Influence of fullerene (C60) on soil bacterial communities: aqueous aggregate size and solvent co-introduction effects

Fullerene C-60 nanoparticles are being used in broad range of applications. It is important to assess their potential impacts in the environment. We evaluated the effects of C-60 introduced as aqueous suspensions of nC(60) aggregates of different particle size or via organic solvents on soils with different organic matter contents in this study. Impacts of the application were evaluated by measuring total microbial biomass, metabolic activity and bacterial community structure. Results show that nC(60) aggregates, introduced as an aqueous suspension, had size-dependent effects on soil bacterial community composition in the low organic matter system, but induced minimal change in the microbial biomass and metabolic activity in soils with both high and low organic matter contents. Fullerene C-60, co-introduced via an organic solvent, did not influence the response of soil microbes to the organic solvents. Our results suggest that nC(60) aggregates of smaller size may have negative impact on soil biota and soil organic matter may play a key role in modulating the environmental effect of nanomaterials.