It is said that algicidal bacteria can be used as biological control agents for algal blooms. We examined influences of algicidal bacteria on microbial communities in a laboratory experiment as a first step of ecological risk assessment. A microcosm, which consists of wild protozoa, bacterioplankton, and cultured Microcystis aeruginosa NIES 99, was constructed as a model microbial ecosystem of eutrophic lakes with algal blooms. Lysobacter enzymogenes subsp. enzymogenes AL-1 (DSM 1895) was added to the microcosm as an algicidal bacterium. Ciliates, flagellates, fungi, and M. aeruginosa NIES 99 were observed in control runs. In the runs with L. enzymogenes AL-1, although M. aeruginosa NIES 99 was not lysed, the other microbes disappeared. We address that applications of algicidal bacteria to actual lakes are considered to be ecologically risky contrary to the previous ideas.JSTさきがけ研究集会 環境問題における数理の可能性. 平成20年6月11日～平成20年6月13日. 札幌
