Evaluation of microorganisms isolated from aquatic environments (Bostancı-Istanbul, İnegöl-Bursa, centre-Çanakkale) in different locations in biotechnological processes

Microalgae have physiological adaptation features that include bioactive metabolites they produce for defense against living creatures sponges and corals. Some molds in the fungus class produce molecules with biological activities such as antibiotics. Microalgae and fungi are of great importance in the production of antimicrobial agents today, as they have metabolites that have natural antimicrobial effects. In addition, they have many uses, such as being used as biofuel raw materials, due to the valuable metabolites such as proteins, carbohydrates, fatty acids, vitamins and minerals that they accumulate inside the cells. The aim of this thesis is to identify the species of microorganisms isolated from fresh (stream) and salt (sea) water samples taken from different locations, and to investigate their antimicrobial activities and usage capacities as biofuel raw materials. Water samples were taken from İstanbul Bostancı Coast, Çanakkale Port and Kalbur Creek in Bursa İnegöl. One mold and two microalgae were isolated from the water samples taken and their molecular identifications were made. After the extracts of the isolates identified as Rhizopus stolonifer, Chlorella vulgaris and Tetradesmus obliquus were obtained using ethanol, methanol, diethyl ether and dichlora methane solvents, their antimicrobial activities were determined by disk diffusion and minimum inhibition concentration (MIC) methods. It was determined that Tetradesmus obliquus and Rhizopus stolonifer extracts did not have any significant antimicrobial activity. On the other hand, the MIC value of the dichloromethane extract of Chlorella vulgaris was determined to be 78.125 µg/mL. Fatty acid methyl esters (FAME) analysis was performed with GC-FID to determine the usability of the isolates as biofuel feedstock. Butyric acid, caproic acid and palmitic acid were found in high levels in common in all three microorganisms. As a result, it has been determined that the local isolates can be used in biotechnological applications as a sustainable and environmentally friendly energy source.