Effect of eucalyptus saponin and sophorolipid amendment on soil and sediment microbial communities and seed germination: potential application for PAH bioremediation

Abstract Purpose The potential toxic effects due to the application of sophorolipid and novel saponin biosurfactant extracted from leaves Eucalyptus camaldulensis for purpose bioremediating PAH-contaminated soils sediments were studied. Methods phytotoxic eucalyptus determined based on seed germination assays carried out using seeds Lactuca sativa L compared with commonly used rhamnolipid Tween 20 surfactants. Further, biosurfactant-induced changes in soil/sediment bacterial structure diversity investigated by conducting Miseq amplicon sequencing genes. Results Germination indices (GI) demonstrated non-phytotoxic (GI > 80%) biosurfactants (100–500 mg/L), while greater phytotoxicity than at high concentrations (500 mg/L). Saponin-amended soil resulted richness controls, produced opposite effect. These significant variations not observed sediment samples. Incubation 40 days did result any Increased abundance some PAH-degrading bacteria was noted OTU level, presence sophorolipid. Saponin had less impact native relative prevalence significantly shifted OTUs. Conclusion As shown have no adverse impacts microbiome, effects, their sustainable applications remediate can be recommended.