Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

Holmes, DE; Giloteaux, L; Williams, KH; Wrighton, KC; Wilkins, MJ; Thompson, CA; Roper, TJ; Long, PE; Lovley, DR

HERO ID

2036711

Reference Type

Journal Article

Year

2013

Language

English

PMID

23446832

HERO ID 2036711
In Press No
Year 2013
Title Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater
Authors Holmes, DE; Giloteaux, L; Williams, KH; Wrighton, KC; Wilkins, MJ; Thompson, CA; Roper, TJ; Long, PE; Lovley, DR
Journal ISME Journal
Volume 7
Issue 7
Page Numbers 1286-1298
Abstract The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, USA, acetate amendments initially promoted the growth of metal-reducing Geobacter species, followed by the growth of sulfate reducers, as observed previously. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater before the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the ameboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.
Doi 10.1038/ismej.2013.20
Pmid 23446832
Wosid WOS:000320852100005
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword Geobacter, Breviata; Peptococcaceae; Hexamitidae; uranium bioremediation; protozoan predation