Application of T-RFLP analysis to the study of the coastal Black Sea bacterioplankton

Marine bacterioplankton play important roles in biogeochemical cycles in coastal regions of the sea. Despite its ecological importance, the composition of bacterioplankton community of coastal Black Sea, a unique marine basin in the World, is poorly characterized. Thus, the aim of this study was to analyze the bacterial communities in the Black Sea surface waters by terminal-restriction fragment length polymorphism (T-RFLP) analysis, a relatively new, fast and easy molecular method for assessing microbial diversity and community structure. Bacterioplankton assemblages were sampled in shelf surface waters in Constanta Bay between May and August 2004. T-RFLP patterns derived from enzyme digestion with HhaI were analyzed in order to provide a preliminary picture of the relative diversity of this complex microbial community. Members of both prokaryote domains, Archaea and Bacteria, have been successfully identified using T-RFLP analysis of amplified total community 16S rDNA from surface seawaters and were related to the environmental conditions. A minimum of 20 operational taxonomic units (OTU) were identified with T-RFLP. This study contributes to the evaluation of the Black Sea bacterioplankton diversity and it was used for the first time in Romania.