Abstract
Graphene is the thinnest and toughest two-dimensional nanomaterial yet discovered. However, it inevitably enters the biosphere, where it may pose potential risks to ecosystems. We investigated the impact of applied graphene concentrations on bacterial community diversity, physicochemical properties, and enzyme activities of Haplic Cambisols, the zonal soil of Northeastern China. Soils receiving 0, 10, 100, or 1000 mg kg−1 of graphene were incubated for 7, 15, 30, 60, or 90 days. Adding graphene significantly increased the community richness and diversity index of the bacterial community in Haplic Cambisols, as well as their abundances, but this impact varied with graphene concentration and incubation time. Compared with 0 mg kg−1 of graphene applied, soil bacteria abundance and diversity increased significantly during early stages of incubation (i.e., 7 and 15 days) under different concentrations of graphene, and was inhibited or remained unchanged by a longer incubation time, reaching a minima at 60 days but then following an upward trend. Graphene treatments influenced the bacterial community structure and metabolic function in Haplic Cambisols, and the bacterial community’s metabolic regulation mechanism varied with both incubation time and graphene concentration. The rank order of bacterial similarity in soils treated with graphene was 15 > 7 > 30 > 60 > 90 days. Throughout the incubation periods, except for a few unidentified bacteria, the relative abundances of Proteobacteria and Acidobacteria in the soil samples were the highest, with the number of Pseudomonas of Proteobacteria being particularly large. The rank order of bacterial abundance at the phylum level in Haplic Cambisols was 15 > 7 > 30 > 90 > 60 days. Graphene also influenced bacterial community diversity by affecting several key soil environmental factors, such as organic matter and hydrolytic nitrogen contents, as well as urease and catalase activities.
Highlights
Graphene is the thinnest and toughest two-dimensional nanomaterial yet discovered, consisting of a dense layer of carbon atoms wrapped in a honeycomb crystal lattice that features the most stable benzene six-membered ring structural unit [1,2]
Via high-throughput sequencing, our Venn diagram (Figure 1) shows that a total of 7961 operational taxonomic taxonomic units units (OTUs) were detected in Haplic Cambisols receiving the four treatments
We found that changes to main bacterial community members were closely related to graphene concentration and incubation time (Figure 8)
Summary
Graphene is the thinnest and toughest two-dimensional nanomaterial yet discovered, consisting of a dense layer of carbon atoms wrapped in a honeycomb crystal lattice that features the most stable benzene six-membered ring structural unit [1,2]. The basic structural unit of fullerenes, carbon nanotubes, and graphite, has a thickness of only 0.34 nm, a carrier mobility of 15,000 cm V−1 s−1 , a thermal conductivity of 5000 W m−1 K−1 , and its specific surface area is 2630 m2 g−1 [3,4]. This special structure endows it with many excellent properties in optical, electrical, and thermal applications, as well as mechanical strength [1,5,6]. It is vital that we understand graphene’s behavior in the environment, and whether it induces potential toxicity or risks to organisms
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
