Economic importance of bacteria
The economic importance of bacteria derives from the fact that bacteria are exploited by humans in a number of beneficial ways. Despite the fact that some bacteria play harmful roles, such as causing disease and spoiling food, the economic importance of bacteria includes both their useful and harmful aspects.
Biotechnology and bacteria
- Fermentation processes, such as brewing, baking, cheese and butter manufacturing, Bacteria, often Lactobacillus in combination with yeasts and fungi, have been used for thousands of years in the preparation of fermented foods such as cheese, pickles, soy sauce, sauerkraut, vinegar, wine, and yogurt.
- Chemical manufacturing such as ethanol, acetone, organic acid, enzymes, perfumes etc. In the chemical industry, bacteria are most important in the production of enantiomerically pure chemicals for use as pharmaceuticals or agrochemicals.
Genetic engineering and bacteria
Genetic engineering is the manipulation of genes. It is also called recombinant DNA technology. In genetic engineering, pieces of DNA (genes) are introduced into a host by means of a carrier (vector) system. The foreign DNA becomes a permanent feature of the host, being replicated and passed on to daughter cells along with the rest of its DNA. Bacterial cells are transformed and used in production of commercially important products. The examples are production of human insulin (used against diabetes), human growth hormone (somatotrophin used to treat pituitary dwarfism), and infections which can be used to help fight viral diseases.
Bacterial populations, especially that of Clostridium butyricum, are used to separate fibres of jute, hemp, flax, etc., the plants are immersed in water and when they swell, inoculated with bacteria which hydrolyze pectic substance of the cell walls and separate the fibres.These separated fibres are used to make ropes and sacks.
Some bacteria living in the gut of cattle, horses and other herbivores secrete cellulase, an enzyme that helps in the digestion of the cellulose contents of plant cell walls. Cellulose is the major source of energy for these animals. Generally plant cells contain cellulose. The bacteria present in the stomach of cattle will help in the digestion of cellulose.
Escherichia coli that lives in the human large intestine synthesize vitamin B and releases it for human use. Similarly, Clostridium butyclicum is used for commercial preparation of riboflavin, and vitamin B.
Bacteria can also be used in the place of pesticides in the biological pest control. This commonly uses Bacillus thuringiensis (also called BT), a Gram-positive, soil dwelling bacterium. This bacteria is used as a Lepidopteran-specific insecticide under trade names such as Dipel and Thuricide. Because of their specificity, these pesticides are regarded as Environmentally friendly, with little or no effect on humans, wildlife, pollinators, and most other beneficial insects.
Some bacteria are harmful and act either as disease-causing agents (pathogens) both in plants and animals, or may play a role in food spoilage.
Plant pathogenic bacteria
Plant disease caused by bacterial plant pathogens is a major problem worldwide for agriculture. Besides bacterial pathogens that are already established in many areas, there are many instances of pathogens moving to new geographic areas or even the emergence of new pathogen variants. In addition, bacterial plant pathogens are particularly difficult to control because of the shortage of chemical control agents for bacteria, apart from antibiotics. However, the use of antibiotics is restricted in many countries due to the potential for evolution of antibiotic resistance and the transmission of antibiotic resistance to bacteria that can cause human disease.
Agents of disease
Organisms which cause disease are called pathogens. Some bacteria are pathogenic and cause diseases both in animals and plants. However, pathogenic bacteria more commonly affect animals than plants. Certain bacteria that exist in the normal flora on skin and in the mouth and human intestine are also known to cause disease when imbalances have weakened the immune system.
Saprotrophic bacteria attack and decompose organic matter. This characteristic has posed a problem to mankind as food such as stored grains, meat, fish, vegetable and fruits are attacked by saprotrophic bacteria and spoiled. Similarly milk and products are easily contaminated by bacteria and spoiled.
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