In this master's thesis, we investigated the phenotypic diversity of 18 yeast strains belonging to the genus Hanseniaspora and the relationship between their genomic characteristics, growth rate and the production of primary metabolites. The strains were cultivated under aerobic and anaerobic conditions, and growth parameters, cell size, sporulation ability and the concentrations of glycerol, acetic acid and ethanol were determined. All strains exhibited faster growth under aerobic conditions than under anaerobic conditions, while anaerobic cultivation resulted in increased ethanol and glycerol production and decreased acetic acid production, indicating that all strains retained fermentative metabolism. No statistically significant differences in growth rate were observed between the closely related Hanseniaspora smithiae and Hanseniaspora valbyensis. However, H. valbyensis produced higher amounts of ethanol under anaerobic conditions. Increased ethanol production under aerobic conditions was observed in some H. valbyensis strains, suggesting the Crabtree effect. A positive correlation between genome size and maximum specific growth rate was observed. Strains possessing larger genomes grew faster and produced less ethanol under aerobic conditions. Analysis of genomic data also showed that the presence or organization of the mitochondrial genes COX1, COX2 and COX3 was not associated with the ability to form ascospores. The results indicate that oxygen availability is the primary factor affecting growth and primary metabolite production in the studied strains, while genomic diversity contributes to the observed phenotypic diversity.
|
