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shymanta
Mad Scientist
Registered: 01/27/05
Posts: 907
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Developing contaminate resistant strains.
#10795792 - 08/03/09 11:01 PM (14 years, 7 months ago) |
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I had an interesting experience with strain isolation. Having very bad luck with starting mycelium on agar with spore syringes, I gave up (the water was encouraging bacteria to grow, prints are better) in favor of another plan.
I used the remaining solution to inoculate grain jars. They colonized and before I spawned them to substrate, I opened them in front of the flowhood and transferred growing mycelium to agar. This took a shorter amount of time. Fewer strain being present on a kernel of rye.
One syringe must have had trich spores mix in, too because it would always grow in jars inoculated with that sample. I gave up on that strain. I left the jar sitting until I had time to run it through the pressure cooker and clean the jar. I forgot about it. A week or so later, I find the jar with much green and black and gray. Also, the most pristine little white spot. Growing happily among the forest of contaminants was the mycelium I wanted. I ran the flowhood for a few hours with the jar, lid loosened, sitting in front of it. Later, I turned it off and immediately removed the lid and without touching the jar or disturbing anything inside, I removed a small piece of tissue with a very long pair of tweezers, transferred to agar and waited. Of three samples, none showed contamination. The mycelium grew fast overtaking the spores sure to be present on the tissue. Several transfers later I had clean, pure culture.
Now to the point, for those of you still reading. Perhaps by allowing a multi-spore culture to contaminate, the contaminants will force a natural selection of strains. Eliminating weak ones and becoming food for stronger ones. If mycelium learns to metabolize trichoderma, for example, maybe it will be resistant in future encounters.
If this is a trait that is learned by the mycelium, then you can "teach" any strain to overcome with a small loss in P value. However, if it is a trait that selected on a genetic level, then it can be bred into new strains.
Thoughts?
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solumvita
Q.B.E.
Registered: 02/12/08
Posts: 2,061
Loc: South Africa
Last seen: 9 months, 16 days
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Re: Developing contaminate resistant strains. [Re: shymanta]
#10795866 - 08/03/09 11:20 PM (14 years, 7 months ago) |
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I think that you would be able to select for a form of tolerance, the question is what it the eventual yield and you need to be sure to do the selection with the "right" molds/bacteria present in the substrate.
Of course the best strains are usually discovered by chance and if the strain you have now got growing can out compete trichoderma that would be excellent.
A way to test it would be to cultivate properly identified trichoderma in a petri and then introduce your strain and the cultivated trichoderma into the same petri at opposite ends to determine if it really can compete with the trichoderma.
-------------------- One of these days all the answers will be revealed until then we learn from each other! www.mushrush.co.za
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RogerRabbit
Bans for Pleasure
Registered: 03/26/03
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Loc: Seattle
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Re: Developing contaminate resistant strains. [Re: solumvita]
#10795944 - 08/03/09 11:44 PM (14 years, 7 months ago) |
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I suspect that spot of 'white mycelium' was fresh trich germinated from the green spores. I've seen that happen before, and it always follows suit and turns green. You can quickly determine if it's trich or mushroom mycelium with a microscope. 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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troncotron
Stranger
Registered: 12/13/08
Posts: 79
Last seen: 11 years, 2 months
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Re: Developing contaminate resistant strains. [Re: RogerRabbit]
#10797392 - 08/04/09 09:15 AM (14 years, 7 months ago) |
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Hey shymanta, difficult project. Each group involving pathogen(cubensis) - trichoderma, shows different interaction, sometimes related with parasitism (IE: trichoderma - rizhoctonia solani), sometimes with the production of enzymes or antibiotics (IE: Trichoderma - Glomus) Harman et al.(1) suggests that micoparasitism is the principal mechanism used by trichoderma to control pathogens. We should know first which is the mechanism that trichoderma uses to attack cubensis hyphae. Maybe you can find some strain resistant to this kind of antibiotic, but if Harman is right, i donĀ“t know how can cubensis resist trichoderma strangulation.
(2)
(1)Harman, G., Chet, I. and Baker, R. 1981. Factors affecting Trichoderma hamatum applied to seed as a biocontrol agent. Phytophatology 71:569-572 (2) Image from I.N.T.A
Edited by troncotron (08/04/09 09:20 AM)
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fastfred
Old Hand
Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
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Re: Developing contaminate resistant strains. [Re: troncotron]
#10799162 - 08/04/09 02:32 PM (14 years, 7 months ago) |
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Shymanta, you probably need to get your contamination problems under control first. I say this time and again, but here goes...
You NEED to have negative controls and test your procedures. Otherwise you'll never track down what your problem is.
For the PC, always do an extra jar and stow it away. That's your negative control and verifies your PC is sterilizing properly.
To test your flow hood prepare a petri dish or two with PDA or MEA and expose them to the airflow for a minute or so. Stow them away and check for contams.
For verifying your technique prepare a blank syringe with distilled water then sterilize. Prepare 2 petri dishes. One is the negative control for your dish prep, take the other and innoc with your water syringe. You'll probably want to do a jar also.
A lot of people just keep trying and get frustrated without ever doing these few simple things to track down the problem.
As for the trich... It parasitizes by using it's own chitinase to dissolve myc cell walls and absorb the contents. It's a complex relationship involving the trich recognizing it's prey, being able to grow into the myc, and being able to dissolve it's cell walls.
So it's certainly possible you could evolve resistance to a strain of trich. The problem is that there's hundreds if not thousands of trich strains, and it's likely that one of them will still be able to attack the myc.
You could also be experiencing some non-genetic acquired or passive immunity. If that's the case you won't get very far trying to breed that characteristic.
-FF
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DropScience
Stranger
Registered: 03/22/09
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Re: Developing contaminate resistant strains. [Re: fastfred]
#10843798 - 08/12/09 03:05 AM (14 years, 7 months ago) |
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Im siding with FastPhred on this one,
in the original post you make a number of suppositions with no real support behind them. Blanket statements that prints are better then syringes because water causes bacteria sound more like prejudice of limeted personal experience than rigorously controlled experiments. You see alot of posteres making all sorts of assumptions based whatever their last batch of jars did under whatever circumstances rather than the harder reality of cultivation practices, with such undocumented and lack of cross checking with so many variables at play many are simply incapable of determining the full reality of their grow, let alone go on to speculate on far more complex procedures such as developing a super stain resistent to all green mold.
The best way to get rid of green mold would simply not to have it present in the first place, and to be able to confirm it as such with a great degree of certainty.
Edited by DropScience (08/12/09 03:07 AM)
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shymanta
Mad Scientist
Registered: 01/27/05
Posts: 907
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Re: Developing contaminate resistant strains. [Re: DropScience]
#22998013 - 03/12/16 12:11 AM (8 years, 18 days ago) |
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Yeah, yeah. I get it. No one is allowed to make suppositions, guesses or hypothesisize about anything. If it's not your dogma, it's wrong. If I ever mentioned an iperfect fungi, the assumption is that I have contams I can't get rid of. No one will talk about an imperfect fungi because most of you are completely ignorant of them besides "Ewe, bad!". Instead, you attack any post about it with... Well. I'm starting to remember why I stopped posting here. Dude, this isn't a university and I'm not writing a thesis paper. I'm just saying "Hey, guys. Check out what happened. What do you think?" Not, "Grade my paper, professor." Learn to realize, people make statements about their own situation, not yours.
Mycology is more than Breaking Bad with shrooms. Some of us here are researching more than how to grow psychedelic mushrooms.
I have a lot of respect for many of the cultivators on here, but there's always someone to come along and show the pretentious side of this science. Oh, yeah. Before I forget... DICK!
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shymanta
Mad Scientist
Registered: 01/27/05
Posts: 907
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Re: Developing contaminate resistant strains. [Re: fastfred]
#22998016 - 03/12/16 12:13 AM (8 years, 18 days ago) |
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FF. Thank you for your input. 6 years late.
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Kizzle
Misanthrope
Registered: 08/30/11
Posts: 9,866
Last seen: 20 days, 12 hours
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Re: Developing contaminate resistant strains. [Re: shymanta]
#23001972 - 03/13/16 07:28 AM (8 years, 17 days ago) |
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Yeah what a dick, offering his opinion of which you asked for like that
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