Suntree Kulkeratiyut. FTIR as possible tool for bacterial identification and bound carbonyl in poly (methl methacrylate) adsorbed on silica . Doctoral Degree(Medical Technology). Mahidol University. : Mahidol University, 2004.
FTIR as possible tool for bacterial identification and bound carbonyl in poly (methl methacrylate) adsorbed on silica
Abstract:
Seven species of Salmonella and five specis of Shigella were chosen for study on identification of Enterobacteriaceae grown on four different growth media using transmission Fourier-transform infrared (FTIR) spectroscopy. The four growth media were Casein peptone/soy meal peptone (CASO) agar, Columbia blood agar, MacConkey agar and Salmonella-Shigella (SS) agar. The reproducibility of the spectra of every strain was good. The hierarchical cluster analysis of the first derivative spectra showed the Salmonella and Shigella strains grown on each media could be discriminated by combination of 5 wavelength regions.
For the effect of incubation time on FT-IR identification method, three strains Cryptococcus neoformans were studied. During 1-8 day of culture on Sabouraud dextrose agar (SDA), all three strains were analyzed by FT-IR to obtain spectra for cluster analysis. The hierarchical cluster analysis of the second derivative spectra of every wavelength showed that 3-4 day cultures gave the best result for differentiation of each strain.
The synthetic polymer, poly(methyl methacrylate) (PMMA), was chosen to study of hydrogen bonded carbonyl group in protein. The fraction of directly-bound carbonyls of surface-adsorbed PMMA was determined using transmission FTIR spectroscopy. The small size of the silica used allowed these measurements to be made directly in the transmission mode from dried casts deposited on KBr crystals. Curve fitting of the carbonyl-stretching region allowed the estimation of both the relative amounts and also the relative ratio of the absorption coefficients for the free and bound components. The bound fractions were found to vary smoothly from 0.35 to 0.1 for adsorbed amounts from 0.3 to 1.2 mg PMMA/m2. The bound fractions depended primarily on the adsorbed amount of polymer. Only very small, perhaps even negligible, direct effects of the solvent composition (toluene vs benzene/acetonitrile) or molecular mass (32 to 420 kg/mol) were observed.