T.C. MARMARA UNIVERSITY INSTITUTE FOR GRADUATE STUDIES IN PURE AND APPLIED SCIENCES INVESTIGATION OF THE EFFECT OF ANTIMICROBIAL AGENTS ON MICROORGANISMS Çağakan ÖZBALCI THESIS FOR THE DEGREE OF MASTER OF SCIENCE IN BIOENGINEERING SUPERVISOR Asist. Prof. Berna SARIYAR AKBULUT CO-ADVISOR Prof. Dr. Dilek KAZAN İSTANBUL 2009