Microorganisms exist in a mixed state in nature. To obtain the desired strains, they must be isolated. Accidental contamination during the preservation of the bacteria should also be purified. There are many methods of microbial isolation and purification, but the basic principle is similar, that is, the sample to be isolated is diluted to a certain extent, and the microbial cells (or spores) will exist in a dispersed state as far as possible, and then they will grow into a single colony of pure species. The above work is inseparable from inoculation, which is the process of transferring one microorganism to another sterilized medium.
For the cultivation of specific bacteria, one or more special media suitable for the growth of specific bacteria are often used. The culture of bacteria, fungi, and actinomycetes is common, and the culture of single species can also be carried out.
