AGRICULTURAL SCIENCES
MUSHROOM CULTIVATION
(AGA -453)
B.Sc. (Hons.), B.Sc. Integrated MBA
Chandigarh University
Gharuan (Mohali)
Aim: Mushroom Spawn Production- the techniques of getting pure culture, preparation of
master culture, and its further multiplication for commercial spawn production.
Spawn and its Production
Spawn means the vegetative mycelial network of a mushroom developed after the germination
of one or more than one fungal spore (s) grown on a convenient medium. Mother spawn is the
mushroom fungus grown on a grain based medium.
Steps involved in spawn production are:
1. Raising/ procurement of pure culture of mushroom.
2. Preparation of master/ stock culture.
3. Commercial spawn production.
Requirements for Spawn production: Pure culture of mushroom, substrate, Laminar air flow,
inoculation needle, 70 % ethanol, polypropylene bags, and non-absorbent cotton.
Spawn Production of Mushrooms:
Raising or procurement of pure culture of mushroom: The pure culture of a fungus can be
raised either by the spore print technique or the tissue culture technique. Once pure culture of a
particular mushroom is established or procured from some reliable source, the process of
production of mushroom spawn starts. The important steps involved in spawn production are:
1. Substrate preparation: spawn can be prepared on any kind of cereal grain such as
wheat, maize, bajra, jowar or rye etc. The size of grains is also very important for example- large
sized grains have more reserved food material which sustains the inoculum of mushroom
mycelium till its establishment on the substrate, while small sized grains provide more points of
inoculum per gram of the spawn. While we go for spawn preparation, care must be taken to
choose a healthy disease or insect injury free lot of cereal grains. In addition to this, large
substrate area should also be available for fungal colonization. Steps involved in substrate
preparation are as follows:
To remove soil debris, straw, undesirable seeds of other crops/ grasses etc., wash
the cereal grains 3-4 times in water.
Thereafter, soak the washed seeds in sufficient water for 20-30 minutes.
10 kg of soaked wheat grains are boiled in 15 ltr of water for 20-25 minutes
(grains should absorb 55 to 60 % moisture). Excess water from the boiled grains is
drained off and the grains are put over the sieve or on a wire mesh tray for 8-10 hours to
dry or remove excess of water.
After that the grains are mixed with Gypsum (calcium sulphate) and chalk
powder (Calcium carbonate) at the rate of 2% and 0.5%, respectively on dry weight basis.
10 Kg of dry wheat grains will require about 200g gypsum and 50g chalk powder.
Addition of these chemicals helps to check the pH of the medium and also prevent
sticking of grains with one another.
Note: Gypsum and chalk powder are mixed separately and thereafter, the mixture of both is
thoroughly mixed with grains.
2. Mother/ master spawn preparation:
Prepared substrate is filled into half or 1 litre glucose bottles or 300 gm of
substrate is filled into PP bags and plugged with non-absorbent cotton.
Filled bottles are the autoclaved at 22 lb p.s.i pressure for 1.5-2 hrs.
After 24 hrs of autoclaving, these serilized botlles are exposed to UV light inside
the inoculation chamber for about 15-30 minutes.
The bits of agar medium colonized with mycelium are then transferred to these
bottles and inoculated bottles are incubated at 25± 1ºC. Bottles are shaken vigorously on
5/ 7 days of inoculation so that the mycelial threads are well mixed with the grains
In 15-20 days (or two week after inoculation), the bottles are ready as stock
culture for further multiplication.
Note: for A. bisporus, Pleurotus spp., Lentinula spp., Auricularia spp.-the incubation
temperature is 22-25°C; while for Volvariella spp. and Calocybe spp.-the incubation
temperature is 30-32°C.
3. Commercial spawn preparation:
Master spawn is used as an inoculum for the inoculation of large number of other
grain bags/ bottles prepared by the same technique. Generally few mycelia coated grains
from one master culture bottle/ bag are inoculated into 30-40 grain bags aseptically in front
of the HEPA ( High Efficiency Particulate Air ) filters of a Laminar flow and then
incubated at 25 ± 1°C for 12-15 days. The commercial spawn thus prepared is used for
inoculating the compost beds as seed.
4. Spawn Storage and transport:
Spawn bags after completion of log growth phase can be maintained up to 3-4
months at 4°C. Fresh spawn should always be used for seeding and its long time storage
should generally be avoided.
Care must be taken during transit that spawn bottles are not exposed to bright
sun light and a temperature higher than 30 oC. To avoid such risks, spawn bottles are
packed in thermocol boxes containing ice cubes or should be transported during night
hours when it is cool.
Characters of Good Spawn:
There should be proper coating of the mycelium around every grain used as
substrate for spawn.
The growth of the mycelium in the spawn bottles should not be cottony or
fluffy type but it should be strandy.
The growth of fresh spawn is more or less white. Brown coloration develops
as spawn grows.
There should not be any slimy growth in the spawn bottles which is an
indication of bacterial contamination.
There should not be any greenish or blackish spot in the spawn bottles. Such
type of spots indicates that the spawn is contaminated with moulds.
Precautions to be taken:
1. Strict hygiene should be maintained right from raising of pure culture to storage and
transport. Inoculation room should be disinfested regularly by using formalin or by using
UV.
2. Excessive visits to inoculation & incubation room should be denied.
3. The contaminated bags should be removed immediately after their autoclaving to avoid
inoculum build up in the vicinity of mushroom unit.
4. Cultures and spawn should never be stored at sub zero temperatures in deep freezers.
However, using cryprotectants cultures could be preserved at ultra low temperatures.
5. Avoid overcooking of grains as it may lead to splitting of grains. Don’t dry the cooked
grains on the floor, always dry over hessian cloth, spread on a raised platform or on a
wire mesh tray.
6. Use only recommended dose of CaCO3 for mixing with the cooked grains. Mixing over
dose reduces the fungal growth in the inoculated bags.
7. Avoid further sub culturing of the second generation spawn. This leads to loss of vigour
of the spawn which again leads to reduced yield. Repeated sub culturing leads to
complete loss of vigour. In such cases the fungal growth may be noted in the compost
beds but buttoning may be completely arrested.
A B C
A. Culture of mushroom; B. Pure culture of mushroom and C. Spawn of mushroom in PP bag
