|
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
dalls_boy
Stranger
Registered: 02/21/06
Posts: 7
Last seen: 14 years, 2 months
|
contamination outbreak with rye unicorn bags
#11369728 - 11/02/09 02:25 PM (14 years, 4 months ago) |
|
|
I've been using the same source of rye for about 2-3 years now. Up until about 6 months ago I've had nothing but contamination from this same rye .
The contaminants I'm getting are varried between blue/green, fuzzy black, tomentose ringed pattern like white growth. I'm guessing penicilium, black pin moulds, possible others?
Here are a few possible situations which I think have influenced this massive contamination outbreak.
1.) 1 year ago I let a friend borrow my PC to prepare some rye grain in jars, during sterilization the jars broke inside the Pressure Cooker and he did not clean the mess up, When I came to pick up the PC weeks later, I opened it up and there was abunch of moldly multi coloured contaminated rye grain cooked onto the PC which I then cleaned out. I'm considering this as a possible source of contamination - a contaminated pressure cooker...Is this possible?
2.) Another possible is my rye prep technique is not clean enough. I start by adding 3lbs dry rye into unicorn bags, add 1400ml of water and then let it presoak for 24hrs (for endospore germination) then I PC at 15psi+ for atleast 3 hours, usually 4 hrs. In the past when I had great success I would 24hr presoak, simmer, and then PC in jars.
3.) Or could I possibly have contaminated prints? I am currently testing this by doing a batch of rye and only inoculating 50% of the batch, and waiting to see if the uninoculated rye contaminates by itself..
4.) Maybe the rye vendor suddenly got a shipment of bad rye ? This source is a large farm and feed supplier. and they sell it as "fall rye"
5.) The last but unlikely(in my mind) possible is that contaminants are passing through the tyvek filter, post sterilization. These are the original 8" x 20"? unicorn bags with filter. During sterilization the plastic tops are folded ontop of itself as to not let steam or water to have direct contact with filter? Can contaminants pass through tyvek?
Additional notes.
-I do not rinse/clean my rye , just add water and let presoak 24 hrs, then PC . Just as it says in TMC.
-I preseal the bags prior to sterilization and have no problem with them expanding and blowing out like some people have.
Once the rye has cooled I wipe it down with ISO alcohol and stick the needle through the top of the bag and inoc straight down onto the rye , I then quickly cover the needle hole with tape( I can't see this tiny hole covered in tape being the issue, as I don't shake the bags after inoculating. All inoculation is via multispore.
-This outbreak of contamination started around the time that I got back the borrowed moldy Pressure Cooker , prior to that I used the same rye grain in quart jars and often had 100% success.
-After pc'ing bags for at least 3 hrs, I wait until the pressure has released and then take the bags/jars out of the PC to cool. This is the way I've done it forever.
It would be great to get some second opinions on this, as I have nobody I can personally I can discuss this with. Possibly somebody sees something that I may have overlooked?
Apologies for the long, boring post. I would add pictures if I hadn't recently lost my camera.
|
solumvita
Q.B.E.
Registered: 02/12/08
Posts: 2,061
Loc: South Africa
Last seen: 9 months, 17 days
|
Re: contamination outbreak with rye unicorn bags [Re: dalls_boy]
#11375869 - 11/03/09 10:23 AM (14 years, 4 months ago) |
|
|
Quote:
dalls_boy said: 1.) a contaminated pressure cooker...Is this possible?
I doubt it, clean the seals and any obvious crusting, but no, not that.
Quote:
dalls_boy said: 2.) Another possible is my rye prep technique is not clean enough. I start by adding 3lbs dry rye into unicorn bags, add 1400ml of water and then let it presoak for 24hrs (for endospore germination) then I PC at 15psi+ for atleast 3 hours, usually 4 hrs.
rather after soaking rinse the grain under clean water allow to drain and then put into bags and pc.
Quote:
dalls_boy said: 3.) Or could I possibly have contaminated prints? I am currently testing this by doing a batch of rye and only inoculating 50% of the batch, and waiting to see if the uninoculated rye contaminates by itself..
good idea!
Quote:
dalls_boy said: 5.) Can contaminants pass through tyvek?
no, unless it is wet but then generally only bacteria and you are mostly dealing with fungi.
Quote:
dalls_boy said:-I do not rinse/clean my rye , just add water and let presoak 24 hrs, then PC . Just as it says in TMC.
rinse it and let it drain
Quote:
dalls_boy said: -This outbreak of contamination started around the time that I got back the borrowed moldy Pressure Cooker , prior to that I used the same rye grain in quart jars and often had 100% success.
you also started using the unicorn bags and changed your basic procedure.
finally are you sure that the pc is working correctly and getting up to pressure?
-------------------- One of these days all the answers will be revealed until then we learn from each other! www.mushrush.co.za
|
dalls_boy
Stranger
Registered: 02/21/06
Posts: 7
Last seen: 14 years, 2 months
|
Re: contamination outbreak with rye unicorn bags [Re: solumvita]
#11376188 - 11/03/09 11:17 AM (14 years, 4 months ago) |
|
|
Thanks for the reply solumvita!
I'll continue to wash and disinfect my pc regularily.
Yes, I have changed my basic procedure from: Presoaking, washing, simmering, and sterilizing to presoaking and sterilizing. I can definately see how the bacteria and spore count in unrinsed grain will be higher that if it was, but I'm curious how some people can get away with successful batches using the exact method i'm using. Each time I prepare the bags I grit my teeth abit, because im so used to simmering and washing. It feels dirty!
My only worry with washing out the rye after the 24hr presoak is that I won't have proper moisture content(exactly 1300-1400ml) I've found that even a +/- deviance of 200 ml can cause the grains to become either dry to to moist(burst kernals).
Do you think it would be possible to wash prior to the 24 hr presoak instead and still have adequate results?
About the pc being up to temperature. I really have no assurance that everything is working fine. I'm considering buying a roll of sterilization indication tape. Each time I pc I make sure the tops of the bags are folded and weighted down so as they dont inflate and block the pressure release or gauges.
Thanks again - today i'll be preparing a washed batch as you recommended and see how it goes.
|
solumvita
Q.B.E.
Registered: 02/12/08
Posts: 2,061
Loc: South Africa
Last seen: 9 months, 17 days
|
Re: contamination outbreak with rye unicorn bags [Re: dalls_boy]
#11376743 - 11/03/09 12:42 PM (14 years, 4 months ago) |
|
|
The reason they might get away with it is the use of clean spore prints or better yet clones. The quality of the grains as you say you might have had a bad batch , you can not say if the grain got wet before you bought it or something lke that.
Moisture content is simple, as long as you have soaked the grain long enough beforehand and then allowed it to drain it should be right. I normally go by feel rather than by formula.
I am sure you could wash before the pre-soak.
-------------------- One of these days all the answers will be revealed until then we learn from each other! www.mushrush.co.za
|
dalls_boy
Stranger
Registered: 02/21/06
Posts: 7
Last seen: 14 years, 2 months
|
Re: contamination outbreak with rye unicorn bags [Re: solumvita]
#11701848 - 12/22/09 07:25 PM (14 years, 3 months ago) |
|
|
I'd just like to update this thread for anyone who may have been curious. The source of contamination was contaminated prints. I transfered some tissue from an old petri culture I had stored to a new plate, grew it out and transfered to a malt lc. the lc grew out and i inoculated rye bags with freshly sterilized syringes. colonization was lightning fast with zero contamination. First flush pins of invitro bags are now forming.
I also carried out a test without inoculating some of the grain, and there was no contamination for along time, then i inoculated them with some left over lc, they colonized fine also.
So, lesson learned - Take clean prints in a clean area(I'll be taking prints from invitro bags from now on I think)
My reason for originally attemping ms to grain is because I wanted to spawn to straw and find more specimens to culture on agar, I prefer to go from fruited specimen tissue on agar VS multispore on agar.
Edited by dalls_boy (12/23/09 07:47 PM)
|
|
|
You cannot start new topics / You cannot reply to topics HTML is disabled / BBCode is enabled
Moderator: Shroomism, george castanza, RogerRabbit, veggie, mushboy, fahtster, LogicaL Chaos, 13shrooms, Stipe-n Cap, Pastywhyte, bodhisatta, Tormato, Land Trout, A.k.a 1,598 topic views. 10 members, 87 guests and 112 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ] |
|