title: Preliminary physiological characteristics of thermotolerant Saccharomyces cerevisiae clinical isolates identified by molecular biology techniques.
abstract: The aim of the study was a molecular identification and physiological characteristic of the five Saccharomyces cerevisiae strains isolated from patients. The tested isolates were compared with control strains (which are of laboratory or commercial origin). The relation of the isolates to baker's yeast S. cerevisiae was studied using species-specific primers in PCR analysis of the ITS-26S region of DNA. Five isolates were genetically identified as the yeast belonging to the genus S. cerevisiae. The effects of temperature and carbon sources on the growth of the yeast strains were analysed. A quantitative characterization of growth kinetics approve that some tested isolates are thermotolerant and are able to grow at range 37-39°C. Among them, one representative is characterized by the highest specific growth rate (0·637 h(-1) ). In conclusions, some strains are defined as potential candidates to use in the biotechnology due to a higher growth rate at elevated temperatures. Screening for further evaluation of biotechnological significance of the tested isolates will be done (e.g. ethanol and trehalose production at higher temperatures). The physiological characterization and confirmation of species identification by molecular methods for yeasts important in the context of biotechnology industry were demonstrated.
  
  
  CONCLUSIONS
  Thermotolerant microbial strains are required in various industrial applications, for improving productivity and for decreasing the risk of undesirable contaminations when higher temperatures are used. It is important to search for such strains in extreme environments or exotic niches. In this paper, new thermotolerant strains were identified belonging to the Saccharomyces cerevisiae, but differed from typical bakers' yeast, essentially by their growth rate at higher temperature. The described yeast strains are promising for using in biotechnological industry, especially, for production of ethanol and other products at higher temperatures.
authors.affiliation: Biotechnology Centre for Applied and Fundamental Sciences, Department of Biotechnology, University of Rzeszow, Kolbuszowa, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Siedlarz
authors.affiliation: Biotechnology Centre for Applied and Fundamental Sciences, Department of Biotechnology, University of Rzeszow, Kolbuszowa, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Sroka
authors.affiliation: Department of Genetics, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Dyląg
authors.affiliation: Department of Microbiology, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: U
authors.initials: U
authors.lastname: Nawrot
authors.affiliation: Biotechnology Centre for Applied and Fundamental Sciences, Department of Biotechnology, University of Rzeszow, Kolbuszowa, Poland.|Institute of Cell Biology, National Academy of Science of Ukraine, Lviv, Ukraine.
authors.forename: M
authors.initials: M
authors.lastname: Gonchar
authors.affiliation: Biotechnology Centre for Applied and Fundamental Sciences, Department of Biotechnology, University of Rzeszow, Kolbuszowa, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Kus-Liśkiewicz
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology; D021901:DNA, Intergenic / Q000235:genetics; D000431:Ethanol / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D021901:DNA, Intergenic; D000431:Ethanol
keywords: Saccharomyces cerevisiae; clinical isolates; growth rate; molecular identification; thermotolerance