Phosphatase Activity in Animal Manure-amended Soils and Molecular Profiling of Microbial Community in Tnt-spiked Soils

Abstract

This study was conducted to examine microbial communities in soil agro-ecosystems amended with organic and inorganic fertilizers and in soils contaminated with nitroaromatic 2,4,6-trinitrotoluene (TNT). Effects of fertilizer treatment on soil phosphorus concentrations and phosphatases were determined. Another soil treated with TNT at 250-5000 mg kg-1 soil, an untreated control was used. Bacterial community changes induced by treatments were tested using fingerprints of bacterial 16S rRNA genes. Beef manure application increased soil total and Mehlich-3 extractable phosphorus. Acid and alkaline phosphatase activities were significantly high at 0-10 cm soil and decreased with increasing soil depth. Phosphodiesterase and inorganic pyrophosphatase activities increased with increasing soil depths from 0-30 cm. Distinct trends among four phosphatases implied their activity in different agro-ecosystems. Soils contaminated with TNT showed presence of TNT tolerant bacteria and their potential involvement in TNT degradation needs further attention.