Modification and application of a soil ATP determination method

• Published in: Soil biology & biochemistry Vol. 37; no. 11; pp. 1999 - 2006
• Main Authors: Wen, Guang, Voroney, R.P., Curtin, D., Schoenau, J.J., Qian, P.Y., Inanaga, S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2005; New York, NY Elsevier Science
• Subjects: adenosine triphosphate; agricultural soils; Agronomy. Soil science and plant productions; analytical methods; Autoclave; bioassays; Biochemistry and biology; Biological and medical sciences; calibration; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Internal standard calibration method; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil ATP; soil microorganisms; soil organic matter; soil pH; Soil science; soil texture; Standard curve method; Tricine buffer; Tris buffer; Tris buffer; Standard curve method; Internal standard calibration method; Autoclave; Tricine buffer; Soil ATP; Microbial activity; Soils; Methodology; Standard curve; Soil science; ATP
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2005.01.032

Accurate estimation of microbial adenosine 5′-triphosphate (ATP) is a pre-requisite to quantify the impact of varying environments on microbial activity of soil. We investigated the effectiveness of a high efficiency soil ATP determination method (PA) [Webster, J.J., Hampton, G.J., Leach, F.R., 1984. ATP in soil: a new extractant and extraction procedure. Soil Biology & Biochemistry 4, 335–342] in 10 Ontario (Canada) soils collected along a 100 m transect and spanning a textural class gradient ranging from a sandy loam to clay loam with increasing organic matter. Modifications of the method involved using an extract of autoclaved soil to make the standard curve, as it was found that the light emitted by ATP luciferin–luciferase bioluminescence reaction in the pure extractant was different from that in the extracts. Replacing Tricine with Tris buffer in the assay significantly improved the light emission. On an average, the internal standard calibration method (ISM) measured a smaller amount of extracted ATP (1199 ng ATP g −1 soil) and a lower recovery of ATP spike (82.4±7.2%) than did the standard curve method (SCM) (1246 ng ATP g −1 soil and 91.2±4.5%, respectively) ( P<0.05 for both comparisons). However, the average total estimated ATP was higher with ISM (1474±102 ng ATP g −1 soil) than with SCM (1373±88 ng ATP g −1 soil) ( P<0.07). While the recovery rates determined using SCM were consistent among the soils tested, the rates measured using ISM was negatively correlated with soil clay and organic matter content, implying that the latter assay was affected by the soil properties. Our results confirmed that the recovery rates obtained by the PA method were the highest among those reported, when only SCM was used.