The family Actinomycetaceae

Abstract

Actinomycetaceae, the only family classified in the order Actinomycetales of the phylum Actinobacteria, embraces the genera Actinomyces, Actinobaculum, Arcanobacterium, Mobiluncus, Trueperella, and Varibaculum. Of these genera, the genus Actinomyces has been indicated to be quite diverse, and in a phylogenetic tree based upon 16S rRNA, it showed polyphyletic branching into a number of different clusters and individual lineges. Therefore, it is evident that the generic limits within the family are still uncertain, and although the genera Actinobaculum, Arcanobacterium, Mobiluncus, Trueperella, and Varibaculum have been studied in considerable detail, their relationship to the lesser known hypothetical genera is still unresolved. Members of the family are defined by a wide range of morphological and chemotaxonomic properties, such as polar lipids, fatty acids, amino acids of peptidoglycan, and whole-cell sugars which are used for the delineation of genera and species. Although many of the species of Actinomycetaceae have been extensively studied, using standard biochemical tests, the applicability of such tests have remained limited because the results are often irreproducible. The family harbors many important species which can be found in a wide range of habitats including human, animal, and environmental. Many of these species have been proven to be the casual agents of many human and animal infections.