Cyanobacteria also have various enz

Cyanobacteria also have various enzymatic defences against reactive oxygen species, such as superoxide
dismutase. Finally, cyanobacteria have a variety of damage repair mechanisms to identify and repair
UV-damaged proteins, for example, in photosynthetic reaction centers, and DNA. This combination of
mechanisms and high tolerance to UV radiation, perhaps also combined with the multiple ‘back-up’ copies
(six or more identical ‘chromosomes’) of the cyanobacterial genome in each cell, likely contribute
to the ecological success of cyanobacteria in many types of habitats exposed to bright sunlight, for
example, as surface blooms, as benthic layers in shallow waters, and in the picoplankton of oligotrophic,
transparent lakes.