GMU:DIY Bio: doing things with biology/Antje Danz/Physarum Polycephalum and light

Physarum Polycephalum cultivation

Preparation

Preparing new petri dishes with decoction of oat flakes. Everytime I put the oat flakes on top of the medium I experienced mold growing only after 2 days. So this time I try it with the decoction. I also autoclaved everything this time.

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  Decoction of oat flakes

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  Filtering the oat flakes out

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  UV

27th November 2018

Again too much mold growing in the dish. No I just want to try to get clean polycephalum samples to be able to do my experiments. Prepared a few new dishes and extracted PP from the old ones. I try to change it everyday to get rid of all the contamination.

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  Different Samples

pink_traces_pp1

3nd December 2018

Polycephalum is really bad contaminated. So I tried to clean it in water und extract the mold. I also cooked new media to attach PP to it after cleaning. One dish for the really clean examples of PP and one for the one that still got some contamination on them. Let's see if I manage to get them healthy again in order to work with them.

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  Cleaning PP in a petri dish

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  Cleaning PP on paper

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  Cleaning

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  Cleaning close up

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  Contamination blue light

While I let PP water a bit I checked some of the small pieces under the microscope to see whether they are still alive and pulsing. Some of them were, some not and some of them were in dormant state and need to be watered.

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  PP fragment

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  PP fragment close up

6th December 2018

I received an example from Paola, because my Polycephalum wouldn't show up and grow. I also used something of her Potatoe-oat mix for agar plates. Paola experienced some pink stuff showing up in the dish after a while, thinking its some sort of bacteria. But only with a few examples. The example she gave to me is also doing the same. And it's somehow amazing. I did some reading and found out that everywhere PP moves it leaves slime traces full of chemicals. Mostly carbohydrates and sugars in it. This is an external spatial memory. It lets the organism remember where it already was in ordner not return back twice. In hour case thos tracks turn pink in the dish with the potato-oat mix. So everywhere PP was he leaves now those colorful traces. But they also seem to disappear after a while, well at least the colour effect. Seems like this special plasmodium of the organism produces chemicals in its tracks that react with carbohydrates and protein proofing the existenz by showing a pink colouring. Like a chemical indicator. This is great in terms of observation. When you look after the organism after a few hours again, you'll be able to guess where it went.

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  Pink traces dish 1

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  Pink traces dish 2

7th & 8th December 2018

I took my new samples of polycephalum home again and they seem to like it better there. Its much more active at 19 degrees. I also tried a new medium with instant full grain oats, peptone, water and agar. Seems to work as well. But this time the pink stuff doesn't show up. I also noticed that even in the dish with the pink stuff, Polycephalum is not leaving those pink traces at all times.

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  Plasmodium stereomicroscopic view

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  plasmodium and pink traces stereomicroscopic view

I also had another sample which seemed dead but I didn't throw it away. And only after one day it moulded completely and you could see Polycephalum on top of the mold mountains trying to escape it. I had a closer look with the microscope and could still see the plasmodial flow.

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  camera view

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  microscopic view

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Pink Traces

The pink traces don't seem to be only some sort of chemical reaction. As I had a closer look with the microscope one could see its colonies of bacteria. I tried to do some researches on them in oder to know what they are and if they are pathogen or not. I found something that looks like this organism and its serratia rubidaea which is pathogen.

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