Impact of bacterial motility on biosorption and cometabolism of pyrene in a porous medium

Rhizosphere-enhanced biosurfactant action on slowly desorbing PAHs in contaminated soil

“…On the other hand, if such optimization is not performed, such an increased bioavailability may result in increased exposure to the mobilized pollutants by potential human or 19 ecological targets. The latter implications align with recent considerations of the potential risks caused at the initial stages of bioremediation as a result of unmodulated biological processing of the pollutants that leads to the eventual formation of byproducts that are more toxic than the parent PAHs (Rolando et al, 2020).…”

Advancing Eco-Sustainable Bioremediation for Hydrocarbon Contaminants: Challenges and Solutions

“…Hydrocarbons can influence bacterial chemotaxis, allowing them to migrate toward contaminated areas [3]. For instance, the strain Pseudomonas putida G7 can absorb and participate in the cometabolism of pyrene, making it available for biodegradation [99]. Stenotrophomonas sp., isolated from crude oil-contaminated soil, has grown on various PAHs as a carbon and energy source, with specific genes involved in PAH degradation [100].…”

Root-mediated bacterial accessibility and cometabolism of pyrene in soil

“…The flagellated bacterium P. putida G7, which degrades pyrene by cometabolism, was cultivated and prepared differently for soil slurry experiments, metabolite analysis and greenhouse experiments. For soil slurry experiments, the strain was cultivated in 250-mL Erlenmeyer flasks with 100 mL of an inorganic salt solution (mineral medium (MM), pH 5.7) supplemented with 5 mM sodium salicylate as the sole carbon source and incubated at 30 °C on a rotary shaker at 150 rpm for 48 h, which was sufficient for reaching the early stationary phase and stable cell motility 6 .…”

“…The flasks were closed with Teflon-lined stoppers, from which a 5-mL vial containing 1 mL of 0.5 M NaOH was suspended to trap 14 Measurements of the mineralization of radiolabeled pyrene were carried out as described elsewhere 29 . To measure the partitioning of pyrene, the 14 C-labeled analyte concentrations were determined from the radioactivity in the aqueous suspension 6 . The concentrations were calculated from the initial amounts of labeled and unlabeled pyrene present in the O-rings and expressed as 14 C-pyrene equivalents partitioned into the aqueous phase to account for the likely transformation into pyrene byproducts through cometabolism.…”

“…In the absence of such stimuli, intrinsic flagellar motility led to limited bacterial transport and accessibility as a result of an enhanced tendency for deposition. This bacterium was also used as an experimental model for examining the potential role of bacterial motility in the cometabolism and biosorption of pyrene in a porous medium 6 . The study indicated that through these two processes, motile bacteria may even increase the risk associated with contaminant mobilization in soils.…”