Define the Composition of Potato Dextrose Agar?
This media is used for cultivation of yeasts, fungi and moulds.
Potato (Peeled) - 200.0 gm
Dextrose - 20.0 gm
Agar - 15.0 gm
Distilled water - 1000.0 ml
pH - 5.6
Peel off the potatoes. After cutting into small pieces, boil them in 500 ml distilled water and filter the extract through cheesecloth. Mix all the ingredients to the filtrate and make the volume to 1000.0 ml by distilled water. Potato dextrose agar is a non-selective and non-differential medium having potato infusion which encourages growth of yeasts and moulds. It contains potato tubers extract, dextrose, peptone and agar. Addition of tartaric acid (1.85 ml of 10% tartaric acid per 100 ml of PDA) lowers its pH and make it inhibitory for the growth of most of the bacteria.