Premium
Growth and Toxin Production by Type E Clostridium Botulinum Below 40°F a
Author(s) -
SCHMIDT C. F.,
LECHOWICH R. V.,
FOLINAZZO J. F.
Publication year - 1961
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1961.tb00807.x
Subject(s) - toxin , spore , clostridium botulinum , microbiology and biotechnology , inoculation , food science , strain (injury) , clostridium , chemistry , biology , bacteria , horticulture , anatomy , genetics
SUMMARY Mildly heat‐shocked spores of four strains of Type E Clostridium botulinum (VH, Beluga, Iwanai, and 8E) were inoculated into a heat‐sterilized beef stew substrate and incubated at 34, 36, and 38°F. Inoculum levels of approx 4‐12 million spores per tube were used with different strains. At 38°F, toxin production and visible outgrowth as evidenced by gas formation beneath a vaspar seal occurred in one or more tubes of each of the strains within 31–45 days. No evidence of growth was visible after 14 days at 38°F, and at this time duplicate tubes of each strain were not toxic. After 31 days, strains Iwanai and Beluga showed 2 of 8 tubes with gas and toxin. None of 8 tubes of the VH and 8E strains showed gas after 31 days. Two tubes of each strain were not toxic. After 45 days, tubes of the VH and 8E strains showed visible gas production and toxin. Inoculated tubes incubated at 34 or 36°F showed no gas production during 104 days. Samples of all strains at both temperatures were toxin assayed at 54 days and 104 days, and toxin was absent in all cases. These results suggest a rather sharply defined critical temperature above and below which spores of Type E Cl. botulinum are or are not capable of germinating and initiating toxic outgrowth. The significance of these results in relation to extended refrigerated storage of food products is discussed.