Micro-organisms affect everyone. Some are helpful, while others are harmful. This program explores pathogenic micro-organisms that can cause diseases like sore throats, influenza, tuberculosis and HIV. Decomposer micro-organisms decay rotting plant and animal matter, returning important nutrients back into the soil. Microorganisms are also being used in the fuel industry to develop new non-petroleum based products. Food spoilage micro-organisms such as mould can ruin stored food. Other bacteria and yeasts are vital to the production of food and drinks like yoghurt and bread, along with beer and wine. Within this program we will examine where they come from and some examples of positive uses relating to many foods we eat.