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Abstract  Indigenous yeasts associated with surfaces in three North Patagonian cellars were isolated by means of selective media developed for the isolation of Dekkera/Brettanomyces yeasts; 81 isolates were identified as belonging to Candida boidinii (16%), Hanseniaspora uvarum (38%), Pichia guilliermondii (3%), Saccharomyces cerevisiae (1%), Geotrichum silvicola (16%) and the new yeast species Candida patagonica (26%). No Dekkera/Brettanomyces isolate was obtained, however, 41 isolates (51% of the total isolates) produced some enologically undesirable features under laboratory conditions including the production of 4-ethylphenol and 4-vinylphenol, observed in the Candida boidinii and Pichia guilliermondii isolates. The sensitivity of the 41 spoilage isolates and seven Brettanomyces bruxellensis collection strains was evaluated against a panel of 55 indigenous and ten reference killer yeasts. Killer cultures belonging to Pichia anomala and Kluyveromyces lactis species showed the broadest killer spectrum against spoilage yeasts, including Dekkera bruxellensis collection strains. These killer isolates could be good candidates for use in biocontrol of regionally relevant spoilage yeasts. [ABSTRACT FROM AUTHOR]

Abstract  A novel anamorphic yeast species belonging to the genus Candida has been isolated from cellar surfaces in North Patagonia. Morphological and physiological observation and phylogenetic analysis were performed. Pseudomycelium was plentifully produced. No sexual reproduction was observed. From sequence analysis of the 26S rDNA D1/D2 region, Candida bituminiphila and Zygoascus hellenicus were the closest species with 40 and 79 bp substitutions, respectively. C. bituminiphila differed physiologically from the novel species in its ability to assimilate sucrose and erythritol, in not fermenting any sugars, in growing without some vitamin compounds, and in growing at 40C. All these data support the hypothesis that the new yeast, named Candida patagonica, is a novel species related to C. bituminiphila. The type strain is UNCOMA 159.5 (= CECT 12029 = CBS 10443). [ABSTRACT FROM AUTHOR]

Abstract  The amplification by PCR of the intergenic spacer region (IGS) of rDNA followed by restriction fragment length polymorphism (RFLP) analysis was evaluated as a potential method for discriminating the 16 species belonging to the genus Debaryomyces. The digestion of this region with some or all the enzymes used in this study (HapII, HhaI and MboI) produced species-specific patterns that permitted differentiation of the species in the genus. With the exception of Debaryomyces vanrijiae, the technique was also efficient for␣distinguishing the varieties in the species Debaryomyces hansenii (var. hansenii, var. fabryi), Debaryomyces occidentalis (var. occidentalis, var. persoonii) and Debaryomyces polymorphus (var. africanus, var. polymorphus), respectively. PCR-RFLP analysis of the IGS region of rDNA is proposed as a clear and reproducible technique for the practical discrimination of species of the yeast genus Debaryomyces. [ABSTRACT FROM AUTHOR]

Abstract   Saccharomyces cerevisiae is the most widely used yeast in industrial/commercial food and beverage production and is even consumed as a nutritional supplement. Various cases of fungemia caused by this yeast species in severely debilitated traumatized or immune-deficient patients have been reported in recent years, suggesting that this species could be an opportunistic pathogen in such patients. To determine whether the industrial S. cerevisiae strains can be included in this virulent group of strains, we carried out a comparative study between clinical and industrial yeasts based on the various phenotypic traits associated with pathogenicity in two other yeast species (Candida albicans and Cryptococcus neoformans). The majority of the clinical isolates were found to secrete higher levels of protease and phospholipase, grow better at 42°C and show strong pseudohyphal growth relative to industrial yeasts. However three industrial yeast strains, one commercial wine strain, baker’s yeast and one commercial strain of S. cerevisiae (var. boulardii), were exceptions and based on their physiological traits these yeasts would appear to be related to clinical strains. [ABSTRACT FROM AUTHOR]

Summary  In this paper, a study of the relationship between genetic patterns, obtained by the combination of mtDNA-RFLP and PCR-amplified inter-δ sequence DNA polymorphism analysis, and relevant enological phenotypic data (fermentative power, specific productivity, volatile and total acidity) was carried out on Argentinean Saccharomyces cerevisiae isolates from north Patagonia. The use of a powerful statistical tool, Generalized Procrustes analysis, allowed us to weigh the relationship for each isolate in particular, denoting a good enough degree of agreement between molecular and physiological data for most of the population analysed. The inclusion of a physiological feature, as the killer sensitivity biotype, within identification methods resulted in a higher degree of discrimination among isolates and in better correlation between both characterizations. The combined use of methods based on molecular polymorphisms and killer biotype could be applied so as not to miss any isolate with differential enological properties in selection protocols. [ABSTRACT FROM AUTHOR]

The aim of this work was to characterize the indigenous wine Saccharomyces cerevisiae diversity within the Argentinean Patagonia. Two cellars with particular enological practices located in different winegrowing areas were selected and 112 indigenous S. cerevisiae isolates were obtained from spontaneous red wine fermentations carried out in them. Thirty-five and 19 patterns were distinguished among the total indigenous isolates using mtDNA-RFLP and killer biotype analysis, respectively. The combination of both typing techniques rendered a higher variability with 42 different patterns, i.e. 42 strains, evidencing a great diversity in S. cerevisiae populations associated with spontaneous red wine fermentations in Northwestern Patagonia. The analysis of the relatedness among strains using Principal Coordinates Analysis from combined data allowed the clustering of the strains into two populations significantly related to their origin fermentations. The combined use of the mtDNA-RFLP analysis together with the killer biotype method proved to be a powerful tool in the fingerprinting of the enological S. cerevisiae strains. [ABSTRACT FROM AUTHOR]

The PCR amplification and subsequent restriction analysis of the ribosomal region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene is applied to the identification of yeasts belonging to the genus Candida. This methodology has previously been used for the identification of some species of this genus, but in the present work this application has been applied to the identification and characterisation of a greater number of species of the genus Candida, with a special survey of species of clinical and biotechnological interest. Among the species of the genus Candida, the high variability observed, both in the length of the amplified region (ranging between 390 and 900 bp) and in their restriction patterns, allows the unequivocal identification to the species level, with the exception of the group of species that comprises C. membranifaciens, C. conglobata, C. atlantica, C. atmosphaerica, and C. oleophila, that required the sequencing of the D1/D2 domain of the 26S rRNA gene or the 5.8S–ITS region for their proper differentiation. The 5.8S–ITS restriction analysis also failed in the differentiation of species within the pairs C.aaseri/C.butyri,C.fructus/C.musae,C.santa/math> var. santamariae/C. beechii and C. zeylanoides/C. krissii. In this case, the high sequence similarities obtained for their 26S D1/D2 domain and the 5.8S–ITS region indicate that each pair of species should be considered as a single species. The main purpose of this work is to generate a database for a high number of yeast species, of both biotechnological and clinical interest, and to facilitate their easy, fast, and reliable identification. The present work improves the database available online at the IATA web page (http://motor.edinfo.es/iata/) with the patterns of 75 species belonging to the genus Candida. [ABSTRACT FROM AUTHOR]

Yeasts involved in velum formation during biological ageing of sherry wine have to date been classified into four races of Saccharomyces cerevisiae (beticus, cheresiensis, montuliensis, rouxii) according to their abilities to ferment different sugars. It has been proposed that race succession during biological ageing is essential for the development of the organoleptical properties of sherry wines. In this work we studied the physiological characteristics, the molecular differentiation and the phylogenetic relationships of the four races employing type and reference strains from culture collections and natural environments. Using restriction analysis of the ribosomal region that includes the 5.8S rRNA gene and internal transcribed regions (5.8S-ITS) we were able to differentiate ‘flor’ and non-‘flor’S. cerevisiae yeast strains. However, no correlation between fermentation profile, mitochondrial DNA restriction analysis or chromosomal profiles and these races was found. Moreover, sequences of the D1/D2 domain of the 26S rRNA gene and the 5.8S-ITS region from these strains were analysed and no genetic differences were noted suggesting that ‘flor’ yeast cannot be grouped into four different races and the four races are identified as S. cerevisiae. Since the yeasts isolated from velum in sherry wine present a unique 5.8S rRNA pattern different from the rest of the Saccharomyces cerevisiae strains we propose that they should be included as a single race or variety inside the S. cerevisiae taxon. [ABSTRACT FROM AUTHOR]

Random amplified polymorphic DNA–polymerase chain reaction (RAPD–PCR) analysis was applied to differentiate the sibling species Saccharomyces bayanus, S. cerevisiae, S. paradoxus and S. pastorianus, which constitute the most common strains of the Saccharomyces sensu stricto complex. Six decamer primers of arbitrary sequences were used to amplify the DNA of 58 strains. Species-specific (diagnostic) bands were obtained for each species. Two phylogenetic trees constructed by the neighbour-joining and maximum parsimony methods clearly showed that the delimitation of these related yeast species is possible by using RAPD analysis. Four groups of strains, corresponding to the species S. bayanus, S. cerevisiae, S. paradoxus and S. pastorianus, were obtained. Within the S. bayanus taxon, two groups of strains were observed. One includes the former type strain of S. uvarum, CECT1969T, and closely related wine strains (S. bayanus var. uvarum), whilst the other contains S. bayanus type strain CECT1941T and strains CECT1991 and 10513 (S. bayanus var. bayanus). The heterogeneous S. paradoxus group was divided into three lineages, corresponding to different geographic origin, American, Japanese and European populations. In addition, due to the multilocus nature of the RAPD–PCR marker, this method is both useful and appropriate for the identification of the hybrid origin of S. pastorianus. The hybrid nature was deduced from the analysis of the fraction of bands shared by each hybrid strain and the parental species. Among the 58 strains analysed, six S. pastorianus strains were hybrids, although the fraction of genome coming from each parent varied depending on the strain. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]