Growth, Sporulation, and Germination of Clostridium perfringens in Media of Controlled Water Activity

摘要

Requirements in terms of water activity (aw) for the growth, sporulation, and germination of Clostridium perfringens were determined. Strain A48 was used in all phases, and in addition either NCTC 8239 or NCTC 8797 was used for growth, sporulation, and germination studies. The desired aw of the test media was obtained by the addition of one of three solutes: glycerol, sucrose, or sodium chloride. The freezing point depression method was used to determine the aw. The basal medium for growth and germination was Fluid Thioglycollate Medium. It had an aw of 0.995 and produced maximum growth and fastest growth rate among the six levels of aw tested. The lowest aw supporting growth and germination of C. perfringens was between 0.97 and 0.95 in the test media made with sucrose or sodium chloride and 0.93 or below in the test media adjusted with glycerol. Spore production by C. perfringens in Ellner's or modified medium required a higher aw than growth.