Investigation of microbial community of cystoseira (ochrophyta)-nereididae (polychaeta) association distributed along the sinop coasts (black sea)

The brown macroalgae Cystoseira sensu lato (sl) (Ochrophyta) facies has a widespread distribution in the Black Sea and provides habitat for polychaetes. The microbiota associated with marine organisms plays a critical role for the balance of marine ecosystems and the maintenance of biodiversity. In this thesis study, it was aimed to investigate the microbial community of Cystoseira sl facies in association with individuals belonging to Nereididae, a polychaete family, to understand the microbial relationship between host and host, to determine the microbial determination of seawater samples, and to determine the similarities and differences between the stations. DNA extraction was performed for water, algae and polychaete samples from three sampling stations on the Sinop coast, and the thesis study was carried out by SSCP method using the V4-V5 region of the 16S rRNA gene. Sequence analysis of the bands visualized on polyacrylamide gel was performed and high similarity bacterial species were identified as a result of GenBank-BLAST search. The phyla common to all samples were Bacteriodetes, Proteobacteria and Firmicutes, and in addition to these phyla, Cyanobacteria were found in water samples. As a result of the BLAST search, uncultured marine bacterium clones were identified the most. When the phylogenetic trees constructed based on the UPGMA dendrogram used to observe the communite structures among the samples and the sequence data obtained for the band profiles were examined; it was observed that there was no remarkable affinity between water and algae samples, as well as between algae and polychaete samples. In one of the three stations sampled, there was similarity between host and host (algae and polychaete) in terms of the presence of Bacillus species. In addition, the BLAST search revealed bacterial samples that were similar to some human and animal pathogenic species. Furthermore, carbon and cellulose filters used for the filtration of seawater samples prior to DNA extraction were compared and no advantage was found in terms of enabling the detection of multiple bands and/or species. Inhibitory substances that are likely to be present in environmental samples and the difficulty of achieving optimizations in the SSCP method are among the difficulties encountered in this thesis study. This study contributes to the complex interactions of marine microbiota with the organisms it contains.