Even under extreme conditions, microbes are found all over the world.
They are viruses, viroids, prions, fungi, protozoa, bacteria and other microscopic animals.
They can be potentially fatal, but they have an important role in human welfare.
You can grow microbes in laboratories and at large scale industrial scales for research purposes or production of many useful products.
Many ways microbes are beneficial to the environment and humans in general
1. Household Products
- Curd-The bacteria Lactobacillus makes lactic acid, which partially coagulates the milk proteins. It also increases vitamin B 12. These bacteria can also be found within the gut, and they control the growth of other microbes.
- Fermented dough is used to make South Indian delights, e.g. Dosa and Idli. The fermentation of the dough occurs due to CO 2production from bacteria
- Use the yeast Saccharomyces cerevisiae to produce bread
- By fermenting Palm sap, you can make toddy.
- For delicious dishes, microbes can be used to ferment soybeans and fish.
- Different cheeses have different textures and tastes.
E.g. Large holes in Swiss cheese – Propionibacterium shermanii
Roquefort cheese- Penicillium roqueforti
Camembert cheese- Penicillium camemberti
2. Industrial Products
In fermenters, microorganisms can be grown for industrial-scale production. Many alcoholic beverages, drugs and other chemicals are made for commercial use.
a. Fermented Beverages
Saccharomyces cerevisiae (Brewer’s yeast) is used to make alcoholic beverages out of malted cereals.
Different beverages can be made depending on the raw materials and fermentation methods used. There are two types of beverages: without distillation- beer and wine; and with distillation- whisky rum and brandy.
b. Antibiotics and Vaccines
Penicillin was the first antibiotic ever developed. Alexander Fleming discovered the antibiotic from the fungus penicillium notatum. Ernest Chain and Howard Florey derived the antibiotic. It was used in World War II to treat American troops. Florey Chain and Fleming won the Nobel prize in 1945 for their contributions.
Many antibiotics have been developed since then. These are just a few examples.
|
Name and description of the antibiotic |
Source |
Uses of |
|
Bacitracin |
Bacillus subtilis |
Syphilis, Lymphonema |
|
Streptomycin |
Streptomyces griseus |
Tuberculosis, Pneumonia,Meningitis |
|
Chloromycetin |
Streptomyces venezuelae |
Typhoid |
|
Erythromycin |
Streptomyces erythreus |
Typhoid. Whooping cough. Diphtheria |
|
Gentamicin |
Micromonospora purpurea |
It is effective against Gram (+) bacteria |
|
Tetracycline |
Streptomyces aureofaciens |
Conjunctivitis, urinary, and intestinal tract infections |
Many synthetic antibiotics are available today.
Vaccines can be made from microorganisms that have been weakened or eliminated. Your body becomes immune to the particular pathogen.
Edward Jenner created the first smallpox vaccine.
For various viral diseases, many vaccines have been created. DPT, Polio and Measles, Hepatitis A, B, Pneumococcal and Influenza are some of the vaccines that have been developed.
c. Enzymes and chemicals
Many chemicals, such as organic acids, can be produced by microorganisms. These are just a few examples:
Butyric acid- Clostridium itylicum
Citric acid – Aspergillus niger
Ethanol- Saccharomyces cerevisiae
Lactic acid- Lactobacillus
Acetic acid- Acetobacter aceti
Also, microorganisms produce enzymes which can be used commercially for many purposes. E.g. Streptococcus produces an ingenious enzyme called streptokinase that is genetically modified for use as a clot-buster to remove blood clots.
Bottled juices can be clarified with proteases or pectinases
Lipases – These are used to remove oily stains and detergents
There are many uses for bioactive molecules.
Statins are made by Monascuspurpureus (yeast). It lowers blood cholesterol levels by inhibiting cholesterol synthesis
Trichoderma polysporum (fungus), produces Cyclosporin A. It acts as a suppressor of the immune system.
3. Sewage Treatment
It is vital to treat wastewater before it is released. For this purpose, sewage treatment plants are used (STPs). The sewage water is treated with microbes (heterotrophic)that are naturally present in it.
Primary treatment
The first step is filtration and sedimentation. This removes floating debris and grit. Small pebbles and soil are the two main components. The primary sludge, which is the solid that settles, and the primary effluent, is the supernatant fluid.
Secondary treatment
It is also known as a biological treatment. It facilitates the growth of aerobic microbes by pumping air into large aeration tanks and mechanically stirring the effluent. This lowers the biochemical oxygen requirement (BOD). BOD, which is the rate of oxygen uptake in microorganisms, refers to the amount of organic matter present in the sample.
After reducing BOD by a significant amount, the effluent may settle in the settlement tank. The activated Sludge is a bacterial flocs, which is a bacterial mass that forms a mesh-like structure with fungal filaments.
The activated waste is then digested in an anaerobic sulfur sludge digester. A small amount of the sludge may be allowed to return to the aeration tank, where it serves as an inoculum. Biogas (a mixture or gases, e.g. methane, CO2, H2S, etc.) It is made from digested sludge and can be used for fuel.
The secondary effluent gets released into rivers and streams. Releasing only treated sewage water can help keep rivers cleaner. For this purpose, the Ganga and Yamuna Action Plan has been initiated by the Government.
4. Biogas Production
Methanogens, e.g. The anaerobic waste sludge contains methanobacterium, which produces biogas for sewage treatment. The mixture of methane and other gases is predominant. These bacteria are also found in the rumen of cattle, and they aid in the digestion of cellulose.
Gobar Gas is made from the dung and milk of cattle. It is used in various villages for different purposes.
IARI (Indian Agricultural Research Institute), KVIC (Khadi Village Industries Commission) have spent a lot of time developing technology for biogas.
5. Biocontrol of diseases and pests
Insecticides and chemical pesticides are effective in killing both useful and harmful organisms. It is possible to develop a biocontrol strategy by studying natural predation and interconnected webs.
Ladybugs and dragonflies are good at controlling mosquitoes.
Baculoviruses from the genus and Nucleopolyhedrovirus make excellent biocontrol agents. They not only attack arthropods, they are also harmful to plants and other animals, such as birds and fish.
Trichoderma, a fungus, is used to control many plant pathogens. The fungus can be found in the roots.
Bacillus thuringiensis can be used to control insects and caterpillars. Some plants have been genetically altered and the gene code for this toxin was introduced into the plant genome. E.g. Bt-cotton resists pests.
6. Biofertilisers
Excessive use of chemical fertilizers can cause pollution and have harmful side effects. Bio fertilizers made from microorganisms are highly recommended.
The main sources for biofertilizers come from bacteria, fungi and cyanobacteria.
Azotobacterand Azospirillumare both free-living nitrogen-fixing bacteria that are found in the soil.
Rhizobium exists in the root nodules and roots of leguminous vegetables. It fixes atmospheric Nitrogen. Alternatively, you can grow leguminous plants to increase the soil’s nitrogen level.
The soil also benefits from fungal association through mycorrhiza. The plant gets phosphorus from the fungi of the genus .
These symbiotic interactions not only enrich the nutritional content, but also provide disease resistance as well as tolerance to drought and salt.
Most cyanobacteria can fix nitrogen in the atmosphere, e.g. Nostoc, Anabaena, Oscillatoria, etc. As a biofertilizer, Cyanobacteria are widely used in paddy farms. Blue-green algae is an autotrophic species that can be found in both aquatic and terrestrial habitats. They enhance soil fertility by adding organic material.