An Ultraviolet (242 nm Excitation) Resonance Raman Study of Live Bacteria and Bacterial Components

Ultraviolet-excited (242 nm) resonance Raman spectra have been obtained for the first time for five types of bacteria: Escherichia coli, Pseudomonas fluorescens, Staphylococcus epidermidis, Bacillus subtilis, and Enterobacter cloacae. Detailed, highly reproducible spectra show substantial differences in both the intensities and the energies of peaks, which suggests that such spectra provide unique “fingerprints” reflecting the unique combinations of chemotaxonomic markers present in each type of organism. Many of the spectral features excited by 242-nm radiation probably arise from cellular RNA, DNA, and the amino acids tyrosine and tryptophan. Background fluorescence has been shown to be negligible.