High Prevalence of Gammaproteobacteria in the Sediments of Admiralty Bay and North Bransfield Basin, Northwestern Antarctic Peninsula

• Published in: Frontiers in Microbiology
• Main Authors: Franco, Diego C., Signori, Camila N., Duarte, Rubens T. D., Nakayama, Cristina R. UNIFESP, Campos, Lucia S., Pellizari, Vivian H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media Sa 2017
• Subjects: marine sediments; microbial diversity; bacterial community structure; Antarctica; polar microbiology; Antarctic; Antarctic Peninsula; King George Island; South Shetland Islands; Admiralty Bay; Antarc*; IPY; Sea ice
• Online Access: https://repositorio.unifesp.br/handle/11600/55123; https://doi.org/10.3389/fmicb.2017.00153

Microorganisms dominate most Antarctic marine ecosystems, in terms of biomass and taxonomic diversity, and play crucial role in ecosystem functioning due to their high metabolic plasticity. Admiralty Bay is the largest bay on King George Island (South Shetland Islands, Antarctic Peninsula) and a combination of hydro-oceanographic characteristics (bathymetry, sea ice and glacier melting, seasonal entrance of water masses, turbidity, vertical fluxes) create conditions favoring organic carbon deposition on the seafloor and microbial activities. We sampled surface sediments from 15 sites across Admiralty Bay (100502 m total depth) and the adjacent North Bransfield Basin (6931147 m), and used the amplicon 454-sequencing of 16S rRNA gene tags to compare the bacterial composition, diversity, and microbial community structure across environmental parameters (sediment grain size, pigments and organic nutrients) between the two areas. Marine sediments had a high abundance of heterotrophic Gammaproteobacteria (92.4% and 83.8% inside and outside the bay, respectively), followed by Alphaproteobacteria (2.5 and 5.5%), Firmicutes (1.5 and 1.6%), Bacteroidetes (1.1 and 1.7%), Deltaproteobacteria (0.8 and 2.5%) and Actinobacteria (0.7 and 1.3%). Differences in alpha-diversity and bacterial community structure were found between the two areas, reflecting the physical and chemical differences in the sediments, and the organic matter input. Brazilian National Council for Scientific and Technological Development - CNPq (MABIREH/IPY/CAML) CAPES-Master's fellowship Univ Sao Paulo, Inst Oceanog, Dept Oceanog Biol, Sao Paulo, Brazil Univ Fed Santa Catarina, Ctr Ciencias Biol, Florianopolis, SC, Brazil Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Ambientais, Diadema, Brazil Univ Fed Rio de Janeiro, Inst Biol, Dept Zool, Rio De Janeiro, Brazil Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Ambientais, Diadema, Brazil CNPq (MABIREH/IPY/CAML): ...