Bull. Spec. CORESTA Congress, Brighton, 1998, p. 133, P19

Monitoring of whole microbial communities using fatty acid methyl ester (FAME) analysis

Clemson University, Dept. of Plant Pathology and Physiology, Pee Dee REC, Florence, SC, USA.
Fatty Acid Methyl Ester (FAME) analysis was evaluated as a tool to rapidly monitor the rhizosphere microbial community of three plant species (tobacco, corn and soybean) grown in soil with a resident population of Ralstonia solanacearum . Fatty acids were extracted from two sources: directly from rhizosphere soil and R2A minimal medium cultures from the rhizosphere soil. Cluster analysis of the fatty acid gas chromatograph (GC) retention time profiles resolved the fatty acids isolated from these two sources. Analysis of the direct soil extraction profiles revealed clustering as a function of plant species, supporting previous reports that plant-specific exudates influence the composition of the rhizosphere community. Distinct clustering according to plant species was not observed for the profiles from the R2A cultures. These results suggest that fatty acids extracted directly from soil may be influenced by bacteria that were not culturable on the R2A medium. FAME analysis can be used to rapidly monitor the soil microbial community via direct extraction and avoid the biases resulting from cultivation on artificial media.