Quasichemical description of the cell death kinetics of cellular biosensor Spirostomum ambigua for testing the biological activity of aqueous solutions

A kinetic method of biotesting of aqueous solutions using isolated cells of unicellular organism Spirostomum ambigua has been described. A kinetic scheme of interaction of cellular biosensor with ligands based on the Michaelis-Menten mechanism was proposed. It was shown that the death rate of S. ambigua featured the Arrhenius-type dependence on temperature. The activation energy was determined for different toxicants and drugs. For many compounds the activation energy of slow stage of the process of cellular biosensor death linearly correlates with parameter DL50 for the same substances at their oral administration to laboratory animals.