Taxonomy, which is the science of biological classification, is divided into 3 main interconnected parts that include identification, classification and nomenclature. Microbial identification system is made possible through the systematic classification, identification, and naming (nomenclature) of microorganisms; and this is made possible based on the shared morphological and/or physiological characteristics that microorganisms share. The three categories of taxonomy include: classification, identification and nomenclature.

  • Identification: This is the practical side of taxonomy which helps to determine that a particular microorganism isolated from a given sample belongs to a recognized taxon (group) of organisms. In identifying an organism, varying experiments are often undertaken in order to characterize and designate the organism to a given taxon following already laid down classification scheme.
  • Classification: This is the arrangement of living organisms into different groups (or taxa) based on some shared similarity or evolutionary relatedness shared by the organisms being classified. In classifying a microorganism (e.g. bacteria), an understanding of the results obtained from observational, experimental, biochemical, morphologic and physiological examinations carried out on the organism is always taken into consideration when assigning an organism to a given taxon.
  • Nomenclature: This is the component of taxonomy that assign names to organisms based on already published guidelines or principles. The characteristics of a given organism (e.g. bacteria) is also taken into consideration when assigning it a name

Microorganisms have wide taxonomic distribution and this includes organisms such as viruses, bacteria, protozoa, algae, fungi, and Archaea. See subsequent sections for the description of these taxonomic groups of microorganisms.


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