Halotolerant Yeasts: Biodiversity and Potential Application

Abstract

Halotolerant yeasts represent a heterogeneous group of unicellular fungi able to survive and thrive under hypersaline conditions. This review examines the biodiversity of halotolerant yeasts in various habitats with high salt content and the potential practical applications of this group of microorganisms in industry and agriculture. Halotolerant yeasts are found in various habitats with elevated salt content, including seawater, hypersaline ponds and salterns, saline soils and wastewaters, salt-containing foods. Habitats with moderate salinity, e.g. seawater, food products, olive fermentation wastewaters can boast a comparatively large biodiversity of yeasts both ascomycetes and basidiomycetes. Hypersaline niches are mostly inhabited by pigmented and melanized yeasts and yeast-like fungi. The adaptability and robustness of halotolerant yeasts could be exploited in several biotechnological fields, mainly the food industry and bioremediation. Yeasts isolated from food products with elevated salt content are studied as potential starter cultures in the corresponding fermenting products due to their enzymatic and antimicrobial activity and probiotic characteristics. Marine yeasts are of an increasing interest due to their production of various hydrolytic enzymes, biofuel production using seawater, bioremediation of saline wastewaters and the probiotic potential in aquaculture. Halotolerant yeasts found in various saline wastewaters could be used in bioremediation of wastewaters with high salinity containing various organic pollutants. However more research is required to achieve practical utilization of this group of microorganisms.