UV Raman spectral intensities of E. coli and other bacteria excited at 228.9, 244.0, and 248.2 nm
Document Type
Article
Date of Original Version
7-15-2001
Abstract
Resonance Roman spectral intensities per average bacterial cell have been measured quantitatively for Gram-negative Escherichia coli, Citrobacter freundii, and Enterobacter aerogenes, as well as Gram-positive Bacillus subtilis and Staphylococcus epidermidis. Spectra have been obtained from cultures in the lag, log, and stationary growth phases excited in turn by 228.9, 244.0, and 248.2 nm light. Although Roman spectral peak positions (cm-1) excited by a given wavelength are very similar for all five bacterial species, the organisms are characterized by significantly different spectral intensity values. Intensity changes are associated with growth phase changes in all of the species as well. A comparison of measured with estimated average intensities has been made for spectra of log-phase E. coli. It is possible to compare measured intensities with intensities estimated for log-phase E. coli on the basis of the knowledge of its known average cellular molecular composition. A significant degree of hypochromism is observed in E. coli nucleic acid spectra. In contrast, strong average hyperchromism characterizes all aromatic amino acid peaks belonging to the same E. coli cells. Results suggest that knowledge of spectral intensity values will enhance significantly the capability to identify bacteria by means of their UV resonance Raman spectra.
Publication Title, e.g., Journal
Analytical Chemistry
Volume
73
Issue
14
Citation/Publisher Attribution
Wu, Q., T. Hamilton, W. H. Nelson, S. Elliott, J. F. Sperry, and M. Wu. "UV Raman spectral intensities of E. coli and other bacteria excited at 228.9, 244.0, and 248.2 nm." Analytical Chemistry 73, 14 (2001). doi: 10.1021/ac001268b.