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 frequ ently reported yet our current understanding of plant-microbe interactions does not allow us to predict which plant species can encourage the developm ent of rhizosphere communities with enhanced degradation capacity. In a com panion study, five grass species (Sudan grass, ryegrass, tall fescue, crest ed wheatgrass, and switch grass) were grown in a Matapeake silt loam soil t o study the degradation of atrazine and phenanthrene by rhizosphere microor ganisms (see Fang et al., 2000, this vol., Fang, C., Radosevich, M., Fuhrma nn, J. J., 2000. Atrizine and phenanthrene degradation in grass rhizosphere soil. Soil Biology & Biochemistry, in press). In the present paper substra te utilization patterns (BIOLOGQ (R)), and fatty acid methyl ester (FAME) p rofiles of the same rhizosphere microbial communities were determined. Both FAME and BIOLOG (R) analyses detected changes in soil microbial community structure among treatments. However, community structure did not directly c orrelate to either ATR or PHE degradation rates. (C) 2001 Elsevier Science Ltd. All rights reserved.