Exploring the phenotypic diversity of oenological traits in Kluyveromyces marxianus strains.

The use of non-Saccharomyces yeasts in the winemaking process may have several positive outcomes. Kluyveromyces marxianus has recently been revealed as a promising species for this industry. While the majority of studies mention the use of K. marxianus in various industries including food production (e.g. dairy and cocoa), recent studies have also shown that its aroma and pectinase production make it a suitable yeast for the wine industry. Nevertheless, only particular strain, IWBT Y885, was investigated. In this study, five different K. marxianus strains as well as one protoplast fusant (BF2020) were compared to strain Y885. These comparisons focused on various oenological traits such as fermentation performance, fermentation metabolites, hydrogen sulfide, and pectinase production. Throughout the study, variations were found between the K. marxianus strains investigated. Indeed, although common traits such as high pectinase activity appeared conserved among K. marxianus strains, a fairly large phenotypic diversity was also evident. Using cluster analysis, strain groupings emerged with strains L01, L05, Y885, and BF2020 grouping together. Similarly, strains L02 and L04 grouped together while strain L03 appearing to show the most variation between the strains investigated. Variation between strains was observed regardless of the original source of isolation.