Mycelium spawning (inoculation)

Mycelium spawning (inoculation)

step 2

Spawning the mycelium

Once processed raw materials are cooled to 26-28oC, you can start inoculation. It is a process of spawning 

the substrate with oyster mushroom mycelium and packing it into the plastic bags.

Spawning is carried out in a separate room, which is called the clean zone or inoculation room.

If you have a small company or you run oyster mushrooms cultivation at home, a separate inoculation room is a must! Even a small room fenced off by a wooden partition and fitted using a plastic film will be suitable. This will help keep the room relatively clean.

The work is performed wearing uniform – suits of soft tissues:

– shirts without buttons, so that the substrate does not soil the skin and does not interfere with working process,

– pants with a belt and drawstrings,

– kerchief or a surgical cap. The hair must be hidden under it, as it contains a very large amount of mold spores. Therefore taking shower before spawning is a must!

– disposable gloves

– shoes – rubber or plastic slippers, but not flip flops.

If you do not have a shower room, ask your employees to wash their hair the day before inoculation.

The mycelium is mixed with the substrate on the table. It is very convenient, if the table is long. Two bags of steamed raw material – the size of 2 by 0.7 m are placed on such a table. It is possible to carry out the mixing in an old enamel bath – the main thing is that it should not be rusty, as mold can develop in rusted areas. Violation of hygiene during inoculation, as well as the substrate waterlogging can lead to bacterial or mold infection. During incubation such blocks will overgrow slowly and some areas may develop wet spots or mold.

Preparation of mycelium for spawning

If you purchase a batch of mycelium for several inoculations, it should be stored in a refrigerator at a temperature range of -1  +2o C.

15-20 hours before inoculation a part of mycelium packages needed for one inoculation are taken out from the refrigerator to the warm room (20-24oC) previously treated with disinfectants (3% hydrogen peroxide, 10% bleach solution or 3 caps of concentrated Domestos for 5 liters of water). Mycelium temperature should be different from the substrate temperature by not more than 2.3 degrees. This contributes to more coherent mycelium growth into the substrate. If the temperature difference is big, cold mycelium can lead to condensate film formation, and the mycelium can drown and die and mold spores can start to develop on nutrient grains due to outside infection or due to the insufficient disinfection.

During inoculation mycelium bags should be opened as necessary, kneading it in a bowl with your hands to separate the grains.

You can knead only one pack of mycelium in a bowl, without mixing the contents of the various packages or batches! On each package there is a bar code. It is desirable to mark the blocks, indicating with a sticker. You can give the packages identification numbers, indicating a corresponding barcode number in a journal. In this way you will know, which package was used to make certain mycelium blocks. In case of any problems, you will need to contact us, provide information on the bar code and attach photo and problem description.

After that, the substrate on the table has to be evenly sprinkled with mashed grains, mixed well and packed into bags. When filling the bag it is necessary to compress it using your hands. You can lightly hit the bottom of the bag for this. After filling is necessary to squeeze out remaining air from under the film, and close it tightly. You can also fold the film as an envelope and seal with some adhesive tape.

If you produce large number of blocks at the same time, you can make or buy a special press for the production of oyster mushroom substrate blocks.

If you have a clean zone with the direct access to incubator, you can take out and hang filled bags right away. After hanging the blocks should be immediately perforated to ensure normal gas exchange.

If the substrate blocks cannot be hung right away, then you need to put them in a very clean area or in the transition room or hallway.

Before the end of inoculation process do not leave the clean area!

After finishing the spawning process all the bags have to be moved to the incubator, and hung out. It is acceptable to leave them overnight in a clean area, and hang them in the morning. In this case it is necessary to lay the blocks down so that they are not overheated during nighttime.

End of inoculation process.

On the day of spawning you clean and wash all the equipment thoroughly in a clean area and in the room itself. After cleaning the room is treated with disinfectants. Clothes the workers wear should be washed with the addition of the same agents. Before spawning the following procedure is performed 2-3 hours before the operation. Ventilation should be on after disinfection treatment.

For each case, the mycelium application rate can be determined depending on the following factors:

  1. raw materials

The speed at which the mycelium colonizes a block depends on the type of raw material you are working with. For example, on sunflower husk primordia may appear on the 14-15th days after inoculation, straw colonization takes a little longer, and incubation can last for 17-20 days. Sawdust decomposes even longer, it makes sense to add them, if you keep the blocks for 4-5 flushes.

Therefore, for slow-digesting substrates, the mycelium dose can also be increased by up to 4-5%.

  1. Substrate processing.

When steaming raw technology tunnel substrate obtained higher quality, however mycelium 2.5-3% will be sufficient to block overgrown without increasing at the same incubation period.

When heat treated in the tank using hydrothermal method, substrate may still contain a sufficiently large number of foreign spores, at the application rate of 4-5% mycelium creates a large number of growth points. The mycelium grows rapidly, colonizing the entire substrate and does not allow mold spores and bacteria to develop.

  1. Production necessity.

– If you rent a premise, then you need to calculate oyster mushroom growing cycles and determine feasibility of mycelium dose. It could be 5% instead of 3%, for example, in order to reduce the production cycle by 6-7 days and load one more batch for more profit.

– for faster blocks colonization, you can increase the mycelium dose, and make one or two batches more on the later inoculation stages before the holidays, to have more fruiting mushroom blocks for Christmas or Easter.