Top Tips for growing Physarum Polycephalum...

[Heather Barnett]

If you're keen to grow your own the slime mould Physarum Polycephalum, this information may help...

Preferred conditions: dark and damp (for example: petri dishes or tupperware in a shoe box or similar, with a damp base - paper towels or agar base).

Food likes: favourite food is porridge oats, doesn't mind starchy stuff like rice and pasta. Best to give sterilised (i.e. boiled) food, so it doesn't go mouldy as quickly. I often boil flaked oats to make a paste and keep it in the fridge.

The slime mould itself is harmless, but the food you give it will go mouldy (just usual food mould) so some care is needed, and your pet physarum slime mould should move to a new clean environment on a weekly basis.

Its top speed is approximately one centimetre an hour, so not exactly a spectator sport, but its beautiful growth patterns are clearly visible and easily captured with time lapse photography. My films are shot at various frame rates, from one shot every 20 seconds to one every 5 minutes, depending on what I want to show.

If you want to capture protoplasmic streaming (the inner pulse of Physarum polycephalum which transmits nutrients and chemical signals) chose a frame rate of less than 90 seconds as that is the approximate duration of the pulse in each direction.

Happy growing… do share your results...

[Divya Sengar]

Thank you very much Heather, I'll keep this in mind.

[Anna Sagatov]

Hi, what was the advice to keep the slime mold from getting moldy?  Will mold kill the slime mold?

[Alexandra Trenchard]

Hi Heather, I'm studying P. polycephalum for my final year project and am having terrible trouble with mold growth on his oats - any tips? We've tried autoclaving the oats prior to plating, and he's kept in a laminar flow hood, but all to no avail. I'm worried my plates will die off over the Christmas break if I can't fix this problem!

Regards

Alex

[Naksupan]

To avoid the contamination form mold, I found that the small and thin pieces of mushroom can be used for culturing the pet slime mold.

[Divya Sengar]

I have another question, how did you rig up a video camera to look at the maze?

[Heather Barnett]

It's shot on a DSLR (stills camera), one frame very five minutes, on a copy stand (rostrum stand), in a dark room/tent. The entire maze animation is 4-5 days of growth. You'll notice the agar evaporating gradually, as it had to be shot with the lid off. Hope this info helps... Heather

[Anna Sagatov]

Hi Heather, did you use firmware like Magic Lantern to do the timelapse?  I have a DSLR but I've never used it for timelapse before.  Do you have any tips?

[Heather Barnett]

I use the remote shooting software that comes with the camera to automate the time-lapse intervals, and edit the frames together in video editing software such as final cut pro or premiere, adjusting the frame duration to suit (2-8 fps depending on how smooth I want the final animation). Check the discs that came with your DSLR, you should be able to shoot on timed remote settings. Then you just need to master the video editing! 

[Jo Podvin]

I'm trying to figure out the time-lapse stuff and am kind of a camera dummy -- I thought I'd be working on microscopes with these 'microbes', as I didn't realize just how macro Physarum is! So I'm wondering about flash; I'm assuming you're using a flash in the dark room, and am wondering if there's a way to minimize the disruption of the light shock. I'll probably be imaging more frequently than you've been, maybe every minute or 30 seconds. I see that there are videos online with frames taken every 15 seconds, but again, there's no info about the light source. Also wondering if you've got any ideas about misting during the growth/video-taking. Most of my Physarum I have growing in uncovered environments, so I mist it at least once a day.

[Heather Barnett]

I usually use a single flash head attached to the camera. I use neutral density filter over the light source to reduce light interference, but it's difficult to say whether or not the regular light flashes are affecting behaviour - need to do a control experiment under a different light source (i.e. UV, IR) perhaps? Other camera tip, make sure you're not on automatic functions for exposure or white balance, everything should be on manual avoid glitches.

Interval timing can vary depending on how much growth/pulsing you want to show. My animations use 20 seconds, 1 min, 3 mins, depending on what I want to show and how close up I am.

Also haven't absolutely perfected the moisture maintenance issue, I add moisture by hand at reasonably regular intervals, or if its growing on agar, that will gradually evaporate (so you just have to make sure the organism is still in focus if the substrate is gradually disappearing!)

Hope this helps.

[Divya Sengar]

Sorry to bother you again, but what type of Agar does the Physarum like? I've heard of potato dextrose agar and non nutrient agar. Also do you know where  could get one that's not in a petri dish, since I have to make a maze?

[Heather Barnett]

Hi, I tend to use the 2% agar that comes with the Physarum culture kit (I think it's a low nutrient agar). And it doesn't matter what they come in as you can always move a bit (so if it comes in a petri dish you can transfer a piece to your maze).

And do post the results of your maze experiments here. Would be good to see.