Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Viral mortality of marine bacteria and cyanobacteria


DESPITE the importance of cyanobacteria in global primary productivity1and of heterotrophic bacteria in the consumption of organic matter in the sea2, the causes of their mortality, particularly the cyanobacteria, are poorly understood. It is usually assumed that mortality is due to protozoan grazing3,4 rather than to viral infection, probably because abundances of phage and host in nature are presumed to be low5. Previously, either very few marine bacteriophages have been found by plaque assays6–9, or viruses have been simply observed10–12or counted13,14 by transmission electron microscopy, with the assumption that 'phage-looking' forms are locally active bacteriophages. Here we report not only high viral abundance in the ocean but also counts of bacteria and cyanobacteria in the final irreversible stage of lytic infection. The latter counts are necessary to evaluate mortality, because the sources, hosts, viability and ages of observed free viruses are unknown; even finding viruses attached to cells does not prove successful infection. Up to 7% of the heterotrophic bacteria and 5% of the cyanobacteria from diverse marine locations contained mature phage; interpretation via culture data indicates that up to 70% of the prokaryotes could be infected. These data demonstrate the existence of a significant new pathway of carbon and nitrogen cycling in marine food webs and have further implications for gene transfer between marine organisms.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Waterbury, J. B., Watson, S. W., Valois, F. W. & Franks, D. G. in Phyotosynthetic Picoplankton (eds Platt, T. & Li, W. K. W.) 71–120 (Department of Fisheries and Oceans, Ottawa, Canada, 1986).

    Google Scholar 

  2. Azam, F. et al. Mar. Ecol. Prog. Ser. 10, 257–263 (1983).

    Article  ADS  Google Scholar 

  3. Fenchel, T. Mar. Ecol. Prog. Ser. Microbiol. 9, 35–42 (1982).

    Article  ADS  Google Scholar 

  4. Sherr, E. B. & Sherr, B. F. Nature 325, 710–711 (1987).

    Article  ADS  Google Scholar 

  5. Wiggins, B. and Alexander, M. Appl. envir. Microbiol. 49, 19–23 (1985).

    CAS  Google Scholar 

  6. Spencer, R. in Symposium on Marine Microbiology (ed. Oppenheimer, C. H.) 350–365 (Charles Thomas, Springfield, Illinois, 1963).

    Google Scholar 

  7. Kriss, A. E. in Microbial Populations of Oceans and Seas (eds Kriss, A. E., Mishustina, I. E., Mitskevich, N. & Zentsova, E.) 230–237 (St Martins's, New York, 1967).

    Google Scholar 

  8. Hidaka, T., Kawaguchi, T. & Shirahama, M. Mem. Fac. Fish. Kagoshima Univ. 28, 47–55 (1979).

    Google Scholar 

  9. Moebus, K. Helgoländerwiss Meeresunters. 36, 375–391 (1983).

    Article  Google Scholar 

  10. Sieburth, J. McN. Sea Microbes, 62 (Oxford University Press, New York, 1979).

    Google Scholar 

  11. Johnson, P. W. & Sieburth, J. McN. J. Phycol. 18, 318–327 (1982).

    Article  Google Scholar 

  12. Frank, H. & Moebus, K. Helgoländerwiss Meeresunters. 41, 385–414 (1987).

    Article  Google Scholar 

  13. Torrella, F. & Morita, R. Y. Appl. envir. Microbiol. 37, 774–778 (1979).

    CAS  Google Scholar 

  14. Bergh, Ø., Børsheim, K. Y., Bratbak, G. & Heldal, M. Nature 340, 467–468 (1989).

    Article  ADS  CAS  Google Scholar 

  15. Kellenberger, E., Sechaud, J. & Ryter, A. Virology 8, 478–490 (1959).

    Article  CAS  Google Scholar 

  16. Valentine, A. F. & Chapman, G. B. J. Bact. 92, 1535–1554 (1966).

    CAS  PubMed  Google Scholar 

  17. Smith, L. S. & Krueger, A. P. J. gen. Physiol. 38, 161–168 (1954).

    Article  CAS  Google Scholar 

  18. Proctor, L. M., Fuhrman, J. A. & Ledbetter, M. C. Eos 69, 1111–1112 (1988).

    Google Scholar 

  19. Fuhrman, J. A. & McManus, G. B. Science 224, 1257–1260 (1984).

    Article  ADS  CAS  Google Scholar 

  20. Miller, M. in Principles and Techniques of Electron Microscopy (ed. Hayat, M. A.) 89–128 (Van Nostrand, New York, 1974).

    Google Scholar 

  21. Hobbie, J. E., Daley, R. & Jasper, J. P. Appl. envir. Microbiol. 33, 1225–1228 (1977).

    CAS  Google Scholar 

  22. Leach, J. A., Lee, K. W., Benson, R. L. & Martin, E. L. J. Physiol. 16, 307–310 (1980).

    Google Scholar 

  23. Belfort, G., Rotem, Y. & Katznelson, E. Water Res. 10, 279–284 (1976).

    Article  Google Scholar 

  24. Estis, L. F., Haschemeyer, R. H. & Wall, J. S. J. Microscopy 124, 313–316 (1981).

    Article  Google Scholar 

  25. Sherr, B. F., Sherr, E. B. & Fallon, R. D. Appl. envir. Microbiol. 53, 958–965 (1987).

    CAS  Google Scholar 

  26. Johnson, P. W. & Sieburth, J. McN. Limnol. Oceanogr. 24, 928–935 (1979).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Proctor, L., Fuhrman, J. Viral mortality of marine bacteria and cyanobacteria. Nature 343, 60–62 (1990).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing