Examination of Bacteria for Lecithinase
For demonstration of lecithinase activity (especially in the investigation of `bitty cream’ conditions)
add 0.5 or 1.0ml of the emulsion to 10ml of Blood Agar Base CM0055 or Nutrient Broth
No.2 CM0067 - in both cases to clear the medium, raise the final salt concentration by the
addition of 1% of sodium chloride. After incubation for up to 5 days at 35°C, lecithinase-producers
render the broth opalescent, whilst, on the solid medium, their colonies are surrounded by zones of opacity.
Lactose Egg-Yolk Milk Agar1,2 - a medium for the identification of anaerobes which, inaddition to
serving as a half antitoxin-Nagler plate, also demonstrates lactose fermentation and proteolysis.
Egg Yolk Emulsion SR0047 is recommended for use in the preparation of the medium.