title: Identity, ecology and ecophysiology of planktic green algae dominating in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula).
abstract: The aim of this study was to assess the phylogenetic relationships, ecology and ecophysiological characteristics of the dominant planktic algae in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Phylogenetic analyses of 18S rDNA together with analysis of ITS2 rDNA secondary structure and cell morphology revealed that the two strains belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in future. Immotile green algae are thus apparently capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strains grew in a wide temperature range, but the growth was inhibited at temperatures above 20 °C, indicating their adaptation to low temperature. Preferences for low irradiances reflected the light conditions in their original habitat. Together with relatively high growth rates (0.4-0.5 day-1) and unprecedently high content of polyunsaturated fatty acids (PUFA, more than 70% of total fatty acids), it makes these isolates interesting candidates for biotechnological applications.
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic. lindane@natur.cuni.cz.|Centre for Phycology, Institute of Botany, CAS, Dukelská 135, 379 82, Třeboň, Czech Republic. lindane@natur.cuni.cz.
authors.forename: Linda
authors.initials: L
authors.lastname: Nedbalová
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Mihál
authors.affiliation: Centre for Phycology, Institute of Botany, CAS, Dukelská 135, 379 82, Třeboň, Czech Republic.|Centre for Polar Ecology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Kvíderová
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Procházková
authors.affiliation: Institute of Microbiology, CAS, Vídeňská 1083, 142 20, Prague, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Řezanka
authors.affiliation: Centre for Phycology, Institute of Botany, CAS, Dukelská 135, 379 82, Třeboň, Czech Republic.|Centre for Polar Ecology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Elster
mesh_terms: D000222:Adaptation, Physiological; D000864:Antarctic Regions; D044822:Biodiversity; D000460:Chlorophyta / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D046448:Ice Cover; D060106:Lakes; D010839:Phytoplankton / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012337:RNA, Ribosomal, 18S / Q000235:genetics
chemical_list: D005231:Fatty Acids, Unsaturated; D012337:RNA, Ribosomal, 18S
keywords: Antarctica; Ecology; Fatty acids; Ice-covered lakes; Light; Monoraphidium; Phylogeny; Temperature