Periphytic biofilms accumulate manganese, intercepting its emigration from paddy soil

Manganese (Mn) in acidic paddy soil has large potential emigrating from the and pollute adjacent ecosystems. Single microorganisms modulate biogeochemistry process of Mn via redox reactions, while roles microbial aggregates (e.g. periphytic biofilm) modulating its biogeochemical cycle is poorly constrained. Here we collected a series biofilms fields China to explore how biofilm regulates behavior fields. We found that have accumulation potential: contents ranged 176 ± 38 797 271 mg/kg, which were 1.2–4.5 folds higher than corresponding soils. Field experiments verified potential, underlining function as natural barriers intercept soil. Extracellular polymeric substances, especially protein component, mediated adsorption was main mechanism behind by biofilm. Microorganisms general appeared inhibitory effects on accumulation. Climatic conditions nutrients floodwater affect microorganisms, thus indirectly affecting biofilms. This study provides quantitative information extent