Custom Lab Equipment – Culture Blender for Cell Slurry Inoculation

The Custom Culture Blender made by Mushroom Consulting LLC is a specially designed laboratory device used to create a sterile cellular slurry for inoculation of final substrate directly from Petri dishes. This technique speeds up the growth of mushrooms by using a cellular slurry as a liquid inoculum, resulting in full colonization within 3 to 5 days. Since anything that creates a faster growth always results in higher yield, it is common to see a 100% increase in yield with this process compared to earlier techniques. When used with magic mushroom cultures, this usually results in fruiting within 14 days, and commonly yields between 3.5 to 4 ounces dry weight of fruitbodies per bag. Since there is no intermediate step of making grain spawn, this speeds up the process tremendously, knocking 25-30 days off the production process. And since this allows going straight from Petri dishes to the final inoculum in a single step, it allows visual QC, ensuring no contaminants or competitor organisms are present. This is the single biggest breakthrough in high-volume production yet developed.

The culture blender should always be run in a sterile air environment, such as inside the laminar flow hood. This is because the blender has a built-in fan that pulls air through the motor for cooling. If the blender is run in non-sterile air outside the hood, it pulls dust and airborne micro-organisms into the motor. Later when the blender is run in the hood, it will blow these contaminants into your sterile laminar flow hood, spoiling the sterility of your hood and creating a contamination vector that can be difficult to track down. Make sure to use the blender only inside the sterile flow hood.

A regular mouth jar is used as a blender jar. The concept of use is to fill the blender jar about ¾ full with water, which is approx. 750 ml in one quart or one-liter size jar. A standard one-quart mayo jar with a 70-450 lid size is ideal for blender jars. This type of jar works better and lasts longer than a standard canning jar. The jar is filled with water (or a nutrient broth solution), the special jar lid containing the blender mechanism is screwed on and the jar and lid together are sterilized under standard conditions, i.e. 15 PSI steam for 30-45 minutes.

After the sterilized jar cools, open the jar under sterile conditions and add anywhere from one to five well-grown-out Petri dishes of culture. After putting the lid back on the jar, a couple of five-second blend cycles are usually about right to create a good cell slurry. You can blend longer if you need to depending on how tough the culture is, but try not to over-blend the jar. The idea is to break the culture up into small bits, not to make a frothy milkshake. Over-blending can kill the culture by introducing too much cellular destruction.

Once you have a slurry consisting of small bits of culture from 1-5 mm in size, the liquid is ready to use as an inoculum. You can use this by simply adding a little of this liquid inoculum to your bags or bottles. And a little goes a long way. A single one-quart mayo jar of liquid culture made this way can inoculate 30 or 40 bags of grain. So basically, you are now able to use two or three Petri dishes to directly inoculate 300 to 400 pounds of grain.

By skipping the intermediate steps of making G1 and G2 jars, you can save a lot of time. It is not unusual to see savings of 30 to as many as 60 days when using this method. This becomes extremely important in the commercial field, especially with medicinal mushrooms, as we will often get an order for some species that we haven’t grown in a couple of years.

By the time we take it out of the refrigerator, run it through G1 and G2 jars, then go into grain bags, it has taken anywhere from 8 to 12 weeks. And no customer likes to be told they have to wait that long to get their product. By going directly from the petri dish to the inoculation, we knock off a lot of time with no loss of quality. And doing it this way, allows you to visually QC your cultures. You can simply look your culture plates over good and only use those that show perfect fast and even growth with no visible contaminants.

The osmotic pressure of the liquid in the blender jar is very important. While some cultures hold up fine to blending in just pure water, many of the more delicate strains will be killed through the rapid change in osmotic pressure when they are blended in just straight water.

A better option is to add 20 grams of light malt extract powder per liter of water to your blender jar, or you can use a standard liquid broth recipe instead of straight water. Since the typical one-quart blender jar will be charged with 750 ml of water, adding 15 grams of malt powder to the water before sterilization will adjust the osmotic pressure to the correct level and this step will protect the more sensitive cultures. It will also provide a rapidly available sugar source to help kick off the initial growth of the culture after blending.

Another method to really speed up the growth using this method of liquid inoculum is to sterilize a jar of malt solution, then add this sterilized liquid to a grown-out grain jar, preferably a G2 jar.

Using the extended blender mechanism we make, you can blend the jar of grown-out grain into a slurry. This becomes the inoculum for the next step, which is typically used to inoculate grain bags but can also be used to inoculate final substrate bags.

When this method of grain slurry inoculation is used, we typically see fully colonized grain bags in 3 to 5 days. When growing the more “special” species, this means you can have fruiting in 12-14 days from start to finish.

If you have any questions,
please feel free to call Dr. John directly at (775) 230-8975 or email john@mushroom-consulting.com
You can also, order extra blender lids from Mushroom Consulting LLC at the same contact information.