Structure and Functions of Microorganisms:
Production and Use of Material and Energy
3
Robert Matheron and Pierre Caumette
Abstract
The cellular structures of prokaryotic and eukaryotic microorganisms and the characters
distinguishing the three domains of life (Archaea, Bacteria, Eukarya) are first described.
Then, the metabolic diversity of microorganisms is discussed, the knowledge of which is
essential to understand the role of microorganisms in natural and anthropogenic environments.
The different degradation pathways for mineral and organic compounds that provide cellular
energy are described (aerobic and anaerobic respirations, fermentations) as well as the
photosynthetic processes (aerobic and anaerobic photosynthesis). Finally, the mechanisms
of biosynthesis are presented: autotrophy and heterotrophy, assimilation of C1, and assimilation of organic and inorganic compounds (mainly nitrogen and sulfur assimilation).
Keywords
Aerobic respirations Anaerobic respirations CO 2 assimilation Eukaryotic
cells Fermentations Heterotrophic biosynthesis Inorganic compound
assimilation Photosynthesis Prokaryotic cells
3.1
Structure and Functions of Prokaryotes
and Eukaryotes: Major Features
and Differences
The living world is now divided into three major areas (see the
second part of the book, Chaps. 5, 6, and 7) in which the cellular
structure is either of the prokaryotic or eukaryotic type. The
Bacteria and Archaea domains consist of microorganisms of
usually unicellular prokaryotic type, and the Eukarya domain
includes microorganisms and multicellular organisms that are
all of eukaryotic type. One major difference between prokaryotic and eukaryotic cells is the absence of a nuclear membrane
in prokaryotes which is needed to define a true nucleus
(chromosomes have been separated from the cytoplasm by
the nuclear membrane) in eukaryotes (from the Greek eu:
true, caryon: nucleus). In prokaryotes, the generally circular
chromosome present in a single copy is directly in the cytoplasm (pro: that precedes, caryon: nucleus). In some
prokaryotes, it may be linear and in multiple copies
(Rhodobacter sphaeroides: two copies; Halobacterium sp.:
three copies). Both types of structure are also differentiated
by their size and cell contents including the presence of various
organelles in eukaryotes (Fig. 3.1a; Table 3.1).
3.1.1 Prokaryotic Microorganisms (Bacteria
and Archaea, cf. Chaps. 5 and 6)
Prokaryotes are unicellular microorganisms. However, some
may associate to form clusters more or less regular, single
filaments or branched filaments from a few cells to hundreds
R. Matheron* (*)
Institut Me ´diterrane ´en de Biodiversite ´ et d’Ecologie marine et
continentale (IMBE), UMR-CNRS-IRD 7263, Aix-Marseille
Universite ´, 13397 Marseille Cedex 20, France
e-mail: matheron.robert@gmail.com
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
* Chapter Coordinator
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_3, # Springer Science+Business Media Dordrecht 2015
25
Production and Use of Material and Energy
3
Robert Matheron and Pierre Caumette
Abstract
The cellular structures of prokaryotic and eukaryotic microorganisms and the characters
distinguishing the three domains of life (Archaea, Bacteria, Eukarya) are first described.
Then, the metabolic diversity of microorganisms is discussed, the knowledge of which is
essential to understand the role of microorganisms in natural and anthropogenic environments.
The different degradation pathways for mineral and organic compounds that provide cellular
energy are described (aerobic and anaerobic respirations, fermentations) as well as the
photosynthetic processes (aerobic and anaerobic photosynthesis). Finally, the mechanisms
of biosynthesis are presented: autotrophy and heterotrophy, assimilation of C1, and assimilation of organic and inorganic compounds (mainly nitrogen and sulfur assimilation).
Keywords
Aerobic respirations Anaerobic respirations CO 2 assimilation Eukaryotic
cells Fermentations Heterotrophic biosynthesis Inorganic compound
assimilation Photosynthesis Prokaryotic cells
3.1
Structure and Functions of Prokaryotes
and Eukaryotes: Major Features
and Differences
The living world is now divided into three major areas (see the
second part of the book, Chaps. 5, 6, and 7) in which the cellular
structure is either of the prokaryotic or eukaryotic type. The
Bacteria and Archaea domains consist of microorganisms of
usually unicellular prokaryotic type, and the Eukarya domain
includes microorganisms and multicellular organisms that are
all of eukaryotic type. One major difference between prokaryotic and eukaryotic cells is the absence of a nuclear membrane
in prokaryotes which is needed to define a true nucleus
(chromosomes have been separated from the cytoplasm by
the nuclear membrane) in eukaryotes (from the Greek eu:
true, caryon: nucleus). In prokaryotes, the generally circular
chromosome present in a single copy is directly in the cytoplasm (pro: that precedes, caryon: nucleus). In some
prokaryotes, it may be linear and in multiple copies
(Rhodobacter sphaeroides: two copies; Halobacterium sp.:
three copies). Both types of structure are also differentiated
by their size and cell contents including the presence of various
organelles in eukaryotes (Fig. 3.1a; Table 3.1).
3.1.1 Prokaryotic Microorganisms (Bacteria
and Archaea, cf. Chaps. 5 and 6)
Prokaryotes are unicellular microorganisms. However, some
may associate to form clusters more or less regular, single
filaments or branched filaments from a few cells to hundreds
R. Matheron* (*)
Institut Me ´diterrane ´en de Biodiversite ´ et d’Ecologie marine et
continentale (IMBE), UMR-CNRS-IRD 7263, Aix-Marseille
Universite ´, 13397 Marseille Cedex 20, France
e-mail: matheron.robert@gmail.com
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
* Chapter Coordinator
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_3, # Springer Science+Business Media Dordrecht 2015
25