The Thematic Fields of Microbial Ecology
1
Jean-Claude Bertrand, Pierre Caumette, Philippe Lebaron,
and Philippe Normand
Abstract
The microbial world, generally invisible to the naked eye, has largely shaped our environment
and has been instrumental in the emergence and evolution of all other living organisms on
Earth. These microscopic unicellular organisms were for 3 billion years the only forms of life
on our planet.
Their most spectacular action was the modification of the primitive atmosphere: the
dioxygen certainly not present initially reached its present concentration (21 % of the gas
content of the atmosphere) through the action of microorganisms that are able of oxygenic
photosynthesis. For the evolution of life, it is now widely accepted that multicellular life
forms extremely complex have emerged from eukaryote microorganisms classified in the
kingdom Plantae and in the Stramenopiles and Opisthokonta (especially metazoans which
includes humans). These life forms are still dependent on the activity of microorganisms.
If a disaster, whether natural or caused by humans, should annihilate all nonmicrobial
living species, it is likely that some microorganisms that have colonized all oceans (from the
surface to the abyssal domain) and the earth’s crust (to a depth of hundreds of meters) would
be spared and would allow the initiation of a new evolution process, whatever the new
environmental conditions at the end of this disaster, except in the absence of liquid water.
Keywords
Biogeochemical cycle Distribution Diversity Ecosystems Evolution Interactions
Origin Taxonomy Xenobiotics
All authors contributed equally to this chapter.
J.-C. Bertrand
Institut Me ´diterrane ´en d’Oce ´anologie (MIO), UM 110, CNRS 7294
IRD 235, Universite ´ de Toulon, Aix-Marseille Universite ´,
Campus de Luminy, 13288 Marseille Cedex 9, France
e-mail: Jean-Claude.bertrand@univ-amu.fr
P. Caumette
Institut des Sciences Analytiques et de Physico-chimie pour
l’Environnement et les Mate ´riaux (IPREM), UMR CNRS 5254,
Universite ´ de Pau et des Pays de l’Adour, B.P. 1155,
64013 Pau Cedex, France
e-mail: pierre.caumette@univ-pau.fr
P. Lebaron
Observatoire Oce ´anologique de Banyuls, Laboratoire de Biodiversite ´ et
Biotechnologie Microbiennes (LBBM), Sorbonne Universite ´s, UPMC
Univ Paris 06, USR CNRS 3579, 66650 Banyuls-sur-Mer, France
e-mail: lebaron@obs-banyuls.fr
P. Normand
Microbial Ecology Center, UMR CNRS 5557 / USC INRA 1364,
Universite ´ Lyon 1, 69622 Villeurbanne, France
e-mail: philippe.normand@univ-lyon1.fr
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_1, # Springer Science+Business Media Dordrecht 2015
3
1
Jean-Claude Bertrand, Pierre Caumette, Philippe Lebaron,
and Philippe Normand
Abstract
The microbial world, generally invisible to the naked eye, has largely shaped our environment
and has been instrumental in the emergence and evolution of all other living organisms on
Earth. These microscopic unicellular organisms were for 3 billion years the only forms of life
on our planet.
Their most spectacular action was the modification of the primitive atmosphere: the
dioxygen certainly not present initially reached its present concentration (21 % of the gas
content of the atmosphere) through the action of microorganisms that are able of oxygenic
photosynthesis. For the evolution of life, it is now widely accepted that multicellular life
forms extremely complex have emerged from eukaryote microorganisms classified in the
kingdom Plantae and in the Stramenopiles and Opisthokonta (especially metazoans which
includes humans). These life forms are still dependent on the activity of microorganisms.
If a disaster, whether natural or caused by humans, should annihilate all nonmicrobial
living species, it is likely that some microorganisms that have colonized all oceans (from the
surface to the abyssal domain) and the earth’s crust (to a depth of hundreds of meters) would
be spared and would allow the initiation of a new evolution process, whatever the new
environmental conditions at the end of this disaster, except in the absence of liquid water.
Keywords
Biogeochemical cycle Distribution Diversity Ecosystems Evolution Interactions
Origin Taxonomy Xenobiotics
All authors contributed equally to this chapter.
J.-C. Bertrand
Institut Me ´diterrane ´en d’Oce ´anologie (MIO), UM 110, CNRS 7294
IRD 235, Universite ´ de Toulon, Aix-Marseille Universite ´,
Campus de Luminy, 13288 Marseille Cedex 9, France
e-mail: Jean-Claude.bertrand@univ-amu.fr
P. Caumette
Institut des Sciences Analytiques et de Physico-chimie pour
l’Environnement et les Mate ´riaux (IPREM), UMR CNRS 5254,
Universite ´ de Pau et des Pays de l’Adour, B.P. 1155,
64013 Pau Cedex, France
e-mail: pierre.caumette@univ-pau.fr
P. Lebaron
Observatoire Oce ´anologique de Banyuls, Laboratoire de Biodiversite ´ et
Biotechnologie Microbiennes (LBBM), Sorbonne Universite ´s, UPMC
Univ Paris 06, USR CNRS 3579, 66650 Banyuls-sur-Mer, France
e-mail: lebaron@obs-banyuls.fr
P. Normand
Microbial Ecology Center, UMR CNRS 5557 / USC INRA 1364,
Universite ´ Lyon 1, 69622 Villeurbanne, France
e-mail: philippe.normand@univ-lyon1.fr
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_1, # Springer Science+Business Media Dordrecht 2015
3