bluescreen said:

I've been getting weak growth on LME, great on grain water and PDA. Put a bit of regular old baking yeast in and wow! 400ml water, 8g lme, 8g agar 0.4g yeast. Poured another sleeve yesterday, I'm liking this. The blue plate is with yeast, and 2 days younger than the straight LME.




I do think it's more of an aesthetic thing though; I put a more grown out "weak" plate to 3 jars a week ago and some good LI to 3 others and they're all killing and neck and neck.

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Fantastic Mr. Fox said:

Not even a full 24hrs and already recovering with lightning speed!

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Wow, your agar plates are super transparent.
They look fantastic. 
Which recipe are you using?

wearetheborg said:

Fantastic Mr. Fox said:

Not even a full 24hrs and already recovering with lightning speed!

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Wow, your agar plates are super transparent.
They look fantastic. 
Which recipe are you using?

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Fantastic Mr. Fox said:

Hey wearetheborg,
Thank you.
I'm not using agar, the plates you see in the photos are made with Gellan gum.
Gellan gum is a crystal clear high-performance gelling agent. Unlike agar which comes from seaweed, Gellan gum is produced from the fermentation of glucose using a special bacteria called Sphingomonas elodea.

There's two types of Gellan gum, "High-Acyl" and "Low-Acyl"
The High-Acyl produces soft, elastic and flexible gels.. (kinda like gelatin)
Low-Acyl creates firm, brittle, and crisp gels that kinda "snap" when you cut/slice it.

The plates I made in the photo were made using Low-Acyl.

When making the Gellan gum gels you need to add a source of positive ions, like magnesium chloride, sodium chloride, or Calcium chloride in order to bind the molecules together and make the gel set since Gellan gum is ionic but only possesses negative ions.

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Beautiful plates indeed, any chance you could share the recipe

mobyhat said:

I have agars like this..how many time in months I can store they:

1. out of the fridge at 23/25°C?

2. in the fridge at 6/7°C?

thank you!!

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You have had several good replies, but I did not see anyone mention preventing dehydration.
If you plan to store your agar plates for more than a couple of weeks at room temperature, I advise placing them in a large clean zip lock / plastic bag. That will slow down dehydration that over time will make your agar less supportive of growth and possibly resistant to germinating spores. Happy “Agaring” to you!

Kloakk said:

Fantastic Mr. Fox said:

Hey wearetheborg,
Thank you.
I'm not using agar, the plates you see in the photos are made with Gellan gum.
Gellan gum is a crystal clear high-performance gelling agent. Unlike agar which comes from seaweed, Gellan gum is produced from the fermentation of glucose using a special bacteria called Sphingomonas elodea.

There's two types of Gellan gum, "High-Acyl" and "Low-Acyl"
The High-Acyl produces soft, elastic and flexible gels.. (kinda like gelatin)
Low-Acyl creates firm, brittle, and crisp gels that kinda "snap" when you cut/slice it.

The plates I made in the photo were made using Low-Acyl.

When making the Gellan gum gels you need to add a source of positive ions, like magnesium chloride, sodium chloride, or Calcium chloride in order to bind the molecules together and make the gel set since Gellan gum is ionic but only possesses negative ions.

---

Beautiful plates indeed, any chance you could share the recipe

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Buthoscorpio said:

Usually 6-10g/L Gellan gum and 1g/l Magnesium Sulfate heptahydrate are used to archive a solid gel for microbiological/mycological purposes. I prefer 10g/l. Other ingredients can be added as you like, but you should avoid high Calcium concentrations due to interactions with Gellan gum.

It should be mentioned some fungi show different growth patterns one Gellan gum compared to Agar.

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Thanks, so 1% gellan gum and 0,1% Magnesium sulfate, I will be using calcium lactate, do you know if 0,1% still applies?

Kloakk said:

Buthoscorpio said:

Usually 6-10g/L Gellan gum and 1g/l Magnesium Sulfate heptahydrate are used to archive a solid gel for microbiological/mycological purposes. I prefer 10g/l. Other ingredients can be added as you like, but you should avoid high Calcium concentrations due to interactions with Gellan gum.

It should be mentioned some fungi show different growth patterns one Gellan gum compared to Agar.

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Thanks, so 1% gellan gum and 0,1% Magnesium sulfate, I will be using calcium lactate, do you know if 0,1% still applies?

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Buthoscorpio said:

In theory it should work with 0,1% Calcium lactate. It is the right concentration of divalent cations. 4-5 mmol is to be aimed for. But I never tried something else than magnesium sulfate, so I can't speak from experience. Calcium is said to lead to more brittle gels.

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It seems to be the most common gellan gum activator, but I guess that is for food and not plates, but I'll give it a whirl, thanks again