Every day, tons of caffeine is consumed by humans in beverages, medications or supplements, and a significant amount of this stimulant is released in domestic sewage. Once in aquatic environments caffeine interacts directly with the periphytic community, which is responsible for a significant part of primary production in aquatic ecosystems. However, the effects of exposure to caffeine are mostly unknown for both the periphyton and their predators. Aiming to comprehend the interaction between caffeine and the periphytic community, ecotoxicological experiments were performed by exposing a periphytic biofilm cultivated in the laboratory to different concentrations of caffeine, following concentrations found in domestic sewers. The impact of exposure to this contaminant was observed on the structure of the community through taxonomic evaluation, as well a set of physiological variables linked to primary production. After exposure to the highest caffeine concentration (300 µg L⁻¹), the density of the genus Scenedesmus was severely affected, leading to an increase in cyanobacteria and diatoms. Both richness and diversity decreased after exposure, and there was lower photosynthetic activity, with light saturation point changing from 186 µmol m⁻² s⁻¹ in the control treatment to 108 µmol m⁻² s⁻¹ after exposure. Caffeine accumulation within the biofilm was also observed during the first 24 h, in the concentration of 0.14 µg /cm².

每天，人类都会在饮料，药物或补品中消耗大量咖啡因，并且大量的这种兴奋剂会从生活污水中释放出来。咖啡因一旦进入水生环境，就会直接与周围植物群落相互作用，这是水生生态系统初级生产的重要组成部分。然而，咖啡因和捕食者对咖啡因的暴露大多是未知的。为了理解咖啡因与周围植物群落之间的相互作用，通过在实验室中培养的周围生物膜暴露于生活污水中发现的不同浓度的咖啡因后，进行了生态毒理学实验。通过生物分类评估观察到了暴露于这种污染物对社区结构的影响，以及与初级生产相关的一组生理变量。暴露于最高咖啡因浓度（300 µg L^-1），严重地影响了场景动物的属的密度，导致蓝细菌和硅藻的增加。既丰富性和多样性曝光后下降，并有较低的光合活性，与光饱和点从186微摩尔米改变^-2 小号^-1在控制处理，以108微摩尔米^-2 小号^-1曝光后。在最初的24小时内，还观察到咖啡因在生物膜中的积累，浓度为0.14 µg /cm²。