Diversity of Arctic Bacteria forming Marine Biofilms

Abstract

Bacterial diversity in Arctic marine biofilms was analyzed through cultivation and cultivation ？independent methods. We collected biofilms formed on a floating-pier and a plastic cable under seawater which were located around the Korea Arctic Research Station Dasan at Ny-Alesund, Svalbard, Norway (79°N, 12°E). A total of 95 strains were cultured, and 22 species were finally identified by phylogenetic analysis on the basis of 16S rRNA gene sequences. They belonged to γ-proteobacteria, high GC Gram +, CFB group. The phylogenetic analysis of 110 clones which were randomly selected from 16S rDNA clone libraries showed that the most frequent clone was an uncultured Cytophaga sp. DGGE of the partially amplified 16S rRNA gene was performed and DNA fragments in the most intense bands were sequenced. The majority of retrieved sequences were associated with an uncultured bacterium and an uncultured Cytophaga sp. Diversity of cultured bacteria was quite different from bacterial diversity obtained from cultivation-independent methods.