Gibbs energies of reaction and microbial mutualism in anaerobic deep subseafloor sediments of ODP Site 1226
Spivack, Arthur J.（Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA）
D'Hondt, Steven（Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA）
- 海洋环境－已发表论文 
In situ Gibbs energies of reaction (AG) for acetate-oxidizing sulfate reduction, acetate-oxidizing iron reduction, and acetoclastic methanogenesis, and sulfate-reducing methanotrophy are consistently negative and relatively constant throughout most of the sediment column at the eastern equatorial Pacific Ocean Drilling Program (ODP) Site 1226. The energy yields (-Delta G) closely match the values (for acetate-oxidizing sulfate reduction and acetoclastic methanogenesis) in published culturing experiments with actively growing cells and, for sulfate-reducing methanotrophy, in other environments. Although microbes mediating these reactions compete for substrates, mutualistic interactions between them appear to sustain their co-existence in deep subseafloor sediments for millions of years (the interval over which the sediments have been deposited). These competing and mutualistic interactions collectively constitute a highly coupled reaction network where relative rates of reaction are regulated by the in situ Gibbs energies of reaction. (C) 2010 Elsevier Ltd. All rights reserved.