The Morphology and Ultrastructure of the Spore and Exosporium of Some Clostridium Species

The spores of original isolates of Clostridium species obtained from fresh and processed marine fish and from marine bottom deposits were compared with the spores of culture collection strains of the same species. These strains were Clostridium botulinum type E, C. sporogenes, C. bifermentans and C. sordellii. Spores of unclassified, non-toxigenic isolates which resemble C. botulinum type E, of ‘OS mutants’, of culture collection strains of C. botulinum types A and B and an isolate of type F were also examined. The gross morphology and ultrastructure of the spores and exosporia were studied in electron microscopic preparations by using the techniques of metal shadowing, carbon replica, negative-staining and ultra-thin sectioning. Spores of some strains were found to possess tubular appendages. The morphology of the spores and the ultrastructural detail of the spore appendages and exosporia are described.