Abstract
The Bradyrhizobium-soybean symbiosis was makedly influenced by the presence of Rhodopseudomonas capsulata. There was an enhancement of nodulation, plant growth and nitrogen fixation in the soybean plants inoculated with mixed cultures of B. japonicum and R. capsulata. Their excreted substances promoted root growth and the nodulation efficiency of their respective host plants. A positive correlation between the extracellular polysaccharide production and nitrogen-fixing effectiveness of B. japonicum was revealed.
