Bergey’s Classification:
Modern schemes for the classification of bacteria use a number of properties from, arrangement, Gram stain, motility, various enzymic properties, and any other sort of information that can serve to delimit an organism of a group of organisms.
A system of classification of Schizomycetes that is used by all bacteriologists and that has an Internation standing is “Bergey’s Manual of Determinative Bacteriology“. The scientific world of today accepts Bergey’s classification of Bacteria (1957). It represents the collaborative efforts of over 100 of the best on the International Rules of Nomenclature of the Bacteria and Virues established by the International Committee of Bacteriological Nomenclature in 1947.
i. Pseudomonadales: Cells rigid, spheroidal or rod-like, straight curved or spiral, some groups from trichomes, motile species have polar flagella.
ii. Chlamydobacteriales: Rod-like cells in trichomes, often sheathed, deposit iron hydroxide in the sheath, flagella sub-polar when present.
iii. Hyphomicrobiales: Cells spheroidal or ovoid connected on stalk or threads, no trichomes exhibit budding and longitudinal fission, flagella polar when present.
iv. Eubacteriales: Typically unicellular spheroidal or rod-like cells, no trichomes, sheath, or other accessory structures, motile species have peritrichous flagella.
v. Actinomycetales: Cells branch, many species form mycelia and mold-like conidiophores and sporangiophores, polar flagellate, sporangiospores in only one species.
vi. Caryophanales: Trichomes often very long, peritrichous flagella.
vii. Beggiatales: Alga like trichome or coccoid cell, accumulate elemental S, gliding and oscillatory or rolling motion, no flagella.
viii. Myxobacteriales: Cells coccoid, rod-like or fusiform, communal slime, fruting bodies, cells flexuous, gliding motility in contact with solid surface, no flagella.
ix. Spirochaetales: Elongated, spiral cells, rotatry and flexing motions and translatory motility, no flagella.
x. Mycoplasmatales: PPLO extremely pleomorphic and easily distored cells without cell walls, complex life cycle, non-motile.