Inhibition of selected bacterial growth by three hydrocarbons: Mathematical evaluation of toxicity using a toxicodynamic equation

The individual toxicity of different hydrocarbons (naphthalene, cyclododecane and aniline) on the growth of selected bacteria (Pseudomonas sp., Phaeobacter sp. and Leuconostoc mesenteroides) was studied by means of a toxicodynamic model combination of two sigmoid equations (logistic and Weibull). All the toxicological effects on growth parameters and kinetic properties were characterized and the global toxicity of such chemicals was evaluated. It was observed that two kinetic parameters (maximum growth and maximum growth rate) were in almost all cases influenced by the hydrocarbons studied. Aniline was less toxic than cyclododecane and naphthalene. The presented approach is a reasonable starting point for understanding and modeling complete and real assessment of chemical toxic effects on bacterial growths. The values of EC50,τ could be used for a most efficient comparison of the individual toxicity of chemicals.