▎ 摘　　要

PurposeRecently, the application of graphene has sparked growing concerns about its effects, and graphene inevitably enters soils, resulting in widespread coexistence with various pollutants including heavy metal. Our aim was to clarify the effect of graphene on the formation of bacterial community composition, structure, and diversity in cadmium-contaminated soil.MethodsCd-polluted Haplic Cambisols were exposed to different doses of graphene (0, 10, 100, and 1000 mg kg(-1)) over four incubation periods (15, 30, 45, and 60 days). Several bacterial parameters, including community diversity, structure, composition, and metabolic function, were identified. We also measured pH, hydrolytic nitrogen and available phosphorus, potassium, and Cd contents of soil samples.ResultsGraphene increased the richness of bacterial communities in cadmium-contaminated soil. The structure of bacterial community was changed, and the impact was dependent on incubation time rather than graphene concentrations. The relative abundance of the majority of bacterial phyla (e.g., Proteobacteria and Actinobacteria) increased after graphene addition, but graphene also exerted an adverse effect on the relative abundance of some phyla (e.g., Verrucomicrobia and Acidobacteria).ConclusionGraphene significantly altered bacterial community and metabolic function varying with its concentration and incubation time. The functional bacteria (Proteobacteria and Gemmatimonadetes) related to carbon and nitrogen cycling were affected, which, consequently, may influence nutrient cycling in soil. The changes in soil pH and available phosphorus had significant correlations with bacterial community composition. Our findings imply that graphene can increase the richness and diversity of bacterial community in Cd-polluted Haplic Cambisols in a time-dependent manner, thus favoring the multifunctionality of soil ecosystems.