One technique in culturing other beneficial microorganism is getting them fro your local aged forest. One way is finding a healthy old robust tree in your local forest.
Check the humus litter around the tree. The tree should have accumulated real deep humus, litter, compost of at least 2 feet to 1 yard deep. In this area through observation, we can deduce that soil fertility and microbial biodiversity are high.
Our goal is to trap and culture these diversed, aged beneficial indigenous microorganisms. The technique that we use in trapping these microorganisms is the use of carbohydrate like cooked rice. Microorganisms will be attracted to food.
So generally, what we do is to put the cooked rice on a flatter container with lid. For example, you can use a plastic lunch box and add about an inch of cooked rice allowing air space in the container. What is important here is a larger area to trap those microorganisms. It is suggested that you cover this container with metal netting or equivalent protecting it from animals like rats that may undig your container once you bury it in the litter, humus of your local forest. In 2-10 days (relative to temperature), you may undig your container and will notice contamination of microorganisms like white and other color molds on the cooked rice.
The cooked rice has been infected now with microorganisms of your local forest. The next step is to add 1/3 amount of crude sugar or molasses to the infected cooked rice. After a week, the concoction will look like sticky, liquidy rice. You may then add equal amount of crude sugar or molasses to keep it for storage, arresting microbial activities, in a cooler area.
To use, you may dilute this serum with 20 parts water. This diluted form shall then serve as your basic forest microorganisms. You may strain it and put in a container.
Another version of trapping similar forest microorganisms is simply getting the litter, humus and spreading them sparingly to the top your cooked rice. Forest leaf molds can also be used.
The same procedure will be followed as described in the culture of local forest microorganisms.