Microbial Systematics

Abstract

This chapter aims at presenting an overview of different aspects of the classification and nomenclature of the prokaryotes, i.e., the domains Bacteria and Archaea. Concepts of systematics, taxonomy, classification, nomenclature, and identification are discussed. The number of species of prokaryotes – Bacteria and Archaea combined – is surprisingly small, 8,226 as of November 2009. It is obvious that the true number of different species much larger: we probably know less than 1% of the types of prokaryotes in Nature. Classification of prokaryotes and description of species based on a polyphasic approach that includes phenotypic as well as genotypic properties. Nomenclature is governed by the rules of the Bacteriological Code (International Code of Nomenclature of Prokaryotes), as determined by the International Committee on Systematics of Prokaryotes.