- 著者
- SHINKURO TAKENAKA TAKESHI YOSHIKAWA SHUSAKU KADOWAKI SUGURU OKUNISHI HIROTO MAEDA
- 出版者
- The Society for Antibacterial and Antifungal Agents, Japan
- 雑誌
- Biocontrol Science (ISSN:13424815)
- 巻号頁・発行日
- vol.22, no.2, pp.79-87, 2017 (Released:2017-06-27)
- 参考文献数
- 28
- 被引用文献数
- 3 4
A marine raphidophyte Heterosigma akashiwo is a causative agent of harmful microalgal blooms, which often cause the massive mortality of aquacultured finfish. In the present study, the Pacific oyster Crassostrea gigas was reared with H. akashiwo, and effect of the microalga on filter-feeding behavior and microflora of the gastrointestinal tract was investigated. The intake of the raphidophyte cells inhibited the molluscan filter-feeding activities, suggesting the negative physiological effect of the microalgal cell contents. However, the bivalves ingested the H. akashiwo cells to the same extent as the diatom Chaetoceros calcitrans, a non-harmful indicator to estimate the filtration rate, showing a continuation of their non-selective ingestion of the phytoplankton. Microflora of the oyster soft tissue was dominated by bacteria affiliated with the family Rhodobacteraceae, some of which are associated with microalgae. In addition, the Bacteroidetes species, in which algicidal bacteria are included, were also found in the bivalve individuals exposed to H. akashiwo. These results suggested that the ingested phytoplankton affected the microbial flora in the gastrointestinal tracts, some constituents of which helped the mollusc assimilate the ingested red tide phytoplankton. This study will provide beneficial information to clarify mechanisms by which the oyster evades the ichthyotoxicity of harmful microalgae and the participation of the intestinal microorganisms in these processes.
- 著者
- Suguru Okunishi Naoaki Yoshimura Hiroto Maeda Takeshi Yoshikawa Taizo Sakata
- 出版者
- 日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
- 雑誌
- Microbes and Environments (ISSN:13426311)
- 巻号頁・発行日
- vol.17, no.3, pp.148-152, 2002 (Released:2002-10-02)
- 参考文献数
- 26
- 被引用文献数
- 2 3
A new cyanophage, strain S-KM1, infecting a phycoerythrin-rich Synechococcus sp., strain KFM001, was isolated from seawater of Kagoshima Bay. Transmission electron micrography of negative-stained specimens revealed that the phage isolate has an isometric head with a diameter of 83 nm and a contractile tail 166 nm in length and that it belongs to the family Cyanomyoviridae. The cyanophage was apparently virulent to the host strain KFM001 with a burst size of less than 70-80. The cyanophage may affect the population structure of the dominant picoplankton species in Kagoshima Bay.