Seven As-resistant bacteria (ARB) have been isolated from the rhizosphere of As-hyperaccumulator Pteris vittata from the field in North Central Florida ( Ghosh et al., 2011). P. vittata prefers to grow in alkaline soils, which are characterized by low P and Fe availability and/or high concentrations of As ( Lessl and Ma, 2013). Phosphorus and As compete for uptake into bacterial cells, so bacteria have developed an effective system to increase P solubility from soils. Bacterial siderophores effectively release As from insoluble minerals like FeAsO4 and AlAsO4 (Ghosh et al., 2011). In addition to inorganic P, a major source of organic P in plant rhizosphere is phytate so the studied bacteria may also produce phytase to extract P from phytate.