TY - JOUR

T1 - Phenotypic and genetic diversity of Saccharomyces contaminants isolated from lager breweries and their phylogenetic relationship with brewing yeasts

AU - Jespersen, Lene

AU - Kühle, Alis Van der Aa

AU - Petersen, Kamilla M.

PY - 2000

Y1 - 2000

N2 - A taxonomic study was carried out for isolates of Saccharomyces spp. identified as contaminants ("wild yeast") in 24 different lager breweries. With reference to the current taxonomy all isolates were found to belong to the Saccharomyces sensu stricto complex and 58% of the isolates were further identified as S. cerevisiae, 26% as S. pastorianus and 3% as S. bayanus. The remaining isolates (13%) could not be identified to the species level based on their phenotypic characteristics. However, some of these isolates were identified as S. cerevisiae by HaeIII restriction digest of PCR-amplified intergenic transcribed spacer (ITS) regions. Chromosome length polymorphism (CLP) was evident among the Saccharomyces brewing contaminants with chromosome profiles typical of Saccharomyces sensu stricto. Based upon cluster analysis of their chromosome profiles the majority of the brewing contaminants could be grouped as either S. cerevisiae or S. pastorianus/S. bayanus. Further, the technique was able to differentiate between almost all brewing contaminants and to separate them from any specific lager brewing yeast. The diversity of the Saccharomyces brewing contaminants clearly demonstrated by their CLP was further reflected by MAL genotyping. For the majority of the isolates more than two MAL loci were found with MAL1, MAL2 MAL3, MAL4 and MAL11, MAL31, MAL41 as the dominant genotypes. For all isolates MAL11 and MAL31 were found whereas MAL61 only was found for one isolate. The high number of MAL loci found in the SaccharomYces brewing contaminants indicate their adaptation to a maltose-enriched environment.

AB - A taxonomic study was carried out for isolates of Saccharomyces spp. identified as contaminants ("wild yeast") in 24 different lager breweries. With reference to the current taxonomy all isolates were found to belong to the Saccharomyces sensu stricto complex and 58% of the isolates were further identified as S. cerevisiae, 26% as S. pastorianus and 3% as S. bayanus. The remaining isolates (13%) could not be identified to the species level based on their phenotypic characteristics. However, some of these isolates were identified as S. cerevisiae by HaeIII restriction digest of PCR-amplified intergenic transcribed spacer (ITS) regions. Chromosome length polymorphism (CLP) was evident among the Saccharomyces brewing contaminants with chromosome profiles typical of Saccharomyces sensu stricto. Based upon cluster analysis of their chromosome profiles the majority of the brewing contaminants could be grouped as either S. cerevisiae or S. pastorianus/S. bayanus. Further, the technique was able to differentiate between almost all brewing contaminants and to separate them from any specific lager brewing yeast. The diversity of the Saccharomyces brewing contaminants clearly demonstrated by their CLP was further reflected by MAL genotyping. For the majority of the isolates more than two MAL loci were found with MAL1, MAL2 MAL3, MAL4 and MAL11, MAL31, MAL41 as the dominant genotypes. For all isolates MAL11 and MAL31 were found whereas MAL61 only was found for one isolate. The high number of MAL loci found in the SaccharomYces brewing contaminants indicate their adaptation to a maltose-enriched environment.

KW - Beer

KW - Cluster Analysis

KW - Electrophoresis, Gel, Pulsed-Field

KW - Food Contamination

KW - Food Microbiology

KW - Genetic Variation

KW - Genotype

KW - Maltose

KW - Phenotype

KW - Phylogeny

KW - Polymerase Chain Reaction

KW - Saccharomyces

KW - Saccharomyces cerevisiae

U2 - 10.1016/S0168-1605(00)00326-3

DO - 10.1016/S0168-1605(00)00326-3

M3 - Journal article

C2 - 11014521

VL - 60

SP - 43

EP - 53

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

IS - 1

ER -