Dr Janez Kosel
The Oenology Paper of the Year was awarded to Dr Janez Kosel from the Faculty of Mechanical Engineering, University of Ljubljana for their paper titled
Maximum residue limit of fungicides inhibits the viability and growth of desirable non‐Saccharomyces wine yeasts, Kosel, J., Raspor, P. and Čadež, N. (2019) Australian Journal of Grape and Wine Research 25: 43-52. doi:10.1111/ajgw.12364
Although the yeast Saccharomyces cerevisiae is the main organism responsible for the conversion of grape juice into wine, indigenous yeasts species play an important role in the development of geographically unique wine aroma. For these reasons, the ecology of natural yeast microbiota is an important factor influencing wine quality. Nevertheless, yeast community dynamics are fragile and can be influenced by climatic changes and agrichemicals. Vineyards with increased rainfall rates are commonly infested by the fungus Botrytis cinerea, a causal agent of grey mould disease, and chemical fungicides are routinely employed to prevent its growth (Bizaj et al. 2011). Although their application is effective, they can also act non-specifically on wine yeasts other than the target fungus breaking the balance between yeast species and reducing their diversity (Čadež et al. 2010). Consequently, wine aroma quality is hampered especially when wine spoiladge yeasts such as Dekkera bruxellensis prevail. Infact, our research has confirmed high tolarence of this yeast to the examined fungicides and revealed its dominance at later stages of wine maturation (Kosel et al. 2018). Therefore, special focus was dedicated to studying mechanisms of microbial interactions between yeasts D. bruxellensis and S. cerevisiae. Gene expression analysis revealed that both yeasts were competing for resources especially for vitamin thiamine and for amino acids (Kosel et al. 2017).
- Faculty of Mechanical Engineering, University of Ljubljana, 1000, Ljubljana, Slovenia;
- Biotechnical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia