What are metabolites?

[eikon]

Metabolites often incorrectly called "myc piss" are not a contamination or a waste material but are an excretion produced by mycelium. It appears to be as yellow, red, brown or golden droplets that pool up on mycelium. Primary metabolites are produced to help break down (digest) potential food sources and secondary metabolites (antibodies produced by the mycelium) are usually produced by the mycelium when a competing mold or bacteria is present. Metabolites are normal, especially in manure based substrates which are naturally high in bacteria and competing molds.

Remember, if you see yellow, red, brown or golden droplets it is not a mold, molds will not be in liquid form.

metabolite2.jpg (126.39 KiB) Viewed 128 times

metabolite1.jpg (89.51 KiB) Viewed 128 times

[AOS]

Thank you for that post! Very good to know.

[FoolonFruity]

I noticed that the production of metabolites increases on higher temperatures and that casings or jars on a low temperatures don't show any metabolites at all.

[eikon]

Thanks AOS.

And yes FF, Stress from high temps can cause metabolite production because bacteria love warmer temps and the mycelium trys it's best to fight it off. This is why I incubate at lower temps... around 22c. When the grain is colonizing it produces a lot of internal heat.


Question: Should I worry about metabolites?


Answer:

For the most part no you shouldn't be too worried when Metabolites are present. It can however be a clear indication that there are competing bacteria or molds present - so keep that in find. A colonized tray would be less of a worry then say a BRF or grain jar. Imo opinion, the mycelium is healthy and strong and by releasing metabolites the mycelium is keeping in control.

The secondary metabolites are antibodies to help keep the mycelium healthy. Penicillin for example is a mushroom metabolite and a person could actually take a syringe and suck up the pooled metabolites shown in the pics and use it in agar work to kill bacteria - The metabolite will kill bacteria on a petri in just a few hours. pretty cool yeah?

Some say not to use jars that are showing metabolites as spawn but, I have never had an issue. Yes, metabolites can be an indicator that foreign molds and bacteria are present - that really doesn't matter if the mycelium stays vigorous because there will always be competitor molds and bacteria present.

Just because it's the nature of things, Mycelium will eventually grow old and weaken. I have personally prolonged a substrate for up to eight or more flushes by dunking with Calcium hydroxide and thiamine... until the flushes just became to weak and exhaust the food source. Calcium hydroxide keeps the substrate alkaline which helps inhibit bacteria and many molds because bacteria and many mold thrive in an acidic environment and the thiamine helps keep the mycelium strong. Most of the time though when you do see metabolites it is a primary and the mycelium is just trying to break down grain, compost or woodier components in the Sub to digest.