Microbial Mats

Synonyms

Benthic mats; Biofilms; Cyanobacterial mats; Farbstreifen Sandwatt; Laminated microbial ecosystems; Living stromatolites; Microbially Induced Sediment Structures (MISS); Modern stromatolites

Definition

Microbial mats are benthic small-scale ecosystems that generally develop under environmental conditions that exclude fauna, often referred to as “extreme environments.” The biogeochemical cycles in microbial mats are usually largely closed, although small fluxes of elements are exchanged with the geo-, bio-, and atmosphere. An important feature of microbial mats is their carbon and nitrogen autotrophy, i.e., the fixation of inorganic carbon and atmospheric nitrogen are key processes. In illuminated environments, therefore, the photoautotrophic cyanobacteria are the mat-building organisms while in the deep sea or in some caves, chemosynthetic bacteria and archaea are the primary producers.

Overview

The term microbial matoriginates from the macroscopic structure that these...