The impact of petroleum products on the aquatic microbiome. Monitoring for safety

Introduction. Water pollution with oil products poses a serious threat to human health. When oil and its derivatives enter water bodies, the natural ecosystem is disrupted, rendering the water unsuitable for drinking and household use. Ensuring biological safety is essential due to the ongoing adverse impact of pollution of aquatic components by various chemical factors on the formation of the environment’s microbiome and public health.The aim of this study was to investigate the viability of the aquatic microbiome under conditions of increased oil product loads on water bodies.Materials and methods. The state of microbial communities in the water of water bodies was studied under experimental conditions with the addition of petroleum products to river water: unleaded AI-95 gasoline and M-100 fuel oil. Gasoline was added to twenty eight experimental model reservoirs – at the level of MPC (0.1 mg/dm³), 10 MPC, 100 MPC, 1000 MPC and a suspension of potentially pathogenic test microorganisms Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and pathogenic microorganisms Salmonella typhimurium. Fuel oil was applied to 16 model ponds, creating a 1 cm thick film or suspension of droplets in the water column and suspension of Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, and pathogenic microorganisms Salmonella enterica subspecies enterica serotype enteritidis. The infectious microorganisms for model reservoirs was 10² CFU/dm³, 10³ CFU/dm³, 10⁴ CFU/dm³. The experiment to study the effect of gasoline on sanitary-indicative and pathogenic microorganisms lasted 14 days, fuel oil – 30 days.Results. Concentrations of petroleum products up to 10 MPC inhibited the growth of total microbial counts and the sanitary indicator microorganisms E. coli and E. faecalis. Maintaining an associative link with pathogenic microorganisms for up to 12 days of exposure when gasoline spilled into water bodies and up to 20–31 day when fuel oil spilled droplets. Gasoline concentrations of 100× and 1000× MPC, as well as a fuel oil spill in water as a film, resulted in 100% mortality of E. coli and E. faecalis after 6 days of exposure. Elevated concentrations of petroleum products in water bodies resulted in a significant increase in the hydrocarbon-oxidizing bacteria Pseudomonas aeruginosa with prolonged contact time.Limitations. The obtained experimental data will be confirmed by in-kind studies of water in reservoirs.Conclusion. When significant concentrations of petroleum products enter a water body during emergency situations or the discharge of insufficiently treated wastewater from oil refineries, it is advisable to monitor the safety of water bodies using the sanitary indicator microorganisms E. coli and E. faecalis. In case of long-term release of high concentrations of petroleum products into water bodies, water safety monitoring should be carried out for the formation of hydrocarbon-oxidizing bacteria, including Pseudomonas aeruginosa.Compliance with ethical standards. This study does not require the conclusion of a biomedical ethics committee or other documents.Contribution: Trukhina G.M. – concept and design of the study, analysis of obtained data, writing text, editing; Borisova N.A. – concept and design of the study, data collection and analysis, writing text; Sinitsyna O.O. – writing text, editing. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study was conducted as part of the state program “Ensuring Chemical and Biological Safety of the Russian Federation for 2021–2024.Received: November 21, 2025 / Revised: December 15, 2025 / Accepted: December 19, 2025 / Published: January 15, 2026