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Anais Da Academia Brasileira de Ciencias 2023Harsh and extreme environments, such as Antarctica, offer unique opportunities to explore new microbial taxa and biomolecules. Given the limited knowledge on microbial...
Harsh and extreme environments, such as Antarctica, offer unique opportunities to explore new microbial taxa and biomolecules. Given the limited knowledge on microbial diversity, this study aimed to compile, analyze and compare a subset of the biobank of Antarctic fungi maintained at the UNESP's Central of Microbial Resources (CRM-UNESP). A total of 711 isolates (240 yeasts and 471 filamentous fungi) from marine and terrestrial samples collected at King George Island (South Shetland Islands, Antarctica) were used with the primary objective of investigating their presence in both marine and terrestrial environments. Among the yeasts, 13 genera were found, predominantly belonging to the phylum Basidiomycota. Among the filamentous fungi, 34 genera were represented, predominantly from the phylum Ascomycota. The most abundant genera in the marine samples were Metschnikowia, Mrakia, and Pseudogymnoascus, while in the terrestrial samples, they were Pseudogymnoascus, Leucosporidium, and Mortierella. Most of the genera and species of the CRM-UNESP biobank of Antarctic fungi are being reported as an important target for biotechnological applications. This study showed the relevance of the CRM-UNESP biobank, highlighting the importance of applying standard methods for the preservation of the biological material and associated data (BMaD), as recommended in national and international standards.
Topics: Antarctic Regions; Biological Specimen Banks; Fungi; Yeasts; Ascomycota; Basidiomycota
PubMed: 38126380
DOI: 10.1590/0001-3765202320230603 -
Microorganisms Oct 2021Wine reflects the specificity of a , including the native microbiota. In contrast to the use of commercial starters, a way to maintain wines' microbial identities,...
Wine reflects the specificity of a , including the native microbiota. In contrast to the use of commercial starters, a way to maintain wines' microbial identities, guaranteeing at the same time the predictability and reproducibility of the wines, is the selection of autochthonous and non- strains towards optimal enological characteristics for the chosen area of isolation. This field has been explored but there is a lack of a compendium covering the main methods to use. Autochthonous wine yeasts from different areas of Slovakia were identified and tested, in the form of colonies grown either on nutrient agar plates or in grape must micro-fermentations, for technological and qualitative enological characteristics. Based on the combined results, PDA W 10, 5-1-1 and 125/14 were selected as potential wine starters. This paper, as a mixture of experimental and review contributions, provides a compendium of methods used to select autochthonous wine yeasts. Thanks to the presence of images, this compendium could guide other researchers in screening their own yeast strains for wine production.
PubMed: 34835348
DOI: 10.3390/microorganisms9112223 -
Scientific Reports Apr 2020As a complex microbial ecosystem, wine is a particularly interesting model for studying interactions between microorganisms as fermentation can be done by microbial...
As a complex microbial ecosystem, wine is a particularly interesting model for studying interactions between microorganisms as fermentation can be done by microbial consortia, a unique strain or mixed culture. The effect of a specific yeast strain on its environments is unique and characterized by its metabolites and their concentration. With its great resolution and excellent mass accuracy, ultrahigh resolution mass spectrometry (uHRMS) is the perfect tool to analyze the yeast metabolome at the end of alcoholic fermentation. This work reports the change in wine chemical composition from pure and mixed culture fermentation with Lachancea thermotolerans, Starmerella bacillaris, Metschnikowia pulcherrima and S. cerevisiae. We could clearly differentiate wines according to the yeast strain used in single cultures and markers, which reflect important differences between the yeast species, were extracted and annotated. Moreover, uHRMS revealed underlining intra species metabolomics differences, showing differences at the strain level between the two Starmerella bacillaris. Non volatile metabolomics analysis of single and sequential fermentations confirmed that mixed fermentations lead to a different composition. Distinct metabolites appeared in wines from sequential fermentation compared to single fermentation. This suggests that interactions between yeasts are not neutral.
Topics: Alcohols; Fermentation; Metabolome; Microbiota; Saccharomycetales; Volatile Organic Compounds; Wine
PubMed: 32269331
DOI: 10.1038/s41598-020-63182-6 -
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 -
Microbiological Research Jun 2024Saccharomycopsis species are natural organic sulphur auxotrophs. Their genomes do not encode genes for the uptake and assimilation of sulphate and thus these species...
Saccharomycopsis species are natural organic sulphur auxotrophs. Their genomes do not encode genes for the uptake and assimilation of sulphate and thus these species cannot grow on media lacking e.g. methionine. Due to the similarity between sulphate and selenate, uptake and assimilation of selenate occurs through the same pathway starting from sulphate transporters encoded by the homologs of the SUL1 and SUL2 genes in S. cerevisiae. Lack of these transporters renders Saccharomycopsis species resistant to selenate levels that are toxic to other microorganisms. We used this feature to enrich environmental samples for Saccharomycopsis species. This led to the isolation of S. schoenii, S. lassenensis and a hitherto undescribed Saccharomycopsis species with limited by-catch of other yeasts, mainly belonging to Metschnikowia and Hanseniaspora. We performed growth and predation assays to characterize the potential of these new isolates as predacious yeasts. Most Saccharomycopsis species are temperature sensitive and cannot grow at 37°C; with the exception of S. lassenensis strains. Predation assays with S. schoenii and S. cerevisiae as prey indicated that predation was enhanced at 20°C compared to 30°C. We crossed an American isolate of S. schoenii with our German isolate using marker directed breeding. Viable progeny indicated that both strains are interfertile and belong to the same biological species. S. lassenensis is heterothallic, while S. schoenii and the new Saccharomycopsis isolate, for which we suggest the name S. geisenheimensis sp. nov., are homothallic.
Topics: Saccharomycopsis; Saccharomyces cerevisiae; Selenic Acid; Biological Transport; Sulfates; Sulfate Transporters; Saccharomyces cerevisiae Proteins; Anion Transport Proteins
PubMed: 38492364
DOI: 10.1016/j.micres.2024.127691 -
Microbiological Research Dec 2015Saccharomyces and non-Saccharomyces represents a heterogeneous class in the grape/must/wine environments including several yeast genera (e.g., Saccharomyces,... (Review)
Review
Saccharomyces and non-Saccharomyces represents a heterogeneous class in the grape/must/wine environments including several yeast genera (e.g., Saccharomyces, Hanseniaspora, Pichia, Candida, Metschnikowia, Kluyveromyces, Zygosaccharomyces, Torulaspora, Dekkera and Schizosaccharomyces) and species. Since, each species may differently contribute to the improvement/depreciation of wine qualities, it appears clear the reason why species belong to non-Saccharomyces are also considered a biotechnological resource in wine fermentation. Here, we briefly review the oenological significance of this specific part of microbiota associated with grapes/musts/wine. Moreover, the diversity of cultivable non-Saccharomyces genera and their contribute to typical wines fermentations will be discussed.
Topics: Biodiversity; Fermentation; Food Microbiology; Industrial Microbiology; Microbiota; Vitis; Wine; Yeasts
PubMed: 26521127
DOI: 10.1016/j.micres.2015.10.005 -
PloS One 2021Currently, one of the most important challenges is to provide sufficient and affordable food and energy for a fast-growing world population, alongside preserving natural...
Inoculation of pear flowers with Metschnikowia reukaufii and Acinetobacter nectaris enhances attraction of honeybees and hoverflies, but does not increase fruit and seed set.
Currently, one of the most important challenges is to provide sufficient and affordable food and energy for a fast-growing world population, alongside preserving natural habitats and maintaining biodiversity. About 35% of the global food production depends on animals for pollination. In recent years, an alarming worldwide decline in pollinators has been reported, putting our food production under additional pressure. Therefore, there is an urgent need to find sustainable ways to ensure this crucial ecosystem service. Recent studies have shown that floral nectar is generally colonized by microorganisms, specifically yeasts and bacteria, which may alter nectar chemistry and enhance attraction of pollinators. In this study, we investigated changes in pollinator foraging behavior and pollination success in European pear (Pyrus communis L.) cultivars 'Regal Red' and 'Sweet Sensation' (red sports of 'Doyenné de Comice') after flower inoculation with the typical nectar-inhabiting microorganisms Metschnikowia reukaufii and Acinetobacter nectaris, and a combination of both. Pollination success was monitored by measuring the number of flower visits, fruit set and seed set in two consecutive years, 2019 and 2020. Results revealed that application of a mixture of M. reukaufii and A. nectaris resulted in significantly higher visitation rates of honeybees and hoverflies. By contrast, no effects on flower visits were found when yeasts and bacteria were applied separately. Fruit set and seed set were not significantly affected by any of the inoculation treatments. The only factors affecting fruit set were initial number of flower clusters on the trees and the year. The absence of treatment effects can most likely be attributed to the fact that pollination was not a limiting factor for fruit set in our experiments. Altogether, our results show that inoculation of flowers with nectar microbes can modify pollinator foraging patterns, but did not lead to increased pollination success under the conditions tested.
Topics: Animals; Bees; Flowers; Fruit; Plant Nectar; Pollination; Pyrus
PubMed: 33886638
DOI: 10.1371/journal.pone.0250203 -
Environmental Microbiology Aug 2021Floral nectar often contains pollen and microorganisms, which may change nectar's chemical composition, and in turn impact pollinator affinity. However, their individual...
Floral nectar often contains pollen and microorganisms, which may change nectar's chemical composition, and in turn impact pollinator affinity. However, their individual and combined effects remain understudied. Here, we examined the impacts of the nectar specialist yeast, Metschnikowia reukaufii, and the addition of sunflower (Hellianthus annus) pollen. Pollen grains remained intact, yet still increased yeast growth and amino acid concentrations in nectar, whereas yeast depleted amino acids. Pollen, but not yeast, changed nectar sugar concentrations by converting sucrose to its monomers. Both pollen and yeast contributed emissions from nectar, though yeast volatiles were more abundant than pollen volatiles. Yeast volatile emission was positively correlated with pollen concentration and cell density, and yeast depleted a subset of pollen-derived volatiles. Honey bees avoided foraging on yeast-inoculated nectar and foraged equally among uninoculated nectars regardless of pollen content, underscoring the importance of microbial metabolites in mediating pollinator foraging.
Topics: Animals; Bees; Odorants; Plant Nectar; Pollen; Pollination; Yeasts
PubMed: 33876542
DOI: 10.1111/1462-2920.15528 -
Frontiers in Microbiology 2015Saccharomyces cerevisiae is by far the most widely used yeast in oenology. However, during the last decade, several other yeasts species has been purposed for winemaking... (Review)
Review
Saccharomyces cerevisiae is by far the most widely used yeast in oenology. However, during the last decade, several other yeasts species has been purposed for winemaking as they could positively impact wine quality. Some of these non-conventional yeasts (Torulaspora delbrueckii, Metschnikowia pulcherrima, Pichia kluyveri, Lachancea thermotolerans, etc.) are now proposed as starters culture for winemakers in mixed fermentation with S. cerevisiae, and several others are the subject of various studies (Hanseniaspora uvarum, Starmerella bacillaris, etc.). Along with their biotechnological use, the knowledge of these non-conventional yeasts greatly increased these last 10 years. The aim of this review is to describe the last updates and the current state-of-art of the genetics of non-conventional yeasts (including S. uvarum, T. delbrueckii, S. bacillaris, etc.). We describe how genomics and genetics tools provide new data into the population structure and biodiversity of non-conventional yeasts in winemaking environments. Future challenges will lie on the development of selection programs and/or genetic improvement of these non-conventional species. We discuss how genetics, genomics and the advances in next-generation sequencing will help the wine industry to develop the biotechnological use of non-conventional yeasts to improve the quality and differentiation of wines.
PubMed: 26793188
DOI: 10.3389/fmicb.2015.01563 -
Antonie Van Leeuwenhoek Mar 2020Four yeast strains (RIFY 10001, RIFY 10002, RIFY 10003, and RIFY 10004) were isolated from flowers growing in fields of mustard and broad beans in Japan. Ascospore...
Four yeast strains (RIFY 10001, RIFY 10002, RIFY 10003, and RIFY 10004) were isolated from flowers growing in fields of mustard and broad beans in Japan. Ascospore formation was not observed. Sequence analysis of the D1/D2 domain of the large subunit ribosomal RNA (LSU rRNA) gene of the four strains indicated that they belong to the genus Metschnikowia and are closely related to Metschnikowia hawaiiana strain CBS 9146 and Metschnikowia orientalis strain CBS 10331. The D1/D2 domain of the LSU rRNA gene and internal transcribed spacer regions of strain RIFY 10001 were 85.7% identical to those of M. hawaiiana strain CBS 9146. All four strains were distinguished from the M. hawaiiana strain CBS 9146 by their inability to ferment glucose. Hence, these four strains are novel species and were named as Metschnikowia miensis (holotype: RIFY 10001; isotypes: NBRC 112445 = CBS 14749).
Topics: DNA, Fungal; Flowers; Japan; Metschnikowia; Mycological Typing Techniques; Phenotype; Phylogeny; RNA, Ribosomal
PubMed: 31637663
DOI: 10.1007/s10482-019-01340-1