Define Procedure for Determination of Fungal and Yeast Count?
Now carry out the exercise following the steps enumerated herewith:
1. Shake the food sample and aseptically transfer 1 ml of it to a 9 ml dilution blank tube marked 10-1 . Similarly prepare further tenfold dilutions till 10-6.
2. Dispense 0.1 ml of each dilution on to the labeled agar plates.
3. Spread the inoculum evenly on the plates using a sterile bent glass spreader. Sterilization of a spreader is done by dipping it in the alcohol jar and passing through the flame. Caution - Always keep the alcohol away from the flame.
4. Incubate plates at 28+2°C for 4-5 days undisturbed.
5. Count the number of yeasts and moulds. Yeast colonies are similar to bacteria whereas mould colonies are larger and fuzzier. Counting can be done from underside of plates if moulds are overgrown.
6. Calculate the CFU/ml of the food sample. Try to identify the fungi.