In recent years the incidence of algal blooms caused by Nodularia to become one of the serious problems and is threated life of aquatic organisms in the southern Caspian Sea. Nodularia is Blue - green algae (cyanobacteria phylum) and due to production of nodularin toxin is importance. In this study, the first, three species of Pseudomonas including Pseudomonas aeruginosa, P .putida and P. fluorescens were isolated from Tajan river estuary and identified using biochemical tests and compared to standard species. The trend of Nodularia spumigena biomass (log 5) and Pseudomonas species (log 7 and 8) were examined in 30 treatments for 10 days in aquarium scale.
The results showed that the decline trend of Nodularia in P. aeruginosa and mixed species treatments were better than other treatments and log 8 of bacterium was also more inhibitory effect than to log 7. Similar results were observed in double layer on agar medium and latter treatments had algaecide effect on nodularia. However, P. putida and P. fluorescens treatments had algaestatic properties.
The conclusion showed that different strains of Pseudomonas are able to reduce the population of algae N. spumigena in aquarium scale and the results observed in combination treatment were better than other treatments.