Chapter 3
Microbes and Marine Sediments: A
Lifelong Relationship on Earth’s Biosphere
Jerónimo Pan
Abstract The relationship between microbes and marine sediments probably dates
back to the very origin of life on Earth. This intimate association is exemplified by
how the physical and geochemical environment within sediments determines which
microbes dominate a certain consortium and, in turn, how microorganisms have
profound effects on sediment properties through their metabolic activities at various
(spatial and temporal) scales. Microbial mats, the oldest ecosystems on Earth with a
fossil record dating back to 3.4 Ga, are biosedimentary structures in which microbes
exploit all environmental niches that arise in relation to strong gradients in light,
redox potential, the concentration of viable substrates for energy acquisition, as well
as toxic compounds. In fact, microbial mats have been thought to be the environment
where several metabolic pathways evolved, establishing microbial lineages and
biogeochemical processes that last to this day. This chapter provides a concise
summary of the evolution of those early microbial lineages, to then revisit modern,
hypersaline microbial mats, and some of the microbially induced sedimentary
structures (MISS) that arise from mats colonizing siliciclastic sediments. Salient
ecological features and the metabolism of their microbes are briefly discussed, while
emphasis is made on what can be learned from their study through the actualistic
perspective of GeoBiology. Emergent properties of microbe-sediment interactions
essential for the development, establishment, and preservation of microbial mats in
modern and fossil settings are discussed.
J. Pan (*)
CONICET, National Scientific and Technical Research Council, Buenos Aires, Argentina
Instituto de Geología de Costas y del Cuaternario (IGCyC, CIC-UNMdP), Mar del Plata,
Argentina
Instituto de Investigaciones Marinas y Costeras (IIMyC), Mar del Plata, Argentina
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_3
57
Microbes and Marine Sediments: A
Lifelong Relationship on Earth’s Biosphere
Jerónimo Pan
Abstract The relationship between microbes and marine sediments probably dates
back to the very origin of life on Earth. This intimate association is exemplified by
how the physical and geochemical environment within sediments determines which
microbes dominate a certain consortium and, in turn, how microorganisms have
profound effects on sediment properties through their metabolic activities at various
(spatial and temporal) scales. Microbial mats, the oldest ecosystems on Earth with a
fossil record dating back to 3.4 Ga, are biosedimentary structures in which microbes
exploit all environmental niches that arise in relation to strong gradients in light,
redox potential, the concentration of viable substrates for energy acquisition, as well
as toxic compounds. In fact, microbial mats have been thought to be the environment
where several metabolic pathways evolved, establishing microbial lineages and
biogeochemical processes that last to this day. This chapter provides a concise
summary of the evolution of those early microbial lineages, to then revisit modern,
hypersaline microbial mats, and some of the microbially induced sedimentary
structures (MISS) that arise from mats colonizing siliciclastic sediments. Salient
ecological features and the metabolism of their microbes are briefly discussed, while
emphasis is made on what can be learned from their study through the actualistic
perspective of GeoBiology. Emergent properties of microbe-sediment interactions
essential for the development, establishment, and preservation of microbial mats in
modern and fossil settings are discussed.
J. Pan (*)
CONICET, National Scientific and Technical Research Council, Buenos Aires, Argentina
Instituto de Geología de Costas y del Cuaternario (IGCyC, CIC-UNMdP), Mar del Plata,
Argentina
Instituto de Investigaciones Marinas y Costeras (IIMyC), Mar del Plata, Argentina
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_3
57