Identification of single cultured micro-organisms based on their whole-community fatty acid profiles, using an extended extraction procedure.

Fatty acid profiles obtained from single cultured organisms have been used to estimate which taxonomic groups are actually represented. The lipid extraction was modified to liberate fatty acids with ester-linkages, as well as those with non-ester-linkages and classify them in different chemically relevant groups. The discriminatory power of fatty acids, in different chemically relevant fractions and subfractions varied considerably. Saturated fatty acids were least able to predict actual group membership (ca. 75%), while nonester-linked hydroxy fatty acids, which largely go undetected by the simple extraction procedure, gave the highest predictability values (ca. 94%). The discriminatory power of the method used was enhanced by increasing the number of well-defined fatty acid methyl esters. The estimation capacity of the results was improved, when the fatty acids, which were presumed to be common and widespread, were excluded from the whole-community fatty acid profiles prior to multivariate analysis.