HYPOLITHIC CYANOBACTERIA COLONIZATION OF QUARTZ AT SOUTH DESERT

Hypolithic microbial communities (found underneath rocks) were encountered in the southern desert of Qatar where quartz rocks are ubiquitous and are a substrate for hypoliths. These hypoliths thrive where extreme temperature, moisture stress and high light intensity limit the occurrence of higher plants and animal life. A small-scale ecological survey indicated that 80% of the quartz rocks in the area were colonized by green hypolithic microbial communities dominated by colonization of cyanobacteria. Using light and electron microscopic analyses; the cyanobacterial community structure of hypoliths was shown to be dominated by cyanobacteria affiliated to the genera Chroococcidiopsis, Aphanothece, Pleurocapsa, Oscillatoria, Lyngbya, Leptolyngbya, Phormidium and Scytonema).