I am interested in understanding on a very fundamental level why certain chemicals are used in growth of actinobacteria.

For example, corn steep liquor, meat extract, dextrin, CaCO3 etc.

This list is obviously not all inclusive but in general I noticed these chemicals being used. Please add more and state their purpose in the growth medium.

Also, if you have practical experience working with dextrin, please let me know. I have tried dissolving this and I get goo. Is it supposed to be goo-like?