|Ibekwe, Abasiofiok - Mark
Submitted to: American Society of Agronomy
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/1998
Publication Date: N/A
Technical Abstract: Fatty acid methyl ester (FAME) profiles from soil can be used to describe soil microbial community structure without reliance on culturing soil microorganisms which may underestimate community structure. To verify soil microbial community structure with changes in fatty acid fingerprints a laboratory study was conducted. Palouse silt loam in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) was inoculated with different concentrations of Pseudomonas fluorescens strain D7 and Xanthomonas maltophilia and incubated for 24 h. Microbial ID, Inc. (MIDI) system was used to determine FAME profiles of the community. Similarities and differences of FAME profiles among soil microbial communities were identified using principal components (PCA) and cluster analyses. MIDI-FAME profiles of soil samples inoculated with Xanthomonas maltophilia of a given community were similar in terms of fatty acid yield, while samples inoculated with Pseudomonas fluorescens strain D7 were dissimiler. PCA of FAME profiles of soils inoculated with X. maltophilia resulted in a clear separation of the two communities with soil samples in wheat clustering on the first PCA axis, and samples in barley on the second. Soils inoculated with D7 or mixed population did not show this pattern. On the basis of our data, application of certain bacterial species to soil may be a good assay to determine dominant fatty acid profiles in the community. However, caution should be taken since knowledge of community fatty acid profiles in soils in terms of taxonomic composition is qualitative.