@article{GerloffEliasBaruaMoelichetal.2006,
  author    = {Gerloff-Elias, Antje and Barua, Deepak and M{\"o}lich, Andreas and Spijkerman, Elly},
  title     = {Temperature- and pH-dependent accumulation of heat-shock proteins in the acidophilic green alga Chlamydomonas acidophila},
  issn      = {0168-6496},
  doi       = {10.1111/j.1574-6941.2006.00078.x},
  year      = {2006},
  abstract  = {Chlamydomonas acidophila, a unicellular green alga, is a dominant phytoplankton species in acidic water bodies, facing severe environmental conditions such as low pH and high heavy metal concentrations. We examined the pH-, and temperature-dependent accumulation of heat-shock proteins in this alga to determine whether heat-shock proteins play a role in adaptation to their environment. Our results show increased heat-shock proteins accumulation at suboptimal pHs, which were not connected with any change in intracellular pH. In comparison to the mesophilic Chlamydomonas reinhardtii, the acidophilic species exhibited significantly higher accumulations of heat-shock proteins under control conditions, indicating an environmental adaptation of increased basal levels of heat-shock proteins. The results suggest that heat- shock proteins might play a role in the adaptation of C. acidophila, and possibly other acidophilic algae, to their extreme environment},
  language  = {en}
}
@article{SpijkermanBaruaGerloffEliasetal.2007,
  author    = {Spijkerman, Elly and Barua, Deepak and Gerloff-Elias, Antje and Gaedke, Ursula and Heckathorn, S. A.},
  title     = {Stress responses and metal tolerance of Chlamydomonas acidophila in metal-enriched lake water and artificial medium},
  doi       = {10.1007/s00792-007-0067-0},
  year      = {2007},
  abstract  = {Chlamydomonas acidophila faces high heavy-metal concentrations in acidic mining lakes, where it is a dominant phytoplankton species. To investigate the importance of metals to C. acidophila in these lakes, we examined the response of growth, photosynthesis, cell structure, heat-shock protein (Hsp) accumulation, and metal adsorption after incubation in metal-rich lake water and artificial growth medium enriched with metals (Fe, Zn). Incubation in both metal-rich lake water and medium caused large decreases in photosystem II function (though no differences among lakes), but no decrease in growth rate (except for medium + Fe). Concentrations of small Hsps were higher in algae incubated in metal-rich lake- water than in metal-enriched medium, whereas Hsp60 and Hsp70A were either less or equally expressed. Cellular Zn and Fe contents were lower, and metals adsorbed to the cell surface were higher, in lake-water-incubated algae than in medium- grown cells. The results indicate that high Zn or Fe levels are likely not the main or only contributor to the low primary production in mining lakes, and multiple adaptations of C. acidophila (e.g., high Hsp levels, decreased metal accumulation) increase its tolerance to metals and permit survival under such adverse environmental conditions. Supposedly, the main stress factor present in the lake water is an interaction between low P and high Fe concentrations.},
  language  = {en}
}