Interpretation of the Metabolic Enthalpy Change, ΔHmet, Calculated for Microbial Growth Reactions in Soils
Authors: Barros, N.; Feijóo, S.1; Simoni, A.; Critter, S.; Airoldi, C.2
Source: Journal of Thermal Analysis and Calorimetry, Volume 63, Number 2, February 2001 , pp. 577-588(12)
Publisher: Springer
Abstract:
The microcalorimetric method was used to calculate the metabolic enthalpy change per mol of glucose degraded by soil microorganisms, ΔHmet. This parameter has been calculated by microcalorimetry for many organic, inorganic and biochemical reactions, but there is only some information about its quantification for microbial growth reactions in soils. Values of ΔHmet were calculated for different soil samples collected in Galicia (Spain) and Campinas (Săo Paolo, Brazil). Exponential microbial growth was stimulated in all soil samples by the addition of glucose and power—time curves were recorded. Results showed changes in the values of ΔHmet calculated for all the soil samples, suggesting a dependence of this value with the microbial growth rate constant, with the percentage of growth, with the initial number of microorganisms of soil samples, with the quantity of glucose added and with the strain of bacteria growing in soil.The interpretation of variations of ΔHmet provides important qualitative and quantitative information. It reports data that allow to interpret from a qualitative point of view, the increase in biomass as a consequence of the degradation of the organic matter in soil, to understand changes in the percentages of soil organic matter and to know if the microbial population growing in differential soil samples is homogeneous. Therefore, to report that value would be very important in ecological studies, but beforehand, it is necessary to solve some problems that can appear in the experiments done to make the quantification.Keywords: metabolic enthalpy change; microbial soil activity; microcalorimetry
Document Type: Research article
DOI: http://dx.doi.org/10.1023/A:1010162425574
Affiliations: 1: Email: fanieves@lugo.usc.es 2: Email: airoldi@iqm.unicamp.br
Publication date: 2001-02-01
- In this: publication
- By this: publisher
- In this Subject: Physical & Theoretical Chemistry , Heat
- By this author: Barros, N. ; Feijóo, S. ; Simoni, A. ; Critter, S. ; Airoldi, C.

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