Experiment-4
Aim: Preparation of culture media for Mushroom cultivation.
Theory: Culture media, also known as growth media, are specific mixtures of nutrients and
other substances that support the growth of microorganisms such as bacteria and fungi. They
may be solid, liquid, or semi-solid designed to support the growth of a population of
microorganisms or cells via the process of cell proliferation. Different types of media are
used for growing different types of cells. The two major types of growth media are those used
for cell culture, which use specific cell types derived from plants or animals, and those used
for microbiological culture, which are used for growing microorganisms such as bacteria or
fungi. Culture media are essential for isolation of mushroom fungi and maintaining them in a
pure culture either in test tubes or in Petri plates. The fungal cultures may be grown in liquid
media (broths) or on solid agar media.
Types of Culture media for Mushroom cultivation:
1. Broth Media
i) Potato Dextrose Broth: Potato Dextrose Broth is used for the cultivation of
fungi in a laboratory setting. Potato Dextrose Broth is a general purpose broth
for yeasts and molds. The low pH of this medium inhibits bacterial growth.
Potato Dextrose Broth is the same formula as Potato Dextrose Agar, but agar
has been omitted.
Ingredients Gms / Litre
Potatoes, infusion from 200.000
Dextrose 20.000
Final pH (at 25°C) 5.1±0.2
ii) Malt Extract Broth: Malt Extract Broth is used for the isolation, cultivation
and enumeration of yeasts and molds from foods. Malt extract provides the
carbon, protein and nutrient sources required for the growth of
microorganisms.
Composition:
Ingredients Gms / Litre
Malt extract 17.000
Mycological peptone 3.000 Final
Final pH (at 25°C) 5.4±0.2
Procedure:
i) Weight the required amount of Potato Dextrose Broth (PDA)/ Malt Extract Broth
(MEA) from granulated PDB/MEB. (Mix the weight PDA/MEA and distilled
water in a conical flask and close the lid with a cotton plug.
ii) Autoclave it at 121°C and 20psi for 20minutes.
iii) After autoclave pour the media in a sterile container in a laminar air flow.
iv) Allow it to cool.
2. Agar Base Media:
i) Potato Dextrose Agar: Potato Dextrose Agar (PDA) is used for the cultivation of
yeasts, molds and fungi. Potato Dextrose Agar is composed of dehydrated Potato
Infusion, Dextrose and Agar. Potato Infusion and Dextrose serve as the
nutritionally rich base which allows robust fungal growth. The agar serves as the
solidifying agent.
Composition:
Ingredients Gms / Litre
Potatoes, infusion from 200.000
Dextrose 20.000
Agar 15.000
Final pH (at 25°C) 5.6±0.2
ii) Malt Extract Agar: Malt Extract Agar is a nutrient-rich medium for the use of
cultivation, isolation and enumeration of a broad-spectrum of environmental and
pathogenic yeasts and molds. This medium is recommended for the examination
of yeasts and molds in clinical, veterinary and environmental samples.
Composition:
Ingredients Gms / Litre
Malt extract 20.000
Peptone 1.000
Dextrose (Glucose) 20.000
Agar 20.000
Materials required: Potato Dextrose Agar, Malt Extract Agar, Conical flask, distilled water,
cotton, autoclave, laminar air flow and sterile petri plate.
Procedure:
v) Weight the required amount of Potato Dextrose agar (PDA)/ Malt Extract Agar
(MEA) from granulated PDA/MEA. (For Himedia 39 grams per 1000ml of
distilled water).
vi) Mix the weight PDA/MEA and distilled water in a conical flask and close the lid
with a cotton plug.
vii) Autoclave it at 121°C and 20psi for 20minutes.
viii) After autoclave pour the media in a sterile petri plate inside a laminar air flow.
ix) Allow it to solidify it for 20 minutes.
Discussion:
