Studies by Alexander Gurwitsch in the 1920' s with onion root cells revealed the phenomenon of
mitogenetic radiation
. Subsequent works by Popp, Van Wijk, Quickenden, Tillbury, and Trushin have demonstrated a link between Gurwitsch's mitogenetic radiation and the biophoton, emissions of light correlated with biological processes. The present study seeks to expand upon these and other works to explore whether biophoton emissions of bacterial cultures is used as an information carrier of environmental stress. Bacterial cultures (
Escherichia coli
and
Serratia marcescens
) were incubated for 24 hr in 5 ml of nutrient broth to stationary phase and cell densities of ~10
7
cells/mL. Cultures of
E. coli
were placed upon a photomultiplier tube housed within a dark box. A second bacterial culture, either
E. coli
or
S. marcescens
, was placed in an identical dark box at a distance of 5 m and received injections of hydrogen peroxide. Spectral analyses revealed significant differences in peak frequencies of 7.2, 10.1, and 24.9 Hz in the amplitude modulation of the emitted biophoton signal with respect to whether a peroxide injection occurred or not, and whether the species receiving the injection was
E. coli
or
S. marcescens
. These and the subsequent results of discriminant functions suggest that bacteria may release biophotons as a non‐local communication system in response to stress, and that these biophotons are species specific.