A microcalorimetric method for studying the toxic effect of different diphenol species on the growth ofEscherichia coli

Abstract

A microcalorimetric technique based on bacterial heat-output was explored to evaluate the toxic effect of different diphenol species on the growth of Escherichia coli (E. coli). Power-time curves of the growth metabolism for E. coli in the presence of different diphenol species were studied using a multi-channel microcalorimetric system with an ampoule method at 37 degrees C. The growth rate constant (k), generation time (t(G)), inhibitory ratio (I), half-inhibitory concentration (IC(50)) and the total thermal effect (Q(T)) for E. coli were obtained. The results show that catechol and hydroquinone are more toxic to E. coli than resorcinol. In all cases, the growth rate constants of E. coli (in log phase) decreased as the concentrations of these diphenols increased. Among these diphenols species, catechol was found to be the most poisonous species at an IC(50) of 323.5 micro g/mL against E. coli. Hydroquinone exhibited moderate virulence with an IC(50) of 1196 micro g/mL and resorcinol had the lowest toxicity with an IC(50) of 2113 micro g/mL. The microcalorimetric bioassay can be a quantitative, inexpensive, and versatile method for acute cellular toxicity study.

Study on the toxic effects of diphenol compounds on soil microbial activity by a combination of methods

“…sistent with the literature results [26][27][28][29]. However, in our previous study, we found that catechol among these diphenols was found to be the most toxic compound with an IC 50 of 323.5 g/mL against E. coli [19].…”

Isolation and characterization of aniline-degradingRhodococcussp. strain AN5

“…[23] Table 2 displayed the growth rate constant (k) of strain AN5 at various concentrations of aniline. From Table 2, it was noted that in the range of 0-2000 mg/L, concomitant with the increase of aniline, the growth rate constant decreased lentamente, which implied aniline of low concentration had only a slight depressive effect on the growth of strain AN5.…”

Study of the Influence of Different Diphenol Compounds on Soil Microbial Activity by Microcalorimetry

“…2,3,18 The values of the peak-time, t p , were obtained when the maximum activity was displayed. 12 The total thermal effect (Q total ), which relates to the degradation of the carbon source and reflects the amount of the carbon source used, was calculated by integrating each power-time curve from the beginning to the end.…”