Evaluation of Guzelçamli - Davutlar coast region in Aydin province in terms of microplastic pollution

Objective: In this thesis, it was aimed to determine the microplastics diversity, and the bacterial biodiversity by isolation of bacteria from microplastics, coastal sea water as well as surrounding beach sand of Aydın Province Güzelçamlı-Davutlar, and to determine the ability of isolated bacteria to degrade microplastics. Materials and Method: In the study, sieving and density separation methods were applied to separate microplastics from seasonally collected beach sand and coastal sea water from 5 different stations between November 2021 and August 2022. Optical fluorescence microscopy and stereomicroscope were used to characterize isolated microplastics. Morphological and molecular analyzes were performed from the microplastic surface, surrounding beach sand and coastal sea water. Results: A total of 2.039,766 units/kg of MPs was determined in the study. In all seasons, it was determined that the most dominant color was blue, the shape was fragment and the size was 5 mm. In addition, pathogenic and non-pathogenic strains were determined by the identification of 60 bacterial isolates with different morphological and cultural characteristics. The ability of the strains isolated by the pre-screening process to degrade microplastics was determined. FTIR and SEM analyzes of the most common type of microplastic were performed. Conclusion: As a result of the study, it was determined that various bacterial groups were present on the microplastic surface and bacterial isolates that were pre-studied degraded polyethylene. In this study 18 new strain, which are Bacillus altitudinis, Exiguobacterium aquaticum, Exiguobacterium aestuarii, Exiguobacterium profundum, Kluyvera intermedia, Sphingomonas paucimobilis, Sphingomonas sp, Kocuria rosea, Staphylococcus succinus, Staphylococcus saprophyticus, Staphylococcus pasteuri, Planococcus rifietoensis, Alkalihalobacillus hunanensis, Proteus mirabilis, Stutzerimonas stutzeri, Cronobacter turicensis, Pantoea alhagi, Priestia megaterium, was reported regarding PE biodegradation. Key words: Microplastic, Coastal pollution, Bacteria, Biodegradation, FTIR, SEM