We have recently extended our studies of the infrared signatures of Bacillus bacterial spores from the mid-infrared to the far-infrared (sometimes called the terahertz, THz) spectral domain. The ultimate goal is to use such signatures to distinguish different strains of spores from unknowns as well as from one another. Five different strains of Bacillus were prepared by culturing the spores, washing repeatedly in sterile water and drying them onto windows that are simultaneously transparent in both the mid- and far-infrared. The strains include B. globigii BG-01, B. thuringiensis subsp kurstaki ATCC 35866, B. subtilis ATCC 49760, B. subtilis ATCC 6051, and B. atrophaeus ATCC 49337. Using different combinations of hardware in the Fourier transform infrared (FTIR) spectrometer, essentially continuous spectral coverage was obtained from ~8 to 6,000 cm-1. Preliminary results indicate that any THz signatures are at least 25 times weaker (based on p-p noise) than the strongest mid-IR amide I bands near 1657 cm-1.
Revised: March 2, 2005 |
Published: October 27, 2004
Citation
Valentine N.B., T.J. Johnson, and S.W. Sharpe. 2004.On the Relative Strengths of Bacillus Spore Signatures in the Terahertz (THz)Versus the Mid-Infrared. In Proceedings of the SPIE, 5585, 122-127. Bellingham, Washington:International Society for Optical Engineering.PNNL-SA-42979.