Recovery of heat‐injured spores of Clostridium perfringens types B, C and D by lysozyme and an initiation protein

Abstract

R.G. LABBÉ AND C.‐A. CHANG. 1995. Heat‐injured spores of several strains of Clostridium perfringens types B, C and D could be partially recovered if lysozyme was included in the recovery medium. As little as 25 ng ml^‐1was effective. D_90°C values of 1.3–2.6 were obtained with an approximate 2–3‐fold increase in the presence of 1 μg ml^‐1of lysozyme. In the absence of lysozyme, prolonged heating of spores resulted in the appearance of satellite colonies surrounding colonies of surviving spores. An initiation protein, previously reported in the case of type A strains, was also produced by type B, C and D strains. When added to the recovery medium it too promoted the recovery of spores from thermal injury though not as effectively as lysozyme.