  The goal of this paper is to explore the possibility to detect and identify
bacteria by sensing their odor via fluctuation-enhanced sensing with commercial
Taguchi sensors. The fluctuations of the electrical resistance during exposure
to different bacterial odors, Escherichia coli and anthrax-surrogate Bacillus
subtilis, have been measured and analyzed. In the present study, the simplest
method, the measurement and analysis of power density spectra was used. The
sensors were run in the normal heated and the sampling-and-hold working modes,
respectively. The results indicate that Taguchi sensors used in these
fluctuation-enhanced modes are effective tools of bacterium detection and
identification even when they are utilizing only the power density spectrum of
the stochastic sensor signal.
