Brevibacterium

Abstract

Bre.v.i.bac.te'ri.um. L. adj. brevis short; L. neut. n. bacterium a small rod; N.L. neut. n. Brevibacterium a short rodlet.

Actinobacteria / Actinobacteria / Micrococcales / Brevibacteriaceae / Brevibacterium

Aerobic, catalase-positive, non-acid-fast, asporogenous actinomycetes which have a rod–coccus cell cycle when grown on complex media. Usually nonmotile, but some species show motility. Both rod and coccoid forms are Gram-stain-positive, but some strains and older cultures decolorize readily. Cells are variable in length but generally are 0.6–1.0 µm in diameter; those from older cultures (3–7 d) are composed mainly or entirely of coccoid cells or coccobacilli. On transfer to a suitable fresh medium, these forms grow out to give the irregular, slender rods characteristic of exponential phase cultures. Many cells are arranged at an angle to give V-forms. Primary branching may occur but not a true mycelium. Respiratory mode of metabolism. Optimum growth temperature is 20–37°C depending on the species and strain. Grows well on peptone-yeast extract agar at neutral pH. Little or no acid is produced from glucose or other carbohydrates in a peptone medium. Proteinases produced. The cell-wall peptidoglycan contains meso-diaminopimelic acid as the diamino acid and is of the A1γ type. Contains dihydrogenated menaquinones with eight isoprene units as the predominant isoprenologue and major proportions of branched cellular fatty acids, notably C_15:0 anteiso and C_17:0 anteiso. Mycolic acids are absent.

DNA G+C content (mol%): 55–70.

Type species: Brevibacterium linens (Wolff 1910) Breed 1953a, 13^AL emend. Collins, Jones, Keddie and Sneath 1980, 7 (“Bacterium linens” Wolff 1910).