diffusion of fermenter-produced organic acids was juxtaposed with abundant sulfate availability. In addition, dissolved-gas measurements revealed very low levels of MB activity, with consistent methane maxima within separate stratigraphic units.
These studies illustrate the persistence of microbial life in ecosystems that are severely limiting to microbial activity. In addition, they suggest that microbial activity may be detected through careful sampling of affected and effective geochemical parameters, without recourse to direct detection of microbes or microbial activity via experimentation.
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