Phylogenetic analyses of bacteria in sea ice at Cape Hallett, Antarctica

• Published in: New Zealand Journal of Marine and Freshwater Research
• Main Authors: Maas, EW, Simpson, AM, Martin, A, Thompson, S, Koh, EY, Davy, SK, Ryan, KG, O'Toole, RF
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sir Publishing 2012
• Subjects: Biological Sciences; Ecology; Marine and estuarine ecology (incl. marine ichthyology); Antarctic; Cape Hallett; Hallett; Southern Ocean; Antarc*; Antarctica; Sea ice
• Online Access: https://doi.org/10.1080/00288330.2011.579981; http://ecite.utas.edu.au/83706

Every year, an area of sea ice forms around the continent of Antarctica that is inhabited bycommunities of microbes. Although the microbial component of this habitat has been postulatedto play an ecologically important role in the Southern Ocean, our understanding of the diversityof Antarctic sea-ice bacteria is limited. The aim of this study was to identify bacterialcomponents present in sea ice at Cape Hallett. Total community DNA was isolated from sea-icecores and the 16S ribosomal RNA genes were amplified by polymerase chain reaction (PCR)using a range of universal and targeted primer sets. PCR products were de-replicated usingrestriction fragment length polymorphism (RFLP) and distinct RFLP types were sequenced. Themajor bacterial classes identified consisted of a-proteobacteria, γ-proteobacteria, Cytophaga-Flavobacteria-Bacteroides group and a small number of Gram-positive species. Our findingsindicate that the bacterial component of sea ice at Cape Hallett is primarily heterotrophic.Cyanobacteria and Archaea were not detected using the methods and primer sets employed inthis study. However, bacteria whose 16S rDNA sequences cluster with species that encodephototrophic genes were detected in our sea-ice samples. This raised the possibility that bacterialphototrophy may occur in Antarctic sea ice.