| Flexible, helicoidal organisms usually 6–20μm long, 0.1μm diameter; one or
both ends hooked or straight; not visualised by direct light, but by darkfield
microscopy; not easily stained. There are two subterminal periplasmic flagella,
one at each end. G+C% ratios 35.3–43.4mol%. Characteristic motility. Aerobic
and microaerophilic; utilise ammonium salts as a nitrogen source, unsaturated
fatty acids as a carbon source, and purines. Growth optimum pH 7.2–7.6,
at 28–30°C. Optimum growth in 6–14 days, but variable, in liquid media;
subsurface slow colonial growth. Strains may be parasitic or free living [80]. |
