Interaction between Graphene Oxide and the Mycelia ofMorchella sextelata

Abstract

Graphene oxide (GO) is expected to be harmful to the environment due to the toxicity. Accordingly, this work aimed to assess the potential harm of GO to the environment by investigating the toxicity of GO to the M. sextelata, and the effects of M. sextelata to GO. The dry weights, IR spectra, morphology, ultra-structures of mycelia, pH, conductivities of culture media, the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) contents were measured to display the potential hazards of GO to M. sextelata. Then the Raman spectroscopy, dispersibility, and X-ray photoelectron spectroscopy (XPS) of GO were measured to show the effect of M. sextelata on GO. The results indicated that the lower GO concentrations promoted the growth of M. sextelata while the high level of GO inhibited the growth process of M. sextelata. After 7 d of culture, the effect was suppressive, with the biomass significantly reduced by 10.10%, the MDA content of G200 increased by 69.06%. GO nanosheets covered the surface of mycelia which caused change of the mycelial microstructures. Correspondingly, M. sextelata induces more defects in GO, accompanied by poor dispersion of GO in ethanol. Based on the XPS analysis, in the G10, G50 and G200 treatments, their atomic percentage of nitrogen in GO increased by 3.03%, 4.28% and 2.2%, respectively, and the atomic percentage of oxygen in GO reduced by 8.61%, 9.42% and 4.09%, respectively. The effect of mycelia on GO is mainly in deoxygenated and nitrogen-doped. We expected that the above results would provide a reference for the environmental hazard of GO.