Deoxyribonucleic Acid Homology of Prosthecomicrobium and Ancalomicrobium Strains

Abstract

Deoxyribonucleic acid base sequence homology studies have been conducted on 14 strains of the Prosthecomicrobium-Ancalomicrobium group as well as selected strains of other prosthecate bacteria in the genera Hyphomicrobium and Caulobacter. By this procedure Prosthecomicrobium and Ancalomicrobium are not closely related to either the Hyphomicrobium or Caulobacter strains tested. The type strains of P. enhydrum, P. pneumaticum, and A. adetum are discrete from one another, therefore justifying the current taxonomic treatment of the group. In addition to these species, there are at least two additional groups of strains fitting the description of Prosthecomicrobium and Ancalomicrobium but differing from the type strains. One group is comprised of short-appendaged motile and nonmotile strains which morphologically resemble P. enhydrum but show insignificant polynucleotide reassociation with it. The other group, represented by at least four strains, has both short and long appendages and in other respects shares properties with both P. enhydrum and A. adetum.