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United States Department of Agriculture

Agricultural Research Service

Research Project: NUTRIENT CYCLING AND UTILIZATION ON ORGANIC DAIRY FARMS

Location: New England Plant, Soil and Water Research Laboratory

Title: Enzymatic Quantification of Phytate in Poultry Manure

Authors
item He, Zhongqi
item Waldrip, Heidi
item Erich, M Susan - UNIVERSITY OF MAINE
item Honeycutt, Charles
item Senwo, Zachary - ALABAMA A&M UNIVERSITY

Submitted to: International Symposium on Soil and Plant Analysis
Publication Type: Abstract Only
Publication Acceptance Date: February 19, 2007
Publication Date: June 11, 2007
Citation: He, Z., Waldrip Dail, H.M., Erich, M., Honeycutt, C.W., Senwo, Z.N. 2007. Enzymatic Quantification of Phytate in Poultry Manure. International Symposium on Soil and Plant Analysis. Page 54

Technical Abstract: Phytate (inositol hexaphosphate) has been identified as a major organic P form in soil, animal manure and other environmental samples. Although a number of methods are available for quantitative isolation and determination of phytate, they are time-consuming and not amenable to routine analysis. We developed a simple, rapid method for enzymatic determination of phytate in poultry manure. Wet poultry manure was extracted by 1 M HCl, 0.1 M sodium acetate (NaAc, pH 5.0), H2O or, 0.5 M NaOH-0.05 M EDTA. Extracts were diluted (1/10-1/150) and adjusted to pH 5.0 in sodium acetate buffer. The diluted extracts were then incubated at 37oC for 1 h in the absence and presence of fungal 3-phytase (PHY) and potato acid phosphatase (PAP). Enzymatic hydrolyzable organic P was calculated as the difference in inorganic P (Pi) in the mixtures with and without enzymes. Our data indicated that enzymatic incubation of properly-diluted and pH-adjusted HCl or NaOH/EDTA extracts released phytate P. The complementary substrate specificity of the two enzymes is considered to enhance the effectiveness of enzymatic hydrolysis. Consequently, we recommend this method of combining PAP and PHY for quantifying phytate P. Additional research is being conducted to verify the general use of this method across a wider range of soils and manures.

Last Modified: 8/21/2014
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