Soil Yeasts in the Vicinity of Syowa Station, East Antarctica: Their Diversity and Extracellular Enzymes, Cold Adaptation Strategies, and Secondary Metabolites

Masaharu Tsuji,Sakae Kudoh

doi:10.3390/su12114518

Abstract

Antarctica is known as one of the harshest environments on Earth, with a frigid and dry climate. Soil yeasts living in such extreme environments can grow by decomposing organic compounds at sub-zero temperatures. Thus far, a list of lichen and non-lichen fungi isolated from the area near Syowa Station, the base of the Japanese Antarctic research expedition, has been compiled and a total of 76 species of fungi have been reported. Yeast, especially basidiomycete yeast, is the dominant fungus in Antarctica. This mini-review summarizes a survey of the yeast diversity in the soil of Eastern Ongul Island and the ability of these yeasts to secrete extracellular enzymes. We also describe the yeast diversity in the soil of the Skarvesnes ice-free region and how these yeasts have adapted to the sub-zero environment. Further, we describe the secondary metabolites of these yeasts, whose production is induced by cold stress.

Highlights

Most of the Earth’s biosphere is a low-temperature region exposed to temperatures below 5 ◦ C; this includes the polar regions of Antarctica and the Arctic, the deep sea, and high mountains such as the Himalayas and the Alps
About 98% of Antarctica is covered in ice and snow, and coastal temperatures are typically between 5 and −35 ◦ C [2]
Ice- and snow-free areas during the austral summer are distributed along the coast of Antarctica in areas called ice-free regions, where snow and ice melt during the summer months to expose the ground

Summary

Introduction

Most of the Earth’s biosphere is a low-temperature region exposed to temperatures below 5 ◦ C; this includes the polar regions of Antarctica and the Arctic, the deep sea, and high mountains such as the Himalayas and the Alps. [1]. More than 1000 fungal species from about 400 genera have been identified and documented in Antarctica [7] This of species by 400 culture andhave collection included. Station is located, andinvestigated the Skarvesnes ice-free area that in is total of 76 fungal species havethe been documented [8,9]. In this we summarize the diversity ofyeast, yeastsis living in the soil near 60 km from this island. SyowainStation in Antarctica, their mechanisms of adaptation lowintemperatures, andSyowa their This mini-review, we summarize the diversity of yeasts to living the soil near the ability secrete extracellular enzymesofat low temperatures. Station to in Antarctica, their mechanisms adaptation to low temperatures, and their ability to secrete metabolites these yeasts under the coldthe stress of sub-zero temperatures. We summarize secondary metabolites that these yeasts produce, under the cold stress of sub-zero temperatures

Soil Yeast Diversity and Their Ecological Role in East Ongul Island

Findings

Secondary Metabolites Induced by Cold Stress