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blackout
Registered: 07/16/00
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Last seen: 4 months, 22 days
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Sterilizing grains with bleach, will subsequent heating trigger dormant endospores.
#7188088 - 07/17/07 01:10 PM (16 years, 8 months ago) |
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I am trying an experiment soaking barley grain in a sodium hypochlorite solution, about 0.5%. The grain was added dry and is soaking up the bleach, theory being that it will soak up all the water it wants and as the endospores are germinating they are killed instantly. I plan on incubating them at 30C for a few weeks. I am also considering upping this to 60C.
After that time I am unsure what to try, I could leave the nor sterile jar and grains in the sun, I would open the lid slightly and decant off the excess soaking water. The theory here being that the light will degrade the bleach into sodium chloride and chlorine. I have heard that cubensis can be quite tolerant to salt. I also plan on innoculating with LC which might give it a better chance with the salt.
Another option is to heat the grains after decanting off the bleach, this should rapidly degrade the bleach in the jar. It will hopefully also drive off the chlorine gas as steam is formed. This could be done in a short microwaving or steaming. But will this heating trigger dormant endospores?
Ideally it would only need to be left in the sun which would mean massive, thermally sensitive containers could be used. If they show no growth I fully rinse the grains, and boil in excess water, then fully resteam them, yet still hopefully get away without using a PC.
On 14 July I put 200g of barley in a jar, and 100g of whole grain brown rice in another. And yes I know I risk getting mutants.
Edited by blackout (07/17/07 01:12 PM)
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AbyssWP
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Loc: colorado
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: blackout]
#7191238 - 07/18/07 02:22 AM (16 years, 8 months ago) |
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If the point of this is to sterilize grains without a pressure cooker, then read this http://www.shroomery.org/5248/What-is-fractional-sterilization-or-tyndallization
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Boarders
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Registered: 08/19/06
Posts: 333
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: AbyssWP]
#7191257 - 07/18/07 02:36 AM (16 years, 8 months ago) |
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I love the fact you're from Ireland.
What's wrong with using a PC? Tyndallisation is your friend if you must sterilise without pressure.
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blackout
Registered: 07/16/00
Posts: 5,266
Last seen: 4 months, 22 days
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: Boarders]
#7192644 - 07/18/07 12:44 PM (16 years, 8 months ago) |
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Quote:
What's wrong with using a PC?
I can make a 100 litre steamer for €5, a 100L PC costs a fair bit.
Quote:
then read this... Tyndallisation
Have done it a few times successfully, steaming and microwaving. Just want to give this a try a single heat up would be ideal. Waiting for soaking doesnt bother me at all, if I had to wait a year for the bleach in the strained soaked grain to degrade then it would suit me fine. I could fill 2L coke bottles with grain and just leave them till I need them.
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fastfred
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Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: blackout]
#7193124 - 07/18/07 03:20 PM (16 years, 8 months ago) |
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Pasteurizing grains doesn't work AFAIK. If you are going to go the pasteurization route then just use straw and manure. There's lots of info on pasteurization, it's what all the large scale edible growers do.
Bleach is often stabilized with NaOH, so your pH may be way off if you try using it. Transition metal ions will catalyze the decomposition of bleach. Bleach is a strong oxidizer, so any reducing agent should neutralize it. H2O2 (hydrogen peroxide) will also react with bleach.
I think you also used too high of a concentration to begin with. Then again there is plenty of material to be oxidized in a jar of rye, so the bleach may be consumed too quickly to be effective. Bleach is used to sterilize seeds and makes a good surface sterilizer, but you're going to have to do some experimentation to get things right.
One other thing you might check out it a product called "chlorout". You can find it in the aquarium section of many stores. It's used to dechlorinate tap water so that it doesn't kill your fish. It's probably sodium thiosulfate or sodium hyposulfate which are effective chlorine neutralizers. I think they are used at around 5mg/L.
Any sort of acid should also consume the bleach, although this will generate chlorine gas.
You might also think about just rinsing it away with sterilized water. You can probably get away with using distilled water or water purified by RO. Another thing you could try is adding bleach to your water, then neutralizing it with chlorout, then using it to wash your grains.
Anyways, be sure to post your results.
-FF
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blackout
Registered: 07/16/00
Posts: 5,266
Last seen: 4 months, 22 days
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: fastfred]
#7202498 - 07/20/07 01:11 PM (16 years, 8 months ago) |
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Quote:
fastfred said: Pasteurizing grains doesn't work AFAIK. If you are going to go the pasteurization route then just use straw and manure. There's lots of info on pasteurization, it's what all the large scale edible growers do.
Bleach is often stabilized with NaOH, so your pH may be way off if you try using it. Transition metal ions will catalyze the decomposition of bleach. Bleach is a strong oxidizer, so any reducing agent should neutralize it. H2O2 (hydrogen peroxide) will also react with bleach.
I think you also used too high of a concentration to begin with. Then again there is plenty of material to be oxidized in a jar of rye, so the bleach may be consumed too quickly to be effective. Bleach is used to sterilize seeds and makes a good surface sterilizer, but you're going to have to do some experimentation to get things right.
One other thing you might check out it a product called "chlorout". You can find it in the aquarium section of many stores. It's used to dechlorinate tap water so that it doesn't kill your fish. It's probably sodium thiosulfate or sodium hyposulfate which are effective chlorine neutralizers. I think they are used at around 5mg/L.
Any sort of acid should also consume the bleach, although this will generate chlorine gas.
You might also think about just rinsing it away with sterilized water. You can probably get away with using distilled water or water purified by RO. Another thing you could try is adding bleach to your water, then neutralizing it with chlorout, then using it to wash your grains.
Anyways, be sure to post your results.
-FF
Thanks for the great advice, very encouraging. I have been reading up more and heard about the H2O2, to be added slowly as it can react viloently. I had heard of the chemical names of the chlorout but didnt know it was as readily available as that. I must check the pH of my bleach it is cheap thin bleach, unperfumed.
What concentration would you have recommended? Mine is fully submerged so do you think I could just add chlorout and then open the cap slightly and decant? Probably should leave it a few days again to fully get into the core of the grains and neutralise them. I also wonder if there is some sort of indicator chemical I could add so when I add my chlorout (or acid if needed) that I could tell I have the right amount.
I read a bit on endospores & bleach, some were talking of 0.5% solutions and measureing death times in a matter of hours.
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fastfred
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Registered: 05/17/04
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Loc: Dark side of the moon
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: blackout]
#7203078 - 07/20/07 03:46 PM (16 years, 8 months ago) |
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> What concentration would you have recommended?
That's hard to say. I probably would have started with 1:100 household bleach. Then again there is so much organic material in a jar of grain that the bleach is probably consumed pretty quickly. All you should really have to do is sterilize the surface of the grain though, so it might not take all that much.
> do you think I could just add chlorout and then open the cap slightly and decant?
Pouring out the liquid will suck air in, so you'd need a source of clean air, like a flow hood or at least a good glove box. To avoid that you might try using a syringe to shoot in some chlorout and then suck out the water. You could attach a micropore filter or use a polyfilled hole in the jar to vent it while you suck the air out through some sort of silicone or rubber stopper.
There's probably a better way to do it, but I can't really think of one at the moment. Having a vac pump or aspirator would probably work for sucking out the water without much effort.
> Probably should leave it a few days again to fully get into the core of the grains and neutralize them.
Simply sterilizing the surface should probably be enough. I would still let it soak a good 24 hours though.
> I also wonder if there is some sort of indicator chemical I could add
You can get chlorine test strips. Restaurants and the like use them to test their sanitizing water. You can probably find them cheaper, but here's a link.
http://www.indigo.com/science-supplies/chlorine-test-strip.html
-FF
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deucedbi9
Stranger
Registered: 10/24/06
Posts: 4,613
Loc: UK
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: fastfred]
#7225539 - 07/26/07 08:49 AM (16 years, 8 months ago) |
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came across this at mycotopia a while back->
Antibacterial Grain Soak Experiment. by "reverend trips"@mycotopia
"What I 'hope' comes from this is an easy way to prepare grains without the use of a pressure cooker and to put an end to losing jars to wet spot and other bacterial infections common to this hobby. I know thats asking for a lot, but I think it can be achieved.
My first experiment looks promising.
What I did was put some rye berries in a container and filled it with water, and squeezed in an unmeasured amount of Sunlight antibacterial dish soap (not sure how much really, but it was a good squirt, enough that I thought there was no way in hell that mycelium would want anything to do with the grains) stirred it up real good and put the lid on the container and let it sit for 24 hours. Then I poured the soapy rye berries into a strainer and tossed them around a bit to drain them. Loaded a quart jar with the soapy rye berries, put on a lid with polyfil, covered with tinfoil and put it in a pot with a couple paper towels on the bottom. I then put enough water in the pot to bring the water level up to cover 2/3rds of the jar. I brought the water to a boil and turn the heat down enough so it was a slow boil, put a lid on the pot and let it go for an hour and a half. The next day I inoculated the grain with an LC I had and that jar is growing healthy myc with no sign of contams.
Pretty cool.
The idea behind this is that the soap will kill bacteria and any endospores will be hatched into a world of hurt. They won't have enough time on this planet to know they even existed, let alone fuck up my grain. And mycelium doesn't seem to be affected by it, not at all, not even at a high concentration.
So far I am having 100% success, but that was only one jar."
maybe worth playing with till you can get a pc. check out the link below to see if you have a local group.
-------------------- whether low pressure sucks or high pressure blows... it's a bugger to cycle in. even though I'm feeling good Something tells me I'd better activate my prayer capsule
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blackout
Registered: 07/16/00
Posts: 5,266
Last seen: 4 months, 22 days
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: deucedbi9]
#7236112 - 07/29/07 10:18 AM (16 years, 7 months ago) |
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I have bleached and steamed some barley I also found this page which talks of washing rice with bleach.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=92979
I have also found that rice made to a 50% moisture content then rinsed, towel dried and steamed is perfectly shakeable. I think this could be useful to many since making a big steamer container is very cheap and easy to do.
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blackout
Registered: 07/16/00
Posts: 5,266
Last seen: 4 months, 22 days
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: blackout]
#7278071 - 08/09/07 02:12 PM (16 years, 7 months ago) |
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I had some injected but it turned out to be a contamd syringe, LCs and grain that were PC'd got infected. Have a new syringe on the way to me now. I soaked some rice in bleach and a 4% glucose solution with bleach. Just wanted to see if the rice would colonise faster with extra sugar (I know it will be more open to contams, but more proof it is really sterile.
The new rice was strained and still seems a little wet, I think I will have to heat it- just enough to get moisture to absorb, not even boiling. I steamed other soaked rice and it puffed up a little, looks more absorbent, and I like adding lots of LC to thristy grains
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blackout
Registered: 07/16/00
Posts: 5,266
Last seen: 4 months, 22 days
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Re: Sterilizing grains with bleach, will subsequent heating trigger dormant endospores. [Re: blackout]
#11220408 - 10/10/09 11:35 AM (14 years, 5 months ago) |
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Just bumping this old thread. I found this page about sterilizing grains with sodium hypochlorite. http://www.plantphysiol.org/cgi/reprint/11/3/635.pdf They were just sterilizing the outside of the grains for up to 5 hours and trying to grow them. You can see the grains done for 5 hours had much lower germination rates. I am talking about soaking for weeks or months in bleach.
I also found this page about sterilizing chocolate powder. http://www.freepatentsonline.com/3860730.html It is heating and using hydrogen peroxide to kill endospores. Highest temp mentioned was 200F
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