The commercial formulations of herbicides rely on surfactants which increase the efficiency of active substance. Herbicidal ionic liquids (ILs), in which cationic surfactants are combined with herbicidal anions, allow for additives’ reduction and ensure very good herbicide performance with lower doses. We aimed to test the impact of synthetic and natural cations on biological degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). Although primary biodegradation was high, the mineralization in agricultural soil indicated incomplete conversion of ILs to CO₂. Even the introduction of naturally-derived cations resulted in an increase in the herbicide’s half-lives – from 32 days for [Na][2,4-D] to 120 days for [Chol][2,4-D] and 300 days for the synthetic tetramethylammonium derivative [TMA][2,4-D]. Bioaugmentation with 2,4-D-degrading strains improves the herbicides’ degradation, which was reflected by higher abundance of tfdA genes. Microbial community analysis confirmed that hydrophobic cationic surfactants, even those based on natural compounds, played a negative role on microbial biodiversity. Our study provides a valuable indication for further research related to the production of a new generation of environmentally friendly compounds. Moreover, the results shed a new light on the ionic liquids as independent mixtures of ions in the environment, as opposed to treating them as new type of environmental pollutants.

除草剂的商业配方依赖于提高活性物质效率的表面活性剂。除草离子液体 (IL)，其中阳离子表面活性剂与除草阴离子结合，可以减少添加剂的用量，并确保在较低剂量下具有非常好的除草性能。我们旨在测试合成和天然阳离子对 2,4-二氯苯氧乙酸 (2,4-D) 生物降解的影响。尽管初级生物降解率很高，但农业土壤中的矿化表明离子液体未完全转化为 CO ₂. 即使引入天然衍生的阳离子也会导致除草剂的半衰期增加——从 [Na][2,4-D] 的 32 天到 [Chol][2,4-D] 的 120 天和 300 天用于合成四甲基铵衍生物 [TMA][2,4-D]。使用 2,4- D降解菌株进行生物强化可改善除草剂的降解，这反映在更高的tfdA丰度上基因。微生物群落分析证实，疏水性阳离子表面活性剂，即使是那些基于天然化合物的表面活性剂，对微生物的生物多样性也有负面影响。我们的研究为与生产新一代环保化合物相关的进一步研究提供了有价值的指示。此外，该结果为离子液体作为环境中独立的离子混合物提供了新的思路，而不是将它们视为新型环境污染物。