Some tricks to handle contaminations


#1

What you can do in the space:

  • Wet everything to force germination because it has a high resilience when it is dried (you even have spores that are resistant to radiation). Do that for 4 hours (approximately, depending on type of contamination, look at the time it germinates - more info to be found on that).
  • Then you clean everything with bleach bombing (3-5%, the strongest the contamination the highest the grade) OR H2O2 - oxygen-water (used carefully and never mix both).

General contamination:
Make a checklist from the substrate to the environment to understand where the contamination comes from.

  • Check the substrate and the material
  • Check the bag or the container
  • Measure the pH
  • Check for moister
  • Check control group: set up control groups

Method to minimize contamination:
Bring the mycelium from the bag to pots. This will allow you to only work with one pot at the time and avoid to open and close the mycelium bag each time. The best is to only work with the quantity of mycelium needed.

  • Sterilize the pots in the autoclave with aluminium on the top
  • Wait for the pots to cool down
  • Put on the Bunsen brander
  • Disinfect your hands and arms with alcohol
  • Disinfect the table with alcohol
  • Disinfect the outside of the pots with alcohol and place 1 on the table
  • Disinfect the spoon with alcohol and place in over the Bunsen brander
  • Disinfect the outside of the mycelium bag with alcohol
  • Place the mycelium bag on the table with the opening to the Bunsen brander
  • Open the mycelium bag with a disinfected scissor
  • Disinfect the inside opening of the mycelium bag with alcohol carefully
  • Cut out pieces of the mycelium and put in the pots
  • Disinfect the ring of the pot, the spoon and the inside of the bag every time
  • Close the pot every time.

#2

Thank you for this Elise ! :slight_smile:

Do we have growth parameters of Trichoderma (which is the biggest contaminant here) and do we know any living being or micro-organism able to eat/clean it and able to co-exist with any mushroom culture?

Cheers


#3

Good questions, but I don’t know. You might wanna do some research about it, cause it will reduce a lot of cost for sterilisation :wink:


#4

Yes definitely :slight_smile:
And about the coriolus versicolor, do we know his competition ratio between the different mushrooms after the substrate sterilization?

Cheers


#5

#6

I’ve pinned the topic because it’s valuable info! :slight_smile:


#7

Hello I’m back!

Still about the contaminations: do we have all the informations about Coriolus Versicolor ?
For example his seasonnality: is this mushroom growing better in summer than winter ? Is it local ? Etc.

Amicaly :slight_smile:


#8

What information are you exactly looking for? About the contamination after sterilisation, I didn’t really found academic research. It’s assumed all other micro-organisms are killed at 121°C and inoculation is done in sterile environment.

Furthermore we know that Trametes versicolor will produce more enzymes as a defensive function when it interacts with Trichoderma. So, by producing those enzymes T. versicolor will start to acquire more nutrients. That’s the tactic to protect itself against intruders. This increase enzymatic activity is also present in other species.

In my opinion adding more micro-organisms in the mixture in order to fight contamination will make everything more complex. But by being able to induce the correct enzymes T.versicolor can fight Trichoderma by itself.

Anyway, if you still want to try: this patent gives you the answer about co-cultivation of some bacterias https://patents.google.com/patent/US9469838B2/en?oq=US9469838

You can address your questions about seasonality/locality directly to your provider of spawn (Mycelia), because this parameters are depending on the strain (M9912), not the species.


#9

OK thank you very much for all the infos. I’m just curious about how to make a production with less energy:

  • with eventually cold pasteurization for example (Bacillus Subtilis bateria is very famous!)
  • changing the strain compare to seasonality

#10

Enzymes would be a costly alternative, less widely used ones can be quite expensive even at industrial quantities. @LumiFungi you also use lime for pasteurisation now, what would be the problems with keep using that?


#11

The enzymes are not added, they are produced by the mycelium themselves.