Ecological and biogeographic relationships of class Flavobacteria in the Southern Ocean

摘要: The abundance, spatial distribution and diversity of class Flavobacteria were investigated in the Southern Ocean euphotic zone across a latitudinal transect ice pack off Eastern Antarctica. Surface seawater samples filter-fractionated into 0.8 μm particulate 0.2 m planktonic fractions with different molecular techniques. abundance particle-associated Flavobacteria, ascertained real-time PCR DGGE band analysis using Flavobacteria-specific primers, was found to be significantly higher Polar Front Zone (PFZ) Antarctic (AZ) water than nutrient limited Temperate (TZ) Sub-Antarctic (SAZ) waters. Abundance correlated positively chlorophyll concentrations, suggesting that increased may relate enhanced primary production PFZ AZ. This is supported by comparison profiles demonstrated significant differences total community structure 16S rRNA gene between from AZ those TZ SAZ. Sequence revealed broad amongst several clades detected waters not SAZ putatively represent psychrophilic taxa. data included large, so far uncultivated, cosmopolitan phylogenetic clade (“DE cluster 2”) distributed throughout Ocean.