Analysis of Bacterial Community Change in Arctic Marine Biofilm

Abstract

We analyzed bacterial community change in marine biofilm samples collected from Ny-Alesund, Svalbard, Norway for 15 days and tried to isolate the strains of the major OTUs, as a basic study of signal transduction from reconstruction of biofilm in the laboratory. Pyrosequencing approach was applied to analyze microbial community of biofilm. Analyses of 23,780 sequence reads showed that communities of biofilm were consisted of Actinobacteria (0.63%), Bacteroidetes (44.52%), Cyanobacteria (1.90%), Firmicutes (0.95%), Alphaproteobacteria (37.65%), Betaproteobacteria (0.71%), Gammaproteobacteria (8.38%), Proteobacteria_unclassfied (1.37%), WS3 (0.10%), and so on. Especially, Flavobacteriales (9.84%) in Bacteroidetes, Rhodobacterales (13.67%) in Alphaproteobacteria and Alteromonadales (0.70%) in Gammaproteobacteria were the major components in the marine biofilm. An OTU had 98.8% sequence similarity with Sulfitobacter pontiacus occupied upto 50% of the total community at day 10. 688 colonies isolated from biofilm samples were physiologically characterized to obtain strains belonging to major OUT. We isolated 22 strains through this physiologic information and identified 12 strains. Bacterial cultures of Rhodococcus (4 strains), Salinibacterium (3 strains), Cryobacterium (2 strains), Demequina (1 strain), Sanguibacter (1strains), and Microbacterium (1 strain) were obtained and none of the bacterial cultures showed high similarity with major components of the biofilm.