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Updated: Jul 13, 2026

Metabolic Profiling to Determine Bactericidal or Bacteriostatic Effects of New Natural Products using Isothermal Microcalorimetry
Published on: October 29, 2020
Temperature effect on bacterial azo bond reduction kinetics: an Arrhenius plot analysis
Blaga Angelova1, Tatyana Avramova, Lilyana Stefanova
1Bulgarian Academy of Sciences, The Stephan Angeloff Institute of Microbiology, Acad. G. Bonchev St., Block 26, 1113 Sofia, Bulgaria.
Abstract:
Studied was the effect of temperature in the range 12-46 degrees C on the rate of bacterial decolorization of the mono-azo dye Acid Orange 7 by Alcaligenes faecalis 6132 and Rhodococcus erythropolis 24. With both strains the raise of temperature led to a corresponding raise of decolorization rate better manifested by R. erythropolis. The analysis of the Arrhenius plot revealed a break near the middle of the temperature range. The regression analysis showed practically complete identity of the observed break point temperatures (T (BP)): 20.7 degrees C for Alc. faecalis and 20.8 degrees C for R. erythropolis. The values of the activation energy of the decolorization reaction (E (a)) were found to depend on both the organism and the temperature range. In the range below T (BP) the estimated values of E (a) were 138 +/- 7 kJ mol(-1) for Alc. faecalis and 160 +/- 8 kJ mol(-1) for R. erythropolis. In the range above T (BP) they were 54.2 +/- 1.8 kJ mol(-1) for Alc. faecalis and 37.6 +/- 4.1 kJ mol(-1) for R. erythropolis. Discussed are the possible reasons for the observed abrupt change of the activation energy.
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