BACTERIAL DIVERSITY AT SURFACE-WATER IN 3 LOCATIONS WITHIN THE BALTICSEA AS REVEALED BY CULTURE-DEPENDENT MOLECULAR TECHNIQUES

Diversity of culturable bacteria inhabiting the Baltic sea surface wat ers was studied in three separate locations. Based on electrophoretica lly separated whole cell proteins the number of operational taxonomic units (OTU) within each sampling location was high. Most of the OTUs w ere unique to single locations. Within each sampling location 8-22% of isolates belonged to a single OTU. Rarefaction analysis revealed that the bacterial community was more divergent at a polluted location tha n at clean areas. Also the most common OTUs were different in clean lo cations compared to the polluted site suggesting that both diversity a nd species composition of the bacterial community is greatly affected by pollution. The partial 16S rRNA gene sequences of the isolates of t he most common OTUs are unique. Intragroup variation and an OTU-specif ic bacteriocin system was observed among the isolates of the second co mmon OTU. The bacteriocin activity was linked to restriction fragment length polymorphism grouping, although additional variation correlatin g to geographic origin of isolates was observed.