Permalink : http://hdl.handle.net/2115/61051

JaLCDOI : 10.14943/bull.fish.66.1.19

KEYWORDS : Cyanobacterial blooms;Microcystis aeruginosa;algicidal bacteria;growth-inhibiting bacteria;Pharagmites australis;Ohnuma Quasi-National Park;prevention;mitigation

Toxic blooms of cyanobacteria have negative impacts on fresh water ecosystems, and there is an urgent need to develop strategies to control those blooms. Algicidal bacteria that kill noxious species of cyanobacteria are expected as tools for mitigating impacts of the toxic cyanobacterial blooms. This study carried out to search algicidal bacteria against toxic cyanobacteria from biofilm on reeds and water samples in reed communities in Ohnuma Quasi-National Park and evaluated for control ability of cyanobacterial bloom by bacteria from reeds. Bacteria were isolated from the biofilm on reed and water samples, and the algicidal ability was examined using Microcystis aeruginosa by co-culture experiments. Algicidal bacteria were detected in high densities(order of 10⁵-10⁶ CFU g⁻¹ wet reed weight) from the biofilm of reeds including artificially planted reeds. Water samples from reed communities also contained more algicidal bacteria than those samples from no reed communities. The results suggested a possibility that reeds supply algicidal bacteria to adjacent water and reed communities have high potential ability to control toxic cyanobacterial blooms via bacteria possessing algicidal and groth-inhibiting activities.