Mushroom cultivation is a delicate process. Much can go right, but it can even go wrong if you’re not doing things correctly. A serious obstacle to growth can come in the form of contamination. When your mushrooms are contaminated, they either cease growing, or the growth process becomes stymied. Everyone needs a guide to prevent mushroom contamination, and we set out to provide just such a guide below.
Symptoms of Contamination
How do your mushrooms look when they’re contaminated? Here are a few things to look for:
They’re Slimy
Many common forms of bacteria that contaminate mushroom cultures can give them a slimy appearance. It occurs in many places, notably where the mycelium presses against the glass or as yellow or brown residue around the grains.
They Smell Funny
This could be the first sign of any contamination. Even if the mycelium looks fine, an odor is one of the first indicators that something isn’t quite right.
Discoloration
Each mushroom has a specific color scheme, so what if it’s tinged slightly differently than it should be? Luckily for you, it may be more obvious than you think. Molds are usually green, bluish, yellow, and white. However, a slight tinge in color isn’t always an indicator that something is amiss, so don’t consider that a golden standard.
Distinct Borders
Distinct borders between two mycelia are indicative of sectoring, which occurs when two mushrooms are growing at the same time. It’s almost like they’re fighting for more space.
Smooth and Spongy
If the mushroom is smooth and spongy, the unwanted mold has filled up the volume of the container it’s in. This is a key sign that something isn’t quite right and that the mold is spreading throughout your substrate.
What Are Some Common Contaminates?
There are many contaminates to look out for. So what are some of the common types? Read on to find out here:
Bacterial contamination is a serious concern for mushroom growth. They can be heat-resistant, which means they’ll survive the pressure-cooking process. The most common type of bacteria is the “sour rot.” All you need to do is prevent this is keep it from forming a favorable microclimate. Limit irrigation, and you should be fine.
Trichoderma is also known as “green mold.” It affects yield because it grows exceedingly fast, which can take away nutrients from the fungi you’re trying to grow. This causes less growing space for your mushrooms and overcrowding.
Cobweb mold also spreads fast and can prevent your mushrooms from growing altogether. When a cobweb mold touches the mushroom, the mold envelops it and causes it to rot. Penicillium is usually non-pathologic to humans. However, immunocompromised people can cause death for the substrate that comes in the mushroom cultivation kit and even cause problems for your mushroom-growing supplies.
Different Ways Mushrooms Can Become Contaminated
There are so many different ways that mushrooms are contaminated.
Airbourne infections are common, given that mushrooms can be exposed to the air during much of the mushroom growing process. Spores aren’t exactly visible to the naked eyes, so be careful. Reduce contaminants in the air by using a flow hood. This allows clean air to stream in to help you cultivate your mushrooms and eliminates airborne contaminants. You can also build one yourself.
Substrate contamination results from incomplete sterilization or improper pasteurization of your substrate. The causes competing for organisms in your bulk substrate fight for nutrients and other organic resources that belong to the mushrooms you’re trying to grow. To eliminate this problem, sterilize your mushroom grain spawn before using it. Subjecting your substrate to high pressure and temperatures for an extended period also helps.
Unfortunately, you are also a source of contamination. Dirty hands, clothes, saliva and spittle, hair, and skin can all be the culprit when your mushrooms become contaminated. Clean your hands thoroughly, including under your fingernails, and use hand sanitizer before and during the cultivation process. Wash your clothes and consider wearing a facemask as you cultivate. Your tools can also be contaminated. Sterilize your scalpel and other tools during culture transfers. Try running your scalpel over a flame until it’s glowing red. You can do this with a lighter, but an alcohol lamp is more efficient.
Get the Right Tools
Here are a few of the tools you’ll need to make your project contaminant-free:
Alcohol Lamp
An alcohol lamp is a jar full of alcohol with a wick. It can be utilized to provide a consistent flame to your lab area. It’s wonderful for sterilizing scalpels or syringes. As we mentioned earlier, you can also use a lighter to sterilize your tools. Still, it isn’t nearly as effective as an alcohol lamp.
Parafilm
Parafilm is a porous material used to seal agar and is typically used as a form of biological culture, as it allows air to transfer but filters out anything else that tries to get in. This is perfect since—as we mentioned before—many contaminants are airborne. This ensures that clean air will get to your mushrooms.
Alcohol Bottle
This makes it so that you can release alcohol and can be squeezed it onto surfaces for efficient sterilization. You can also pour it out of the original bottle normally.
Scalpel
A scalpel is important since you want to use it for culture transfers and clones without worrying about using your hands. Using your hands is the last thing you should do when working with your substrate or culture.
Gloves
Gloves are needed whenever you work with your substrate. Make it a point to put a barrier between your hands and your substrate. They are a key part of preventing mushroom contamination. As stated, skin-to-skin contact isn’t recommended when working with cultures. Gloves are the best way to prevent mushroom contamination in this guide, so don’t neglect this supply.
In short, the best way to prevent mushroom contamination is to take all the right precautions. Using the information above, you should be able to make your substrate as sterile as possible. It’s not hard to cultivate. As long as you’re careful, you’ll do just fine. Here at Midwest Organics LLC, we take time to get you the best supplies and cultivation kits on the market. Shop Midwest Organics today!
