Distribution of culturable endophytic bacteria in aquatic plants and their potential for bioremediation in polluted waters

Plant-bacterial asscociations can improve the degradation of organic pollutants in soil. However, little is known about the diversity and distribution of endophytic bacteria associated with aquatic plants and their potential to enhance phytoremediation of aquatic environments. In the present study, endophytic bacteria were isolated from 4 species of aquatic plants: Phragmites communis, Potamogeton crispus, Nymphaea tetragona and Najas marina. The isolated bacteria were classified into 12 genera in the Gammaproteobacteria, Bacilli, Alphaproteobacteria, Flavobacteria and Actinobacteria. In addition, different strains and/or different concentrations of the bacteria were isolated from different parts of the 4 plants, suggesting the different parts of the 4 plants harbored different endophytic bacteria. Some of the isolates de graded naphthalene and pesticides and some showed potential to dissolve insoluble phosphate. This is one of the first studies to isolate and compare culturable endophytic bacteria among different aquatic plants. This research indicates that culturable endophytes in aquatic plants are very diverse, but are dominated by Gammaproteobacteria, and have the potential to enhance in situ phytoremediation.