Open AccessA newly isolated Chlorella sp. from desert sand crusts exhibits a unique resistance to excess light intensity
Author(s) -
Treves Haim,
Raanan Hagai,
Finkel Omri M.,
Berkowicz Simon M.,
Keren Nir,
Shotland Yoram,
Kaplan Aaron
Publication year - 2013
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/1574-6941.12162
Subject(s) - biology , photoinhibition , botany , photosynthesis , chlorella , chlorella sorokiniana , light intensity , algae , ecology , photosystem ii , physics , optics
We recently isolated a small green alga from a biological sand crust ( BSC ) in the NW N egev, I srael. Based on its 18S rRNA and rbcL genes, it is a close relative of C hlorella sorokiniana and of certain strains of C . vulgaris and C . variabilis , but differs substantially in many aspects from C . sorokiniana . Because the classification of C hlorellales is still not resolved, we designated this species as C . ohadii ( T rebouxiophyceae ) in honor of P rofessor I tzhak O had. 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. CO 2 ‐dependent O 2 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 BSC s activity.