ENRICHMENT AND IsOLATION PROCEDURES
Conditions for enrichment and cultivation of Thiospirillum jenense are essentially the same as those described for Chromatiumspecies. The large cells of T: jenense (generally 30-10 um in length) grow only in agar shake cultures, when the final concentration of thoroughly washed agar is below 0.6-0.8% (w/v). In such agar cultures, colonies of Thiospirillum appear irregular and wisp-shaped. Individual cells can be recognized by using a low power, binocular microscope. Cultures containing not more than 1-2 mM sulfide should be incubated at low light intensity (200-5001ux).Colonies from agar shake cultures grow well in liquid medium, provided culture vessels of small volume are used first, e.g., screw-capped test tubes of 10-15 ml volume