Psychrophilic yeasts in glacial environments of Alpine glaciers

Abstract

The presence of psychrophilic yeasts in supra‐ and subglacial sediments, ice and meltwater collected from two glaciers of the Italian Alps (Forni and Sforzellina – Ortles‐Cevedale group) was investigated. After incubation at 4 °C, subglacial sediments contained from 1.3 × 103 to 9.6 × 103 CFU of yeasts g−1. The number of yeast cells in supraglacial sediments was c. 10–100‐fold lower. A significant proportion of isolated yeasts exhibited one or more extracellular enzymatic activities (starch‐degrading, lipolytic, esterolytic, proteolytic and pectinolytic activity) at 4 °C. Selected isolates were able to grow at 2 °C under laboratory‐simulated in situ conditions. In all, 106 isolated yeasts were identified by MSP‐PCR fingerprinting and 26S rRNA gene sequencing of the D1/D2 region as belonging to 10 species: Aureobasidium pullulans, Cryptococcus gilvescens (over 50% of the total), Cryptococcus terricolus, Mrakia gelida, Naganishia globosa, Rhodotorula glacialis, Rhodotorula psychrophenolica, Rhodotorula bacarum, Rhodotorula creatinivora and Rhodotorula laryngis. Four strains, all belonging to a new yeast species, yet to be described, were also isolated.

Phylogenetic Diversity and Metabolic Potential Revealed in a Glacier Ice Metagenome

“…Thus, the Proteobacteria, Bacteroidetes, and Actinobacteria represented the predominant phyla in glacier ice from the Northern Schneeferner. These groups were also abundant in ice derived from several other glaciers (32,54,51) and other permanently cold habitats, such as subglacial meltwater (9,19,44), snow (40), or Antarctic lakes (33). These results support the perception that related phylotypes exist in geographically diverse cold environments because of similar strategies for survival and remaining active at low temperatures (36).…”

“…However, studies of the microbial composition of European glaciers are rare. These glaciers have been mainly investigated with respect to the presence of yeasts (51) and bacterial population sizes (41).…”

The diversity, extracellular enzymatic activities and photoprotective compounds of yeasts isolated in Antarctica

“…This species was also isolated from subglacial and meltwater glacier sediments in Italy (38). The maximum growth temperature of the type strain of this species is 20 o C. However, two isolates in our study were able to grow at 25 o C.…”

Rhodotorula portillonensis sp. nov., a basidiomycetous yeast isolated from Antarctic shallow-water marine sediment

“…CBS 9087 and CBS 9086 were isolated from water in Antarctica. It is interesting to note that other strains of R. laryngis (not included in the phylogenetic trees) were isolated from children's faeces in Hungary (CBS 5695), seawater in Sweden (CBS 8020), grapes in Australia (Prakitchaiwattana et al, 2004), nectarine trees in USA (Janisiewicz et al, 2010), the Dead Sea (Butinar et al, 2005), glaciers and freshwater habitats in Argentina and Italy (de García et al, 2007;Turchetti et al, 2008;Libkind et al, 2010), and a soil sample from King George Island in Antarctica (Carrasco et al, 2012). Furthermore, other strains of R. pinicola (not included in the phylogenetic trees) were isolated from freshwater habitats in Argentina (Libkind et al, 2003(Libkind et al, , 2010, wines in Greece (Nisiotou & Gibson, 2005), an industrial malting ecosystem in Finland (Laitila et al, 2006), nectarine trees in USA (Janisiewicz et al, 2010) and marine sponges from Fildes Bay in Antarctica (Vaca et al, 2013).…”