Short communication: Effect of combined fungicide treatments on fatty acid content in Eisenia fetida earthworms

Aim of study: To study the toxic effects of a combined fungicide in Eisenia fetida earthworms and in its lipid fatty acid composition. Material and methods: We investigated the acute toxicity (LC50, 14 days) of a combined fungicide (active ingredients: carbendazim + cyproconazole) in Eisenia fetida using artificial substrate. The quantitative content of fatty acids (FAs) of body lipids was determined by the method of high-sensitivity gas chromatography. Main results: Moderate toxicity of the combined fungicide was determined for Eisenia fetida earthworms. Changes in behavioral response, biomass loss, and mortality of test objects were detected. A decrease in the content of saturated FAs was found. At the same time, an increase of long-chain polyunsaturated FAs content of ω6 and ω3 families, which are involved in the regulation of a wide range of physiological processes, was revealed. Modulation of the lipid FAs profile in Eisenia fetida worms is explained by the participation of the FAs in the restructuring of the organism reactivity system under fungicidal load. Research highlights: The reorganization of the FA profile can be considered as an early criterion of metabolic perturbations in earthworms under the action of fungicides. Understanding the toxic potential of fungicides to organisms in soil ecosystems is essential for practical risk assessment in response to pesticide application.