Journal Article 2 Research Support, U.S. Gov't, Non-P.H.S. 2 facultative mutualism Comment 1 Research Support, Non-U.S. Gov't 1 Review 1 aquatic plants 1 mehr ... bacterial competition 1 beneficial inoculants 1 cable bacteria 1 chemosynthetic symbioses 1 environmental variation 1 facilitative interaction 1 legume-rhizobia 1 nitrogen fixation 1 nodule occupancy 1 plant-microbe interaction 1 thiotrophs 1 weniger ...