47

Taxonomy, Physiology,

and Ecology of Aquatic

Microorganisms

4

4.1 Taxonomy of Microorganisms in Aquatic Environments

In this section, the classification of microorganisms
will be discussed and emphasis will be laid on those
microorganisms found in aquatic systems. The follow­
ing are the organisms to be discussed:
Bacteria
Archeae
Eukarya
Fungi
Algae
Protozoa
Viruses

4.1.1 Nature of Modern Taxonomy

Modern taxonomy is the science of biological classifi­

cation. It consists of three sections:

(a) Classification: The theory and process of arran­

ging organisms into taxonomic groups or

taxa (singular, taxon), on the basis of shared

properties.

(b) Nomenclature: The assignment of names to taxo­

nomic groups.

(c) Identification: The determination of the taxon to

which a particular organism belongs, based on the

properties of the organism.

Abstract

The principles behind the taxonomy of the microorganisms, especially the

molecular approach (using the sequence of the 16S RNA in the small subunit of

the ribosome) in the identification of bacteria, are discussed. The detailed taxon­

omy of bacteria, fungi, algae, protozoa, and viruses (including bacteriophages) is

discussed, and emphasis is laid on those microorganisms which are aquatic. The

chapter includes information on some of the smaller macroorganisms found in

water such as nematodes and rotifers. The activities of aquatic microorganisms in

photosynthesis, and the global cycling of nitrogen and sulfur is discussed.

Keywords

Taxonomy of microbial groups • Photosynthesis in aquatic microorganisms

• Aquatic nitrogen and sulfur cycles • Rotifers and nematodes • Bacteria • Fungi


• Protozoa • Algae • Three domains of living things • Woese • 16S or 18S RNA

N. Okafor, Environmental Microbiology of Aquatic and Waste Systems,
DOI 10.1007/978-94-007-1460-1_4, © Springer Science+Business Media B.V. 2011