3 ms·

But then what about mushroom farms? If everything needs to be so sterile, how do the commercial mushroom farm I've visited work? I know of one that is basically

by roel_v 10y ago

But then what about mushroom farms? If everything needs to be so sterile, how do the commercial mushroom farm I've visited work? I know of one that is basically in a few stables next to other stables where cows are kept, with the sterility you' expect from the average farm; and another one inside old limestone quarries, because the temperature there is low, constant and it's moist. Not the most sterile place I've seen either - they do daily tours even! Is the sterile thing only for some species?

Synaesthesia 10y ago
It depends, what's important is that you don't want a bacterium or other organism taking over your substrate, which can happen easily especially with agar gel and nutrient rich substrates. But if the mushrooms acquire a critical mass they can actually kill bacteria. There are many techniques, some emphasizing sterility. Others use a weak peroxide solutions which kills other organisms but not fungi. And others say sterility is overrated and just grow mushrooms in big plastic bags.
Obi_Juan_Kenobi 10y ago
Obviously wild mushrooms aren't grown in sterile conditions, either. However, wild mushrooms have the luxury of only needing to grow in those unlikely places where conditions are just right for them to thrive. If you hope to grow a mushroom monoculture on a rich media (e.g. grains), you'll need to avoid the other fungi and bacteria that would easily out-compete your desired species. Once the mycelia is established, it's quite robust, at least relatively speaking. Un-colonized substrate, however, will readily harbor trichoderma, cobweb mold, etc. that will spread and kill your mushrooms. On a commercial farm, you're typically not looking at the colonization phase. If you see actual fruiting bodies, these are mushrooms at the very end of the crop cycle where contamination is no longer a risk. The initial colonization is often done on pasteurized substrate in a clean environment. Strict sterility is neither economical nor required, but effort must be made to give the desired species ideal conditions for growth. And then, contamination is a significant risk for the farmer. Once the mushrooms have been cased, exposure to fresh air is an important pinning trigger and contamination is not an issue.

by roel_v 10y ago

Synaesthesia 10y ago

It depends, what's important is that you don't want a bacterium or other organism taking over your substrate, which can happen easily especially with agar gel and nutrient rich substrates. But if the mushrooms acquire a critical mass they can actually kill bacteria. There are many techniques, some emphasizing sterility. Others use a weak peroxide solutions which kills other organisms but not fungi. And others say sterility is overrated and just grow mushrooms in big plastic bags.

Obi_Juan_Kenobi 10y ago

Obviously wild mushrooms aren't grown in sterile conditions, either. However, wild mushrooms have the luxury of only needing to grow in those unlikely places where conditions are just right for them to thrive. If you hope to grow a mushroom monoculture on a rich media (e.g. grains), you'll need to avoid the other fungi and bacteria that would easily out-compete your desired species. Once the mycelia is established, it's quite robust, at least relatively speaking. Un-colonized substrate, however, will readily harbor trichoderma, cobweb mold, etc. that will spread and kill your mushrooms. On a commercial farm, you're typically not looking at the colonization phase. If you see actual fruiting bodies, these are mushrooms at the very end of the crop cycle where contamination is no longer a risk. The initial colonization is often done on pasteurized substrate in a clean environment. Strict sterility is neither economical nor required, but effort must be made to give the desired species ideal conditions for growth. And then, contamination is a significant risk for the farmer. Once the mushrooms have been cased, exposure to fresh air is an important pinning trigger and contamination is not an issue.