Microbial Food Webs in Aquatic
and Terrestrial Ecosystems
13
Behzad Mostajir, Christian Amblard, Evelyne Buffan-Dubau,
Rutger De Wit, Robert Lensi, and Te ´lesphore Sime-Ngando
Abstract
In microbial food webs, different types of interactions occur between microorganisms
themselves and with meio- and macroorganisms. After an historical and general introduction, the biological components of the microbial food webs in the pelagic and benthic
marine and lake ecosystems, as well as in the terrestrial ecosystems, are presented. The
functioning of the microbial food webs in different ecosystems is illustrated and explained,
including the trophic pathways and transfer of matter from microbial food webs toward
meio- and macroorganisms of the superior trophic levels, the nutrient recycling in the
aquatic environments, and the decomposition of organic matter in soils. Finally, the factors
regulating microbial food webs, primarily “top-down” and “bottom-up” controls, are
described with a special focus on the role of viruses in the aquatic microbial food webs.
Keywords
Biodiversity Biogeochemical cycles Ecological interactions Microbial food
webs Microbial loop
13.1 Introduction
13.1.1 Pelagic Ocean and Lake Ecosystems
The quantitative and functional importance of
microorganisms in aquatic food web was considered seriously only since around 40 years (Pomeroy 1974). This is in
spite of the fact that Lohmann, at the beginning of the 1900s
(quoted in Laval-Peuto et al. 1986), already recognized the
importance of the microzooplankton. In the same way,
Vernadskii (1926, quoted in Pomeroy 1991) referred frequently to microorganisms as an important component of
the general functioning of the oceans, making reference,
especially, to protozoan and to their roles in the flows of
matter and energy and in the biogeochemical cycles. In fact,
before the discovery of the functional role of
microorganisms, the interactions between the organisms, in
particular heterotrophic ones, were considered in a simplistic
way. The structure of the food web for the aquatic systems
was so considered as being established by three levels: the
production of organic matter (OM) by the phytoplankton, its
B. Mostajir* (*) R. De Wit
E ´ cologie des syste `mes marins co ˆtiers (ECOSYM, UMR5119),
Universite ´s Montpellier 2 et 1, CNRS-Ifremer-IRD, 34095 Montpellier
Cedex 05, France
e-mail: Behzad.Mostajir@univ-montp2.fr;
rutger.de-wit@univ-montp2.fr
C. Amblard* (*) T. Sime-Ngando
Laboratoire Microorganismes: Ge ´nome et Environnement (LMGE),
UMR CNRS 6023, Universite ´ Blaise Pascal, Clermont Universite ´, B.P.
80026, 63171 Aube `re Cedex, France
e-mail: christian.amblard@univ-bpclermont.fr;
telesphore.sime-ngando@univ-bpclermont.fr
E. Buffan-Dubau
Laboratoire d’E ´ cologie Fonctionnelle et Environnement (ECOLAB),
UMR CNRS 5245, Universite ´ Paul Sabatier, 31062 Toulouse Cedex 9,
France
e-mail: evelyne.buffan-dubau@univ-tlse3.fr
R. Lensi
Centre d’E ´ cologie Fonctionnelle et E ´ volutive (CEFE), De ´partement
d’E ´ cologie Fonctionnelle, UMR 5175, 34293 Montpellier Cedex 5,
France
* Chapter Coordinators
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_13, # Springer Science+Business Media Dordrecht 2015
485
and Terrestrial Ecosystems
13
Behzad Mostajir, Christian Amblard, Evelyne Buffan-Dubau,
Rutger De Wit, Robert Lensi, and Te ´lesphore Sime-Ngando
Abstract
In microbial food webs, different types of interactions occur between microorganisms
themselves and with meio- and macroorganisms. After an historical and general introduction, the biological components of the microbial food webs in the pelagic and benthic
marine and lake ecosystems, as well as in the terrestrial ecosystems, are presented. The
functioning of the microbial food webs in different ecosystems is illustrated and explained,
including the trophic pathways and transfer of matter from microbial food webs toward
meio- and macroorganisms of the superior trophic levels, the nutrient recycling in the
aquatic environments, and the decomposition of organic matter in soils. Finally, the factors
regulating microbial food webs, primarily “top-down” and “bottom-up” controls, are
described with a special focus on the role of viruses in the aquatic microbial food webs.
Keywords
Biodiversity Biogeochemical cycles Ecological interactions Microbial food
webs Microbial loop
13.1 Introduction
13.1.1 Pelagic Ocean and Lake Ecosystems
The quantitative and functional importance of
microorganisms in aquatic food web was considered seriously only since around 40 years (Pomeroy 1974). This is in
spite of the fact that Lohmann, at the beginning of the 1900s
(quoted in Laval-Peuto et al. 1986), already recognized the
importance of the microzooplankton. In the same way,
Vernadskii (1926, quoted in Pomeroy 1991) referred frequently to microorganisms as an important component of
the general functioning of the oceans, making reference,
especially, to protozoan and to their roles in the flows of
matter and energy and in the biogeochemical cycles. In fact,
before the discovery of the functional role of
microorganisms, the interactions between the organisms, in
particular heterotrophic ones, were considered in a simplistic
way. The structure of the food web for the aquatic systems
was so considered as being established by three levels: the
production of organic matter (OM) by the phytoplankton, its
B. Mostajir* (*) R. De Wit
E ´ cologie des syste `mes marins co ˆtiers (ECOSYM, UMR5119),
Universite ´s Montpellier 2 et 1, CNRS-Ifremer-IRD, 34095 Montpellier
Cedex 05, France
e-mail: Behzad.Mostajir@univ-montp2.fr;
rutger.de-wit@univ-montp2.fr
C. Amblard* (*) T. Sime-Ngando
Laboratoire Microorganismes: Ge ´nome et Environnement (LMGE),
UMR CNRS 6023, Universite ´ Blaise Pascal, Clermont Universite ´, B.P.
80026, 63171 Aube `re Cedex, France
e-mail: christian.amblard@univ-bpclermont.fr;
telesphore.sime-ngando@univ-bpclermont.fr
E. Buffan-Dubau
Laboratoire d’E ´ cologie Fonctionnelle et Environnement (ECOLAB),
UMR CNRS 5245, Universite ´ Paul Sabatier, 31062 Toulouse Cedex 9,
France
e-mail: evelyne.buffan-dubau@univ-tlse3.fr
R. Lensi
Centre d’E ´ cologie Fonctionnelle et E ´ volutive (CEFE), De ´partement
d’E ´ cologie Fonctionnelle, UMR 5175, 34293 Montpellier Cedex 5,
France
* Chapter Coordinators
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_13, # Springer Science+Business Media Dordrecht 2015
485