Prefered substrate

[Nuno]

Hello everyone!

I'm really curious about the substrates you use and why you do.

Unfortunately I'm not able to set up a poll, but so far I'm aware of the following:

.: Agar (non-nutrient)

.: Filter paper

.: Kitchen towels

.: Soil, Bark, Twigs (Vivarium?)

I started with agar, but I find myself shifting more and more to filter paper.
Filter paper just gives me the impression of being easier to maintain and the slime looks healthier in the long term. Maybe it doesn't accumulate as much bad bacteria?

When part of the petri starts looking "unhealthy", I just cut that part off and replace it by fresh filter paper. The slime simply shifts from one end to the other and I'm able to keep that petri forever.
Agar on the other hand needs to be fully replaced at least once a week...

What's you methodology? Any tricks/tipps?

Thanks!

[ian]

Hi

Paper's definitely easier. Another method I've seen in labs is to just fill a petri with oats and innoculate, when it's filled the dish half is dug out and the gap refilled with fresh oats 

[Fred Bartlett]

What a terrific topic, thanks for starting this, Nuno. 

So far I've used agar, somehow I don't remember filter paper working that well. Maybe I kept it too wet or too dry? How does one handle moisture levels with fitler paper? The agar agar already has water in it, so that really isn't an issue.

Has anone tried making a media with food already incorporated into it, such as powdered oates in the agar medium? I'll give Ian's idea of just using oats themselves as a growing medium a try too...!

[ian]

Nutrient agar isn't a great option - you need it autoclaved to be sterile and it's prone to growing contaminants. Slime will grow on it but it only forms structures when there's a gradient of food available so on nutrient agar it just makes a sheet.

I'm using cartridge paper ( the stuff that's too think for paper l, too thin for card) and brown kraft paper - for both I either spray or pour on water and pour off what doesn't soak in.

I did find coffee filters aren't great - the pores are large enough for the slime to get through.