Degradation and Microbial Uptake of C_(60) Fullerols in Contrasting Agricultural Soils.

摘要

The environmental fate of functionali2eđ carbon nanomaterials (CNM) remains poorly understood. Using ~(13)Clabeled nanomaterial we present the results of a study investigating the mineralization and microbial uptake of surface-functionalized C_(60)) (fullerols) in agricultural soils with contrasting properties. Soil microcosms rapidly mineralized fullerol C, as determined by ~(13)C-content in the respired CO_2, with higher fuilerol mineralization in an organic, clay-rich soil versus a silty, low C soil (~56.3% vs ～30.9% fuilerol C mineralized over 65 days). By tracking the enriched ~(13)C from fullerol into microbial phospholipid fatty acids (PLFA) we also report, for the first time, the incorporation of nanomaterial-derived C into soil microbial biomass, primarily by fungi and Gram-negative bacteria. While more fullerol C was incorporated into PLFA in the organic C-rich soil (0.77% vs 0.19% of PLFA C), this soil incorporated fuilerol C into biomass less efficiently than the silty, low C soil (0.1396 and 0.84% of assimilated fuilerol C, respectively). These results demonstrate that, in contrast to pristine C_(60), surface functionalized C_(60) are unlikely to accumulate in surface soils and are readily mineralized by a range of soil microorganisms.