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matchhead
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Registered: 11/01/16
Posts: 15
Last seen: 6 years, 10 months
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hops antibiotic action on agar?
#23790732 - 11/01/16 09:13 AM (7 years, 2 months ago) |
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Hello all! This is my first post on this forum but i´ve been learning from it for many years. For that I thank everybody that have been in anytime involved in this great information spreading, posting or moderating or else.
I´ve gathered a few ganoderma lucidum and aplanatum on my last hike, and decided to try to clone one of them, a ganoderma lucidum, with a bit of tissue from the part just above the pores of the guy inoculated to agar.
I have been a bit busy with beer brewing, and had little time to think to much about the agar, so decided to use for base of it the mixture i a´m using for starter of beer yest, that i had to spare, with agar extract added to gelatinise.
Well my starter is hoped. I a´m capturing wild yeasts, and the hops(humulus lupulus) somehow helps selecting yeast over enteric bacteria or other organisms that tend to compete with these desired organisms.
My starter recipe is a hoped solution of malted barley mash and maltose extract with a final gravity of aroud 1025-1030 wicth, if i´m not mistaken is about 7 grams per 100ml of water, witch i reckon might be a little high. So on 3 of the plates (i made 6)i diluted with tap water to half the concentration, rectifing the proportion of agar extract.
I´ve done this yesterday, and then started thinking, will the hops inhibit grow of the ganoderma mycelium?
It seems to have a more dramatic effect in bacteria as far as microbial toxicity goes, is solution, or this is the idea i got from my experience wit beer making. But probably, it does have some anti-mycological composts in it, that might affect some group of fungus, even if it does not seems to affect negatively some yeasts at these concentrations.
Does anybody have any experience with agar containing hops in it? Did anybody ever considered it might actually even be beneficial as it effectively inhibit many types of bacterial growth?
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drake89
Mushroom Magnate



Registered: 06/26/11
Posts: 4,168
Loc: TN
Last seen: 4 years, 10 months
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Re: hops antibiotic action on agar? [Re: matchhead]
#23790940 - 11/01/16 10:40 AM (7 years, 2 months ago) |
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interesting, but usually we don't need antibiotics. clean technique should do. i doubt it will inhibit mycelium much since yeast is a fungus. note that it does inhibit yeast growth a bit, you won't find many breweries pulling yeast from the bottom of an IPA fermentor cone...
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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Re: hops antibiotic action on agar? [Re: drake89]
#23791005 - 11/01/16 11:07 AM (7 years, 2 months ago) |
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Isohumulone disrupts ionophoric activity. And that's how it's antibacterial.
It's stressful to a lot of fungi but brewers yeasts are adapted. As are many bacteria.
I wouldn't suggest using hopped anything. If you want to experiment with hop oils in media then get some transisohumulone and start with something like 5-10-15-20 ppm and see what happens vs a control
Harvesting off an IPA is a recipe for low viability and vitality and higher than optimal slurry pH.
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matchhead
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Registered: 11/01/16
Posts: 15
Last seen: 6 years, 10 months
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Re: hops antibiotic action on agar? [Re: bodhisatta]
#23791561 - 11/01/16 02:31 PM (7 years, 2 months ago) |
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Hi! Thanks for your replies.
That was my reasoning also: fungi seems more tolerant to hops, but its true that Ganoderma and Sacharomyces are not exactly very close in the kingdom...might not share a lot in metabolism.
Yes i´m aware that hops in some higher concentration may have detrimental effects even on yeast fitness, but I beleve at least to some extent breweries pitch "fresh" yeast more to secure genetic stability-and hence flavor profile- than because the yeast cake on the botom of carvoy might be weak or uncapable of fermenting. In fact, I tend to reuse my yeast cake more than once with no noticeable decrease in fermentation rate, and like mushrooms, it seems to keep strong if you cycle through different media like from a different grain bills, or fruit juices like reusing it to brew cider for applejack or mead, thus avoiding "senescence" for longer.
I was not really after the anti-biotics in the hops, just lazy to prepare my usual PDA and decided to give the beer starter agar a go. Then began reflecting on possible consequences...
Well, in a few days we shall know the results of the experience.
Any other consideration on the interaction of higher fungi and hops are welcome.
Thanks
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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Re: hops antibiotic action on agar? [Re: matchhead]
#23791721 - 11/01/16 03:26 PM (7 years, 2 months ago) |
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You can use the yeast 100+ brew "generations" most can't harvest aseptically so going past 5-10 generations leads to infections.
Brewers yeast is aneuploid and polyploid it doesn't really mutate it self heals. Mitochondrial DNA is the first thing that breaks and you usually see petite respiratory mutants before any other problem.
If you harvest from the middle you leave behind the old cells as they bud they get loaded with bud scars and become heavier. The middle cells are mostly new. There's really no senescence issues with brewing yeast. Ideally there should be about three generations in a solid fermentation that is the yeast should double three times and you end up ~8 times as much yeast as you start with. Discarding the bottom 1/3 you end up with a harvest for 3 new beers before reaching the thin too part of the cake.
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matchhead
Stranger
Registered: 11/01/16
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Last seen: 6 years, 10 months
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Re: hops antibiotic action on agar? [Re: matchhead]
#23792585 - 11/01/16 07:14 PM (7 years, 2 months ago) |
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Hello again Bodhisatta
Thats a lot of interesting information in the most condensed form. Now I see that it make sense that there is no senescence even without variation in substrate, since in the traditional breadmaking they would just reuse the shit again and again, in beer making it happened for sure. I always had the habit of "cycling" my yeasts. Flavors seemed to change over batches of beer and I though it had probably to do with genetics naturally changing the yeast behaving differently then. But it coud be as easily explained by introduction of foreign organisms. I´ll think about all that.
But the original questions, Do you think hops in concentration typically found in beer would inhibit growth of Ganoderma sp.?
Or may be this is the kinda thing one cannot expeculate about and I just have to wait and hope somebody already made the experience and see this and can tell me somethig about it or be the first to report.
Nevertheless, thanks for instructional reply.
Cheers
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bodhisatta 
Smurf real estate agent


Registered: 04/30/13
Posts: 61,889
Loc: Milky way
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Re: hops antibiotic action on agar? [Re: matchhead]
#23793108 - 11/01/16 09:25 PM (7 years, 2 months ago) |
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Typical beer if you mean non craft won't inhibit ganoderma. But craft beer may. Especially something above 20 BUs could have that potential.
Most breweries let alone homebrewers don't have good enough QA to even know if and when they start getting organisms other than saccharomyces in their beer
And if you do have QA your media needs to actually support the growth of any contamination you may have. Or your PCRprimers need to catch it too. Many bigger breweries have done plenty of QA and missed contamination because they simply didn't see it using their protocol
Edited by bodhisatta (11/01/16 09:33 PM)
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matchhead
Stranger
Registered: 11/01/16
Posts: 15
Last seen: 6 years, 10 months
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Re: hops antibiotic action on agar? [Re: bodhisatta]
#23793699 - 11/02/16 04:49 AM (7 years, 2 months ago) |
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I cannot say for sure, but I would guess my hoped yeast starter is way bellow 20 BUs. The hops are not boiled for very long.
Incubation temperatures are very fine now. Its been sitting there for a couple of days, so I guess we ll soon know if the hops matters for the mushroom and ten one might consider it as a "preservative" against bacterial contamination.
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