Subsurface sediments were recovered from a 52 m deep borehole cored in the 300 Area of the Hanford Site in southeastern Washington State to assess the potential for biogeochemical transformation of radionuclide contaminants. Microbial analyses were made on 17 sediment samples traversing multiple geological units: the oxic coarse-grained Hanford formation (9-17.4 m), the oxic fine-grained upper Ringold Formation (17.7-18.1 m), and the reduced Ringold Formation (18.3-52m). Microbial biomass (measured as phospholipid) ranged from 7-974 pmols per g in discrete samples, with the highest numbers found in the Hanford formation. On average, strata below 17.4 m had 13-fold less biomass than those from shallower strata. The nosZ gene encoding nitrous oxide reductase had an abundance of 5-17% relative to total 16S rRNA genes below 18.3 m and
Revised: March 8, 2012 |
Published: February 1, 2012
Citation
Lin X., D.W. Kennedy, A.D. Peacock, J.P. McKinley, C.T. Resch, J.K. Fredrickson, and A. Konopka. 2012.Distribution of microbial biomass and the potential for anaerobic respiration in Hanford Site 300 Area subsurface sediment.Applied and Environmental Microbiology 78, no. 3:759-767.PNNL-SA-78604.