Systematic Veterinary Bacteriology and Mycology

Cultural and biochemical characters

CULTURAL AND BIOCHEMICAL CHARACTERISTICS

• It is a strict anaerobe, opt.temp is 30-37⁰ C and pH is 7-7.6. Good growth occurs on ordinary media.
• Surface colonies are large, irregular, and semitransparent with fimbriate border.
• Spores are produced consistently when grown in alkaline glucose gelatin media at 20 to 25 ⁰C.
• In horse blood agar, large transparent colonies with irregular edges are developed with a narrow zone of haemolysis.
• On sheep blood agar C.botulinum produce beta-haemolysis, the colonies are slightly domed with a ragged edge.
• In cooked meat medium, the proteolytic strains type A, B and F produces blackening of meat and non-proteolytic strains C, D and E do not blacken meat.
• Gelatin liquefied rapidly by type A&B and slowly or not at all by type C, D and E.