Misidentification of soil bacteria by fatty acid methyl ester (FAME) and BIOLOG analyses

Fatty acid methyl ester (FAME) analysis is commonly used by soil scientists as a sole method for identifying soil bacteria. We observed discrepancies with this method for identifying certain species of bacteria. Therefore, we used carbon substrate oxidation patterns (BIOLOG) and some simple physical and chemical tests to determine the extent of these discrepancies. Identif ication with FAME profiles gave false positives,for Arthrobacter globiformi s, Micrococcus kristinae, and M. luteus, and identification with BIOLOG pat terns gave a false positive identification for A. globiformis. A visual che ck and Gram stain are recommended when FAME analysis identifies soil isolat es as hi. kristinae or M. luteus, and an additional spore formation test is recommended when FAME and BIOLOG analyses identify isolates as A. globifor mis.