Fatty acid analysis of phytopathogenic coryneform bacteria

Abstract

The classification of plant-pathogenic coryneform bacteria has been revised many times. All plant-pathogenic coryneform bacteria were once classified in the genus Corynebacterium. Currently, all are classified in the genera Arthrobacter, Cluuibacter, Curtobacterium or Rhodococcus. Difficulties still remain regarding the characterization of species and subspecies within these groups. Analysis of cellular fatty acids by high-resolution capillary gas chromatography has recently become a standard method of bacterial identification in many laboratories. In the studies reported here, cellular fatty acid analyses were performed to examine the plant-pathogenic coryneform bacteria as an autonomous group. A total of 189 bacterial strains were profiled. Results from these studies support the division of plant-pathogenic coryneforms into four major groups (genera). Further subdivision was not required for Rhodococcus and Arthrobacter, as each genus contains only one species of plant-pathogenic bacteria. Some, but not all, Curtobacterium pathovars could be differentiated from one another based on fatty acid analysis alone. Infrasubspecific classification of plant-pathogenic Curtobacterium organisms appears to be appropriate. Most of the species or subspecies belonging to the genus Cluuibacter could be differentiated using fatty acid profiles. Other chemotaxonomic methods also differentiate organisms within Cluuibacter. Reclassification is warranted within Cluuibacter michigunense. Cluuibacter michigunense subspecies should be returned to full species status.

Chemotaxonomic Differentiation of Coryneform Bacteria Isolated from Biofilters

“…Numerical analysis of cellular fatty acid compositions has been used successfully to differentiate and identify coryneform and nocardioform bacteria (4,20 (32).…”

Probabilistic identification of coryneform bacteria.

“…Large data bases of physiological data can be used as sources for differentiating characters. Although classification and identification of the coryneform bacteria is largely based on chemotaxonomic data including cell wall chemotypes, phospholipid types (5,7,(32)(33)(34), cell sugar patterns (34), peptidoglycan types (37, 38), fatty acid patterns and menaquinone types (6,7,14,15,29), numerical taxonomic studies have been found to be important to the taxonomy of these genera (8,11,19,20,39,40,47). The study of Seiler (39) showed, in most cases, good agreement of chemotaxonomically and physiologically defined groups.…”

“…Therefore, it will be necessary to extend this data base by incorporation of reference organisms, unambiguously genetically and chemotaxonomically characterized. In addition, the application of chemotaxonomic methods like analyses of cell wall structures (37,38,48), lipids and menaquinones (3)(4)(5)(6)(7)14,29,33,35) and fatty acids (4,14,15,29) is strongly recommended in case of poor identification with the probability matrix. …”

Diversity of Plant Associated Actinobacteria

“…In addition to their host specificity, they present few phenotypic differences such as colony morphology, pigmentation, bacteriocin production (Gross and Vidaver 1979), fatty acid composition (Henningson and Gudmestad 1991), cellular proteins (Carlson and Vidaver 1982) and physiology (Dye and Kemp 1977). However, they show nearly identical protein profiles (Carlson and Vidaver 1982) and other metabolic features (Louws et al 1998) making difficult their differentiation on the basis of phenotypic traits.…”