If you’re a mycologist or enthusiast looking for an easy and efficient way to grow your mycelium, liquid culture recipes are the way to go. Whether you’re a researcher studying how mycelium grows or just looking for some fun at home, this article explains everything you need to know about researching your own spores and liquid cultures. Keep reading to learn more!
What is Liquid Culture?
Liquid culture refers to the process of growing microorganisms in nutrient broth. The nutrient broth contains necessary elements that allow the organisms to receive nutrients from the environment and grow. Liquid culture can also be used to create spore solutions that are used for inoculation of substrates such as grain bags and other materials.
Creating Your Own Liquid Culture Recipe
Creating your own liquid culture recipe is simple and straightforward if you have all the necessary supplies on hand. You will need: malt extract agar (MEA), petri dishes, syringes, a pressure cooker, sterile water, a mixer or blender and other materials depending on your desired medium. To begin, combine all ingredients in a large bowl according to the instructions provided with your specific recipe (make sure to research different recipes as different types of media require different amounts of each ingredient). Once all the ingredients are combined, pour them into mason jars with your injection ports / syringe filters and sterilize them in a pressure cooker. After they are sterilized, allow them to cool before adding agar or other microorganisms. Media bottles are my preferred method for creative liquid cultures since they have small neck it is difficult to add your agar wedges but creates a better seal and more ergonomic design when removing liquid from the system once it is colonized.
1-8 grams of LME (Light malt extract) per liter of spring water is an excellent recipe for beginner and advanced mycologist. By adding 1 gram to a liter of water you will have a culture that is almost clear and will make spotting contamination much easier. Be careful when adding more material to your culture solution the pH and effects can become less than ideal for the mycelium and cause it to stop growing.
Peptone is an excellent additive for increasing yeilds but will also reduce the longevitiy of the culture by adding enzymes. IF you decide to add peptone be sure to use your cultures in a timely manner (4 weeks maximum).
Nutritional yeast is one of the best food sources for your liquid mycelium and can be added for boosting growth time and results. Do not add more than 10 grams of yeast per liter. Start with 2 gram per liter. as a safe measurement to see how your variety's respond.
HOW LONG SHOULD I STERILIZE MY LIQUID CULTURE?
I recommend maintaining 15 PSI for 40 minutes minimum when sterilizing liquid culture. Most pressure cookers can fit multiple media bottles, this will require more time since the amount of material changes the sterilization period. Always add a magnetic stir pill before sealing. your lid this step is crucial once genetics are added you can keep your stir plate running until the culture is finished. Wrap foil on the lids and make sure you do not tighten them down too much, the pressure in the sterilizer may rupture your seals making it counter productive.
Lastly, transfer your spore solution into the sterile syringes and use these syringes to inoculate substrates such as grain bags or jars with your desired medium. Make sure not to over-inoculate as this could result in contamination issues later down the line. If you see liquid sitting at the bottom of your grain jar or bag then you will want to keep shaking and dispersing the culture as best you can before placing it on rack at incubation temperatures. (75 F)When stored in the fridge your liquid cultures can last for years. Microbiology experts have revived liquid cultures on agar after 12 years in some cases. With proper care and maintenance of temperature levels, humidity levels and airflow within your growing area – you should have success with liquid cultures!