Antarctic diatoms

Increased synthesis of MAAs by exposure to high intensity artificial visible light also occurs in the Antarctic diatom Thalassiosira weissflogii, the prasinophyte Pyramimonas parkae, and most markedly in the dinoflagellate Amphidinium carterae (six-fold increase over control).171 However, high visible light exposure does not affect the MAA content of two other unicellular algae, Dunaliella tertiolecta (Chlorophyta) and Isochrysis sp. (Haptophyta). Supplemental exposures with UVA and UVB in combination and alone result in a variety of species-specific responses. 

Riegger, L. and Robinson, D., Photoinduction of UV-absorbing compounds in Antarctic diatoms and Phaeocystis antarctica, Mar. Ecol. Prog. Ser., 160, 13, 1997. 

Baumann MEM, Brandini FP, Staubes R (1993) The influ-cence of light and temperature on carbon specific DMS-release by cultures of Phaeocystis antarctica and three Antarctic diatoms. Mar Chem 45 56-78 Baumann MEM, Lancelot C, Brandini FP, Sakshaug E, John DM (1994) The taxonomic identity of the cosmopolitan prymnesiophyte Phaeocystis a morphological and ecophysiological approach. J Mar Syst 5 23-39 Buma AGJ, Bano N, Veldhuis MJW, Kraay GW (1991) Comparison of the pigmentation of two strains of the prymnesiophyte Phaeocystis sp. Neth J Sea Res 27 173-182... 

Van Oijen T, Van Leeuwe MA, Gieskes WWC, De Baar HJW (2004a) Effects of iron limitation on photosynthesis and carbohydrate metabolism in the Antarctic diatom Chaetoceros brevis (Bacillariophyceae). Eur J Phycol 39 161-171... 

Baumann MEM, Brandini FP, Staubes R (1994) The influence of light and temperature on carbon-specific DMS release by cultures of Phaeocystis antarctica and three antarctic diatoms. Mar Chem 45 129-136... 

CrostaX., Pichon J.-J., and Burckle L. H. (1998) Application of modern analogue technique to marine Antarctic diatoms reconstruction of maximum sea-ice extent at the Last Glacial Maximum. Paleoceanography 13(3), 284—297. 

Figure 2 X-ray diffraction pattern of Antarctic diatoms from plankton tow. The amorphous nature of the siliceous material is apparent from the very broad peak, which occurs at an angle of —20-26° two theta.

G. Dohler (1996). Effect of UV irradiance on utilization of inorganic nitrogen by the Antarctic diatom Odontella weissflogii (Janisch) grunow. Bot. Acta, 109,35-42. 

Figure 1. Relationship between surface area volume ratios and total UV-B-induced photoproducts in 9 marine Antarctic diatoms. 1 Coscinodiscus oculis-iridis 2 Corethron cryophilum 3 Odontella weissflogii 4 Thalassiosira australis 5 Chaetoceros convolutus 6 Thalassiosira subtilis 7 Chaetoceros socialis 8 Chaetoceros neglectus 9 Nitzschia kerguelensis. [Redrawn after Karentz et al. 9.]...

A. McMinn, H. Heijnis, D. Hodgson (1994). Minimal effects of UVB radiation on Antarctic diatoms over the past 20 years. Nature, 370, 547-549. 

Terpenes are the predominant natural product in green macroalgae and diatoms and related groups.92 With the exception of an evaluation of VHOC production, for which these algae are only minor producers,147143 there have been no published investigations of their secondary metabolite chemistry from Antarctic regions. 

An MAA with a possible restricted geographic occurrence is mycosporine-glycine valine. This MAA was first described from a survey of Antarctic species and was initially observed only in consumer organisms (invertebrates and fish), not any of the sampled primary producers.107 Subsequent studies in the Antarctic have identified this MAA in the diatom Fragilariopsis cylindrus, the haptophyte Phaeocystis sp., and mixed assemblages of Southern Ocean phytoplankton.124 126 128 There have been a few tentative identifications of mycosporine-glycine valine in organisms from... 

Nichols, P.D., Palmisano, A.C., Rayner, M.S., Smith, GA., and White, D.C. (1990) Occurrence of novel C20 sterols in Antarctic sea ice diatom communities during spring bloom. Org. Geochem. 15, 503-508. 

Robinson, R. S., BruneUe, B. G., and Sigman, D. M. (2004). Revisiting nutrient utilization in the glacial Antarctic Evidence from a new method for diatom-bound N isotopic analysis. Paleoceanography 19(3), doi 10.1029/2003PA000996. 

---