Biotechnologically relevant yeasts from patagonian natural environments

Abstract

Patagonia region constitutes a vast geographic area with multiple extreme environments having one or more of these stress factors: cold, high UV incidence, desiccation, ultra-oligotrophy, acidity, and the 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 or genes. Here we summarize numerous yeast bioprospection studies performed in the conventional and extreme environments of the Argentinean Patagonia. More than 1000 yeasts and dimorphic fungi were collected and molecularly identified; 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), and cold-active enzymes. In some cases, these traits could be correlated to habitat characteristics and for those (e.g., 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, Saccharomyces uvarum, and Phaffia rhodozyma (synonym of Xanthophyllomyces dendrorhous). The biotechnological potential of selected species is addressed as specific study cases. The present work represents an overview of our findings related to biotechnologically relevant yeasts from Patagonian natural environments.