If we cultivate actinomycetes on solid medium, this kind of cells can grow branches and roots. Branches that stretch in mid-air are called aerial hyphae. Spores of various shapes can be produced at the top of aerial hyphae, which are called sporophytes. Spore silk of actinomycetes grows in various ways, some are linear, some are wavy, and some are bent into spiral. The morphology of sporophyte is the characteristic of actinomycetes, which can help us identify different actinomycetes. Spores are formed by transverse division of sporophytes or protoplasm coagulation, just like a string of beads. It has a thick spore wall, like the hard shell of plant seeds, which can protect spores from harsh external conditions. Different kinds of actinomycetes have spores of different shapes and colors. Some spores are spherical, and some are like dates; Some surfaces are smooth, some are rough, and some have small thorns or flagella.
Spores are tools for actinomycetes to transmit seeds and generations. Spores that leave the bacteria can not die for a long time, and germinate to form new mycelium when they meet suitable conditions.
Collect a large number of mature spores produced by actinomycetes, put them in a small glass tube filled with sand, and put them in the refrigerator without nutrition and water. These spores can be safely preserved in this "small warehouse" for a long time.
In addition to aerial hyphae, there are also vegetative hyphae that extend into the culture medium like roots to absorb nutrients. These vegetative hyphae seem to be roots deeply rooted in the soil, which makes the colonies grow firmly.
Actinomycetes usually exist widely in nature in the form of spores or hyphae. Both quantity and species are the most in the soil. According to the determination, each gram of soil contains tens of thousands or even millions of spores, and the metabolites produced by actinomycetes often make the soil have a special muddy smell.