Killing of marine phytoplankton by a gliding bacterium Cytophaga sp., isolated from the coastal sea of Japan

摘要: A marine gliding bacterium Cytophaga sp. (strain J18/M01) was isolated from Harima-Nada, eastern Seto Inland Sea, Japan in 1990. This preys upon various species of phytoplankton. All the five raphidophycean flagellates, all four diatoms, and one two dinoflagellates examined were killed within a few days when cultured with bacterium. The presumably achieves this by direct attack, because culture filtrate which host organisms totally destroyed had no significant effects on growth same organism (Chattonella antiqua). If or bacterial cells inoculated into C. antiqua culture, killed. proliferated filter-sterilized seawater, suggesting its ubiquitous existence coastal sea. killing phytoplankton bacteria such as J18/M01 may be factor influencing population dynamics nature contribute to sudden disappearance red tides Bacterial destruction also that regulates primary productivity ecosystems.