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En la elaboración de cerveza las levaduras cumplen un rol fundamental. Además de ser responsables de llevar a cabo la fermentación, generando principalmente etanol y dióxido de carbono, también son capaces de metabolizar y producir numerosos compuestos orgánicos que tienen un impacto determinante en el aroma y el sabor final de la cerveza. Las especies Saccharomyces cerevisiae y Saccharomyces pastorianus son utilizadas tradicionalmente para la producción de cervezas ale y lager, respectivamente. No obstante, el continuo crecimiento en el mercado de la cerveza artesanal y el aumento del interés y las exigencias de los consumidores han orientado los esfuerzos hacia la producción de cervezas diferenciales e innovadoras. En este punto, las levaduras no convencionales han cobrado gran protagonismo como herramientas para el desarrollo de nuevos productos. En el presente trabajo se describe y desarrolla la potencial aplicación en el sector cervecero de diferentes especies de levaduras no convencionales pertenecientes a los géneros Brettanomyces, Torulaspora, Lachancea, Wickerhamomyces, Pichia y Mrakia, entre otras, así como también levaduras del género Saccharomyces distintas a las levaduras cerveceras tradicionales. Se detallan las condiciones de fermentación de este tipo de levaduras y su capacidad de asimilar y metabolizar diferentes componentes del mosto y de aportar características particulares al producto final. Este trabajo provee el estado del arte sobre levaduras no convencionales, lo que resulta de gran relevancia para evaluar su aplicación en la producción de cervezas artesanales con características sensoriales diferenciales, cervezas bajas en calorías, cervezas sin alcohol y cervezas funcionales. Yeasts play a crucial role in brewing. During fermentation, besides ethanol and carbon dioxide, yeasts produce a considerable number of organic compounds, which are essential for beer flavor. In particular, Saccharomyces cerevisiae and Saccharomyces pastorianus are traditionally used in the production of ale and lager beers, respectively. Nowadays, the continuous growth of the craft beer market motivates the production of differential and innovative beers; leading specialists and brewers focus on non-conventional yeasts as tools for new product development. In this work, we describe the potential application of non-conventional yeast species such as those of the genera Brettanomyces, Torulaspora, Lachancea, Wickerhamomyces, Pichia and Mrakia in the craft brewing industry, as well as non-traditional brewing yeasts of the Saccharomyces genus. Furthermore, the fermentation conditions of these non-conventional yeasts are discussed, along with their abilities to assimilate and metabolize diverse wort components providing differential characteristics to the final product. In summary, we present a comprehensive review of the state-of-the-art of non-conventional yeasts, which is highly relevant for their application in the production of novel craft beers including flavored beers, non-alcoholic beers, low-calorie beers and functional beers. Fil: Burini, Julieta Amalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina Fil: Eizaguirre, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Loviso, Claudia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina

A set of four strains representing a novel basidiomycetous yeast species Rhodotorula sampaioana f. a., sp. nov. were isolated from two different habitats, subsurface waters of Lake Negra in Argentina, and the gut of a xylophagous termite in India. Phylogenetic analyses of LSU and ITS sequences showed that they belonged to the genus Rhodotorula of the order Sporidiobolales (subphylum Pucciniomycotina) and the closest known relative being R. kratochvilovae. The new species differed from R. kratochvilovae CBS 7436 (AF071436, AF444520) by nine nucleotide substitutions and one deletion (1.7 % sequence variation) in a 593 bp D1/D2 region, and by five nucleotide substitutions and three deletions (1.3 %) in a 592 bp ITS region, respectively. Several morphological and physiological differences were also observed between R. kratochvilovae and the strains obtained during this study. These data support the proposal of Rhodotorula sampaioana as a novel species, with CRUB 1124 as the holotype, CBS 10798 as ex-type, and NFCCI 4872 as an additional strain. The GenBank accession numbers of the LSU and ITS sequences of Rhodotorula sampaioana f. a., sp. nov. are EF595748 and MW879331. The MycoBank number is MB 838533.

During a survey of Nothofagus trees and their parasitic fungi in Andean Patagonia (Argentina), genetically distinct strains of Hanseniaspora were obtained from the sugar-containing stromata of parasitic Cyttaria spp. Phylogenetic analyses based on the single-gene sequences (encoding rRNA and actin) or on conserved, single-copy, orthologous genes from genome sequence assemblies revealed that these strains represent a new species closely related to Hanseniaspora valbyensis. Additionally, delimitation of this novel species was supported by genetic distance calculations using overall genome relatedness indices (OGRI) between the novel taxon and its closest relatives. To better understand the mode of speciation in Hanseniaspora, we examined genes that were retained or lost in the novel species in comparison to its closest relatives. These analyses show that, during diversification, this novel species and its closest relatives, H. valbyensis and Hanseniaspora jakobsenii, lost mitochondrial and other genes involved in the generation of precursor metabolites and energy, which could explain their slower growth and higher ethanol yields under aerobic conditions. Similarly, Hanseniaspora mollemarum lost the ability to sporulate, along with genes that are involved in meiosis and mating. Based on these findings, a formal description of the novel yeast species Hanseniaspora smithiae sp. nov. is proposed, with CRUB 1602H as the holotype.

The unambiguous application of fungal names is important to communicate scientific findings. Names are critical for (clinical) diagnostics, legal compliance, and regulatory controls, such as biosafety, food security, quarantine regulations, and industrial applications. Consequently, the stability of the taxonomic system and the traceability of nomenclatural changes is crucial for a broad range of users and taxonomists. The unambiguous application of names is assured by the preservation of nomenclatural history and the physical organisms representing a name. Fungi are extremely diverse in terms of ecology, lifestyle, and methods of study. Predominantly unicellular fungi known as yeasts are usually investigated as living cultures. Methods to characterize yeasts include physiological (growth) tests and experiments to induce a sexual morph; both methods require viable cultures. Thus, the preservation and availability of viable reference cultures are important, and cultures representing reference material are cited in species descriptions. Historical surveys revealed drawbacks and inconsistencies between past practices and modern requirements as stated in the International Code of Nomenclature for Algae, Fungi, and Plants (ICNafp). Improper typification of yeasts is a common problem, resulting in a large number invalid yeast species names. With this opinion letter, we address the problem that culturable microorganisms, notably some fungi and algae, require specific provisions under the ICNafp. We use yeasts as a prominent example of fungi known from cultures. But viable type material is important not only for yeasts, but also for other cultivable Fungi that are characterized by particular morphological structures (a specific type of spores), growth properties, and secondary metabolites. We summarize potential proposals which, in our opinion, will improve the stability of fungal names, in particular by protecting those names for which the reference material can be traced back to the original isolate.

Among the main beer components, fusel alcohols are important because of their influence on the flavor of the final product, and therefore on its quality. During the production process, these compounds are generated by yeasts through the metabolism of amino acids. The yeasts, fermentation conditions and wort composition affect fusel alcohols profiles and their concentrations. In this review, we provide detailed information about the enzymes involved in fusel alcohols formation and their regulation. Moreover, we describe how the type of yeast used, the fermentation temperature and the composition of carbohydrates and nitrogen source in wort, among other fermentation parameters, affect the biosynthesis of these alcohols. Knowing how fusel alcohol levels vary during beer production provides a relevant tool for brewers to achieve the desired characteristics in the final product and at the same time highlights the aspects still unknown to science.

Cold environments impose challenges to organisms. Polyextremophile microorganisms can survive in these conditions thanks to an array of counteracting mechanisms. Naganishia vishniacii, a yeast species hitherto only isolated from McMurdo Dry Valleys, Antarctica, is an example of a polyextremophile. Here we present the first draft genomic sequence of N. vishniacii. Using comparative genomics, we unraveled unique characteristics of cold associated adaptations. From a total of 6183 predicted coding sequences, we identified 336 genes absent in sister species, encoding solute transfers and chaperones, among others. Among genes shared by N. vishniacii and its closest related species we found orthologs encompassing possible evidence of positive selection (dN/dS > 1). Genes associated with photoprotection were found in agreement with high solar irradiation exposure. Also genes coding for desaturases and genomic features associated with cold tolerance (i.e. trehalose synthesis and lipid metabolism) were explored. Finally, biases in amino acid usage (namely enrichment of glutamine and a trend reduction of proline) were observed, possibly conferring increased protein flexibility. To the best of our knowledge, such a combination of mechanisms for cold tolerance has not been previously reported in fungi, making N. vishniacii a unique model for the study of the genetic basis and evolution of cold adaptation strategies. Fil: Nizovoy, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina Fil: Bellora, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina Fil: Haridas, Sajeet. United States Department of Energy. Joint Genome Institute; Estados Unidos Fil: Sun, Hui. United States Department of Energy. Joint Genome Institute; Estados Unidos Fil: Daum, Chris. United States Department of Energy. Joint Genome Institute; Estados Unidos Fil: Barry, Kerrie. United States Department of Energy. Joint Genome Institute; Estados Unidos Fil: Grigoriev, Igor V.. United States Department of Energy. Joint Genome Institute; Estados Unidos Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina Fil: Connell, Laurie B.. University of Maine; Estados Unidos Fil: Moliné, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina

Phaffia is an orange-colored basidiomycetous yeast genus of the order Cystofilobasidiales that contains a single species, P. rhodozyma. This species is the only fungus known to produce the economically relevant carotenoid astaxanthin. Although Phaffia was originally found in the Northern hemisphere, its diversity in the southern part of the globe has been shown to be much greater. Here we analyze the genomes of two Australasian lineages that are markedly distinct from P. rhodozyma. The two divergent lineages were investigated within a comprehensive phylogenomic study of representatives of the Cystofilobasidiales that supported the recognition of two novel Phaffia species, for which we propose the names of P. australis sp. nov. and P. tasmanica sp. nov. Comparative genomics and other analyses confirmed that the two new species have the typical Phaffia hallmark&mdash, the six genes necessary for the biosynthesis of astaxanthin could be retrieved from the draft genome sequences, and this carotenoid was detected in culture extracts. In addition, the organization of the mating-type (MAT) loci is similar to that of P. rhodozyma, with synteny throughout most regions. Moreover, cases of trans-specific polymorphism involving pheromone receptor genes and pheromone precursor proteins in the three Phaffia species, together with their shared homothallism, provide additional support for their classification in a single genus.

The wild, cold-adapted parent of hybrid lager-brewing yeasts, Saccharomyces eubayanus, has a complex and understudied natural history. The exploration of this diversity can be used both to develop new brewing applications and to enlighten our understanding of the dynamics of yeast evolution in the wild. Here, we integrate whole genome sequence and phenotypic data of 200 S. eubayanus strains, the largest collection known to date. S. eubayanus has a multilayered population structure, consisting of two major populations that are further structured into six subpopulations. Four of these subpopulations are found exclusively in the Patagonian region of South America; one is found predominantly in Patagonia and sparsely in Oceania and North America; and one is specific to the Holarctic ecozone. Plant host associations differed between subpopulations and between S. eubayanus and its sister species, Saccharomyces uvarum. S. eubayanus is most abundant and genetically diverse in northern Patagonia, where some locations harbor more genetic diversity than is found outside of South America, suggesting that northern Patagonia east of the Andes was a glacial refugium for this species. All but one subpopulation shows isolation-by-distance, and gene flow between subpopulations is low. However, there are strong signals of ancient and recent outcrossing, including two admixed lineages, one that is sympatric with and one that is mostly isolated from its parental populations. Using our extensive biogeographical data, we build a robust model that predicts all known and a handful of additional regions of the globe that are climatically suitable for S. eubayanus, including Europe where host accessibility and competitive exclusion by other Saccharomyces species may explain its continued elusiveness. We conclude that this industrially relevant species has rich natural diversity with many factors contributing to its complex distribution and natural history., This material is based upon work supported by the National Science Foundation (https://www.nsf.gov) under Grant Nos. DEB-1253634 (to CTH) and DGE-1256259 (Graduate Research Fellowship to QKL), the USDA National Institute of Food and Agriculture (https://www.nifa.usda.gov) Hatch Project Nos. 1003258 and 1020204 to CTH, and in part by the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science (https://www.energy.gov/science/office-science) Nos. DE-SC0018409 and DE-FC02-07ER64494 to Timothy J. Donohue). QKL was also supported by the Predoctoral Training Program in Genetics, funded by the National Institutes of Health (5T32GM007133, https://www.nih.gov). DP is a Marie Sklodowska-Curie fellow of the European Union’s Horizon 2020 (https://ec.europa.eu/programmes/horizon2020/en) research and innovation program (Grant Agreement No. 747775). DL was supported by CONICET (PIP11220130100392CO, https://www.conicet.gov.ar), FONCyT (PICT 3677, PICT 2542, https://www.argentina.gob.ar/ciencia/agencia/fondo-para-la-investigacion-cientifica-y-tecnologica-foncyt), Universidad Nacional del Comahue (B199, https://www.uncoma.edu.ar), and NSF-CONICET grant (https://www.conicet.gov.ar). CTH is a Pew Scholar in the Biomedical Sciences and H. I. Romnes Faculty Fellow, supported by the Pew Charitable Trusts (https://www.pewtrusts.org/en) and Office of the Vice Chancellor for Research and Graduate Education (https://research.wisc.edu) with funding from the Wisconsin Alumni Research Foundation (WARF, https://www.warf.org), respectively.

This is a pre-copyedited, author-produced version of an article accepted for publication in FEMS Yeast Research following peer review. The version of record "D Libkind, D Peris, F A Cubillos, J L Steenwyk, D A Opulente, Q K Langdon, A Rokas, C T Hittinger, Into the wild: new yeast genomes from natural environments and new tools for their analysis, FEMS Yeast Research, Volume 20, Issue 2, March 2020, foaa008" is available online at: https://doi.org/10.1093/femsyr/foaa008, Genomic studies of yeasts from the wild have increased considerably in the past few years. This revolution has been fueled by advances in high-throughput sequencing technologies and a better understanding of yeast ecology and phylogeography, especially for biotechnologically important species. The present review aims to first introduce new bioinformatic tools available for the generation and analysis of yeast genomes. We also assess the accumulated genomic data of wild isolates of industrially relevant species, such as Saccharomyces spp., which provide unique opportunities to further investigate the domestication processes associated with the fermentation industry and opportunistic pathogenesis. The availability of genome sequences of other less conventional yeasts obtained from the wild has also increased substantially, including representatives of the phyla Ascomycota (e.g. Hanseniaspora) and Basidiomycota (e.g. Phaffia). Here, we review salient examples of both fundamental and applied research that demonstrate the importance of continuing to sequence and analyze genomes of wild yeasts., DL has been funded through CONICET (PIP11220130100392CO) and Universidad Nacional del Comahue (B199). Research in AR's lab has been funded through a National Science Foundation grant (DEB-1442113); JLS and AR have also received funding by the Howard Hughes Medical Institute through the James H. Gilliam Fellowships for Advanced Study program. CTH has been funded through the National Science Foundation (DEB-1442148), USDA National Institute of Food and Agriculture (Hatch Project 1020204), and DOE Great Lakes Bioenergy Research Center (DE-SC0018409). CTH is a Pew Scholar in the Biomedical Sciences and a H. I. Romnes Faculty Fellow, supported by the Pew Charitable Trusts and Office of the Vice Chancellor for Research and Graduate Education with funding from the Wisconsin Alumni Research Foundation, respectively. DP is a Marie Sklodowska-Curie fellow of the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 747775).

In recent years, ‘multi-omic’ sciences have affected all aspects of fundamental and applied biological research. Yeast taxonomists, though somewhat timidly, have begun to incorporate complete genomic sequences into the description of novel taxa, taking advantage of these powerful data to calculate more reliable genetic distances, construct more robust phylogenies, correlate genotype with phenotype and even reveal cryptic sexual behaviors. However, the use of genomic data in formal yeast species descriptions is far from widespread. The present review examines published examples of genome-based species descriptions of yeasts, highlights relevant bioinformatic approaches, provides recommendations for new users and discusses some of the challenges facing the genome-based systematics of yeasts.

We investigated the distribution patterns of yeast communities in freshwater lakes along a latitudinal gradient in order to evaluate yeast biogeography at intercontinental (501–8000 km), regional (0–500 km) and local (0–1 km) geographical scales. We identified 285 yeast isolates belonging to 64 species based on sequence analysis of the ITS-5.8S region and the D1/D2 domains of the large subunit of rRNA genes. Distance decay analysis showed a significant negative slope curve at the intercontinental scale. At the intercontinental and regional scales, the dissimilarity of the yeast communities was correlated with geographical distance, with community similarity decreasing with increasing distance. The physiological profiles of the yeast communities from tropical and Patagonian lakes were similar but were different from those of Antarctic lakes. This is the first report of latitudinal patterns of lake yeast diversity along a gradient extending from Antarctic to tropical environments. Fil: Brandão, Luciana R.. Universidade Federal de Minas Gerais; Brasil Fil: Vaz, Aline B.M.. Universidade Federal de Minas Gerais; Brasil Fil: Espírito Santo, Lilia C.. Universidade Federal de Minas Gerais; Brasil Fil: Pimenta, Raphael S.. Universidade Federal do Tocantins; Brasil Fil: Morais, Paula B.. Universidade Federal do Tocantins; Brasil Fil: Libkind Frati, Diego. Universidad Nacional del Comahue. Centro Regional Universidad de Bariloche. Departamento de Biología. Laboratorio de Microbiología Aplicada y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Rosa, Luiz H.. Universidade Federal de Minas Gerais; Brasil Fil: Rosa, Carlos A.. Universidade Federal de Minas Gerais; Brasil

Background: Lignocellulosic biomass is a common resource across the globe, and its fermentation offers a promising option for generating renewable liquid transportation fuels. The deconstruction of lignocellulosic biomass releases sugars that can be fermented by microbes, but these processes also produce fermentation inhibitors, such as aromatic acids and aldehydes. Several research projects have investigated lignocellulosic biomass fermentation by the baker's yeast Saccharomyces cerevisiae. Most projects have taken synthetic biological approaches or have explored naturally occurring diversity in S. cerevisiae to enhance stress tolerance, xylose consumption, or ethanol production. Despite these efforts, improved strains with new properties are needed. In other industrial processes, such as wine and beer fermentation, interspecies hybrids have combined important traits from multiple species, suggesting that interspecies hybridization may also offer potential for biofuel research. Results: To investigate the efficacy of this approach for traits relevant to lignocellulosic biofuel production, we generated synthetic hybrids by crossing engineered xylose-fermenting strains of S. cerevisiae with wild strains from various Saccharomyces species. These interspecies hybrids retained important parental traits, such as xylose consumption and stress tolerance, while displaying intermediate kinetic parameters and, in some cases, heterosis (hybrid vigor). Next, we exposed them to adaptive evolution in ammonia fiber expansion-pretreated corn stover hydrolysate and recovered strains with improved fermentative traits. Genome sequencing showed that the genomes of these evolved synthetic hybrids underwent rearrangements, duplications, and deletions. To determine whether the genus Saccharomyces contains additional untapped potential, we screened a genetically diverse collection of more than 500 wild, non-engineered Saccharomyces isolates and uncovered a wide range of capabilities for traits relevant to cellulosic biofuel production. Notably, Saccharomyces mikatae strains have high innate tolerance to hydrolysate toxins, while some Saccharomyces species have a robust native capacity to consume xylose. Conclusions: This research demonstrates that hybridization is a viable method to combine industrially relevant traits from diverse yeast species and that members of the genus Saccharomyces beyond S. cerevisiae may offer advantageous genes and traits of interest to the lignocellulosic biofuel industry. Fil: Peris, David. University of Wisconsin; Estados Unidos Fil: Moriarty, Ryan V.. University of Wisconsin; Estados Unidos Fil: Alexander, William G.. University of Wisconsin; Estados Unidos Fil: Baker, EmilyClare. University of Wisconsin; Estados Unidos Fil: Sylvester, Kayla. University of Wisconsin; Estados Unidos Fil: Sardi, Maria. University of Wisconsin; Estados Unidos Fil: Langdon, Quinn K.. University of Wisconsin; Estados Unidos Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Wang, Qi-Ming. University of Wisconsin; Estados Unidos. Institute Of Microbiology Chinese Academy Of Sciences; China Fil: Bai, Feng-Yan. Institute Of Microbiology Chinese Academy Of Sciences; China Fil: Leducq, Jean Baptiste. University of Montreal; Canadá. Laval University; Canadá Fil: Charron, Guillaume. Laval University; Canadá Fil: Landry, Christian R.. Laval University; Canadá Fil: Sampaio, José Paulo. New University Of Lisbon; Portugal Fil: Gonçalves, Paula. New University Of Lisbon; Portugal Fil: Hyma, Katie E.. Washington University in St. Louis; Estados Unidos Fil: Fay, Justin C.. Washington University in St. Louis; Estados Unidos Fil: Sato, Trey K.. University of Wisconsin; Estados Unidos Fil: Hittinger, Chris Todd. University of Wisconsin; Estados Unidos

A novel yeast species was isolated from the sugar-rich stromata of Cyttaria hariotii collected from two different Nothofagus tree species in the Andean forests of Patagonia, Argentina. Phylogenetic analyses of the concatenated sequence of the rRNA gene sequences and the protein-coding genes for actin and translational elongation factor-1α indicated that the novel species belongs to the genus Hanseniaspora. De novo genome assembly of the strain CRUB 1928 T yielded a 10.2-Mbp genome assembly predicted to encode 4452 protein-coding genes. The genome sequence data were compared to the genomes of other Hanseniaspora species using three different methods, an alignment-free distance measure, K r , and two model-based estimations of DNA-DNA homology values, of which all provided indicative values to delineate species of Hanseniaspora. Given its potential role in a rare indigenous alcoholic beverage in which yeasts ferment sugars extracted from the stromata of Cytarria sp., we searched for the genes that may suggest adaptation of novel Hanseniaspora species to fermenting communities. The SSU1-like gene encoding a sulfite efflux pump, which, among Hanseniaspora, is present only in close relatives to the new species, was detected and analyzed, suggesting that this gene might be one factor that characterizes this novel species. We also discuss several candidate genes that likely underlie the physiological traits used for traditional taxonomic identification. Based on these results, a novel yeast species with the name Hanseniaspora gamundiae sp. nov. is proposed with CRUB 1928 T (ex-types: ZIM 2545 T = NRRL Y-63793 T = PYCC 7262 T ; MycoBank number MB 824091) as the type strain. Furthermore, we propose the transfer of the Kloeckera species, K. hatyaiensis, K. lindneri and K. taiwanica to the genus Hanseniaspora as Hanseniaspora hatyaiensis comb. nov. (MB 828569), Hanseniaspora lindneri comb. nov. (MB 828566) and Hanseniaspora taiwanica comb. nov. (MB 828567). Fil: Cadez, Neza. University of Ljubljana; Eslovenia Fil: Bellora, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina. Universidad Nacional del Comahue. Centro Regional Universidad de Bariloche. Departamento de Biología. Laboratorio de Microbiología Aplicada y Biotecnología; Argentina Fil: Ulloa, José Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina Fil: Hittinger, Chris. University of Wisconsin; Estados Unidos Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina

The most common fermented beverage, lager beer, is produced by interspecies hybrids of the brewing yeast Saccharomyces cerevisiae and its wild relative S. eubayanus. Lager-brewing yeasts are not the only example of hybrid vigour or heterosis in yeasts, but the full breadth of interspecies hybrids associated with human fermentations has received less attention. Here we present a comprehensive genomic analysis of 122 Saccharomyces hybrids and introgressed strains. These strains arose from hybridization events between two to four species. Hybrids with S. cerevisiae contributions originated from three lineages of domesticated S. cerevisiae, including the major wine-making lineage and two distinct brewing lineages. In contrast, the undomesticated parents of these interspecies hybrids were all from wild Holarctic or European lineages. Most hybrids have inherited a mitochondrial genome from a parent other than S. cerevisiae, which recent functional studies suggest could confer adaptation to colder temperatures. A subset of hybrids associated with crisp flavour profiles, including both lineages of lager-brewing yeasts, have inherited inactivated S. cerevisiae alleles of critical phenolic off-flavour genes and/or lost functional copies from the wild parent through multiple genetic mechanisms. These complex hybrids shed light on the convergent and divergent evolutionary trajectories of interspecies hybrids and their impact on innovation in lager brewing and other diverse fermentation industries., Work supported by the National Science Foundation (grant nos. DEB-1253634 to C.T.H. and DGE-1256259 (Graduate Research Fellowship to Q.K.L.), the USDA National Institute of Food and Agriculture Hatch Project (nos. 1003258 and 1020204 to C.T.H.) and in part by the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science nos. DE-SC0018409 and DE-FC02-07ER64494). Q.K.L. was also supported by the Predoctoral Training Program in Genetics, funded by the National Institutes of Health (grant no. 5T32GM007133). D.P. is a Marie Sklodowska-Curie fellow of the European Union’s Horizon 2020 research and innovation programme (grant no. 747775).

Cold environments represent the largest fraction of Earth's biosphere, and are known habitats for cold-adapted microorganisms. The aim of this study was to assess the occurrence and biodiversity of cold-adapted fungi associated with the Castaño Overo glacier, Mount Tronador, Patagonia, Argentina. Samples of naked soil, glacial ice and snow were collected and analyzed using tag-encoded 454 pyrosequencing of the nuclear ribosomal internal transcribed spacer (ITS). A total of 1082 OTUs (operational taxonomic units) and 151,669 sequences were obtained. OTUs obtained from soil samples corresponded mainly to the phylum Ascomycota, whereas for snow and ice samples the phylum Basidiomycota was the most represented group. Metabarcoding analysis showed high biodiversity in glacial environments and allowed the detection of hitherto unknown taxa for Patagonia. To the best of our knowledge, this is the first report of fungal diversity in an extreme glacial environment of Patagonian Argentina using amplicon sequencing. Fil: Duo Saito, Rubí Azul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Connell, L.. University Of Maine; Estados Unidos Fil: Rodriguez, R.. Adaptive Symbiotic Technologies; Estados Unidos Fil: Redman, Damian Patricio. Adaptive Symbiotic Technologies; Estados Unidos Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: de Garcia, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina

Budding yeasts (subphylum Saccharomycotina) are found in every biome and are as genetically diverse as plants or animals. To understand budding yeast evolution, we analyzed the genomes of 332 yeast species, including 220 newly sequenced ones, which represent nearly one-third of all known budding yeast diversity. Here, we establish a robust genus-level phylogeny comprising 12 major clades, infer the timescale of diversification from the Devonian period to the present, quantify horizontal gene transfer (HGT), and reconstruct the evolution of 45 metabolic traits and the metabolic toolkit of the budding yeast common ancestor (BYCA). We infer that BYCA was metabolically complex and chronicle the tempo and mode of genomic and phenotypic evolution across the subphylum, which is characterized by very low HGT levels and widespread losses of traits and the genes that control them. More generally, our results argue that reductive evolution is a major mode of evolutionary diversification. Fil: Shen, Xing-Xing. Vanderbilt University; Estados Unidos Fil: Opulente, Dana A.. University of Wisconsin; Estados Unidos Fil: Kominek, Jacek. University of Wisconsin; Estados Unidos Fil: Zhou, Xiaofan. Vanderbilt University; Estados Unidos. South China Agricultural University; China Fil: Steenwyk, Jacob L.. Vanderbilt University; Estados Unidos Fil: Buh, Kelly V.. University of Wisconsin; Estados Unidos Fil: Haase, Max A.B.. University of Wisconsin; Estados Unidos. University of New York. School of Medicine; Estados Unidos Fil: Wisecaver, Jennifer H.. Purdue University; Estados Unidos. Vanderbilt University; Estados Unidos Fil: Wang, Mingshuang. Vanderbilt University; Estados Unidos Fil: Doering, Drew T.. University of Wisconsin; Estados Unidos Fil: Boudouris, James T.. University of Wisconsin; Estados Unidos Fil: Schneider, Rachel M.. University of Wisconsin; Estados Unidos Fil: Langdon, Quinn K.. University of Wisconsin; Estados Unidos Fil: Ohkuma, Moriya. Riken BioResource Research Center. Japan Collection of Microorganisms; Japón Fil: Endoh, Rikiya. Riken BioResource Research Center. Japan Collection of Microorganisms; Japón Fil: Takashima, Masako. Riken BioResource Research Center. Japan Collection of Microorganisms; Japón Fil: Manabe, Ri-ichiroh. Riken Center for Integrative Medical Sciences; Japón. Riken Center For Life Science Technologies; Japón Fil: Čadež, Neža. University of Ljubljana; Eslovenia Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Rosa, Carlos A.. Universidade Federal de Minas Gerais; Brasil Fil: DeVirgilio, Jeremy. United States Department of Agriculture. Agricultural Research Service; Argentina. National Center For Agricultural; Estados Unidos Fil: Hulfachor, Amanda Beth. University of Wisconsin; Estados Unidos Fil: Groenewald, Marizeth. Westerdijk Fungal Biodiversity Institute; Países Bajos Fil: Kurtzman, Cletus P.. United States Department of Agriculture. Agricultural Research Service; Argentina. National Center For Agricultural; Estados Unidos Fil: Hittinger, Chris Todd. University of Wisconsin; Estados Unidos Fil: Rokas, Antonis. Vanderbilt University; Estados Unidos

Heavy metals at elevated concentrations are a major threat to agricultural and human health. Typically, human activities tend to release these metals to the environment in aqueous solutions, generating high levels of pollution due to the mobility of the heavy metals. The aim of the present work was to assess heavy metal tolerance in yeasts isolated from Rio Agrio - Lake Caviahue volcanic acidic aquatic environment and to evaluate the capacity of selected strains to capture metals in acidic culture media conditions. The ability of three yeast species, Cryptococcus agrionensis, Cryptococcus sp. 2, and Coniochaeta fodinicola, to tolerate and capture metals in live cultures has been evaluated. These three yeast species showed high tolerance to low pH and elevated concentrations of metals, thus implying their autochthonous status. Minimal inhibitory concentration (MIC) for growth obtained for these isolates showed elevated tolerance to the six heavy metals evaluated and were significantly higher than those registered for other microorganisms. C. agrionensis was able to capture 15.80 mg (g biomass)-1 of Cu2+ (MIC: 0.22 g L-1 ), Cryptococcus sp. 2 was able to capture 36.25 and 65.28 mg (g biomass)-1 of Ni2+ and Zn2+ , respectively (MIC: 0.56 and 1.68, respectively), and C. fodinicola was able to capture 67.11 mg (g biomass)-1 of Zn2+ (MIC: 3.75). This work reported the ability of yeasts to capture metals in acidic conditions for the first time. We hope that it represents the step-stone for future researches in the ability and metabolism of yeasts form acidic aquatic environment related to metal tolerance and capture.

Las levaduras, durante el proceso de elaboración de cerveza, producen más de 500 compuestos químicos; estos pueden impactar tanto negativa como positivamente en las características organolépticas de la cerveza. En los últimos años, y en particular gracias al avance de la biología molecular y la genómica, se han logrado progresos notables en el conocimiento de las bases moleculares y celulares de la síntesis y regulación de muchos de estos compuestos que inciden en lo que se denomina flavor (aroma y sabor) de la cerveza. Este artículo está enfocado en los ésteres responsables del aroma y el sabor floral y frutado de la cerveza. La formación de estos ésteres depende de diversas enzimas y de factores como la concentración de nutrientes presente en el mosto, la cantidad de oxígeno y dióxido de carbono disuelto, la temperatura de fermentación y, principalmente, la genética de la levadura utilizada. En esta revisión se brinda información de cómo se originan los ésteres y cómo los diferentes parámetros fermentativos impactan en las concentraciones finales de estos compuestos y en la calidad del producto terminado. During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product. Fil: Loviso, Claudia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina

Multiple isolates belonging to the ascomycetous genus Zygotorulaspora were obtained from forest soils and tree bark in Shiba Prefecture in Japan, and Lake Daniels, Lewis Pass, in New Zealand. Phylogenetic analyses employing combined sequences of the D1/D2 domain and ITS region support the recognition of two new species:Zygotorulaspora chibaensis sp. nov. (type strain PYCC 6970T =CBS 15364T) and Zygotorulaspora danielsina sp. nov. (type strain PYCC 6984T =CBS 15365T). Both species are able to grow on D-xylose and L-arabinose and at 35° C, unlike Zygotorulaspora florentina and Zygotorulaspora mrakii, the other two species in the genus. Fil: Carvalho, Cláudia. Universidad Nova de Lisboa; Portugal Fil: Tomás, André. Universidad Nova de Lisboa; Portugal Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Imanishi, Yumi. Kanto Gakuin University; Japón Fil: Sampaio, José Paulo. Universidad Nova de Lisboa; Portugal

Astaxanthin is a xanthophyll pigment of high economic value for its use as a feeding component in aquaculture. Phaffia rhodozyma (Xanthophyllomyces dendrorhous) is a basidiomycetous fungi able to synthesize astaxanthin as its major carotenoid, the only known yeast species bearing the capability to produce this type of carotenoid and the only tremellomycetes with biotechnological application. Recently, the habitat and intraspecific variability of this species have been found to be wider than previously expected, encouraging the search for new wild strains with potential biotechnological applications. Here we describe effective procedures for isolation of P. rhodozyma from environmental samples, accurate identification of the strains, analysis of their astaxanthin content, and proper conservation of the isolates.

Saccharomyces eubayanus is the close relative of the Lager-brewing yeast and was firstly found in North Patagonia associated with Nothofagus trees. In recent years additional strains were found in North America, Asia and New Zealand, and genomic analyses showed the existence of two main populations of this yeast, both of them present in Patagonia. Here, we performed the most comprehensive study of S. eubayanus in Patagonia natural environments (400 samples) and confirmed that this region has the highest isolation success rate for this species described worldwide (more than 10-fold). The genetic characterization of 200 isolates (COX2, DCR1, intFR) revealed five geographically structured subpopulations. We hypothesized that marine ingressions and glaciations, which shaped the Patagonian landscape, contributed on population differentiation. The first large screening of fermentation performance of 60 wild S. eubayanus strains indicated which subpopulations would be more suitable for beer production. Fil: Eizaguirre, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Peris, David. Consejo Superior de Investigaciones Científicas; España Fil: Rodríguez, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina Fil: Lopes, Christian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; Argentina Fil: De Los Ríos, Patricio. Universidad Católica de Chile; Chile. Pontificia Universidad Católica de Chile; Chile Fil: Hittinger, Chris. University of Wisconsin; Estados Unidos Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina

Circadian systems enable organisms to synchronize their physiology to daily and seasonal environmental changes relying on endogenous pacemakers that oscillate with a period close to 24 h even in the absence of external timing cues. The oscillations are achieved by intracellular transcriptional/translational feedback loops thoroughly characterized for many organisms, but still little is known about the presence and characteristics of circadian clocks in fungi other than Neurospora crassa. We sought to characterize the circadian system of a natural isolate of Aureobasidium pullulans, a cold-adapted yeast bearing great biotechnological potential. A. pullulans formed daily concentric rings that were synchronized by light/dark cycles and were also formed in constant darkness with a period of 24.5 h. Moreover, these rhythms were temperature compensated, as evidenced by experiments conducted at temperatures as low as 10 °C. Finally, the expression of clock-essential genes, frequency, white collar-1, white collar-2 and vivid was confirmed. In summary, our results indicate the existence of a functional circadian clock in A. pullulans, capable of sustaining rhythms at very low temperatures and, based on the presence of conserved clock-gene homologues, suggest a molecular and functional relationship to well-described circadian systems. Fil: Franco, Diana Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Canessa, Paulo. Universidad Andrés Bello; Chile. Millennium Nucleus for Fungal Integrative and Synthetic Biology; Chile Fil: Bellora, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Risau Gusman, Sebastian Luis. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Olivares Yañez, Consuelo. Pontificia Universidad Católica de Chile; Chile. Millennium Nucleus for Fungal Integrative and Synthetic Biology; Chile Fil: Pérez Lara, Rodrigo. Pontificia Universidad Católica de Chile; Chile. Millennium Nucleus for Fungal Integrative and Synthetic Biology; Chile Fil: Libkind Frati, Diego. Pontificia Universidad Católica de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Larrondo, Luis F.. Millennium Nucleus for Fungal Integrative and Synthetic Biology; Chile Fil: Marpegan, Luciano. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

During a survey of carotenogenic yeasts from cold and oligotrophic environments in Patagonia, several yeasts of the genus Dioszegia (Tremellales, Agaricomycotina) were detected, including three strains that could not be assigned to any known taxa. Analyses of internal transcribed spacer and D1/D2 regions of the large subunit rRNA gene showed these strains are conspecific with several other strains found in the Italian Alps and in Antarctica soil. Phylogenetic analyses showed that 19 of these strains represent a novel yeast species of the genus Dioszegia. The name Dioszegia patagonica sp. nov. is proposed to accommodate these strains and CRUB 1147T (UFMG 195T=CBMAI 1564T=DBVPG 10618T=CBS 14901T; MycoBank MB 819782) was designated as the type strain. This Dioszegia species accumulates biotechnologically valuable compounds such as carotenoid pigments and mycosporines. Fil: Trochine, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Turchetti, Benedetta. Università Degli Studi Di Perugia; Fil: Vaz, Aline B. M.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; Brasil Fil: Brandao, Luciana. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; Brasil Fil: Rosa, Luiz H.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; Brasil Fil: Buzzini, Pietro. Università Degli Studi Di Perugia; Fil: Rosa, Carlos. Universidade Federal do Minas Gerais; Brasil Fil: Libkind, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina

The brewing industry is experiencing a period of change and experimentation largely driven by customer demand for product diversity. This has coincided with a greater appreciation of the role of yeast in determining the character of beer and the widespread availability of powerful tools for yeast research. Genome analysis in particular has helped clarify the processes leading to domestication of brewing yeast and has identified domestication signatures that may be exploited for further yeast development. The functional properties of non-conventional yeast (both Saccharomyces and non- Saccharomyces) are being assessed with a view to creating beers with new flavours as well as producing flavoursome non-alcoholic beers. The discovery of the psychrotolerant S. eubayanus has stimulated research on de novo S. cerevisiae × S. eubayanus hybrids for low-temperature lager brewing and has led to renewed interest in the functional importance of hybrid organisms and the mechanisms that determine hybrid genome function and stability. The greater diversity of yeast that can be applied in brewing, along with an improved understanding of yeasts' evolutionary history and biology, is expected to have a significant and direct impact on the brewing industry, with potential for improved brewing efficiency, product diversity and, above all, customer satisfaction. Fil: Gibson, B.. Vtt Technical Research Centre Of Finland; Finlandia Fil: Geertman, J. M. A.. Heineken Supply Chain; Países Bajos Fil: Hittinger, C. T.. University of Wisconsin; Estados Unidos Fil: Krogerus, K.. Vtt Technical Research Centre Of Finland; Finlandia. Aalto University; Finlandia Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Louis, E. J.. University of Leicester; Reino Unido Fil: Magalhães, F.. Vtt Technical Research Centre Of Finland; Finlandia. Aalto University; Finlandia Fil: Sampaio, J.P.. Universidade Nova de Lisboa; Portugal

Even though yeasts are normal inhabitants of almost any type of aquatic environment, in comparison to other type of substrates, relatively little research has been carried out on the factors affecting their biodiversity and distribution patterns. The distinction of a yeast species as transient or resident element of an aquatic habitat has long been challenging and has been one of the main difficulties in the study of yeast diversity in, for example, continental lakes and rivers. The present chapter will provide an overview of our current knowledge on yeast diversity and ecology in continental freshwater and marine environments; in particular habitats like tropical and temperate rivers and lakes, seawater, and glacial melting water bodies will be reviewed. Water temperature and trophic state are major factors determining the yeast community composition in water bodies, and as they get more extreme due to the increase of stress factors such as cold temperatures, UV radiation, and scarce nutrient availability, the prevalence of basidiomycetous yeast gets more notorious. As a result of the evolutionary adaptation to extreme conditions, certain biotechnologically relevant traits became evident in extremophilic aquatic yeasts such as the production of carotenoid pigments, UV sunscreens, extracellular cold-adapted enzymes, etc.

Cell-cycle checkpoints and DNA repair processes protect organisms from potentially lethal mutational damage. Compared to other budding yeasts in the subphylum Saccharomycotina, we noticed that a lineage in the genus Hanseniaspora exhibited very high evolutionary rates, low Guanine–Cytosine (GC) content, small genome sizes, and lower gene numbers. To better understand Hanseniaspora evolution, we analyzed 25 genomes, including 11 newly sequenced, representing 18/21 known species in the genus. Our phylogenomic analyses identify two Hanseniaspora lineages, a faster-evolving lineage (FEL), which began diversifying approximately 87 million years ago (mya), and a slower-evolving lineage (SEL), which began diversifying approximately 54 mya. Remarkably, both lineages lost genes associated with the cell cycle and genome integrity, but these losses were greater in the FEL. E.g., all species lost the cell-cycle regulator WHIskey 5 (WHI5), and the FEL lost components of the spindle checkpoint pathway (e.g., Mitotic Arrest-Deficient 1 [MAD1], Mitotic Arrest-Deficient 2 [MAD2]) and DNA-damage–checkpoint pathway (e.g., Mitosis Entry Checkpoint 3 [MEC3], RADiation sensitive 9 [RAD9]). Similarly, both lineages lost genes involved in DNA repair pathways, including the DNA glycosylase gene 3-MethylAdenine DNA Glycosylase 1 (MAG1), which is part of the base-excision repair pathway, and the DNA photolyase gene PHotoreactivation Repair deficient 1 (PHR1), which is involved in pyrimidine dimer repair. Strikingly, the FEL lost 33 additional genes, including polymerases (i.e., POLymerase 4 [POL4] and POL32) and telomere-associated genes (e.g., Repressor/activator site binding protein-Interacting Factor 1 [RIF1], Replication Factor A 3 [RFA3], Cell Division Cycle 13 [CDC13], Pbp1p Binding Protein [PBP2]). Echoing these losses, molecular evolutionary analyses reveal that, compared to the SEL, the FEL stem lineage underwent a burst of accelerated evolution, which resulted in greater mutational loads, homopolymer instabilities, and higher fractions of mutations associated with the common endogenously damaged base, 8-oxoguanine. We conclude that Hanseniaspora is an ancient lineage that has diversified and thrived, despite lacking many otherwise highly conserved cell-cycle and genome integrity genes and pathways, and may represent a novel, to our knowledge, system for studying cellular life without them., A lineage in the budding yeast genus Hanseniaspora has remarkably high evolutionary rates, low GC content, small genome sizes, and lower gene numbers than the rest of the subphylum. Analysis of 25 genomes reveals that this lineage has survived and diversified for tens of millions of years despite lacking dozens of cell cycle and DNA repair genes normally thought to be essential.

Background: The class Tremellomycete (Agaricomycotina) encompasses more than 380 fungi. Although there are a few edible Tremella spp., the only species with current biotechnological use is the astaxanthin-producing yeast Phaffia rhodozyma (Cystofilobasidiales). Besides astaxanthin, a carotenoid pigment with potent antioxidant activity and great value for aquaculture and pharmaceutical industries, P. rhodozyma possesses multiple exceptional traits of fundamental and applied interest. The aim of this study was to obtain, and analyze two new genome sequences of representative strains from the northern (CBS 7918T, the type strain) and southern hemispheres (CRUB 1149) and compre them to a previously published genome sequence (strain CBS 6938). Photoprotection and antioxidant related genes, as well as genes involved in sexual reproduction were analyzed. Results: Both genomes had ca. 19Mb and 6000 protein coding genes, similar to CBS 6938. Compared to other fungal genomes P. rhodozyma strains and other Cystofilobasidiales have the highest number of intron-containing genes and highest number of introns per gene. The Patagonian strain showed 4.4% of nucleotide sequence divergence compared to the European strains which differed from each other by only 0.073%. All known genes related to the synthesis of astaxanthin were annotated. A hitherto unknown gene cluster potentially responsible for photoprotection (mycosporines) was found in the newly sequenced P. rhodozyma strains but was absent in the non-mycosporinogenic strain CBS 6938. A broad battery of enzymes that act as scavengers of free radical oxygen species were detected, including catalases and superoxide dismutases (SODs). Additionally, genes involved in sexual reproduction were found and annotated. Conclusions: A draft genome sequence of the type strain of P. rhodozyma is now available, and comparison with that of the Patagonian population suggests the latter deserves to be assigned to a distinct variety. An unexpected genetic trait regarding high occurrence of introns in P. rhodozyma and other Cystofilobasidiales was revealed. New genomic insights into fungal homothallism were also provided. The genetic basis of several additional photoprotective and antioxidant strategies were described, indicating that P. rhodozyma is one of the fungi most well-equipped to cope with environmental oxidative stress, a factor that has probably contributed to shaping its genome. Fil: Bellora, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Moline, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: David Palma, Márcia. Universidade Nova de Lisboa; Portugal Fil: Coelho, Marco A.. Universidade Nova de Lisboa; Portugal Fil: Hittinger, Chris Todd. University of Wisconsin; Estados Unidos Fil: Sampaio, José P.. Universidade Nova de Lisboa; Portugal Fil: Gonçalves, Paula. Universidade Nova de Lisboa; Portugal Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina

Lager-style beers constitute the vast majority of the beer market, and yet, the genetic origin of the yeast strains that brew them has been shrouded in mystery and controversy. Unlike ale-style beers, which are generally brewed with Saccharomyces cerevisiae, lagers are brewed at colder temperatures with allopolyploid hybrids of Saccharomyces eubayanus x S. cerevisiae. Since the discovery of S. eubayanus in 2011, additional strains have been isolated from South America, North America, Australasia, and Asia, but only interspecies hybrids have been isolated in Europe. Here, using genome sequence data, we examine the relationships of these wild S. eubayanus strains to each other and to domesticated lager strains. Our results support the existence of a relatively low-diversity (π = 0.00197) lineage of S. eubayanus whose distribution stretches across the Holarctic ecozone and includes wild isolates from Tibet, new wild isolates from North America, and the S. eubayanus parents of lager yeasts. This Holarctic lineage is closely related to a population with higher diversity (π = 0.00275) that has been found primarily in South America but includes some widely distributed isolates. A second diverse South American population (π = 0.00354) and two early-diverging Asian subspecies are more distantly related. We further show that no single wild strain from the Holarctic lineage is the sole closest relative of lager yeasts. Instead, different parts of the genome portray different phylogenetic signals and ancestry, likely due to outcrossing and incomplete lineage sorting. Indeed, standing genetic variation within this wild Holarctic lineage of S. eubayanus is responsible for genetic variation still segregating among modern lager-brewing hybrids. We conclude that the relationships among wild strains of S. eubayanus and their domesticated hybrids reflect complex biogeographical and genetic processes., Author Summary Yeasts are key industrial microbes, most notably Saccharomyces cerevisiae, which is used to make a variety of products, including bread, wine, and ale-style beers. However, lager-style beers are brewed with interspecies hybrids of S. cerevisiae x Saccharomyces eubayanus. After its discovery in South America in 2011, rare strains of S. eubayanus have also been isolated outside of South America. Here we compare the genome sequences of several new and recent isolates of S. eubayanus from South America, North America, Australasia, and Asia to unravel the relationships of these wild isolates and their domesticated European hybrids. Two South American populations have the highest genetic diversity. One of these populations is closely related to a relatively low-diversity lineage that is spread across the Northern Hemisphere and includes the S. eubayanus parents of lager yeasts. Interestingly, we find that none of the wild isolates of S. eubayanus is the sole closest relative of lager-brewing hybrids. Instead, we show that standing variation among wild S. eubayanus strains contributed to the genetic makeup of lager yeasts. Our findings highlight the complex ancestries of lager yeasts and the importance of broader sampling of wild yeasts to illuminate our understanding of the sources of genetic variation among industrial hybrids.

Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Fil: Gonçalves, Margarida. Universidade Nova de Lisboa; Portugal Fil: Pontes, Ana. Universidade Nova de Lisboa; Portugal Fil: Almeida, Pedro. Universidade Nova de Lisboa; Portugal Fil: Barbosa, Raquel. Universidade Nova de Lisboa; Portugal Fil: Serra, Marta. Universidade Nova de Lisboa; Portugal Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentina Fil: Hutzler, Mathias. Research Center Weihenstephan for Brewing and Food Quality; Alemania Fil: Gonçalves, Paula. Universidade Nova de Lisboa; Portugal Fil: Sampaio, José Paulo. Universidade Nova de Lisboa; Portugal

The Patagonia region constitutes a vast geographic area with multiple extreme environments having one or more of these stress factors: cold, high UV incidence, desiccation, ultra-oligotrophy, acidity, and the presence of heavy metals, among others. Yeasts that constantly live under stress conditions evolve adaptive mechanisms to minimize or resist their negative effects and thus permit survival and reproduction. These specific mechanisms are promising sources of biotechnologically relevant molecules or genes. Here we summarize numerous yeast bioprospection studies performed in the conventional and extreme environments of the Argentinean Patagonia. More than 1000 yeasts and dimorphic fungi were collected and molecularly identified; when possible, relevant secondary metabolites were screened, as well as their ability to tolerate several types of stress in laboratory conditions. Screened metabolites include carotenoid pigments, mycosporines (UV sunscreens), and cold-active enzymes. In some cases, these traits could be correlated to habitat characteristics and for those (e.g., mycosporines, carotenoid pigments, heavy metal tolerance) their potential role in the adaptive mechanisms to specific stress factors was evaluated. Genome sequencing and analyses were performed for biotechnologically relevant isolates such as Saccharomyces eubayanus, Saccharomyces uvarum, and Phaffia rhodozyma (synonym of Xanthophyllomyces dendrorhous). The biotechnological potential of selected species is addressed as specific study cases. The present work represents an overview of our findings related to biotechnologically relevant yeasts from Patagonian natural environments.

The dramatic phenotypic changes that occur in organisms during domestication leave indelible imprints on their genomes. Although many domesticated plants and animals have been systematically compared with their wild genetic stocks, the molecular and genomic processes underlying fungal domestication have received less attention. Here, we present a nearly complete genome assembly for the recently described yeast species Saccharomyces eubayanus and compare it to the genomes of multiple domesticated alloploid hybrids of S. eubayanus × S. cerevisiae (S. pastorianus syn. S. carlsbergensis), which are used to brew lager-style beers. We find that the S. eubayanus subgenomes of lager-brewing yeasts have experienced increased rates of evolution since hybridization, and that certain genes involved in metabolism may have been particularly affected. Interestingly, the S. eubayanus subgenome underwent an especially strong shift in selection regimes, consistent with more extensive domestication of the S. cerevisiae parent prior to hybridization. In contrast to recent proposals that lager-brewing yeasts were domesticated following a single hybridization event, the radically different neutral site divergences between the subgenomes of the two major lager yeast lineages strongly favor at least two independent origins for the S. cerevisiae × S. eubayanus hybrids that brew lager beers. Our findings demonstrate how this industrially important hybrid has been domesticated along similar evolutionary trajectories on multiple occasions. Fil: Baker, Emily Clare. University Of Wisconsin; Estados Unidos Fil: Wang, Bing. University Of Wisconsin; Estados Unidos Fil: Bellora, Nicolás. Universidad Nacional del Comahue. Centro Regional Universidad de Bariloche. Departamento de Biologia. Laboratorio de Microbiologia Aplicada y Biotecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina Fil: Peris, David. University Of Wisconsin; Estados Unidos Fil: Hulfachor, Amanda Beth. University Of Wisconsin; Estados Unidos Fil: Koshalek, Justin A.. University Of Wisconsin; Estados Unidos Fil: Adams, Marie. University Of Wisconsin; Estados Unidos Fil: Libkind Frati, Diego. Universidad Nacional del Comahue. Centro Regional Universidad de Bariloche. Departamento de Biologia. Laboratorio de Microbiologia Aplicada y Biotecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina Fil: Hittinger, Chris Todd. University Of Wisconsin; Estados Unidos

Recientemente, se ha encontrado que la distribución natural, el hábitat y la diversidad genética de levaduras productoras de astaxantina (p. ej., Phaffia rhodozyma, sinónimo Xanthophyllomyces dendrorhous) son mucho mayores de lo que se pensaba. P. rhodozyma se explota biotecnológicamente debido a su capacidad para producir el pigmento carotenoide astaxantina y, por lo tanto, se utiliza como una fuente natural de este pigmento para la acuicultura. También se encontró que esta levadura es capaz de sintetizar el potente protector solar UVB micosporina-glutaminol-glucósido (MGG). Por lo tanto, más estudios ambientales para dilucidar sus aspectos ecológicos y detectar nuevas cepas potenciales productoras de astaxantina y MGG son necesarios. Sin embargo, la obtención de nuevos aislamientos de P. rhodozyma y especies relacionadas no siempre es fácil debido a su baja abundancia y a la presencia de otras levaduras simpátricas y pigmentadas. En este trabajo se describe el desarrollo exitoso de un cebador especie-específico que tiene la capacidad de detectar rápidamente y con precisión cepas representativas de todos los linajes del género Phaffia previamente reportados (incluyendo nuevas especies del género) y excluir especies estrechamente relacionadas. Para ello, se diseñó un cebador de 20 nucleótidos (denominado PhR) para ser utilizado en combinación con los cebadores universales ITS3 y NL4 en una amplificación multiplex. El método propuesto tiene la sensibilidad y la especificidad requerida para la detección precisa de nuevos aislamientos y, por lo tanto, representa una importante herramienta para la búsqueda ambiental de nuevas levaduras productoras de astaxantina. It has been recently found that the natural distribution, habitat, and genetic diversity of astaxanthin-producing yeasts (i.e. Phaffia rhodozyma, synonym Xanthophyllomyces dendrorhous) is much greater than previously thought. P. rhodozyma is biotechnologically exploited due to its ability to produce the carotenoid pigment astaxanthin and thus, it is used as a natural source of this pigment for aquaculture. P. rhodozyma was also capable of synthesizing the potent UVB sunscreen mycosporine-glutaminol-glucoside (MGG). Therefore, further environmental studies are needed to elucidate its ecological aspects and detect new potential strains for the production of astaxanthin and MGG. However, obtaining new isolates of P. rhodozyma and related species is not always easy due to its low abundance and the presence of other sympatric and pigmented yeasts. In this work we report a successful development of a species specific primer which has the ability to quickly and accurately detecting isolates representing all known lineages of the genus Phaffia (including novel species of the genus) and excluding closely related taxa. For this purpose, a primer of 20 nucleotides (called PhR) was designed to be used in combination with universal primers ITS3 and NL4 in a multiplex amplification. The proposed method has the sensitivity and specificity required for the precise detection of new isolates, and therefore represents an important tool for the environmental search for novel astaxanthin-producing yeasts. Fil: Colabella, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina