this post was submitted on 17 Jun 2023
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Mycology

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submitted 1 year ago* (last edited 1 year ago) by lightingnerd to c/[email protected]
 

Day 4 of growing Pleurotus ostreatus cultures from spore. Only one plate got contaminated, but it was bad. There are two contaminant fungi going to battle, and around three possible bacterial colonies. I must have been losing it at the end, haha! Can't wait to see how they progress!

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[–] [email protected] 3 points 1 year ago (1 children)

Side thought: a lot of people recommend the z-shape swabbing, but it seems kind-of counterproductive if you’re trying to select for the apparent speed and strength of mycelium growth.

Thanks! Interesting to see a line like this :-)

I like preparing a dilutions series and then preparing two or three plates per dilution by adding 1 mL of liquid into the plate. Usually one of the dilutions has a good spore density to get well-separated colonies.

[–] lightingnerd 2 points 1 year ago (1 children)

Oh, that's a great idea! I'm clearly new to mycology, so I'm just kind-of experimenting--but you're right, we're talking billions of spores, and only two need to meet in order to form a strain. Hmm...

[–] [email protected] 3 points 1 year ago (2 children)

only two need to meet in order to form a strain

Yeah! And when they do meet, they form a new anatomical structures called 'clamp connections', so if you have a microscope it is easy to check if the mycelium has already mated.

There is a nice series about breeding and how to isolate single-spore haploid mycelium here: https://www.youtube.com/watch?v=vsJpjQhsDIM

The idea is that if you manage to grow plates from single un-mated mycelium, you can then control their breeding, and this is how you can make new strains and have more control over their genetics. It is a more advanced topic in mycology, but a very interesting one to learn about!

[–] lightingnerd 1 points 1 year ago

I went and skimmed through that whole series, and then I found another video where he discusses the problems of going spore to grain, and even assuming I did get some viable mycelium on these plates, I'm thinking it's going to be nearly impossible to select them properly. I suppose I could just rinse and repeat into new plates, but then I won't know if it's a viable diploid/dikaryon or not.

Yet, the video I initially watched https://www.youtube.com/watch?v=tYK0hLeanVc demonstrated just grabbing some spores with a sterile blade and wiping that across agar. So maybe it is a reasonable method? One thing's for sure, there's a lot of colonies along the inoculation line, and it's already probably too late to start isolating like you would with the method demonstrated by Fresh From the Farm.