TY - JOUR
T1 - Methanotrophic bacteria in the rhizosphere of trichloroethylene-degrading plants
AU - Brigmon, Robin L.
AU - Anderson, T. A.
AU - Fliermans, C. B.
N1 - Funding Information:
This article was prepared in connection with work done under a subcontract to Contract No. DE-AC09-76SR00001 with the U.S. Department of Energy (DOE). RLB was supported in part by an appointment to the U.S. DOE Laboratory Cooperative Postgraduate Research Training Program at the Savannah River Site administered by the Oak Ridge Institute for Science and Education (ORISE). TAA was supported in part by the U. S. DOE Faculty Research Travel Program administered by ORISE. We appreciate the helpful contributions to this study of T. C. Hazen, D. P. Shupack, R. White, and M. M. Franck.
PY - 1999
Y1 - 1999
N2 - The presence and density of methanotrophic bacteria has been shown to play an important role in the bioremediation of trichloroethylene (TCE). This article describes the methanotrophic bacterial densities in rhizosphere soils from two areas of the Department of Energy's Savannah River Site in Aiken, South Carolina. A direct fluorescent antibody (DFA) technique was evaluated to determine the presence of methanotrophic bacteria in roots and rhizospheres from vascular plants. The first site, the Miscellaneous Chemical Basin (MCB), was contaminated with a mixture of chemicals, including chlorinated solvents. The second site will be potentially affected by outcropping of TCE-contaminated groundwater. Significantly higher numbers of methanotrophic bacteria were observed with DFA in rhizosphere soils and on roots of Lespedeza cuneata and Pinus taeda (that previously showed higher rates of 14C-TCE mineralization) compared with nonvegetated soils. In addition, viable and heterotrophic microbial counts were consistently higher in rhizosphere soils and on plant roots compared with nonvegetated soils. Therefore, the presence of these plant species may enhance 14C-TCE mineralization by selectively increasing the microbial population in the root zone. Methanotrophic bacteria were directly observed by DFA in soils, on the surface of root hairs, within plant roots, and in higher densities associated with mycorrhizal fungi. These experiments provide further evidence that specific types of bacterial interactions with vegetation in the rhizosphere may play an important role in remediation of TCE-contaminated soils and groundwater.
AB - The presence and density of methanotrophic bacteria has been shown to play an important role in the bioremediation of trichloroethylene (TCE). This article describes the methanotrophic bacterial densities in rhizosphere soils from two areas of the Department of Energy's Savannah River Site in Aiken, South Carolina. A direct fluorescent antibody (DFA) technique was evaluated to determine the presence of methanotrophic bacteria in roots and rhizospheres from vascular plants. The first site, the Miscellaneous Chemical Basin (MCB), was contaminated with a mixture of chemicals, including chlorinated solvents. The second site will be potentially affected by outcropping of TCE-contaminated groundwater. Significantly higher numbers of methanotrophic bacteria were observed with DFA in rhizosphere soils and on roots of Lespedeza cuneata and Pinus taeda (that previously showed higher rates of 14C-TCE mineralization) compared with nonvegetated soils. In addition, viable and heterotrophic microbial counts were consistently higher in rhizosphere soils and on plant roots compared with nonvegetated soils. Therefore, the presence of these plant species may enhance 14C-TCE mineralization by selectively increasing the microbial population in the root zone. Methanotrophic bacteria were directly observed by DFA in soils, on the surface of root hairs, within plant roots, and in higher densities associated with mycorrhizal fungi. These experiments provide further evidence that specific types of bacterial interactions with vegetation in the rhizosphere may play an important role in remediation of TCE-contaminated soils and groundwater.
KW - Methanotrophic bacteria
KW - Rhizosphere soils
KW - Trichloroethylene
UR - http://www.scopus.com/inward/record.url?scp=0000609905&partnerID=8YFLogxK
U2 - 10.1080/15226519908500018
DO - 10.1080/15226519908500018
M3 - Article
AN - SCOPUS:0000609905
SN - 1522-6514
VL - 1
SP - 241
EP - 253
JO - International Journal of Phytoremediation
JF - International Journal of Phytoremediation
IS - 3
ER -