Abstract

Abstract: Polycyclic aromatic hydrocarbons (PAHs) belong to the group of persistent organic pollutants with detrimental impact on the environment and its living organisms. Soil acts as the main PAH sink why strategies to remediate PAH contaminated soil are needed. Inoculation with plant growth promoting and stress alleviating fungi such as arbuscular mycorrhizal (AM) fungi and saprotrophic fungi could be an efficient bioremediation strategy for PAH contaminated soils, but information about their compatibility is missing. In a greenhouse pot experiment we examined interactions between the AM fungus Rhizophagus irregularis and the saprotrophic fungus Trichoderma viride and their single and dual effects on maize plant growth performance and communities of rhizosphere microorganisms in a Phenanthrene spiked soil. Phenanthrene reduced maize plant growth independent of both fungal inoculants, which were also both inhibited by Phenanthrene. On the other hand strong mutual inhibition between R. irregularis and T.viride was observed, which mitigated their plant growth promoting effects independent of Phenanthrene. In conclusion, the observed mutual inhibition between R. irregularis and T. viride underline the importance of testing for compatibility between microbial inoculants when these are used in combination.