Abstract
The growth, toxicity, and associated bacterial flora of 10 clonal cultures of the toxic benthic dinoflagellates Ostreopsis lenticularis and Gambierdiscus toxicus isolated from the coastal waters of southwest Puerto Rico have been examined. Clonal cultures of O. lenticularis grew more rapidly and at broader temperature ranges than those of G. toxicus. All five Ostreopsis clones were toxic, while only one of the five Gambierdiscus clones was poisonous. The degree of toxicity among poisonous clones was highly variable. The number of associated bacterial genera and their frequency of occurrence were quite variable among clones of both dinoflagellate genera. Bacterial isolates represented six genera (Nocardia, Pseudomonas, Vibrio, Aeromonas, Flavobacterium, and Moraxella) in addition to coryneform bacteria. Extracts of dinoflagellate-associated bacteria grown in pure culture were not toxic. Gambierdiscus clones were characterized by the frequent presence of Pseudomonas spp. (four of five clones) and the absence of coryneforms. In O. lenticularis, only one of five clones showed the presence of Pseudomonas spp., and Moraxella sp. was absent altogether. Detailed analyses of toxicity and associated microflora in a selected Ostreopsis clone, repeatedly cultivated (four times) over a period of 160 days, showed that peak cell toxicities developed in the late static and early negative culture growth phases. Peak Ostreopsis cell toxicities in the stationary phase of culture growth were correlated with significant increases in the percent total bacteria directly associated with these cells. Changes in the quantity of bacteria directly associated with microalgal cell surfaces and extracellular matrices during culture growth may be related to variability and degree of toxicity in these laboratory-cultured benthic dinoflagellates.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aldrich D. V., Ray S. M., Wilson W. B. Gonyaulax monilata: population growth and development of toxicity in cultures. J Protozool. 1967 Nov;14(4):636–639. doi: 10.1111/j.1550-7408.1967.tb02054.x. [DOI] [PubMed] [Google Scholar]
- Chróst R. J. Inhibitors produced by algae as an ecological factor affecting bacteria in water ecosystems. I. Dependence between phytoplankton and bacteria development. Acta Microbiol Pol B. 1975;7(2):125–133. [PubMed] [Google Scholar]
- GUILLARD R. R., RYTHER J. H. Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran. Can J Microbiol. 1962 Apr;8:229–239. doi: 10.1139/m62-029. [DOI] [PubMed] [Google Scholar]
- Hobbie J. E., Daley R. J., Jasper S. Use of nuclepore filters for counting bacteria by fluorescence microscopy. Appl Environ Microbiol. 1977 May;33(5):1225–1228. doi: 10.1128/aem.33.5.1225-1228.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Imam S. H., Bard R. F., Tosteson T. R. Specificity of marine microbial surface interactions. Appl Environ Microbiol. 1984 Oct;48(4):833–839. doi: 10.1128/aem.48.4.833-839.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spikes J. J., Ray S. M., Aldrich D. V., Nash J. B. Toxicity variations of Gymnodinium breve cultures. Toxicon. 1968 Feb;5(3):171–174. doi: 10.1016/0041-0101(68)90085-8. [DOI] [PubMed] [Google Scholar]