Effect of external pH on the growth, photosynthesis and photosynthetic electron transport of Chlamydomonas acidophila Negoro, isolated from an extremely acidic Lake

A Gerloff-Elias, E Spijkerman, Thomas Pröschold

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

In extremely acidic lakes, low primary production rates have been measured. We assumed that proton stress might explain these observations and therefore investigated the photosynthetic behaviour of a Chlamydomonas species, a main primary producer in acidic lakes, over a range of pH values. Identified as C. acidophila using small subunit rDNA analysis, this species is identical to other isolates from acidic environments in Europe and South America, suggesting a worldwide distribution. Laboratory experiments with C. acidophila, revealed a broad pH-tolerance for growth and photosynthesis, the lower pH limit lying at pH 1.5 and the upper limit at pH 7. Growth rates at optimum pH conditions (pH 3 and 5) were equal to those of the mesophilic Chlamydomonas reinhardtii. In contrast, photosynthetic rates were significantly higher, suggesting that higher photosynthetic rates compensated for higher dark respiration rates, as confirmed experimentally. Electron transport capacities of PSI and PSII, P700(+) re-reduction times and measurements of PSII fluorescence revealed the induction of alternative electron transport mechanisms, such as chlororespiration, state transitions and cyclic electron transport, only at suboptimal pH values (pH 1.5; 4 and 6-7). The results indicate, that C. acidophila is well adapted to low pH and that the relatively low primary production rates are not a result of pH stress.
Original languageEnglish
Pages (from-to)1218-1229
Number of pages12
JournalPLANT CELL ENVIRON
Issue number8
DOIs
Publication statusPublished - 2005

    Fingerprint

Keywords

  • CHLORELLA
  • LIGHT-ADAPTATION
  • MINING LAKES
  • QUANTUM YIELD
  • GREEN-ALGA
  • CHLOROPHYTA
  • PHOTOSYSTEM-I
  • INTERNAL PH
  • DUNALIELLA-ACIDOPHILA
  • PHYTOPLANKTON
  • Plant Sciences

Cite this