Archives of Microbiology

, Volume 141, Issue 2, pp 159–163 | Cite as

Effects of UV-B on motility and photobehavior in the green flagellate, Euglena gracilis

  • Donat-P. Häder
Original Papers


UV-B inhibits the motility of the green flagellate, Euglena gracilis, at fluences rates higher than those expected to occur in the natural sunlight even when the stratospheric ozone layer is partially reduced by manmade pollutants. The phototactic orientation of the cells, however, is drastically impaired by only slightly enhanced levels of UV-B irradiation. Since only negative phototaxis (movement away from a strong light source) is impaired while positive phototaxis (movement toward a weak light source) is not, the delicate balance by which the organisms adjust their position in their habitat is disturbed. Under these conditions the cells are unable to retreat from hazardous levels of radiation and are eventually killed not by the UV-B irradiation but by photobleaching of their photosynthetic pigments in the strong daylight at the surface.

Key words

Absorption Eulena gracilis Flagellate Fluorescence Motility Phobic response Photomovement Phototaxis UV-B 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Batschelet E (1965) Statistical methods for the analysis of problems in animal orientation and certain biological rhythms. In: Galles SR, Schmidt-Koenig K, Jacobs GJ, Belleville RF (eds) Animal orientation and navigation. Washington, NASA, pp 61–91Google Scholar
  2. Batschelet E (1981) Circular statistics in biology. Academic Press, LondonGoogle Scholar
  3. Benedetti PA, Lenci F (1977) In vivo microspectrofluorometry of photoreceptor pigments in Euglena gracilis. Photochem Photobiol 26:315–318Google Scholar
  4. Checcucci A, Colombetti G, Ferrara R, Lenci F (1976) Action spectra for photoaccumulation of green and colorless Euglena: evidence for identification of receptor pigments. Photochem Photobiol 23:51–54Google Scholar
  5. Colombetti G, Lenci F (1982) Responses to photic, chemical and mechanical stimuli. In: Buetow DE (ed) The biology of Euglena, vol III. Academic Press, New York, pp 169–195Google Scholar
  6. Colombetti G, Häder D-P, Lenci F, Quaglia M (1982) Phototaxis in Euglena gracilis: effect of sodium azide and triphenylmethyl phosphonium ion on the photosensory transduction chain. Curr Microbiol 7:281–284Google Scholar
  7. Damkaer DM, Dey DB, Heron GA, Prentice EF (1980) Effect of UV-B radiation on near-surface zooplankton of Puget Sound. Oecologia 44:149–158Google Scholar
  8. Diehn B (1969) Action spectra of the phototactic responses in Euglena. Biochim Biophys Acta 177:136–143Google Scholar
  9. Diehn B (1979) Photic responses and sensory transduction in motile protists. In: Autrum H (ed) Handbook of sensory physiology, vol 6. Springer, Berlin Heidelberg New York, pp 23–68Google Scholar
  10. Galbally LE (1976) Man-made carbon tetrachloride in the atmosphere. Science 111:619–624Google Scholar
  11. Garrison LM, Murray LE, Green AES (1978) Ultraviolet limit of solar radiation at the earth's surface with a photon monochromator. Appl Opt 17:683–684Google Scholar
  12. Häder D-P (1981) Computer-based evaluation of phototactic orientation in microorganisms. EDV Med Biol 12:27–30Google Scholar
  13. Häder D-P (1983a) Effects of UV-B irradiation on sorocarp development of Dictyostelium discoideum. Photochem Photobiol 38:551–555Google Scholar
  14. Häder D-P (1983b) Inhibition of phototaxis and motility by UV-B irradiation in Dictyostelium discoideum slugs. Plant Cell Physiol 24:1545–1552Google Scholar
  15. Häder D-P (1984) Effects of UV-B on motility and photoorientation in the cyanobacterium, Phormidium uncinatum. Arch Microbiol 140:34–39Google Scholar
  16. Häder D-P, Colombetti G, Lenci F, Quaglia M (1981) Phototaxis in the flagellates, Euglena gracilis and Ochromonas danica. Arch Microbiol 130:78–82Google Scholar
  17. Lenci F, Colombetti G, Häder D-P (1983) Role of flavin quenchers and inhibitors in the sensory transduction of the negative phototaxis in the flagellate, Euglena gracilis. Curr Microbiol 9:285–290Google Scholar
  18. Lipson ED, Häder D-P (1984) Video data acquisition for movement responses in individual organisms. Photochem Photobiol 39:437–441Google Scholar
  19. Mardia KV (1972) Statistics of directional data. Academic Press, LondonGoogle Scholar
  20. Molina MJ, Rowland FS (1974) Stratospheric sink of chlorofluoromethanes chlorine atoms catalyzed destruction of ozone. Nature 249:810–812Google Scholar
  21. Ohnishi T, Hazama M, Okaichi K, Nozu K (1982) Formation of nonviable spores of Dictyostelium discoideum by UV-irradiation and caffeine. Photochem Photobiol 36:355–358Google Scholar
  22. Steed JM, Owens JA, Miller C, Filkin DL, Jesson JP (1982) Two-dimensional modeling of potential ozone perturbation by chlorofluorocarbons. Nature 295:308–311Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Donat-P. Häder
    • 1
  1. 1.Fachbereich Biologie-BotanikMarburgGermany

Personalised recommendations