The influence of xenobiotics on the bioluminescent enzyme system is considered in terms of molecular action on the primary physicochemical processes-energy, electron and hydrogen (e(-) + H+) transduction. Dyes, non-fluorescent chemically inert organic compounds, redox-active organic compounds and metallic salts were investigated. The influence of the different xenobiotics depends in a complex way on physicochemical characteristics of the xenobiotic molecules (spectral-luminescent characteristics, electron-acceptation energy and redox potential). Copyright (C) 1999 John Wiley & Sons, Ltd.