Functional diversity of bacterioplankton assemblages in western Antarctic seawaters during late spring

• Published in: Marine Ecology Progress Series
• Main Authors: Sala, Maria Montserrat, Arin, Laura, Balague, Vanessa, Felipe, Jordi, Guadayol, Oscar, Vaque, Dolors
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter Research 2005
• Subjects: C180 Ecology; F700 Ocean Sciences; C500 Microbiology; Antarctic; Bransfield Strait; Gerlache; Gerlache Strait; Antarc*
• Online Access: https://eprints.lincoln.ac.uk/id/eprint/16480/; https://eprints.lincoln.ac.uk/id/eprint/16480/1/sala_etal_05.pdf; https://doi.org/10.3354/meps292013

Functional diversity and aminopeptidase activity (AMA) in bacterial assemblages were determined in western Antarctic waters during late spring 2002. Functional diversity was assayed by the patterns of sole carbon source utilization in Biolog-ECO Microplates(TM) and AMA with the fluorogenic substrate leucine 7-amido-4-methylcoumarin. N-acetyl-D-glucosamine and D-cellobiose were the most used carbohydrates. This suggested that used dissolved organic carbon (DOC) was mostly of either zoo-or phytoplankton origin. Principal component analysis of the sole carbon source utilization profiles separated the samples according to salinity and temperature. This separation corresponded roughly with the 3 areas of study: Bransfield Strait (BR), Gerlache Strait (GE) and Belling-shausen Sea (BE). AMA was higher in the upper 40 m, probably associated with the higher organic matter load. Phytoplankton biomass was the factor that accounted for the highest variance in AMA, but did not have a clear influence on functional diversity of bacterioplankton. Our findings indicate that differences in functional diversity of bacterioplankton populations in western Antarctic waters are not directly related to phytoplanktonic abundance. This suggests that bacteria could utilize other carbon sources than DOC freshly released by phytoplankton.