Diatoms and bacteria diversity: study of their relationships in the Southern Adriatic Sea

In the Southern Adriatic Sea (Italian coasts) bacterial and diatom diversity was studied over an annual cycle and the relationships between these two microbial components were analyzed. As regards to the culturable heterotrophic bacteria, Aeromonas was the predominant genus among the Gram-negative bacteria. The presence of Enterobacteriaceae, Cytophaga, Pseudomonas, Acinetobacter and Photobacterium was also remarkable. Flexibacter, Moraxella, Chromobacterium, Flavobacterium and Vibrio were present at less than 5%. Of the 92 diatom species determined, 16 were the most abundant representing the 96% of this phytoplankton group. The results obtained demonstrated that several bacterial genera were significantly related to the most abundant and representative diatoms (Chaetoceros spp., Pseudo-nitzschia pseudodelicatissima and Rhizosolenia spp.).