Inoculating grain spawn with a syringe of spores or liquid culture is a common practice in mycology, the study of fungi. It is especially prevalent in gourmet and medicinal mushroom cultivation. Here is a step-by-step guide on how to do it.
First, let's gather the necessary materials:
1. Grain spawn: Typically, the grains used can be rye, millet, wheat, or a mix of them. These grains should be properly sterilized. Grain spawn often comes prepared and sterilized in a jar or bag, ready for inoculation.
2. Syringe of spores or liquid culture: This is your source of mushroom mycelium. You can either have a syringe filled with millions of spores, or a liquid culture syringe which contains mycelium suspended in a nutrient broth.
3. Gloves: To keep everything as sterile as possible.
4. Mask: This is to prevent your breath from contaminating the sterilized grains.
5. Alcohol wipes or a bottle of isopropyl alcohol and cotton balls: For sterilization purposes.
6. Flame source: Typically a lighter or alcohol lamp, used for sterilizing the needle of the syringe.
7. Heating pad (optional): Used for maintaining the right temperature for mycelium growth post-inoculation.
8. Sterile work area: This could be a glove box or a laminar flow hood, although this guide will assume you're working without those.
Now, let's move on to the actual process:
Step 1: Preparation
Begin by cleaning your work area thoroughly. You can wipe it down with isopropyl alcohol, bleach, or any disinfectant. Make sure to clean nearby surfaces as well, such as knobs and handles. Turn off fans and air conditioners to limit air currents which may carry contaminants.
Step 2: Personal Sterilization
Wash your hands thoroughly, up to the elbows if possible. Wear your mask and put on your gloves. You can sanitize your gloves with isopropyl alcohol.
Step 3: Prepare Your Tools
Take out your spore or liquid culture syringe. Make sure to shake it well before using it. Shaking helps to distribute the spores or mycelium evenly in the syringe.
Step 4: Sterilize the Syringe Needle
Use your flame source to red-hot sterilize the needle of the syringe. Be careful not to burn yourself. After flaming, let the needle cool down for a few seconds. You can test it on a sterile surface to make sure it's not too hot as this could kill the spores or mycelium.
Step 5: Inoculate the Grain Spawn
Now, onto the actual inoculation. If you're using a jar, the lid should have an injection port, which is a small hole covered with a self-healing material like silicone or synthetic filter disk (SFD). If you're using a bag, it should also have an injection port.
Sterilize the injection port with an alcohol wipe or a cotton ball soaked in isopropyl alcohol. Let it dry.
Then, insert the cooled needle into the injection port and depress the syringe plunger to inject about 1-2 cc of the spore or liquid culture. This doesn't have to be precise, but you should distribute it as evenly as possible throughout the grain. You can achieve this by slightly changing the angle of the syringe while you're injecting, which will spread the culture in different directions within the grain.
Step 6: Sealing and Shaking
Once you've injected the spore or liquid culture, remove the needle
and ensure the injection site is sealed. If your jar or bag doesn't have a self-healing injection port, you can seal it with micropore tape.
After inoculation, shake the jar or bag to distribute the spores or mycelium throughout the grain. This step is crucial as it helps the mycelium colonize the substrate more rapidly.
Step 7: Incubation
Now, it's time to wait. Place your jar or bag in a warm (around 75-80°F or 24-27°C) and dark place. You don't want to expose the mycelium to direct sunlight. An optional heating pad can be used to maintain the temperature.
In about 3-7 days, you should start to see some mycelial growth. This will appear as white, cottony fuzz growing on your grains. Shake the bag or jar again once you see initial growth to speed up full colonization.
It's important to keep an eye out for any signs of contamination. This can manifest as odd colors (greens, blacks, yellows, etc.) or a sour or foul smell. If you see any signs of contamination, it's best to discard the entire bag or jar and start over.
Remember that this process requires patience and practice. If you're not successful the first time, don't be discouraged. It's a learning process, and with each attempt, you'll become more adept at the art of mycology. Good luck!