Enthalpies and entropies of proton and cadmium adsorption onto Bacillus subtilis bacterial cells from calorimetric measurements

Enthalpies of proton adsorption onto Bacillus licheniformis at 25, 37, 50, and 75°C

“…Gorman-Lewis (2009) investigated enthalpies of protonation of Gram negative mesophile P. putida, and Gorman- Lewis et al (2006) investigated enthalpies of protonation of Gram positive mesophile B. subtilis in a similar manner to this study, that is combining surface complexation modeling with ITC measurements. These previous investigations derived site-specific parameters, consistent with phosphodiester, carboxyl, phosphoryl, and amine or hydroxyl groups responsible for proton uptake.…”

“…Nearly all chemical reactions either produce or absorb heat. In terms of bacterial surface reactivity, the extent of heat produced is proportional to the extent of adsorption occurring (Gorman-Lewis et al, 2006, 2009. Calorimetric measurements are the only viable means to measure enthalpies of reaction on bacterial surfaces.…”

“…Isothermal calorimeters are also designed to be used at a wide range of temperatures, thus providing a technique to investigate temperature effects on bacterial adsorption reactions. ITC has been previously applied to adsorption reactions with mesophilic bacteria but never at temperatures other than 25°C (Gorman-Lewis et al, 2006, 2009.…”

Modelling of the acid–base properties of two thermophilic bacteria at different growth times

“…Wightman et al (2001) showed that temperature has virtually no effect on titrations of B. subtilis in the range 30-75°C. Gorman-Lewis et al (2006) measured enthalpies of proton adsorption by B. subtilis using calorimetry, and predicted that there should be little change in the acidity constants for bacterial surface functional groups in the range from 25 to 75°C. Metal adsorption has also been observed to be relatively independent of temperature within the range 25-75°C (Marquis et al, 1973;Titus and Pfister, 1982;Hu et al, 1996;Leighton and Forster, 1997;GormanLewis et al, 2006).…”

Calorimetric measurements of proton adsorption onto Pseudomonas putida

“…This approach does not allow for derivation of site-specific enthalpies of adsorption from which one gains a greater understanding of the coordination environment. Gorman-Lewis et al [19] used isothermal titration calorimetry to determine bulk enthalpies of proton and Cd adsorption onto a Gram positive bacterium B. subtilis. By combining their bulk enthalpies with SCMs determined by Fein et al [10] and Borrok et al [20] for proton and Cd adsorption onto B. subtilis, respectively, they also determined the site-specific enthalpies and entropies of proton and Cd adsorption.…”