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 upupup
guardian
Registered: 08/25/01
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 Bacterial Contam in MEA 
#1076478 - 11/22/02 11:48 AM (19 years, 18 days ago) |
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My alter ego is new at MEA. It keeps getting that nasty bacteria that smells like stinky feet that overly wet substrats get sometimes. Here is what I am doing;
I use this tek ala bluthumbs, ala oldtimer, alal rush wayne http://www.shroomery.org/forums/favlinker.php?Cat=&Entry=2765&F_Board=Forum2&Thread=466067&partnumber=1&postmarker=
I am pouring the MEA that I bought from Myco Supply (I love you Lana) into peri's that are washed and sterile from 90% isoprop alco. I let the MEA cool inside my oven. I let it cool till I can touch it then use my oven as the flow hood and poor the MEA. I leave those in the oven till they have cooled enough to innoculate and then do so, again in the oven and using the oven as a flow hood.
I know my syrnge is good as I have done about a zillion jars with it. I am just losing almost all my dishes to the bacteria.
Help appriciated....
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Support bacteria - they're the only culture some people have.
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 blahblahblah
Mad Scientist
Registered: 10/25/01
Posts: 1,022
Loc: South America
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Re: Bacterial Contam in MEA [Re: upupup]
#1076716 - 11/22/02 01:42 PM (19 years, 18 days ago) |
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"(I love you Lana)"
LOL!
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blahblahblah
Mad Scientist
Registered: 10/25/01
Posts: 1,022
Loc: South America
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Two problems I can see right now, first your sterilization might not be enough to kill the endospores of the bacteria and second I wouldnt innoculate with a syringe, a print would be better as you might be getting the conamination from too much water in the petri. When I did my petri dishes I did the same thing and all of them eventually got a bacterial infection. Just some thoughts
Good luck
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Suntzu
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Re: Bacterial Contam in MEA [Re: upupup]
#1076796 - 11/22/02 02:13 PM (19 years, 18 days ago) |
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Where is the bacteria growing, exactly? Is it on the surface of the agar in little blobs [more likely introduced through inoc/cooling after pouring] or does the whole plate just smell funny and look nasty [possibly incomplete sterilization]?
Personally, never had luck with the oven. The contams were more mold than bacteria, though, so it may be working for you. Cooling is an underrated step in sterilization, IMO very often the original source of contamination in petris, jars.
Edited by Suntzu (11/22/02 02:15 PM)
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upupup
guardian
Registered: 08/25/01
Posts: 889
Loc: George "I love Hitler" Bu...
Last seen: 17 years, 9 months
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Re: Bacterial Contam in MEA [Re: Suntzu]
#1077190 - 11/22/02 04:53 PM (19 years, 18 days ago) |
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The bacteria manifests already widespread as if it came out of the pour of MEA but if it was due to lack of sterilization of the MEA then all the dishes would have it No?
It is that damn anerobic bacteria so I think Blah might be onto something.
It is on the surface but not in little blobs. It is all over the surface of the MEA (whole plate smells funny (dirty socks) and look slimy and actually feels slimy. I have seen this same bacteria with too met grain quart jars.
Suntzu- By saying cooling is an underrated stip in strerlilization do you mean cooling of the dishes after they are poured or just the cooldown of the PCer or what?
When I cooled my dishes I left em in the oven with the door closed. I placed a micron filter disc over the top of the Ern whatever flask for the whole proccess until I took it off to pour. Out of all of my dishes, 8 or so, only one did not contam and shows signs of growth.
Anyother ideas? Do most of you innoculate from spores or from syringes onto MEA? Don't the spores need to be rehydrated?
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Support bacteria - they're the only culture some people have.
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Suntzu
Geek
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Re: Bacterial Contam in MEA [Re: upupup]
#1077594 - 11/22/02 08:09 PM (19 years, 18 days ago) |
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Both; As steam condenses or hot air cools, air will be sucked in as the pressure/temperature returns to standard. You know how jars will explode if you PC them with sealed lids? The air expands, so filter disks let this happen. The same amount of air volume exchange happens when the jars cool, except they will implode if they somehow seal up during the PC process. The entire cooker should be cooled in as clean of a place as possible, the valve stem wrapped in a bleached rag or such.
From your description it's tough to pick out the contam source. Because a few plates escaped I'd lead toward the pouring and cooling of the plates. But if it seems like only one type of contam, a bacterial contam, that almost sounds like something that was in the original agar flask. Might be a good idea to leave a few millimeters of agar in the flask itself, cover it and incubate with the rest.
Personally, I'm really suspect about the oven tek. I think it works for some people and not others because of the variability of air quality in different people's kitchens. The first [and only] time I tried the oven tek, the resulting contaminated grain produced little Mycena mushrooms when I dumped it in the worm bin. Environmental mushroom contamination, now that's dirty kitchen air. Never had those problems with even the simplest of lysol/glovebox setups.
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upupup
guardian
Registered: 08/25/01
Posts: 889
Loc: George "I love Hitler" Bu...
Last seen: 17 years, 9 months
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Re: Bacterial Contam in MEA [Re: Suntzu]
#1077935 - 11/22/02 10:51 PM (19 years, 18 days ago) |
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Thanks. It's good to be reminded of the smallest things. So as well as putting the PC in a better spot and wraping the valve, I should pour in the plates in a glove box? And cool in the glove box?
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Support bacteria - they're the only culture some people have.
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Seuss
Error: divide byzero
Registered: 04/27/01
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Re: Bacterial Contam in MEA [Re: upupup]
#1079221 - 11/23/02 01:38 PM (19 years, 17 days ago) |
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You can add antibiotic to your agar... the easy solution.
Try getting away from your oven/kitchen. I did not have good results working with agar until I started using a glove box.
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Just another spore in the wind.
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