Economic importance of Bacteria
Bacteria increase soil fertility
1) Ammonifying bacteria:
Many saprophytic bacteria hydrolyse the protein of dead plant and animal matter present in the soil into aminoacids and organic nitrogenous base. The ammonifying bacteria convert amino acid into ammonia(ammonification). The free ammonia combine with water and carbon dioxide to form ammonium carbonate. These ammonium compound are used by many crops as a source of nitrogen eg. B. ramosus.
Another important source of ammonia in the soil is urea. Animal population of the world excretes more than 200,000 tones of urea per day which is decomposed by Bacillus pasteuri and Sarcina ureae.
2) Nitrifying bacteria:
Oxidation of ammonia to nitrate is known as nitrification. This process brought in nature by two highly specialized groups of obligately aerobic chemoautotrophic bacteria.
3) Nitrogen fixing bacteria:
a) symbiotic nitrogen fixers
Example: Rhizobium
b) Free living bacteria
Example: Azatobacter and Clostridium
Bacteria are used in dairy industries specially lactic acid bacteria is used in the production of milk products. Some bacteria are used in Dextron production example: lactic acid bacteria.
Clostridium is used in the production of acetone and butanol(Fermentation). Acetobacter aceti is used in acetic acid production. Curing of tobacco and tea leaves is done under controlled activity of microorganisms. Bacteria are helpful in decomposition of dead organisms. Many bacteria secrete crystalline protein which kill caterpillar and insects and non toxic to plants and animals. Bacteria are used in Retting process it is a controlled microbial decomposition of pectin without simultaneous decomposition of fibres, thus results in the separation of fibres. Example: C. tetani
Degradation of petroleum hydrocarbons many bacteria are used example: Pseudomonas, Achromobacteria. For industrial and domestic sewage disposal purpose also bacteria are used.
4) Bacteria in Medicine:
Bacteria are also the source of many antibiotic serums and vaccines. Antibiotics are the chemical substances secreted by certain microorganisms which inhibit growth and development of other microbes.
Example: Penicillin- Penicillium notatum
5) Bacteria in Biotechnology:
Bacteria are used in rDNA technology. Human insulin production, stomatostatin production, interferon production etc.
6) Bacteria in pollution control:
Use of bacteria to degrade pollutants from soil, underground water, chemical spills, etc. Is known as bioremediation.
Examples: Pseudomonas and Bacillus
Scientists have also successfully developed genetically engineered bacteria which secrete enzymes effective in cleaning drains.