L Broth (Liver Broth)

L Broth (Liver Broth) is used for examination of food for saccharolytic, putrefactive, mesophilic and thermophilic anaerobes. This medium contains liver particles which support luxuriant growth for saccharolytic or putrefactive mesophilic and thermophilic anaerobes. A 20% w/v solution of the sugar steamed for 30 minutes is inoculated into Liver Broth, sealed with agar. The standard proposed was a maximum of 1 positive tube in six tubes, with 20 ml inocula and incubated for 72 hours at 56°C. Some organisms like Clostridium thermosaccharolyticum produces gas which often pushes the agar plug towards the top of the tube and some organisms digest the solid liver tissues. The medium should be used on the same day of preparation as the stored medium may absorb the air and then re-steaming is necessary which darkens the medium.