Characterization of rhizosphere microbial community structure in five similar grass species using FAME and BIOLOG analyses

Accelerated biodegradation of organic contaminants in planted soil is frequently reported yet our current understanding of plant–microbe interactions does not allow us to predict which plant species can encourage the development of rhizosphere communities with enhanced degradation capacity. In a companion study, five grass species (Sudan grass, ryegrass, tall fescue, crested wheatgrass, and switch grass) were grown in a Matapeake silt loam soil to study the degradation of atrazine and phenanthrene by rhizosphere microorganisms (see Fang et al., 2000, this vol., Fang, C., Radosevich, M., Fuhrmann, J. J., 2000. Atrizine and phenanthrene degradation in grass rhizosphere soil. Soil Biology & Biochemistry, in press). In the present paper substrate utilization patterns (BIOLOG®), and fatty acid methyl ester (FAME) profiles of the same rhizosphere microbial communities were determined. Both FAME and BIOLOG® analyses detected changes in soil microbial community structure among treatments. However, community structure did not directly correlate to either ATR or PHE degradation rates.