Lyophilised cultures of C. sporogenes (MTCC 1349)
and B. cereus (MTCC 470) were procured from IMTECH
Chandigarh, India. C. sporogenes was grown and
its spore suspension was prepared as described by
Crawford, Murano, Olson, and Shenoy (1996). The
spore crop was stored at 4 C until used. B. cereus was
grown in Soybean casein broth (HiMedia) at 37 C for
24 h. The samples were centrifuged in a refrigerated
centrifuge (4 C) (Sorvall RC 2) at 12 100 · g for 10 min
and washed two times with sterile normal saline. The cell
pellet was finally suspended in sterile saline.