Microbial Mats

[maɪˈkroʊ.bi.əl mæts]

Related terms: Biofilm, Bodenhorizont (German), Composition, Holobiont, Life-forms, Marais (French), Skin of the Earth, Stromatolites, Symbiosis

»Bacteria run the planet!« [*]

Microbial mats are the earliest form of life on Earth. They are composed of multi-layered horizontal sheets of microorganisms, made up largely of bacteria and archaea. They were discovered to be the literal »skin« of the Earth, from which all diverse life-forms are born. They are entirely visible to the naked eye and can be most easily found in aquatic settings. Photosynthetic mats were responsible for creating the oxygen-rich atmosphere that we breathe today. Microbial mats colonize almost all environments they can live in (-40 degrees to 120 degrees Celsius). They are responsible for maintaining ecosystems on Earth and are known to turn any matter into »food« to survive and grow; the waste of one species of microbe is another species’ food. In this process, microbes have transformed a very hostile environment into the environment we live in today. Life on Earth did not occur because there was a spontaneously habitable environment for life to come into being – instead, life itself (in the microbial mats) is responsible for the oxygenated environment that allowed microbes to give way to all life-forms on Earth. We are just architecture for bacteria.

[*] Lynn Margulis, in: Symbiotic Earth. Dir. John Feldman. Hummingbird Films, 2017.