[Morphology and cytology of Bacillus benzoevorans, a new filamentous, sheathed mesophilic species, degrading various aromatic acids and phenols].

When cultivated on solid medium or in stationary liquid medium, most of the 11 studied strains of Bacillus benzoevorans grew as unbranched, flexible, immotile filaments (or trichomes) of undefined length and 1.8 micrometer diameter. They were enclosed in a sheath giving an overall diameter of 3.6 micrometer. When cultivated in vigorously shaken liquid medium, several strains grew as separate rods (1.8 X 2.2 micrometer), did not deform the filament and contained dipicolinic acid. The cytoplasm had a granular aspect due to the presence of poly-beta-hydroxybutyric acid. The Gram reaction was variable but the Gram type was positive. Isolated and purified sheath contained 73% proteins, 12.9% reducing sugars and 8% lipids. In stationary liquid medium, the culture had a mycelial aspect and a thick pellicle formed at the surface. Colonies were circular, flat, opaque, whitish, mat and compact; they had irregular edges, spread out on the surface and did not adhere to the agar.