International Journal of Astrobiology



Raman spectroscopy of senescing snow algae: pigmentation changes in an Antarctic cold desert extremophile


Howell G.M. Edwards a1, Luiz F.C. de Oliveira a1a2, Charles S. Cockell a3, J. Cynan Ellis-Evans a3 and David D. Wynn-Williams a3
a1 Chemical and Forensic Sciences, University of Bradford, Bradford BD7 1DP, UK
a2 Nucleo de Espectroscopia e Estrutiva Molecular, Departmento de Quimica, Instituto de Ciencias Exatas, Universidade Federale de Juiz de Fora, Juiz de Fora, Minas Gerais 36036-330, Brazil
a3 British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK e-mail: h.g.m.edwards@bradford.ac.uk

Article author query
edwards hg   [PubMed][Google Scholar] 
de oliveira lf   [PubMed][Google Scholar] 
cockell cs   [PubMed][Google Scholar] 
ellis-evans jc   [PubMed][Google Scholar] 
wynn-williams dd   [PubMed][Google Scholar] 

Abstract

The FT-Raman spectra are described of green and red snow algae, Chlamydomona, involved in the colonization of exposed surfaces of the McLeod Glacier, Jane Col, Signy Island, situated at the northern edge of the Weddell Sea, Antarctica. The protective biochemicals produced by these extremophilic algae give rise to the so-called watermelon snow of Alpine regions. The red colour of the senescent algae is shown to derive from the accumulation of carotenoids and a deficiency of chlorophyll believed to arise from UV-radiation induced breakdown into phaecophytin. A comparison of the Raman spectra of young (green) and old (red) algae is effected and possible bio-markers for spectral detection on extraterrestrial icy moons and planets are identified.

(Published Online December 24 2004)
(Received July 2 2004)
(Accepted August 23 2004)


Key Words: carotenoids; glacier extremophile; Raman spectroscopy; senescence; snow algae.