Microbe-Assisted Rhizoremediation of Hydrocarbons and Growth Promotion of Chickpea Plants in Petroleum Hydrocarbons-Contaminated Soil

The present work aimed to develop and investigate microbial consortia for petroleum hydrocarbons (PHCs) detoxification and plant growth improvement in hydrocarbons-contaminated soil. Here, we isolated several bacteria from PHCs-contaminated soils to make bacterial consortia and two of the best consortia were tested in a pot experiment to evaluate their potential for PHCs removal and chickpea growth promotion in PHCs-contaminated soil. Results demonstrated that the PHCs exerted considerable phytotoxic effects on chickpea growth and physiology by causing a 13-29% and a 12-43% reduction in agronomic and physiological traits, respectively. However, in the presence of bacterial consortia, the phytotoxicity of PHCs to chickpea plants was minimized, resulting in a 7.0-24% and a 6.0-35% increase in agronomic and physiological traits, respectively over un-inoculated controls. Bacterial consortia also boosted nutrient uptake and the antioxidant mechanism of the chickpea. In addition, chickpea plants alone phytoremediated 52% of initial PHCs concentration. The addition of bacterial consortia in the presence of chickpea plants could remove 74-80% of the initial PHCs concentration in soil. Based on our research findings, we suggest that the use of multi-trait bacterial consortia could be a sustainable and environmentally friendly strategy for PHCs remediation and plant growth promotion in hydrocarbons in contaminated soil.

Automated summary

The study developed and tested microbial consortia for the detoxification of petroleum hydrocarbons (PHCs) and promotion of plant growth in hydrocarbons-contaminated soil. Bacteria were isolated from PHCs-contaminated soil to create bacterial consortia, and two of the best consortia were evaluated in a pot experiment. Results showed that PHCs had significant phytotoxic effects on chickpea growth, but the presence of bacterial consortia minimized this phytotoxicity and resulted in increased agronomic and physiological traits. The addition of bacterial consortia also enhanced nutrient uptake and antioxidant mechanisms in the chickpea plants.