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DOI http://dx.doi.org/10.1016/S0016-7037(99)00248-3
Title The effect of microbial glucose metabolism on bytownite feldspar dissolution rates between 5 and 35 C
Creator/Author Welch, S.A. ; Ullman, W.J.
Publication Date1999 Oct 01
OSTI IdentifierOSTI ID: 20003976
Other Number(s)Journal ID: ISSN 0016-7037; GCACAK; TRN: IM200004%%198
Resource TypeJournal Article
Resource RelationJournal Name: Geochimica et Cosmochimica Acta; Journal Volume: 63; Journal Issue: 19-20; Other Information: PBD: Oct 1999
Research OrgUniv. of Delaware, Lewes, DE (US)
Sponsoring OrgUS Department of Energy
Subject54 ENVIRONMENTAL SCIENCES; 58 GEOSCIENCES; FELDSPARS; DISSOLUTION; BACTERIA; GLUCOSE; TEMPERATURE DEPENDENCE; GLUCONIC ACID; SILICON
Description/AbstractThe rate of Si release from dissolving bytownite feldspar in abiotic batch reactors increased as temperatures increased from 5 to 35 C. Metabolically inert subsurface bacteria (bacteria in solution with no organic substrate) had no apparent effect on dissolution rates over this temperature range. When glucose was added to the microbial cultures, the bacteria responded by producing gluconic acid, which catalyzed the dissolution reaction by both proton- and ligand-promoted mechanisms. The metabolic production, excretion, and consumption of gluconic acid in the course of glucose oxidation, and therefore, the degree of microbial enhancement of mineral dissolution, depend on temperature. There was little accumulation of gluconic acid and therefore, no significant enhancement of mineral dissolution rates at 35 C compared to the abiotic controls. At 20 C, gluconate accumulated in the experimental solutions only at the beginning of the experiment and led to a twofold increase in dissolved Si release compared to the controls, primarily by the ligand-promoted dissolution mechanism. There was significant accumulation of gluconic acid in the 5 C experiment, which is reflected in a significant reduction in pH, leading to 20-fold increase in Si release, primarily attributable to the proton-promoted dissolution mechanism. These results indicate that bacteria and microbial metabolism can affect mineral dissolution rates in organic-rich, nutrient-poor environments; the impact of microbial metabolism on aluminum silicate dissolution rates may be greater at lower rather than at higher temperatures due to the metabolic accumulation of dissolution-enhancing protons and ligands in solution.
Country of PublicationUnited States
LanguageEnglish
FormatMedium: X; Size: page(s) 3247-3259
System Entry Date2008 Feb 08

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