Anomalous energy yields in thermodynamic calculations: importance of accounting for pH-dependent organic acid speciation

Jan Dolfing, Aiping Xu, Ian Head

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Methanogenic ecosystems function close to oxidation– reduction equilibrium with change in Gibbs free energy (ΔG) values in the range of −10 to −20 kJ mol−1 (Hoehler et al., 1998; Jackson and McInerney, 2002). With such small margins, attention to detail when making free energy calculations becomes exceedingly important. A pervasive source of confusion, if not error, when making free energy calculations is the fact that organic acids and their anions occur simultaneously (Mazur et al., 2003; Mun et al., 2008). Here, we point out that such confusion is not necessary, as weak acids and their conjugated bases are in thermodynamic equilibrium in anaerobic ecosystems.
Original languageEnglish
Pages (from-to)463-464
Number of pages2
JournalThe ISME Journal
Volume4
Issue number4
DOIs
Publication statusPublished - 18 Feb 2010
Externally publishedYes

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Thermodynamics
organic acid
thermodynamics
organic acids and salts
Ecosystem
Gibbs free energy
Acids
ecosystems
energy
ecosystem function
anions
Oxidation-Reduction
Anions
anion
oxidation
ecosystem
acids
acid
calculation
oxidation-reduction

Cite this

Anomalous energy yields in thermodynamic calculations: importance of accounting for pH-dependent organic acid speciation. / Dolfing, Jan; Xu, Aiping; Head, Ian.

In: The ISME Journal , Vol. 4, No. 4, 18.02.2010, p. 463-464.

Research output: Contribution to journalArticle

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