20.500.12556/RUL-172573 Biofilm formation on polyethylene and polylactic acid microplastics in freshwater influence of environmental factors To overcome the environmental challenges posed by conventional plastics, new alternative plastic materials are being developed and increasingly used. However, their fate in the natural environment is still poorly understood. This study compared biofilm formation on polyethylene (PE) and polylactic acid (PLA) microplastics (MPs) under different conditions i.e. water regimes (static and moving conditions), nutrient levels (excess of nitrogen and phosphorus), light exposure (light and dark), and pollution levels (presence and absence of wastewater). Although PE and PLA differ in their composition and physico-chemical properties, the processes of aging and biofilm formation on both materials exhibited many similarities. Light availability had the strongest influence, as the formation of biofilm on both PE and PLA was suppressed in the dark, as shown by reduced biomass, chlorophyll a content, and extracellular polymeric substances (EPS). The availability of nutrients influenced the composition of the biofilm. High N:P ratios favoured photosynthetic microorganisms with increased chlorophyll a and EPS content, while phosphorus enrichment reduced their presence. Pollution, simulated by adding sterilized municipal wastewater, slightly reduced total biofilm mass but supported the growth of photosynthetic microorganisms. Static condition led to the formation of elongated microbial structures. Biofilm growth altered the density of MPs (increasing for PE, decreasing for PLA), reaching ∼1.1 g/cm³ for both, suggesting biofilm-induced sedimentation. Crystallinity of both PE and PLA decreased by 9–30 % due to the presence of biofilm, which has amorphous structure. The multivariate analysis confirmed environmental factors as primary drivers of biofilm development over polymer type. microplastics environmental conditions biofilm freshwater mikroplastika okoljski pogoji biofilm površinske vode true false true Angleški jezik Slovenski jezik Članek v reviji 2025-09-09 09:22:44 2025-09-09 09:22:46 2026-06-30 04:00:52 0000-00-00 00:00:00 2025 0 0 11 str. iss. 5, art. 118689 Vol. 13 Oct. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 502.51:504.5:678 2213-3437 10.1016/j.jece.2025.118689 247024131 1-s2.0-S2213343725033858-main.pdf 1-s2.0-S2213343725033858-main.pdf 1 3310ABA691E6862434F3DA45A656285E bba364bc42abf3fbb6244d1ea3a1674650613c655d551959ae76eb0db789ec4d edc0bef0-73c1-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=236610 https://www.sciencedirect.com/science/article/pii/S2213343725033858 1 a014d0a5-8d4d-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=216442 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0