著者

深見 公雄 湯澤 篤 西島 敏隆 畑 幸彦

出版者

日本水産學會

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.58, no.6, pp.1073-1077, 1992

被引用文献数

28 83

---

A bacterium 5N-3 possessing a remarkable inhibitory effect on the growth of <i>Gymnodinium nagasakiense</i> was isolated from Uranouchi Inlet, Kochi. This bacterium was tentatively identified as <i>Flavobacterium</i> sp. The growth inhibiting effect of 5N-3 on <i>G. nagasakiense</i> was drastic in particular when the alga was in the logarithmic growth phase, and cell density decreased to less than 1% of the initial concentration within 4 days after inoculating 5N-3, indicating that the effect was algicidal. The effect was obtained when the density of the bacterium was more than 10⁶ cells/m<i>l</i>. However, they grew very rapidly up to 10⁸ cells/m<i>l</i> by using extracellular released organic carbon from various phytoplankton species. On the other hand, the algicidal effect of 5N-3 was only observed on <i>G. nagasakiense</i> but not on <i>Chattonella antiqua</i>, <i>Heterosigma akashiwo</i>, or <i>Skeletonema costatum</i>. These results indicate that the effect of 5N-3 was <i>G. nagasakiense</i>-specific and suggest that it grows to a level of cell density effective in inhibiting the alga in the field by using naturally oc-curring organic carbon from phytoplankton.