How are Crop Inoculants Made?

Ever wonder how crop inoculants are made? These bacterial inoculants are made in fermentation facilities, almost the same way you would brew beer. (Gotta love WI!) That is one of the reasons that our inoculants are made in Wisconsin, next to the pure waters of Lake Michigan. Using a pure water source helps us eliminate any potential additives or unwanted toxins in the water and can make the process much more streamlined and cost effective.

Each inoculant strain will be grown separately in its own fermentation vat. The base bacteria strain, which can be acquired from the USDA ARS culture collection, is mixed with growth media. From there it will sit in the fermentation VAT until it has grown to the desired concentration. Different inoculants will have different concentrations. Generally, the higher concentration of the bacteria in the inoculant will determine the cost. Higher concentrations of certain bacteria take much longer and more media to grow.

After fermentation and concentration, a quality control check is done.  From there, the bacteria alone, called the cell biomass, and cryoprotectants are added and the bacteria is then lyophilized, or freeze dried. When the inoculant is needed it comes out of the freezer and it is milled and all the bacteria strains plus the carrier, which tends to be a type of sugar, and is blended together. From there it goes to another quality control, packaged and finished.

Obviously, this is an overly simplified explanation, but it gives inoculant users an idea of where their inoculant came from and how it's made.