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

作者：Treves Haim; Raanan Hagai; Finkel Omri M; Berkowicz Simon M; Keren Nir; Shotland Yoram; Kaplan Aaron^*

来源：FEMS Microbiology Ecology, 2013, 86(3): 373-380.

DOI：10.1111/1574-6941.12162

• CO2 concentrating mechanism
• light intensity
• photosynthesis
• productivity

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 O-2 evolution was not affected even when exposed to a light intensity of 3500molephotonsm(-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.

• 出版日期2013-12