Metagenomic Approaches for Optimising Hydrocarbon Pollution Rhizoremediation

Abstract Increasing levels of pervasive harmful chemicals like polycyclic aromatic hydrocarbons (PAHs) have been linked to unprecedentedly high cases of several illnesses, loss of biodiversity, and environmental degradation, posing a threat to the sustainability of life. Several biodegradation procedures have been proposed for cleaning up contaminated sites, among which rhizoremediation, a type of phytoremediation, is perceived to be one of the most cost-efficient methods and has good public acceptance. To enhance the effectiveness of rhizoremediation, the use of transgenic plants has been deployed; however, many studies have demonstrated that rhizosphere microbial communities are actively involved in the degradation of hydrocarbons. The plant thus facilitates formidable microbial support and cross-communication through root exudates, a type of rhizodeposition. Unlike conventional microbiology procedures, high throughput metagenomic approaches unveil both individual and microbial community functional capacities, novel species, gene and molecular composition, allowing the alteration of the microbial community in the rhizosphere for plant growth promotion, resistance to PAHs, and the metabolism of contaminant compounds. This article presents an updated overview of the use of metagenomic approaches in modifying the rhizosphere soil microbial community for effective and enhanced rhizoremediation of hydrocarbon-polluted soil. Graphical abstract