However, the plate counting method can only measure those cultivable microorganisms, which often underestimates the actual number of microorganisms in the soil, and there are many interference factors, such as the original bacteria in the soil suspension clustering together or attached to the soil. On the pellets, the number of colonies formed on the plate is lower than the actual number of colonies; the medium or culture conditions used are selective, it is difficult to distinguish all microorganisms equally, and the dilution may inhibit certain types (species). ) Microorganisms. In order to more accurately describe the results of plate colony counts, it is now inclined to use colony forming units to express the number of microorganisms in the sample.
