vitamin-k-semiquinone-radical and 2-4-diaminobutyric-acid

An HPLC procedure which separates D- and L-amino acid isomers was applied to an analysis of peptidoglycan of 2,4-diaminobutyric acid (DAB)-containing actinomycetes. The cell wall peptidoglycans of species of the genera Agromyces, Clavibacter and Rathayibacter contain DAB and have been differentiated principally by their menaquinone profile. These peptidoglycans are known to be identical in structure, all being of the B2 gamma type, possessing both D- and L-DAB. The type strains of all the subspecies of Clavibacter michiganesis have D- and L-DAB in almost equal proportions in their cell wall peptidoglycan as previously reported. In contrast, the type strains of Clavibacter toxicus and all valid species of the genera Agromyces and Rathayibacter contain the L-isomer of DAB almost exclusively. This characteristic is in good agreement with phylogenetic analyses based on 16S rDNA sequences and menaquinone profiles. On the basis of these data, the transfer of Clavibacter toxicus to the genus Rathayibacter as Rathayibacter toxicus comb. nov. is proposed. The isomer profile of DAB is shown to be a good taxonomic marker to differentiate these genera.

Topics: Actinomycetales; Amino Acids; Aminobutyrates; Base Composition; Base Sequence; Cell Wall; DNA, Bacterial; Isomerism; Molecular Sequence Data; Peptidoglycan; Phylogeny; Stereoisomerism; Vitamin K

"Curtobacterium psychrophilum," proposed by Inoue and Komagata in 1976, is a psychrophilic gram-positive irregular rod isolated from Antarctic soil. This organism grew optimally at 9 to 12 degrees C and did not grow at higher than 18 degrees C. Chemotaxonomic characteristics of this organism were the presence of 2,4-diaminobutyric acid in the cell wall and menaquinone-10 as the predominant respiratory quinone. The cellular fatty acid profile, which contained a significant amount of an anteiso-branched monounsaturated acid, 12-methyl tetradecenoic acid, was a distinctive characteristic of this organism and was reasonable for adaptation to low temperature. Phylogenetic analysis based on 16S ribosomal DNA sequences revealed that this organism was positioned at a separate branch in the family Microbacteriaceae, actinomycetes with group B peptidoglycan. We propose the name Cryobacterium psychrophilum gen. nov., sp. nov. for this organism. The type strain is JCM 1463 (= IAM 12024 = ATCC 43563 = IFO 15735 = NCIMB 2068).

Topics: Actinomycetales; Aminobutyrates; Antarctic Regions; Base Composition; DNA, Bacterial; DNA, Ribosomal; Fatty Acids; Molecular Sequence Data; Phylogeny; RNA, Bacterial; RNA, Ribosomal, 16S; Soil Microbiology; Terminology as Topic; Vitamin K