Key points are not available for this paper at this time.
Contamination of soils with hydrocarbons such as diesel is a major concern as the use, processing, storage, and transport of diesel fuel increase. Obtaining a better understanding of how soil microorganisms adapt to diesel fuel contamination during rhizoremediation of a natural soil will help improve remediation processes. In microcosm studies with a pristine soil contaminated with 2 % diesel, the presence of clover increased the dissipation of diesel aromatic compounds after 7 weeks. The bacterial diversity was lowered by diesel contamination, although this decline was mitigated by the presence of clover together with ryegrass. The bacterial community structure was affected more by soil type and diesel contamination than by the presence of plants. Actinobacteriota and Gemmatimonadota declined, while Firmicutes, Bacteroidota and Proteobacteria increased with diesel contamination and in the rhizosphere. Amplified sequence variants (ASVs) belonging to Novosphingobium and Sphingomonas were especially abundant in diesel-contaminated bulk soil and, ASVs belonging to Azospirillum , Rhizobium , Ohtaekwangia , Faecalibacterium , and Subdoligranulum were especially abundant in diesel-contaminated rhizosphere. These enriched bacterial taxa could represent tolerant and possibly biodegradative bacteria with important roles for diesel remediation, as well as possible plant growth promotion capacities under adverse conditions, and deserve further study. This study adds new knowledge of how natural microbial populations react and aid remediation by plants and, therefore, could provide new ways which could be used to improve the removal of diesel from contaminated sites. • Clover presence improves diesel aromatic compound dissipation in soil over time. • Bacterial diversity decline by diesel contamination was mitigated by plant presence. • Bacterial community structure is mostly affected by soil type and diesel. • Sphingomonads, Rhizobia and Azospirillum , play an important role in polluted sites.
Dillewijn et al. (Sun,) studied this question.