The influence of migratory Paraburkholderia on growth and competition of wood-decay fungi

Certain bacteria are capable of migrating along fungal hyphae, using them as a dispersal mechanism to cross otherwise-prohibitory distances. Three strains of fungal-migratory Paraburkholderia were isolated from the mycelium of wood-decay fungi, and inoculated onto ten strains of wood-decay fungi growing on solid agar medium. Two of the three bacteria were able to migrate along the hyphae of all fungi, although to differing extents. No bacteria-associated growth inhibition was observed with eight of the ten fungi, but mycelial extension rate of two strains of Phanerochaete was significantly reduced. Bacteria were also introduced into fungus-fungus competitive pairings, and significantly reduced the competitive performance of one of the Phanerochaete strains. Additionally, in several cases, introducing bacteria into competitive interactions made the outcome unpredictable, whereas in the absence of bacteria one fungus was consistently dominant. This is the first time that bacteria have been shown to influence fungal inter-specific competition. (C) 2020 Published by Elsevier Ltd.