Detection of antimicrobial and anti-quorum sensing activitiy of some microalgae isolated from various freshwater samples

In this study, a total of 60 water samplings were collected from different fresh water sources, solid waste unit and slaughterhouse waste water outlet in the province of Kütahya. Green algae (Chlorophyta) isolation was performed from these samplings. Seven algal species (B1, B6, B27, T14, T15, T16, K3) obtained in their pure form were studied based on their macroscopic, microscopic morphologies and later on their molecular characterization was performed. When the sequence data of the seven algal species were obtained, we will be able to diagnose five species. Although B6, B27, T14, K3 species were identified as Scendesmus sp., and T16 as Stichococcus bacillaris, further phylogenic studies are needed. The isolated seven algal species were grown in the appropriate liquid medium and the antimicrobial activities on Staphylococcus aureus (ATCC 29213), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853), Candida krusei (ATCC 6258) and Escherichia coli (ATCC 25922) species were determined by ethanol, methanol, chloroform and water extracts with disc diffusion method. When evaluating the algal species according to their zone diameter, ethanol extracts of B1 and T16 algae were found to be highly effective against S.aureus species. In the methanol extract, T16 coded algae presented the best activity against S.aureus species, while in the chloroform extract, B1 coded algae was the most efficient. According to these results, it was determined that the seven algal species have a high level of activity against gram positive bacteria while presenting a low level of activity against gram negative bacteria. In addition, quorum sensing activity detection of algal extracts on C. violaceum was studied and it was concluded that there was no activity. The antimicrobial activity of the T16 ethanol extracts with the best result on hospital-acquired MRSA was studied within the scope of this study. It was determined that the ethanol extract, active on S.aureus, has no effect on MRSA species.