Polyphenolic substrates and dyes degradation by yeasts from 25 de Mayo/King George Island (Antarctica)

JOSÉ I ROVATI; HIPÓLITO F. PAJOT; LUCAS RUBERTO; MAC CORMAK ; CASTELLANOS DE FIGUEROA, LUCÍA I.

YEAST

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2013 vol. 30 p. 459 - 470

0749-503X

Antarctica offers a range of extreme climatic conditions, such as low temperatures,high solar radiation and low nutrient availability, and constitutes one of the harshestenvironments on Earth. Despite that, it has been successfully colonized by?cold-loving?fungi, which play a key role in decomposition cycles in cold ecosystems. However,knowledge about the ecological role of yeasts in nutrient or organic matter recycling/mineralization remains highly fragmentary. The aim of this work was to study the yeastmicrobiota in samples collected on 25 de Mayo/King George Island regarding the scopeof their ability to degrade polyphenolic substrates such as lignin and azo dyes. Sixty-oneyeast isolates were obtained from 37 samples, including soil, rocks, wood and bones.Molecular analyses based on rDNA sequences revealed that 35 yeasts could be identifiedat the species level and could be classified in the generaLeucosporidiella, Rhodotorula,Cryptococcus, BulleraandCandida.Cryptococcus victoriaewas by far the most ubiquitousspecies. In total, 33% of the yeast isolates examined showed significant activity for dyedecolorization, 25% for laccase activity and 38% for ligninolytic activity. Eleven yeastsdid not show positive activity in any of the assays performed and no isolates showedpositive activity across all tested substrates. A high diversity of yeasts were isolated in thiswork, possibly including undescribed species and conspicuous Antarctic yeasts, most ofthem belonging to oligotrophic, slow-growing and metabolically diverse basidiomycetousgenera