Short-term variability in bacteria abundance, cell properties, leucine and thymidine incorporation in subarctic sea ice

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

Fersiynau electronig

Dangosydd eitem ddigidol (DOI)

Sea ice is a biome of immense size and provides a range of habitats for diverse microbial communities, many of which are adapted to living at low temperatures and high salinities in brines. We measured simultaneous incorporation of thymidine (TdR) and leucine (Leu), bacterial cell abundance and cell population properties (by flow cytometry) in subarctic sea ice in SW Greenland. Short-term temporal variability was moderate, and steep environmental gradients, typical for sea ice, were the main drivers of the variability in bacterial cell properties and activity. Low nucleic acid (LNA) bacteria, previously linked to oligotrophic ecotypes in marine habitats, were more abundant in the upper ice layers, whereas high nucleic acid (HNA) bacteria dominated in lower ice, where organic carbon was in high concentrations. Leu incorporation was saturated at micromolar concentrations, as known from freshwater and marine biofilm systems. Leu:TdR ratios were high (up to >300) in lowermost ice layers, and when compared to published respiration measurements, these results suggest non-specific Leu incorporation. There was evidence of polyhydroxyalkanoate (PHA)-containing bacteria in the sea ice, shown by brightly fluorescing intracellular inclusions after Nile Blue A staining. High Leu saturating concentrations coupled with the occurrence of PHA-producing organisms further highlight the similarity of sea ice internal habitats to biofilm-like systems rather than to open-water systems.
Iaith wreiddiolSaesneg
Tudalennau (o-i)57-73
CyfnodolynAquatic Microbial Ecology
Cyfrol71
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 27 Tach 2013
Gweld graff cysylltiadau