Poster (f4.04P.8) presentado en SETAC SciCon SETAC Europe 30th Annual Meeting, Open Science for Enhanced Global Environmental Protection 3–7 May 2020 Dublin, Ireland
Polycyclic aromatic hydrocarbons (PAHs) are a recalcitrant group of contaminants, known to be highly persistent in the environment. Most of these compounds, such as pyrene (PYR), are persistent pollutants in the soil. Actually, motility and dispersal are key ecological drivers that allow bacteria to move toward places of bene¿cial environmental conditions and to maintain significant ecosystem functions. Few studies have been carried out on the use of plant growth regulators and their influence on the removal of PAHs from the soil. However, no studies have been conducted on the effect of 14C on crops with sunflowers and its effect on PYR removal efficiency in the soil. The present study aims to investigate the effects of the simultaneous application of 14C PYR by passive dosing (O-rings) and inoculation with Pseudomonas putida G7 on the enhancement of PYR removal in the presence of sunflowers. The experiment was carried out in a greenhouse at 23 ± 1 ºC. The treatments included planted soil with the simultaneous application of bacteria and pyrene (T1), planted soil with pyrene (T2) and unplanted soil with pyrene and bacteria (T3). Planted soil (C1) and planted soil with bacteria (C2) were included as positive controls. Furthermore, in order to identify the metabolites formed during the experiment a preliminary study under laboratory conditions was achieved. Samples of leachates, soil and plant were obtained at different times from cultivation until harvest for the investigation of uptake, transport, and accumulation of the microbially-processed PYR in sunflowers. The results showed that planted soil with simultaneous application of pyrene and bacteria treatments enhanced the efficiency of pyrene transformation. The roots presented the highest levels of uptake and greatest bioconcentration factors. GC¿MS analyses of the extracts from the preliminary studies revealed the presence of 3 metabolites due to pyrene cometabolism by P. putida G7. From the data acquired, we suggest that the combined phytoremediation and bioaugmentation can be a suitable alternative for reducing risks during remediation of PAH-contaminated soils.