Mats, Microbial

Abstract

Microbial mats are defined and distinguished from stromatolites that are, in simple terms, lithified microbial mats. Microbial mats and their microorganisms are described in some detail. Next, the occurrence of extant microbial mats are described with respect to their diverse habitats that include hypersaline waters, geothermal springs, both alkaline and acidic. The lesser known terrestrial crusts and mats are also described in their restricted habitats. This is followed by a more detailed description of mats and their microbial components and the dynamic events that occur in most mat ecosystems. These events include actual movements of many of the organisms, pigment regulations dependent on the external light regime, and the metabolic activities and interactions among the organisms. The methods by which activities within the mats are measured and the methods for identification of component organisms are also described. Two major case studies of microbial mats are described in more detail. Finally, stresses that impact many of the microorganisms and their responses are discussed. These aspects are followed by remarks on the current and future status of microbial mat studies. Many terms are defined in a glossary. A number of books and other publications are listed for further reading.