IMPROVEMENTS IN THE EXTRACTION OF BACTERIAL ATP FROM SOIL WITH FIELD APPLICATION

An improved procedure for the preparation of an extractant and a demon stration of field applicability of that extractant for extracting micr obial ATP from soil samples are reported. Precipitation difficulties t hat occurred during application of the six-component extractant develo ped in this laboratory [Webster et al. (1984) Soil Biol. Biochem., 16, 335] have been eliminated by division of the extractant into two mixe s. Separate additions of phosphoric acid and/or EDTA at the time of ex traction prevented the unwanted precipitation. Although a precipitate formed in the completed extractant, it did not affect ATP extraction f rom soil samples. A substitute detergent for Lubrol (which is no longe r readily available) was selected; it is polyoxyethylene 10 lauryl eth er and it functioned as well as Lubrol in the extraction of ATP from s oil. Extraction procedures done using either a Brinkmann Polytron and wrist-action shaker (in the laboratory procedure) or a Waring blender (for the field procedure) extracted equivalent amounts of ATP from soi l. A detailed protocol is described that works well in the field. The procedure was made field-applicable by using a portable generator, des ktop high speed centrifuge, and a normal laboratory luminometer.