Comparison of optical measurements for better ni tracking in bacteria


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Arts and Sciences, Department of Biology, Turkey

Approval Date: 2015

Student: SILA SUNGUR

Supervisor: AYŞE GÜL GÖZEN

Abstract:

Metal pollution is a common problem in industrial areas. Microorganisms, as well as macroorganisms are affected from metal pollution. In order to cope with this problem, microorganisms develop resistance mechanisms. Traditional microbiological techniques alone are not sufficient in resistance studies. Additional data acquisition by using other measurement techniques and devices are also required. However, there are differences in sentitivities of the measurement devices. A given device may work under a set of conditions and concentrations but may not be suitable when the conditions and concentrations change. Therefore, testing the efficiency of measurement device that is suitable to produce meaningful data is essential. In this study, the possibility and feasibility of using spectroscopy based measurements to quantitate Ni in the spent media of bacterial cultures were explored. The UV-Vis Spectroscope and ATR-FTIR spectroscope were the two optical devices that were compared in this study. Two strains of Microbacterium oxydans, another undefined Microbacterium freshwater isolate, and E. coli were grown at their corresponding minimum inhibitory concentrations of Ni. Then the Ni concentrations left in the culture supernatants following the removal of bacteria were measured by UV-Vis and ATR-FTIR spectroscopes. The data obtained from the two devices were compared. The results indicated that ATR-FTIR spectroscopy had a higher sensitivity and the band intensities provided reasonable approximation for better estimations of Ni concentrations. The data were discussed in terms of detection of metals while the metal sorption capacities of bacteria being evaluated.