Cyanobacteria are among the oldest organisms on earth [1]. These
microorganisms are gram-negative prokaryotes and perform oxygenic
photosynthesis, with a photosynthetic machinery similar to higher
plants [2]. It is thought that they raised the O2 levels in the atmosphere
when the earth was anoxic, 2.3 billion years ago [3]. Presently,
cyanobacteria are broadly distributed in different natural habitats such
as marine and freshwater, different terrestrial and extreme environments