Any ideas of what is going on with fungus and iodine?

[lperepol]

Just wondering about what is happening. I place a drop of Iodine on a fungus (I think sclerotia) and the iodine drop appears to be clearing and the fungus is absorbing a colour. Is this some sort of a cation exchange? The iodine drop beads but something is being pulled out of the iodine. Tried a few other stains, Methylene Blue, India ink, red food colouring and none are behaving like the iodine? The fungus is on a carrot.

[Hobbyst46]

Where is the fungus in the picture? is it growing on the carrot itself, within the white circle, or is it in the background around the carrot?

[lperepol]

I am assuming that there must be some sort of nifty esoteric explanation.
Like what is being absorbed?
The fungus is growing on carrots that were stored in a plastic bag. I kept the fungus growing for further investigation and to attempt a positive Id of the fungus. Sclerotia is a bad omen for some gardeners.

>> where is fungus in the picture

The drop is directly on top of the fungal mass. The white halo is just light refracting of off the top of the drop. Around the perimeter of the drop is all fungal mass. I can see at this time the iodine drop has completely cleared. Just looks like water now. I added a few more pictures.

[Hobbyst46]

I am assuming that there must be some sort of nifty esoteric explanation.
Like what is being absorbed?
The fungus is growing on carrots that were stored in a plastic bag. I kept the fungus growing for further investigation and to attempt a positive Id of the fungus. Sclerotia is a bad omen for some gardeners.

>> where is fungus in the picture

The drop is directly on top of the fungal mass. The white halo is just light refracting of off the top of the drop. Around the perimeter of the drop is all fungal mass. I can see at this time the iodine drop has completely cleared. Just looks like water now. I added a few more pictures.

In principle, no need for esoteric explanation. A solution of iodine in water ("lugol") easily releases molecular iodine. Iodine is a small and reactive molecule. It is much smaller than methylene blue and molecules of other stains that you mentioned. I can envisage iodine being adsorbed from the drop into the organic mass and reacting with some of the organic molecules of the fungus, for example starch or other polysahcharide residues (sorry I am not an expert on the exact composition of fungi), to create bluish or brown products. IF the fungus is hydrophobic (just a guess - I do not know if this is possible) then water soluble stains will crawl into the fungus and absorb only very slowly.

[lperepol]

Thank you for your time and explanation Hobbyst46!!
I have a lot of fungus and a few more stains. I'll do a visual comparison of various stains at time t0 and tn and see what happens. It took a while until I noticed the behaviour of the iodine. I'll see how other stains fair. Something wetter than water should penetrate the fungal mass better.

[Hobbyst46]

Something wetter than water should penetrate the fungal mass better.

Maybe. Add a small drop of dilute soap, for example a kitchen washing liquid soap, into the water to lower its surface tension by orders of magnitude and thus increase its wetting properties.
Stains that are dissolved in alcoholic solutions might also penetrate rapidly.