Assisted phytoremediation of oil contaminated soil by plant growth promoting or hydrocarbon degrading bacteria

Assisted phytoremediation of oil contaminated soil by plant growth promoting or hydrocarbon degrading bacteria

The effective remediation of oil-contaminated soils is one of the arduous tasks, which attracts increasing attention since certain highly toxic and recalcitrant compounds are involved. The effectiveness of plants as a remediant can be enhanced by supplementation with specific plant-associated microbes. To achieve this, an evaluation was conducted using by oildegrading (OD) bacteria and plant-growth-promoting (PGP) bacteria in conjunction with Festuca arundinacea as greenhouse experiment. The effect of the various treatments on oilcontaminated soil measured by assessing the extent of total petroleum hydrocarbon (TPH) degradation, the soil s dehydrogenase activity and the level of phytotoxicity as measured by a bioassay. Combining the planting of F. arundinacea with bacteria boosted the degradation of TPH; the ranking for effectiveness with respect to TPH removal was F. arundinacea + OD F. arundinacea + PGP F. arundinacea no treatment control. The induced increase in dehydrogenase activity achieved in the bioaugmentation/F. arundinacea treatment resulted in substantial reduction in soil phytotoxicity. The indication was that bioaugmentation of F. arundinacea by oil-degrading and/or plant-growth-promoting bacteria can help to improve the effectiveness of phytoremediation in a crude oil contaminated soil.