The synergistic use of plant and isolated bacteria to clean up polycyclic aromatic hydrocarbons from contaminated soil

Abstract

BackgroundBiological methods of polycyclic aromatic hydrocarbons (PAH) contamination elimination typically involve the transformation of contaminants to non-toxic materials by microorganisms and plants and appear to be the most effective methods available.MethodsIn this study, Bacillus licheniformis and Bacillus mojavensis isolated from oil-contaminated soils were inoculated onto Festuca arundinacea seeds before planting in the pot and 3 weeks after planting by syringe injection into the rhizospheric zone in order to study the elimination of PAHs from Festuca’s rhizosphere in the greenhouse. Some physical and chemical properties of the soil, PAH concentrations, seeds germination percentage, root and shoot biomasses of the treated samples were examined.ResultsThe results showed that the treated samples inoculated with both bacteria had a significantly higher percentage of seed germination and root and shoot biomass compared to other treatments. The concentration of some PAHs reduced significantly (Pvalue < 0.05) in the rhizosphere of the treated samples inoculated with both bacteria compared to in contaminated soils. Concentrations of some PAHs (eg. Naphthalene, Phenanthrene, Benzo[a]anthracene and Dibenzo[a,h]anthracene) even reached below the detection limit of the method. The PAHs concentrations in the treated samples inoculated with bacteria was decreased significantly (Pvalue < 0.05). Therefore, the results showed the high efficiency of the Festuca and bacterial inoculation in eliminating PAHs from the soil.ConclusionAccording to the results, the partnership of Festuca with B. licheniformis and B. mojavensis isolates displayed positive effect on PAHs dissipation and can be effective cleanup technology with high performance.

Polycyclic Aromatic Hydrocarbons: Sources, Toxicity, and Remediation Approaches

“…Rhizoremediation is one specific subset of phytoremediation, in which plant-associated rhizosphere microorganisms are used for treatment of polluted soils (Das and Das, 2015). Rhizoremediation is more intensive for PAH degradation and a key of successful rhizoremediation is dependent on the appropriate partnership of plant and microbes that have degradation capabilities (Agnello et al, 2016;Eskandary et al, 2017). Plants provide the huge root surface area for microbial growth and remediate pollutants approximately 10-15 m deep in the soil (Bisht et al, 2015).…”

Antibacterial activity of total flavonoids from Ilex rotunda Thunb. and different antibacterials on different multidrug-resistant bacteria alone or in combination

“…have been documented(Ramezani, Rahmani & Dehestani, 2017;Naz et al, 2017). Few plants extraction and effective bacteriostatic component exhibited synergistic or additive interaction with antibiotics against drug-resistant bacteria(Eskandary, Tahmourespour, Hoodaji & Abdollahi, 2017; Ye et al, 2017). Screening of crude extracts for synergistic or additive interaction with antibiotics is expected to provide bioactive compounds to be used in combinational therapy.…”

Towards understanding the Effect of Oil on Phytoremediation of PCB CoContamination in Transformer Oil Using Chromolaena Odorata

“…This is in agreement with the study of Pinsker [14][15][16], which reported that initial soil PCB has a great effect on the amount of PCB absorbed by plants, its translocation as well as the concentrations of the residual PCB in the soil at the end of a phytoremediation study. There was higher mean percentage reduction of PCB concentration in the entire experiment compared to the mean percentage PCB reductions of other plants species in phytoremediation studies reported in literature per unit time [15][16][17][18][19][20][21][22]. However PCB reduction was also observed at the unplanted control, the reason behind such observation could be attributed to natural attenuation and perhaps other parameters not measured.…”

“…Phytoremediation is cost effective and eco-friendly strategy that can complement or replace conventional approaches especially in the remediation of soil contaminated by PCBs. The principle mechanism of phytoremediation is either by stimulation of soil microbial activity and degradation of contaminants or through plant uptake of contaminants or by even their degradation products [11][12][18][19] Chlomolaena odorata (L) R.M. King & H. Robinson (Siam weed) is an invasive bushy shrub of South American origin.…”