Phosphorus is an important macronutrient, but its availability in soil is limited. Many soil microorganisms improve the bioavailability of phosphate by releasing it from various organic compounds, including phytate. To investigate the diversity of phytate-hydrolyzing bacteria in soil, we sampled soils of various ecological habitats, including forest, private homesteads, large agricultural complexes, and urban landscapes. Bacterial isolate Pantoea sp. strain 3.5.1 with the highest level of phytase activity was isolated from forest soil and investigated further. The Pantoea sp. 3.5.1 agpP gene encoding a novel glucose-1-phosphatase with high phytase activity was identified, and the corresponding protein was purified to apparent homogeneity, sequenced by mass spectroscopy, and biochemically characterized. The AgpP enzyme exhibits maximum activity and stability at pH 4.5 and at 37°C. The enzyme belongs to a group of histidine acid phosphatases and has the lowest K m values toward phytate, glucose-6-phosphate, and glucose-1-phosphate. Unexpectedly, stimulation of enzymatic activity by several divalent metal ions was observed for the AgpP enzyme. High-performance liquid chromatography (HPLC) and high-performance ion chromatography (HPIC) analyses of phytate hydrolysis products identify DL-myo-inositol 1,2,4,5,6-pentakisphosphate as the final product of the reaction, indicating that the Pantoea sp. AgpP glucose-1-phosphatase can be classified as a 3-phytase. The identification of the Pantoea sp. AgpP phytase and its unusual regulation by metal ions highlight the remarkable diversity of phosphorus metabolism regulation in soil bacteria. Furthermore, our data indicate that natural forest soils harbor rich reservoirs of novel phytate-hydrolyzing enzymes with unique biochemical features. P hosphorus is one of the most important macroelements of living cells. It is a crucial component of nucleic acids, highenergy compounds, phospholipids, and other molecules and is essential for normal plant growth. Many soil types are naturally low in inorganic phosphorus, and, as the pressure on agriculture to provide food for the growing human population intensifies, so does the need for a massive use of phosphate fertilizers. However, rock phosphate is a nonrenewable natural resource (1). Furthermore, the vast majority of applied phosphate fertilizer quickly interacts with soil components, leading to its rapid transformation into various organic or precipitated compounds inaccessible to plants. Thus, much attention has recently been paid to alternative sources of phosphorus in soil.Organic phosphorus compounds in soil account for 30 to 50% of total soil phosphorus and are often considered natural alternatives to the use of mineral phosphate fertilizer (2). Phytate is a molecule of myo-inositol with six phosphate residues (3). Phytate concentration varies from 3.9% to 25.3% of total extractable P in carbonate-free cambisol soils and calcareous chernozems, respectively (4), suggesting that in some cases phytate can be one of the major for...