Short-term treatment with lithium and its effect on the content of elements and fatty acids in aquatic species of L. minor

Lemna minor, a fast-growing aquatic plant with significant potential for phytoremediation and bioenergy production, is considered a sustainable candidate for wastewater treatment and resource recovery. This study evaluated the effects of lithium (Li) exposure (0, 1, 3 and 5mg/L) on Lemna minor during a seven-day cultivation period. The investigation included metal accumulation, photosynthetic pigment characterization, lipid extraction, fatty acid profiling, and lipid quality index assessment. Results highlighted the capacity of Lemna minor to tolerate Li exposure while changes were observed in the metals-profile. Exposure to 1–5 mg/L Li caused a reduction in chlorophyll a, chlorophyll b, and carotenoid contents, indicating inhibition of the photosynthetic system. Li exposure altered the elemental composition of the plants, particularly causing a significant decrease in Mg and Zn contents. The obtained biomass demonstrated potential for applications in phytoremediation, biofuels, and value-added bioproducts. Palmitic acid (C16:0), α-linolenic acid (C18:3 n-3), and linoleic acid (C18:2 n-6) were the predominant fatty acids identified in Lemna minor. Changes in fatty acid profiles indicate adaptive metabolic responses of Lemna minor to Li-induced stress conditions. Despite growth inhibition, the antioxidant capacity of the plants was not significantly affected by Li exposure. The study contributes to the understanding of Li-induced stress in aquatic plants and supports the use of Lemna minor in sustainable environmental technologies.