Efficient Biodegradation of Polycyclic Aromatic Hydrocarbons in the Rhizosphere Using Plant Growth Regulators and Biological Agents

Soil contamination with Polycyclic Aromatic Hydrocarbons (PAHs) is becoming a more prevalent problem worldwide. The presented study aimed to establish a new method of an effective and cost-efficient degradation of pyrene (Py) and phenanthrene (Phe) through the combination of planting Festuca grass along with gibberellic acid (GA) supplementation, and the application of arbuscular mycorrhiza fungi (AMF). The study consisted of four experimental groups: T1: soil spiked with 200, 300, and 400 mg kg−1 Phe and Py without any vegetation, T2: cultivation of Festuca grass without any additional treatment, T3: Festuca grass with the gibberellic acid supplementation, T4: Festuca grass with the application of AMF. The results demonstrated that both: GA and AMF increased the number of rhizosphere bacteria. The activity of dehydrogenase (DHA) and peroxidase (POD) enzymes was increased in a clear concentration-dependent manner, which improved PAHs removal. The findings suggest that the use of GA and AMF with plant cultivation can be a promising strategy for the removal of PAHs from soils.