Flexibacter polymorphus, a New Marine Species

SUMMARY: A filamentous, gliding microbe isolated from a marine source is described as a new species of Flexibacter (Cytophagales: Flexibacteraceae). The filaments are typically multicellular. At the end of each cell there is normally a refractile granule of lipid material (not elemental sulphur, as would be the case in a Beggiatoa species). Under certain culture conditions, unicellular elements, helically coiled filaments or, occasionally, branched filaments may be produced. The filaments, which are not photosynthetic, are peach-coloured when grown in light: the pigment is a carotenoid spectroscopically resembling saproxanthin. The guanine + cytosine proportional content in the DNA is 29%.

The organism grows in media prepared with sea water or an equivalent saline solution. It can utilize glucose as sole carbon source; glutamate or Tryptone can serve as a suitable source of both C and N. Cobalamin is the only organic micronutrient essential for growth. The generation (doubling) time is 6 h at 22°C.