Six of 11 strains of endophytic bacteria from pea (Pisum sativum L.) seeds were found in an aqueous medium of seedling-root growth under hydroculture conditions. It was shown that bacterial inoculates of Rhizobium leguminosarum bv. viceae, Pseudomonas syringae pv. pisi, Azotobacter chroococcum and Rhodococcus erythropolis had different effects on the composition and concentration of endophytic bacteria in the pea-seedling rhizosphere. All six endophytes were found to have different capacities for N-phenyl-2-naphthylamine (N-PNA) degradation to produce phthalates. The amount of non-degraded substrate and the proportion of phthalates remaining after substrate degradation indicate different levels of the catabolism of N-PNA, a negative allopathic component of legume root exudates. These parameters determined the degree of participation of endophytic bacteria in the control of the relationship between pea plants and bacteria with different interaction strategies.