Mushroom growing question

[dragonrider]

I recently bought a lionsmane growbag and it's doing realy well. So now i wonder....could i just sterilise some sawdust and mix it with some of the sawdust inside the growbag to multiply my mushroom production?

 

[Jupitor]

Use the right kind of wood for your substrate, and yes absolutely. You can spawn it to infinity if you can avoid contamination.

 

[Loveall]

I think it is reccomended to pasteurize (not sterilize) the sawdust you will spawn into. I think the reason has to do with some not-so-bad surviving organisms helping keep a balance. Going off memory so I could be wrong.

I can say that in practice I have spawend grain to pasteurized substrated and that has worked.

 

[Loveall]

I think it is reccomended to pasteurize (not sterilize) the sawdust you will spawn into. I think the reason has to do with some not-so-bad surviving organisms helping keep a balance. Going off memory so I could be wrong.

I can say that in practice I have spawend grain to pasteurized substrated and that has worked.

Found more info on this. Attached is an article from 2014 (title: "Efficiency of treatments for controlling Trichoderma spp during spawning in cultivation of lignicolous mushrooms" ) that experimented with different treatments before spawning. They found that sterilizing the substrate cuased introduced mold to take over, while pasteurization was effective at controlling it. They propose two reasons for this (S= sterilized, NS = non-sterilized):

It is supposed that S treatment due to high temperature and the cooking effect, released nutrients that benefited the green mold. It is also considered that the reduction of the natural microbial flora of the substrate by the sterilization action increases Trichoderma sp opportunities to colonize the substrate because of a lower presence of competitive micro flora which reduces the possibility of mycelial growth. Bacterial strains can inhibit the growth of Trichoderma sp by production of volatile organic compounds (Mackie and Whetley, 1999) or by releasing antibiotics (Nielsen et al., 2000).

Conclusion as I understand it: when spanning (usually a non sterile process), pasteurization should be used instead of sterilization, otherwise any introduced spores will have an easier time taking over. The authors also observed that pasteurizing at 140F gave them better results than at 176F.

When innoculating (considered a sterile process), sterilization works. The interesting possibility the paper raises is that when steralizing, nutrients are released which could help the mycelium access them amd grow faster. This may explain why we PC grains for so long (90 minutes) so they perform better while liquid cultures simply do well with only 15 minutes. That time difference has allways been a mistery for me, but maybe the extra sterilization time for the grains is about breaking down the grain to release nutrients and not about killing micro organisms.