Isolation and Characterization of a Newly Isolated Algicidal Aeromonas sp.

A new algicidal bacterium strain FM was isolated and identified as Aeromonas sp. based on its 16S rRNA gene sequence analysis. Phylogenic analysis revealed the closest species was an Aeromonas salmonicida. The cell-free filtrate of FM culture was proved to contribute to the algicidal effect, indicating strain FM exerted algicidal effect on cyanobacteria by its extracellular substances. The algicidal substances were tested to be non-proteinaceous, heat stable, and with a molecular weight of less than 1 kDa. Strain FM could effectively inhibit the growth of cyanobacteria, including species of Microcystis, Planktothrix, Pseudanabaena, Oscillatoria and Anabaena. As Aeromonads are ubiquitous in aquatic habitats, Aeromonas sp. strain FM has application potential in control of harmful cyanobacteria.