, Volume 28, Issue 3, pp 335-349

Comparison between geochemical and biological estimates of subsurface microbial activities

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Geochemical and biological estimates of in situ microbial activities were compared from the aerobic and microaerophilic sediments of the Atlantic Coastal Plain. Radioisotope time-course experiments suggested oxidation rates greater than millimolar quantities per year for acetate and glucose. Geochemical analyses assessing oxygen consumption, soluble organic carbon utilization, sulfate reduction, and carbon dioxide production suggested organic oxidation rates of nano- to micromolar quantities per year. Radiotracer timecourse experiments appeared to overestimate rates of organic carbon oxidation, sulfate reduction, and biomass production by a factor of 103–106 greater than estimates calculated from groundwater analyses. Based on the geochemical evidence, in situ microbial metabolism was estimated to be in the nano- to micromolar range per year, and the average doubling time for the microbial community was estimated to be centuries.

The submitted manuscript has been authored by a contractor of the U.S. government under contract No. DE-AC05-840R21400. Accordingly, the U.S. &. Government reserves a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U. S. Government purposes.