Colouring mycelium with organic and synthetic dyes

Hey guys!

I am an architecture student, currently doing research at VUB on a range of different properties of mycelium for a thesis on the potential of the material in an architectural framework. I started out with an exploration of colour. At the moment my approach is very empirical since I am lacking a background in biology and I would love to hear your insight on my experiments :slight_smile:

The objective of my first experiment was to investigate the possibility of implementing either temporal or permanent colour in the material by growing Trametes Versicolor on agar mediums, coloured with both organic and synthetic dyes. The colorants were dissolved in the agar solutions before autoclaving them for 45 minutes.

Inoculation of coloured agar mediums

2% malt agar
1 sample with colourless reference medium
1 sample with pink solid watercolour
1 sample with yellow food colouring
1 sample with turmeric
1 sample with purple organic soap dye
1 sample with red liquid watercolour
1 sample with black solid watercolour
1 sample with blue acrylic paint
1 sample with green textile colorant
Trametes Versicolor
Organic colorants will be used as a source of nutrients; will thus be easily degraded and won’t stay visible for a long period of time. Synthetic dyes will not be degraded as easily, and the pigment will last longer.

Most pigments were degraded by Trametes Versicolor and after five days of growth, almost all petridishes were covered in a white blanket of hyphae. However, the liquid watercolour (red) was introduced in the hyphae system of the organism, resulting in a pink mycelium that is growing brighter in colour over time. I have repeated the experiment with blue liquid watercolour, which also seems to work. After drying the samples, the soap dye (purple) and food colouring (yellow) also left a colour, less vibrant however, to the mycelium.

Trametes Versicolor on medium with liquid watercolour

The sample with acrylic paint (blue) turned yellow-ish as the organism grew through the medium and the gradual degradation of the pigment is well noticeable.

Trametes Versicolor in medium with acrylic paint

When the medium was fully grown through, this sample was also dried. After drying, this sample showed translucent properties.

Sample after drying

I am now trying to understand why liquid watercolour, rather than the other dyes, seems to stay present in the organism (glycerin or ox gall in the watercolour paint?) and what causes the translucent properties of the acrylic paint sample. I will also try colouring mycelium with algae- and fungi-based pigments or with Streptomyces Coelicolor; so any advice on that is always welcome :slight_smile:

Thanks for reading!

Master Thesis by Lennert Van Rompaey, Under supervision of Elise Elsacker, Prof. Lars De Laet and Prof. Eveline Peeters / Vrije Universiteit Brussel / Department of Architectural Engineering and Bioengineering Sciences is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.


Welcome to the forum @Lennert! :slight_smile: A very nice first post. I wonder if the case of trametes on liquid watercolour (3rd picture) is merely the result of the water present in the organism being pinkish. Ie. if, when drying the material, the water with colour will evaporate. Or if the colour will remain fixed.

Did you dry the red sample in the 3rd picture?

Hey! No I haven’t dried that one yet but i don’t think the pigment would evaporate with the water. I will dry the sample in the next few days and i’ll keep you posted! :slight_smile:

@Lennert Nice! Can you add the follow-up experiments too, because I think it’s complementary of what you’ve described.

@winnieponcelet, during the symposium of mycelium materials in Ghent, you’ve invited a prof. that has several great ideas about colouring with fungi. Who was she again?

I’ll pm you her contact info :slight_smile:

No colour loss in the drying process! :slight_smile:

Nice work, any information on the actual compounds used? pigments have a very broad chemistry so just saying watercolour or acrylic doesn’t tell much.

You aer right that most organic based colors are going to be digested, but knowing which functional groups are taken can make a big difference on your conclusions.

Keep on the good work

Great work, super cool results! Did you follow up on this later? :slight_smile: