Extremophiles

, Volume 12, Issue 5, pp 701–711

Identity and physiology of a new psychrophilic eukaryotic green alga, Chlorella sp., strain BI, isolated from a transitory pond near Bratina Island, Antarctica

  • Rachael M. Morgan-Kiss
  • Alexander G. Ivanov
  • Shannon Modla
  • Kirk Czymmek
  • Norman P. A. Hüner
  • John C. Priscu
  • John T. Lisle
  • Thomas E. Hanson
Original Paper

DOI: 10.1007/s00792-008-0176-4

Cite this article as:
Morgan-Kiss, R.M., Ivanov, A.G., Modla, S. et al. Extremophiles (2008) 12: 701. doi:10.1007/s00792-008-0176-4

Abstract

Permanently low temperature environments are one of the most abundant microbial habitats on earth. As in most ecosystems, photosynthetic organisms drive primary production in low temperature food webs. Many of these phototrophic microorganisms are psychrophilic; however, functioning of the photosynthetic processes of these enigmatic psychrophiles (the “photopsychrophiles”) in cold environments is not well understood. Here we describe a new chlorophyte isolated from a low temperature pond, on the Ross Ice Shelf near Bratina Island, Antarctica. Phylogenetic and morphological analyses place this strain in the Chlorella clade, and we have named this new chlorophyte Chlorella BI. Chlorella BI is a psychrophilic species, exhibiting optimum temperature for growth at around 10°C. However, psychrophily in the Antarctic Chlorella was not linked to high levels of membrane-associated poly-unsaturated fatty acids. Unlike the model Antarctic lake alga, Chlamydomonas raudensis UWO241, Chlorella BI has retained the ability for dynamic short term adjustment of light energy distribution between photosystem II (PS II) and photosystem I (PS I). In addition, Chlorella BI can grow under a variety of trophic modes, including heterotrophic growth in the dark. Thus, this newly isolated photopsychrophile has retained a higher versatility in response to environmental change than other well studied cold-adapted chlorophytes.

Keywords

Antarctica Chlorella Green alga Photophysiology Photopsychrophile 

Abbreviations

A

Antheraxanthin

Chl-a

Chlorophyll a

Chl-b

Chlorophyll b

EPS

Epoxidation state of the xanthophyll cycle

F685,695,715

77 K Fluorescence emission maxima at 685, 695, 715 nm

FAMEs

Fatty acid methyl esters

LHC II

Light harvesting II

PAR

Photosynthetically active radiation

PS I

Photosystem I

PS II

Photosystem II

PUFAs

Polyunsaturated fatty acids

Top

Optimal growth temperature

Tmax

Maximum growth temperature

V

Violaxanthin

Z

Zeaxanthin

Supplementary material

792_2008_176_MOESM1_ESM.jpg (414 kb)
False coloured SEM of Chlorella BI grown under mixotrophic conditions 236x211mm (72 x 72 DPI) (JPG 414 kb).
792_2008_176_MOESM2_ESM.jpg (328 kb)
SEM of Chlorella BI grown under mixotrophic conditions 236x211mm (72 x 72 DPI) (JPG 327 kb).
792_2008_176_MOESM3_ESM.tif (3.6 mb)
(JPG 3.62 mb)

Copyright information

© Springer 2008

Authors and Affiliations

  • Rachael M. Morgan-Kiss
    • 1
  • Alexander G. Ivanov
    • 2
  • Shannon Modla
    • 3
  • Kirk Czymmek
    • 3
  • Norman P. A. Hüner
    • 2
  • John C. Priscu
    • 4
  • John T. Lisle
    • 5
  • Thomas E. Hanson
    • 3
    • 6
  1. 1.Department of MicrobiologyMiami UniversityOxfordUSA
  2. 2.Department of Biology and The BiotronUniversity of Western OntarioLondonCanada
  3. 3.Delaware Biotechnology InstituteUniversity of DelawareNewarkUSA
  4. 4.Department of Land Resources and Environmental SciencesMontana State UniversityBozemanUSA
  5. 5.USGS Centre for Coastal and Watershed ResearchSt PetersburgFLUSA
  6. 6.College of Marine and Earth StudiesUniversity of DelawareNewarkUSA

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