Graphene oxide affects soil bacterial and fungal diversity even at parts-per-trillion concentrations

Graphene oxide (GO) is an oxidized form of graphene that is relatively cheap and easy to produce. This has heralds heralded its widespread use in a range of industries, and its with the likelihood of its environmental release into the enviuronment increasing accordingly. Harmful effects of GO have been reported for bacteria grown in culture. The impacts of GO on soil microbial diversity, however, remain poorly characterised, despite the important ecosystem services that these organisms underpin. Here, we characterized the effects of graphene oxide (GO) and graphite, over time and at three concentrations (1 ng, 1 µg and 1 mg kg dry soil-1), on soil bacterial and fungal diversity using 16S rRNA and ITS2 gene amplicon sequencing. Graphite was included as a reference material as it is widely distributed in the environment.