The inhibition of vegetative cell outgrowth and division from spores of Bacillus cereus T by hen egg albumen

Spores of Bacillus cereus T germinated and formed vegetative cells in Tryptone Soya broth (TSB), pH 9‐0 and 7‐4 at 30 o C. Spores germinated but did not form vegetative cells when suspended in hen egg white (pH 9‐0) supplemented with L‐alanine and inosine. Using a split image eyepiece, the volumes of germinating spores in egg white were seen to increase as a result of increases in both length and breadth. In TSB at the same pH, the major volume increase resulted from a progressive increase in cell length. Egg white supplemented with L‐alanine and inosine (pH 7‐6 30 o C) allowed limited outgrowth to occur but the vegetative cells differed in morphology to those in TSB. Fe(NH 4 ) 2 (SO 4 )2.6H 2 O overcame the inhibition of outgrowth in egg white at pH 7–8 but not in egg white at pH 9‐1. Solutions containing trace elements, growth factors and casamino acids could not replace iron in this respect. Sporulation occurred in egg white only when iron was present.