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saintpedro
nom nom nom

Registered: 04/06/06
Posts: 333
Loc: heliosphere
Last seen: 5 years, 7 months
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A sterility question: Shiitakes vs Oysters
#14551232 - 06/02/11 02:55 PM (12 years, 8 months ago) |
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This Spring I am going to give Shiitake a try. I have done several successful Oyster grows, using pasteurized straw substrate. I do all my (semi)sterile work in a glovebox, thoroughly bleached and alcohol'd each use. I've not had a contamination yet.
I'm going to follow RRs sawdust/chips/gypsum/bran substrate tek, sterilize (I have a pressure cooker) and inoculate with grain spawn. I understand this will be tricky without a flowhood, and contamination is more likely at this stage. However, as I'm used to using pasteurized substrates, and haven't had a problem yet, I have a question:
Even if there is a low level of contamination (I honestly can't see there being NO contams introduced when I open up the bag and inoculate in my glovebox), won't the shiitake mycellium still have the upper hand and overcome the contams in a sterile substrate? I understand that in a pasteurized substrate, contaminants are merely knocked back which gives the Oyster mycellium time to kick ass and rule the roost. Can't Shiitake do the same given a blank slate of a bag of sterile media? I also realise Shiitake isn't as vigorous or aggressive, but basically I'm wondering just how sterile (in a relative sense) do you need to be?
I watched a video that someone on here posted of a large scale shiitake farm (sorry, I can't find the post to link), and they were pretty much inoculating out in the open, using a plastic container of dry spawn. This also made me wonder just how sterile the inoculation step has to be?
Many thanks,
saintpedro
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MonkeyKnifeFight
Stranger


Registered: 06/08/10
Posts: 772
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Re: A sterility question: Shiitakes vs Oysters [Re: saintpedro]
#14551459 - 06/02/11 03:42 PM (12 years, 8 months ago) |
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You need to be more or less completely sterile. I've rarely seen any species recover from a contam getting started in a sterile substrate. Any contam that gets going will go completely nuts without competition. You'll see a lot of nonsense about various species eating contams but that's just not how it works. You can sometimes ignore contams and let your mushroom tissue fruit anyway but that doesn't really work with sterile environments. I've seen lion's mane fruit after a contam set in but by and large things don't recover. Pasteurized substrates are much more resistant to competition.
That said I use a gloveless box for all my clean work. Spawning to the sterile sawdust bags is by far the step with the least contams. Agar plates get the most. But that's fine for me since agar plates represent very little of my time where the final blocks represent a lot of my time making spawn and everything.
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saintpedro
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Registered: 04/06/06
Posts: 333
Loc: heliosphere
Last seen: 5 years, 7 months
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Thanks alot for that explanation, MKF. I'm pretty clean and have good sterile technique (as sterile as possible without a flowhood), good to hear it can be done without one though. When you say "gloveless box", do you mean you use a glove box but don't bother putting gloves on? Do you just spray and wipe with iso on your hands? Cheers
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MonkeyKnifeFight
Stranger


Registered: 06/08/10
Posts: 772
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Re: A sterility question: Shiitakes vs Oysters [Re: saintpedro]
#14551987 - 06/02/11 05:42 PM (12 years, 8 months ago) |
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I just mean a plastic rubbermade type bin that i rigged as my clean box. No gloves just some palstic over the openings. I wipe down the inside with lysol before every use and wear gloves (not attached to the box). Still air box may be a better term for it. Here is a pic:
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saintpedro
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Registered: 04/06/06
Posts: 333
Loc: heliosphere
Last seen: 5 years, 7 months
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Sweet, that box looks real good. Plenty of height too, important when dealing with bags in there I guess. Thanks mate.
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RogerRabbit
Bans for Pleasure



Registered: 03/26/03
Posts: 42,214
Loc: Seattle
Last seen: 1 year, 12 days
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Re: A sterility question: Shiitakes vs Oysters [Re: saintpedro]
#14555273 - 06/03/11 11:54 AM (12 years, 8 months ago) |
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Quote:
saintpedro said:
I'm going to follow RRs sawdust/chips/gypsum/bran substrate tek, sterilize (I have a pressure cooker) and inoculate with grain spawn.
Follow that recipe for oysters, but for shiitake, I'd suggest cutting the amount of bran by half. If you use bran in substrate, keep it sterile when you inoculate. A still air box like monkey posted above will work pretty good until you get hooked on the hobby and want a flow hood. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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saintpedro
nom nom nom

Registered: 04/06/06
Posts: 333
Loc: heliosphere
Last seen: 5 years, 7 months
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Re: A sterility question: Shiitakes vs Oysters [Re: RogerRabbit]
#14556190 - 06/03/11 03:40 PM (12 years, 8 months ago) |
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Quote:
RogerRabbit said:
Follow that recipe for oysters, but for shiitake, I'd suggest cutting the amount of bran by half. If you use bran in substrate, keep it sterile when you inoculate. A still air box like monkey posted above will work pretty good until you get hooked on the hobby and want a flow hood. RR
Thanks RR, I'll be sure to half the bran in the substrate for shiitakes. This mushroom growing certainly has me hooked. I don't think any other hobby I've ever had has given me so much satisfaction and sense of wellbeing. The only thing holding the scale of my obsession back is the fact that I'm currently overseas working in the UK temporarily (infact I routinely do work in Class II biological safety hoods - if only I could do my mushroom culture at work!).
When I return home to NZ, a flowhood is first on the project list. One of those 55 gallon drum sterilizers that you built looks like a good investment too. Cheers
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