Influence of an arsenate-reducing and polycyclic aromatic hydrocarbons-degrading Pseudomonas isolate on growth and arsenic accumulation in Pteris vittata L. and removal of phenanthrene

• PAHAs-1 is an arsenate-reducing and PAH-degrading Pseudomonas isolate.
• Inoculation with PAHAs-1 increased biomass of Pteris vittata L.
• Inoculation with PAHAs-1 enhanced arsenic uptake and translocation in P. vittata.
• Removal of phenanthrene from the solution was mostly via degradation by PAHAs-1.
• PAHAs-1 helps in remediation of PAHs and arsenic co-contamination.

Polycyclic aromatic hydrocarbons (PAHs) and arsenic often co-occur at polluted sites, but remediation strategies for this are scarce. In this study, the effect of bacterial inoculation on plant growth and arsenic uptake by Pteris vittata and phenanthrene dissipation was investigated hydroponically using an arsenate-reducing and PAH-degrading Pseudomonas isolate. In a 12-d experiment, despite reduced dry weight in some cases, the isolate generally promoted the growth of P. vittata. The aboveground and belowground biomass increased by 21.0–38.7% and 3.5–66.3%, respectively. In addition, bacterial inoculation greatly enhanced arsenic uptake by P. vittata compared to un-inoculated treatments (from 246.7–438.9 and 102.6–231.4 to 754.1–1425.7 and 121.5–351.4 mg kg−1 As in aboveground and belowground biomass, respectively). Accordingly, arsenic transfer factor increased by 116–315%. The enhancement was attributed to the bacteria-mediated As(V) reduction in growth media. A dissipation of phenanthrene from growth media was observed and attributed to the degradation of the chemical by the isolate, as the contribution of P. vittata in phenanthrene removal was negligible. The present results demonstrated the versatile arsenate-reducing and PAH-degrading bacteria can effectively enhance arsenic uptake and translocation by P. vittata and remove phenanthrene.