The non-pathogenic bacteria are more interesting and come in more shapes. It is easy to prepare foods for your organisms from milk, potato, liver, meat, starch, sugar, and other foods around the kitchen. If you have a pressure cooker, you can sterilize the foods and do great things. If you do not have a pressure cooker, you are in the same boat as the old-timers and can still do many things. For example, you can put your foods in a covered pan on a rack and steam the food for an hour.
Lets begin our study of bacteria by considering the balance of nature.
If there is food, some organism will eat it. If there is a place to live, some organism will live there. Every species has a great ability to produce offspring and its population expands until it runs out of food or it is limited by competition, its own waste products, or some other factor. Changes in climate or introduction of a new species from elsewhere can greatly affect the balance of nature. These simple sentences summarize the interactions of living things on earth.