plant and insect host species.
Topics: Animals; Coleoptera; DNA, Fungal; DNA, Ribosomal Spacer; Ecosystem; Flowers; Metschnikowia; Molecular Sequence Data; Mycological Typing Techniques; Phylogeny; Plant Nectar; Sequence Analysis, DNA; South Africa
PubMed: 25106927
DOI: 10.1099/ijs.0.068445-0 -
Foods (Basel, Switzerland) Dec 2020Non- yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than . As such, there has been a focus... (Review)
Review
Non- yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than . As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as spp., spp. and , are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non- yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to . Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as and , highlighting the potential of these yeast as inoculants for specific wine styles.
PubMed: 33374550
DOI: 10.3390/foods10010013 -
BioRxiv : the Preprint Server For... Jul 2023Eukaryotic life depends on the functional elements encoded by both the nuclear genome and organellar genomes, such as those contained within the mitochondria. The...
Eukaryotic life depends on the functional elements encoded by both the nuclear genome and organellar genomes, such as those contained within the mitochondria. The content, size, and structure of the mitochondrial genome varies across organisms with potentially large implications for phenotypic variance and resulting evolutionary trajectories. Among yeasts in the subphylum Saccharomycotina, extensive differences have been observed in various species relative to the model yeast , but mitochondrial genome sampling across many groups has been scarce, even as hundreds of nuclear genomes have become available. By extracting mitochondrial assemblies from existing short-read genome sequence datasets, we have greatly expanded both the number of available genomes and the coverage across sparsely sampled clades. Comparison of 353 yeast mitochondrial genomes revealed that, while size and GC content were fairly consistent across species, those in the genera and trended larger, while several species in the order Saccharomycetales, which includes , exhibited lower GC content. Extreme examples for both size and GC content were scattered throughout the subphylum. All mitochondrial genomes shared a core set of protein-coding genes for Complexes III, IV, and V, but they varied in the presence or absence of mitochondrially-encoded canonical Complex I genes. We traced the loss of Complex I genes to a major event in the ancestor of the orders Saccharomycetales and Saccharomycodales, but we also observed several independent losses in the orders Phaffomycetales, Pichiales, and Dipodascales. In contrast to prior hypotheses based on smaller-scale datasets, comparison of evolutionary rates in protein-coding genes showed no bias towards elevated rates among aerobically fermenting (Crabtree/Warburg-positive) yeasts. Mitochondrial introns were widely distributed, but they were highly enriched in some groups. The majority of mitochondrial introns were poorly conserved within groups, but several were shared within groups, between groups, and even across taxonomic orders, which is consistent with horizontal gene transfer, likely involving homing endonucleases acting as selfish elements. As the number of available fungal nuclear genomes continues to expand, the methods described here to retrieve mitochondrial genome sequences from these datasets will prove invaluable to ensuring that studies of fungal mitochondrial genomes keep pace with their nuclear counterparts.
PubMed: 37577532
DOI: 10.1101/2023.07.28.551029