Biotechnologically Relevant Yeasts from Patagonian Natural Environments

Abstract

Patagonia region constitutes a vast geographic area with multiple extreme environments due to one or more of these stress factors: cold, high UV incidence, desiccation, ultra-oligotrophy, acidity, presence of heavy metals, among others. Yeasts that constantly live under stress conditions evolve adaptive mechanisms to minimize or resist their negative effects and thus permit survival and reproduction. These specific mechanisms are promising sources of biotechnologically relevant molecules and/or genes. Here we summarize numerous yeast bioprospection studies performed in conventional and extreme environments of the Argentinean Patagonia. Over 1000 yeasts and dimorphic fungi were collected, molecularly identified, and when possible relevant secondary metabolites were screened, as well as their ability to tolerate several types of stress in laboratory conditions. Screened metabolites include carotenoid pigments, mycosporines (UV sunscreens), cold active enzymes, among others. In some cases, these traits could be correlated to habitat characteristics and for those (ex. mycosporines, carotenoid pigments, heavy metal tolerance) their potential role in the adaptive mechanisms to specific stress factors was evaluated. Genome sequencing and analyses were performed for biotechnologically relevant isolates such as Saccharomyces eubayanus, S. uvarum and Phaffia rhodozyma (synonym of Xanthophyllomyces dendrorhous). The biotechnological potential of selected species will be addressed as specific study cases. The present work represents an overview of our findings related to biotechnologically relevant yeasts from Patagonian natural environments.