Effect of Low Temperatures on Growth of Clostridium botulinum Spores in Meat of the Blue Crab.

The ability of unheated and heated spores of Clostridium botulinum types B. E, and F to grow and produce toxin in crabmeat from the blue crab at low temperatures was investigated. Sterilized crabmeat was seeded with 10 unheated spores/g or 10 heated spores/g and incubated anaerobically at 4, 8, 12, and 26 C. Broth cultures served as controls. Both unheated and heated spores of the three strains grew and produced toxin in crabmeat at 26 C in 3 and 6 days, respectively. In addition, unheated spores of the nonproteolytic type E strain grew and produced toxin in crabmeat at 12 C in 14 days. Neither heated spores of type E nor heated or unheated spores of types B and F grew in crabmeat at any refrigerated temperature within 180 days.