A newly isolated Chlorella sp. from desert sand crusts exhibits a unique resistance to excess light intensity. Issue 3 (9th July 2013)

• Record Type: Journal Article
• Authors: Treves, Haim; Raanan, Hagai; Finkel, Omri M.; Berkowicz, Simon M.; Keren, Nir; Shotland, Yoram; Kaplan, Aaron
• Is Part Of: FEMS microbiology ecology. Volume 86:Issue 3(2013)
• Page Start: 373
• Page End: 380
• Publication Date: 2013-07-09
• Subjects: CO2 concentrating mechanism -- light intensity -- photosynthesis -- productivity; Microbial ecology -- Periodicals; Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1574-6941.12162
• Languages: English
• ISSNs: 0168-6496

Abstract

Abstract: 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.