Use and misuse of PLFA measurements in soils

The determination of the phospholipid fatty acid (PLFA) pattern of soil organisms has become one of the most commonly used methods to study microbial community structure. Here we recapitulate the background of our work applying the PLFA method to soil in the early 1990s. We also stress that although the PLFA method was, and still is, a rapid and sensitive method to detect changes in the microbial community in soil, as with all popular methods it can be misused. We discuss problems in PLFA interpretation, the extent of turn-over of PLFAs in soil, and the flawed use of diversity indices to evaluate PLFA patterns.

► We describe the development of PLFA analyses to study microbial community composition.
► Problems with associating individual PLFAs to specific microbial groups are discussed.
► There is uncertainty about the rate of PLFA turnover in soil.
► We also point to the erroneous use of PLFA data to calculate diversity indices.