The surface properties of 7 different micro–organisms with their 14 different strains were examined. The contact angles of the micro–organism films were measured by a captive–bubble technique. Surface free energies were calculated from the contact angles. Hydrophobicities were also evaluated by adhesion to p–xylene. | Turk J Biol 24 (2000) 215–231 © TÜBİTAK Hydrophobicities and Electrostatic Behavior of Different Micro–organisms Abbas YOUSEFI RAD, Bayındır Hospital, Medical Center, Söğütözü, Ankara–TURKEY Hakan AYHAN, Erhan PİŞKİN* Hacettepe University, Chemical Engineering Department, Bioengineering Division, and TÜBİTAK–Centre of Excellence: Polymeric Biomaterials, Beytepe, Ankara–TURKEY Özgül KISA Gülhane Medicine Academy of Military, GATA, Microbiology and Clinic Microbiology Division, Ankara–TURKEY Received: Abstract: The surface properties of 7 different micro–organisms with their 14 different strains were examined. The contact angles of the micro–organism films were measured by a captive–bubble technique. Surface free energies were calculated from the contact angles. Hydrophobicities were also evaluated by adhesion to p–xylene. The zeta potentials and surface charges of the micro–organisms were measured using a zeta potential analyser system. The contact angles of the gram positive micro–organisms, gram negative micro–organisms and Candida ablicans were in the ranges 48–70°, –55°, and 69–75° respectively, while the corresponding surface free energies were in the ranges – –2, – –2 and – –2 respectively. The p–xylene adhesions were in parallel to the hydrophobicities defined by the contat angles: –, –, and – for the gram positive bacteria, gram negative bacteria and Candida albicans yeasts respectively. The zeta potentials for these bacteria were in the ranges – mV, – mV, and – mV respectively. Most of the bacteria were negatively charged, except for the CNS–2 and CPS–1 strains. Key Words: Micro–organisms, hydrophobicity, contact angle, surface free energy, p–xylene adhesion, zeta potential, surface charge. Farklı Mikroogranizmaların Hidrofobisitesi ve Elektrostatik Davranışları Özet: Bu çalışmada 7 farklı mikroorganizmanın 14 değişik suşlarının yüzey özellikleri
