There are 3 types of micro-organisms:

1. Useful micro-organisms
2. Pathogenic micro-organisms
3. Spoilage micro-organisms
   

• Useful micro-organisms can help make such things as Yoghurt, Alcohol, Bread,Sauerkraut and Salami.
  
• Pathogenic micro-organisms are disease causing and can begin with a common cold or could lead to death.
  
• Spoilage micro-organisms usually render food unfit for human consumption.
  

The four main types of micro-organisms associated with the food industry:

1. Bacteria
2. Yeasts
3. Moulds
4. Viruses