The effect of temperature on bacterial degradation of EDTA in pH-auxostat

Abstract

The effect of temperature on the maximum specific growth rate and the cell yield was studied during cultivation of two bacterial strains (LPM-4 and Pseudomonas sp. LPM-410) on EDTA under unlimited cell growth conditions in a pH-auxostat. Both strains displayed linear dependence of reciprocal biomass yield against reciprocal specific growth rate, from which the values of rate of substrate expenditure for cell maintenance and the ''maximum'' yield (i.e., hypothetical yield without cell maintenance processes) were estimated. Analysis of the maximum yield values based on mass-energy balance theory suggested that oxidation of the carboxylic acid side chains of EDTA by a monooxygenase had zero or low energetic efficiency. An Arrhenius equation with different values of Arrhenius parameters within different temperature ranges gave a good fit with the temperature dependence of both growth rate and biomass yield. Specific growth rates of both strains showed a more pronounced temperature dependence than did the cell yields. A possible kinetic mechanism was suggested which might be responsible for the modes of the temperature dependences of specific growth rate and yield that were found. The mechanism is based on a hypothetical key substance governing the metabolic flows, which is formed in a zero-order reaction and destroyed in a first-order reaction, both rate constants depending on temperature according to the Arrhenius law.

Kinetics of toluene and sulfur compounds removal by means of an integrated process involving the coupling of absorption and biodegradation

“…2(a)). It corresponded to the assimilation of EDTA as a carbon and an energy source, in agreement with several reports dealing with EDTA biodegradation 36–38. However, possible EDTA biodegradation should be subsequently confirmed.…”

Temperature effect on bacterial azo bond reduction kinetics: an Arrhenius plot analysis

“…Break points on the Arrhenius plot have been reported for the effect of temperature on microbial specific growth rate on different substrates (Ingraham 1958;Kuhn et al 1980;Mutafov and Minkevich 1986;Minkevich et al 2006), biomass yield (Chistyakova et al 1983;Mutafov and Minkevich 1986), Monod's saturation constant (Mutafov and Minkevich 1986), thermal inactivation of microbial cells (Kuhn et al 1980;Verrips and Kwast 1977), the nitrification rate of Nitrosomonas cells (Benyahia and Polomarkaki 2005).…”

Activation Energy, Temperature Coefficient and Q10 Value Estimations of the Growth of 2,4-dinitrophenol-degrading Bacterium on 2,4-dinitrophenol

“…Heat shocks also have the potential to cause the accumulation of ribosomes that have become inactive [26,27,[57][58][59][60][61][62]. Molecular thermosensors could be built using molecular switches as the building blocks.…”

“…To calculate the apparent activation energy, H*, which is believed to be present for either growth or decay on different metabolic substates, it is usual practice to apply the temperature function Arrhenius model. The temperature function Arrhenius model is gaining in popularity as a tool for analyzing the growth and decay rates of bacteria, and this trend is expected to continue in the foreseeable future [25][26][27][28][29][30][31][32][33].…”