Influence of elevated temperature on starch hydrolysis by enterotoxin-positive and enterotoxin-negative strains of Clostridium perfringens type A.
Enterotoxin-positive (Ent+) and enterotoxin-negative (Ent-) strains of Clostridium perfringens were cultured in Duncan-Strong sporulation medium containing starch at 37 and 46 degrees C. At 37 degrees C, all strains degraded starch and sporulated well. However, only Ent- strains could hydrolyze starch, grow extensively, and sporulate at 46 degrees C. Growth, sporulation, and starch hydrolysis by Ent+ strains at 46 degrees C were equivalent to those obtained at 37 degrees C when alpha-amylase was added to the cultures during growth. The total amount of extracellular plus intracellular amylase in cultures of Ent+ strains was significantly less in cells incubated at 46 degrees C than in cells incubated at 37 degrees C. These results contradict an earlier report that Ent+ strains cannot sporulate well near their optimal growth temperature (R. G. Labbe and C. L. Duncan, Can. J. Microbiol. 20:1493-1501, 1974) and suggest that synthesis of alpha-amylase in Ent+ strains is regulated by temperature.
Departmento de Microbiologia e Inmunologia, Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Monterrey, Mexico.
J S
JS
García-Alvarado
M A
MA
Rodriguez
R G
RG
Labbé
D000681:Amylases / Q000378:metabolism; D003016:Clostridium perfringens / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D004768:Enterotoxins / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008854:Microscopy, Electron; D013045:Species Specificity; D013171:Spores, Bacterial; D013213:Starch / Q000378:metabolism*; D013696:Temperature
D004768:Enterotoxins; C035598:enterotoxin, Clostridium; D013213:Starch; D000681:Amylases