Many bacteria are harmful to human beings, plants and other organisms, but there are also a good number of bacteria which are beneficial.
1) Human diseases: Bacteria cause a number of diseases in humans, such as- Typhoid, Pneumonia etc.
2) Animal diseases: Animals suffer from diseases, such as- Anthrax, Chicken-cholera etc.
3) Plant diseases: There are several bacterial diseases of plants e.g. Ring spot of Tobacco, bacterial wilting of tobacco, cotton root rot etc.
4) Spoilage of food: Spoilage of fruits, butter, milk etc, may be caused by bacteria.
5) Loss of at fertility: Some bacteria, convert nitrite and nitrate into nitrogen which later escapes into the air causing a loss of soil fertility.
1) Medicine: Extracts from bacteria are used to prepare antibiotics. Such as- Polymixin, Tyrothricin etc.
2) Food Industry: A good number of food products are manufactured due to bacterial activities e.g. butter, Cheese etc.
3) Industry and Agriculture: Some bacteria are used in industries and also in Agriculture. Example:
- The tanning of leather
- Extraction of fibres from jute and hemp
- Production of vinegar, acetone, lactic acid, citric acid, vitamin etc.