Opacity around colonies of clostridium perfringens is due to
Theta toxin
Lecithinase
Desmolase
Cytokinin
Alpha toxin is produced by all thoracic clostridium perfringes. Alpha toxin is lecithinase C. Demonstrated by Nagler's reaction. Nagler reaction; When Clostridium perfringes are grown in media containing 6 % agar, Fildes peptic digest of sheep blood and 20% human serum, with antitoxin spread on one half of plate, colonies in the other half without antitoxin will be surrounded by a zone of opacity. No opacity around the colonies on the half of plate with antitoxin. This is due to the specific neutralization of the alpha-toxin or lecithinase C. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 259
Bacteriology