Physiological characterization of polyextremotolerant yeasts from cold environments of Patagonia

Abstract

Yeasts from cold environments have a wide range of strategies to prevent the negative efects of extreme conditions, includingthe production of metabolites of biotechnological interest. We investigated the growth profle and production of metabolites in yeast species isolated from cold environments. Thirty-eight strains were tested for their ability to grow at diferenttemperatures (5–30 °C) and solute concentrations (3–12.5% NaCl and 50% glucose). All strains tested were able to grow at5 °C, and 77% were able to grow with 5% NaCl at 18 °C. We were able to group strains based on diferent physicochemical/lifestyle profles such as polyextremotolerant, osmotolerant, psychrotolerant, or psychrophilic. Five strains were selected tostudy biomass and metabolite production (glycerol, trehalose, ergosterol, and mycosporines). These analyses revealed thatthe accumulation pattern of trehalose and ergosterol was related to each lifestyle profle. Also, our fndings would suggestthat mycosporines does not have a role as an osmolyte. Non-conventional fermentative yeasts such as Phafa tasmanicaand Saccharomyces eubayanus may be of interest for trehalose production. This work contributes to the knowledge of nonconventional yeasts with biotechnological application from cold environments, including their growth profle, metabolites,and biomass production under diferent conditions.