A newly isolated Chlorella sp. from desert sand crusts exhibits a unique resistance to excess light intensity

FEMS Microbiol Ecol. 2013 Dec;86(3):373-80. doi: 10.1111/1574-6941.12162. Epub 2013 Jul 9.


We recently isolated a small green alga from a biological sand crust (BSC) in the NW Negev, Israel. Based on its 18S rRNA and rbcL genes, it is a close relative of Chlorella sorokiniana and of certain strains of C. vulgaris and C. variabilis, but differs substantially in many aspects from C. sorokiniana. Because the classification of Chlorellales is still not resolved, we designated this species as C. ohadii (Trebouxiophyceae) in honor of Professor Itzhak Ohad. Under controlled laboratory conditions, C. ohadii showed marked structural and photosynthetic performance changes, depending on the carbon source used during growth, as well as remarkable resistance to photoinhibition. CO2 -dependent O2 evolution was not affected even when exposed to a light intensity of 3500 μmole photons m(-2) s(-1) , over 1.5 times the maximal intensity reached at the BSC surface, whereas the variable fluorescence declined sharply. We briefly discuss the use of fluorescence to assess photosynthetic rate and the implications of this finding for the assessment of global BSCs activity.

Keywords: CO2 concentrating mechanism; light intensity; photosynthesis; productivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlorella / classification*
  • Chlorella / cytology
  • Chlorella / isolation & purification*
  • Chlorella / physiology
  • Chlorophyta
  • Desert Climate
  • Israel
  • Light
  • Photosynthesis
  • Phylogeny
  • Silicon Dioxide*


  • Silicon Dioxide