[RossTaylor2440]

Bacteria live in virtually all the environments on earth, including the soil, water, and air. Most bacteria can be divided into three groups according to their shapes such as cocci, bacilli and spirilla. Bacteria plays many beneficial roles in the environment. some species of bacteria live on the roots of pod-bearing plants they provide nitrogen trough air to the plants. Many dead materials are decomposed by bacteria. If there were no bacteria, the environment would have been polluted and full of harmful microorganisms In the food industry, bacteria are used to prepare many products, such as cheeses, fermented dairy products, sauerkraut, and pickles.