Skip to main content

Open Access Strategies of adaptation by Antarctic cyanobacteria to ultraviolet radiation

Download Article:
(PDF 428.3 kb)
Effects of UVA and UVB radiation were evaluated on two cyanobacterial strains (Phormidium murrayi and Oscillatoria priestleyi) isolated from the McMurdo Ice Shelf, Antarctica. The two isolates showed some similarities, but also major differences in their qualitative and quantitative responses to ultraviolet radiation (UVR). Growth decreased with increasing UVR, but with a 5-fold (UVA) or 10-fold (UVB) greater effect on O. priestleyi than P. murrayi. In both isolates, cellular concentrations of phycobiliproteins (measured by in vivo absorbance), and to a lesser extent chlorophyll a, diminished with increasing UVR exposure. Spectral scans of methanol extracts indicated the presence of UVR-screening compounds in O. priestleyi but not P. murrayi; however, the absorbance per unit dry weight was low, and similar in cultures with and without UVR. Carotenoid pigments increased up to a threshold UVB flux and thereafter decreased. In both isolates, moderate UVA lessened the effect of growth inhibition by UVB, consistent with a UVA-activated repair mechanism. Comparative motility tests showed that O. priestleyi is a fast gliding species that can rapidly relocate in response to changes in ambient light, while P. murrayi is non-motile. The ability of O. priestleyi to escape UVR by gliding, and the greater ability of P. murrayi to tolerate UVA and UVB exposure, illustrate the differences in UVR survival strategies even between closely related species of cyanobacteria.
No References for this article.
No Supplementary Data.
No Article Media
No Metrics

Keywords: Antarctica; Oscillatoria; Phormidium; UV; blue-green algae; cyanobacteria; damage; ultraviolet

Document Type: Research Article

Affiliations: Dépt. de biologie & Centre d'études nordiques, Université Laval, Sainte-Foy, Québec G1K 7P4, Canada

Publication date: 26 November 1997

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more