Investigation of the antibiofilm effect of different plant extracts and oils by microbiological and molecular methods

There is an increase in the need for new antimicrobial agents, as biofilm gives microorganisms superior properties than their planktonic structures and improves their antibiotic resistance. In our thesis, it was aimed to determine the antibiofilm effects of various plant extracts, essential oils and fixed oils of Chondrus crispus on microorganisms. For this purpose, after determining the biofilm forming capacities of microorganisms and antimicrobial activities of our test materials by microdilution method, antibiofilm activities were determined. Antibiofilm experiments were evaluated in terms of the effects of test materials on both biofilm prevention and removal of formed biofilms. The effects of our test materials on the swarming movement, which is important in biofilm formation, were also investigated. The total phenolic, total flavonoid contents, antioxidant activities and components of the oils used were determined for the investigated test materials. Changes in the expression of genes (Hly and gtfI) that contribute to biofilm formation of L. monocytogenes 4b 19115 and S. mutans 2a7 bacteria were determined by RT-PCR. The effects of the test materials on each microorganism were different, and differences were observed even in the effects of strains within the same species. However, by supporting the materials showing antibiofilm activity with additional studies, it will be possible to obtain natural products that can be used in the health and food sectors.