Glucose Yeast Extract Agar is prepared according to the formula described by Evans and Niven (1) and Rogosa et al (2) and is used for enumeration and cultivation of Lactobacilli in pharmaceutical preparations.
The medium contains a variety of salts like sulphates, phosphates to support the growth of Lactobacilli. Necessary nitrogenous nutrients for Lactobacilli are provided by peptic digest of animal tissue and yeast extract. Glucose is the source of fermentable carbohydrate. The metallic salts are sources of ions essential for the replication of lactic acid bacteria.
Directions:Suspend 28.32 grams in 1000 ml distilled water. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Mix well and pour into sterile Petri plates.