A preliminary integrated experimental and in Silico assessment of insulating oil leakage effects on soil microbiota and plant germination

Abstract Leakage of high-voltage insulating oils into soil represents an underexplored source of environmental contamination with potential biological consequences. This study aimed to evaluate the impact of insulating oil (ISOLEC KL 2-3) on soil microbial communities and plant germination under realistic field conditions. Soil samples were collected from an actual leakage site, including both contaminated and uncontaminated soils. Microbial populations were assessed using culture-based enumeration under aerobic and anaerobic conditions. Functional microbial activity was further examined using Winogradsky columns, while plant response was evaluated through a basil (Ocimum basilicum L.) seed germination assay with and without microbial inoculation. The silico analysis was done to characterize the physicochemical properties of representative C10–C13 linear alkylbenzene homologs. The results showed that no detectable cultivable microbial growth was observed in contaminated soils, whereas uncontaminated soils supported active aerobic and anaerobic populations. Consistently, Winogradsky columns prepared from contaminated soil failed to develop visible stratification, in contrast to well-defined microbial layering observed in uncontaminated columns. In the germination assay, partial germination occurred after 3 days in contaminated treatments; however, no detectable germination was recorded after 7 days. Microbial inoculation, including aerobic, anaerobic, and mixed consortia, did not improve germination or restore soil functionality. In silico analysis confirms that C10–C13 alkylbenzene derivatives exert broad-spectrum biological toxicity primarily through the disruption of cell membrane integrity rather than specific protein-target inhibition. The observed agreement between computational physicochemical predictions and experimental findings provides a plausible mechanistic hypothesis involving membrane perturbation, proton gradient disruption, and bioenergetic impairment. As a proof-of-concept study, these interpretations remain exploration and require targeted biochemical validation in future investigations