ABSTRACT
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In natural environments, microorganisms grow rarely in isolation as a single species or population. Highly specic and less understood interactions among unrelated species play a crucial role in the establishment of a successful microbial assemblage in the form of microbial biolms or mats. Multilayered microbial assemblage, generally with a coherent structure, growing on or within some substratum is called a microbial mat. There are many varieties of microbial mats including mats of diatoms and biolms. Microbial mats can be dened as stratied communities of microorganisms that develop along physiochemical gradients at the interface of water and solid substances held together by a dense matrix. In a mat, different groups of microorganisms are protected from deleterious effects of harsh environments like high and low temperatures, hypersalinity, temperature extremes, acidic pH, and many other factors.
