Arsenic (As) is a pollutant of major concern worldwide, posing as a threat to both human health and the environment. Phytoremediation has been proposed as a viable mechanism to remediate As-contaminated soil environments. Pot experiments were performed to evaluate the phytoextraction efficiency of As by Pteris vittata, a known As hyperaccumulating fern, from soil amended with different concentrations of arsenate [As(V)] and arsenite [As(III)], the more common, inorganic As forms in soil. The greatest accumulation of As (13.3 ± 0.36 g/kg Dwt) was found in fronds of plants grown in soil spiked with 1.0 g As(V)/kg. The maximum As-bioaccumulation factor (27.3 ± 1.9) was achieved by plants grown in soil amended with 0.05 g As(V)/kg. A total of 864 bacterial cultures were isolated and examined for their ability to enhance phytoremediation of As-contaminated soils. Traits examined included tolerance to As (III and V), production of siderophores, and/or ability to solubilize calcium phosphate and indole acetic acid (IAA) production. A culture-based survey shows greater numbers of viable and As-resistant bacteria were found in the rhizosphere of As-grown plants compared to bulk and unplanted soils. The percentage of bacteria resistant to As(V) was greater (P < 0.0001) than those resistant to As(III) in culture medium containing 0.5, 1, 1.5, and 2 g As/L. Higher (P < 0.0001) percentages of siderophore producing (77%) and phosphate solubilizing (61%) bacteria were observed among cultures isolated from unplanted soil. About 5% (44 of 864) of the isolates were highly resistant to both As (III) and As (V) (2 g/L), and were examined for their As-transformation ability and IAA production. A great proportion of the isolates produced IAA (82%) and promoted As (V)-reduction (95%) or As(III)-oxidation (73%), and 71% exhibited dual capacity for both As(V) reduction and As(III) oxidation. Phylogenetic analysis indicated that 67, 23, and 10% of these isolates belonged to Proteobacteria, Actinobacteria, and Firmicutes, respectively. Analysis of the 16S rRNA gene sequences confirmed that these isolates were closely related to 12 genera and 25 species of bacteria and were dominated by members of the genus Pseudomonas (39%). These results show that these isolates could potentially be developed as inocula for enhancing plant uptake during large scale phytoremediation of As-impacted soils.

砷是全世界主要关注的污染物，对人类健康和环境均构成威胁。植物修复已被提议为修复被砷污染的土壤环境的可行机制。进行盆栽实验以评价黑胸蕨提取砷的效率，一种被称为超积累蕨类植物，是由土壤中不同浓度的砷酸盐[As（V）]和亚砷酸盐[As（III）]修饰而成的，是土壤中最常见的无机砷形式。在以1.0 g As（V）/ kg加标的土壤中生长的植物叶片中发现了最大的As积累量（13.3±0.36 g / kg Dwt）。通过在土壤中添加0.05 g As（V）/ kg修正的植物生长，可以实现最大的As生物累积因子（27.3±1.9）。总共分离了864种细菌培养物，并检查了它们增强被As污染土壤的植物修复的能力。研究的特征包括对砷（III和V）的耐受性，铁载体的产生和/或增溶磷酸钙和吲哚乙酸（IAA）产生的能力。基于文化的调查显示，与大量和未种植的土壤相比，在已生长植物的根际中发现了更多的存活细菌和抗As细菌。抵抗As（V）的细菌百分比更高（P  <0.0001），而在含有0.5、1、1.5和2 g As / L的培养基中对As（III）具有抗性的那些。 从未种植的土壤中分离出的培养物中观察到较高的（P <0.0001）比例的产生铁载体的细菌（77％）和可溶解磷酸盐的细菌（61％）。约5％（864的44）分离株对As（III）和As（V）（2 g / L）均具有高度抗性，并对其As转化能力和IAA产生进行了检查。很大一部分分离物产生IAA（82％）并促进As（V）还原（95％）或As（III）氧化（73％），而71％的分离物既具有As（V）还原能力，又具有AsA（V）还原能力。 As（III）氧化。系统发育分析表明，这些分离株中有67％，23％和10％分别属于变形杆菌，放线菌和厚壁菌门，分别。对16S rRNA基因序列的分析证实，这些分离株与12属和25种细菌密切相关，并以假单胞菌属成员（39％）为主导。这些结果表明，这些分离株有可能被开发成接种物，以在受As污染的土壤进行大规模植物修复期间增强植物的吸收。