What are Microbes?
Here, we will discuss about the What is Microbes/ Microorganisms and Uses of Microorganisms in our daily life.
In simple words, Microbes are the variety of Microorganisms that exhibit important and beneficial activities. They contains small algae, fungi, bacteria etc. Microbes are used in very branches of biology such as medical, food industry etc.
The branch of Biology which deals with the study of microbes or microorganisms is called as Microbiology.
Uses of Microbes :
1. Microbes in Sewage treatment:
We know that, there are large quantity of waste water is generated every day in big cities and towns. This waste water is called as sewage. Sewage water includes high levels of organic, matter human excreta and domestic waste and microorganisms. Microbes can be pathogenic. They are important to remove organic matter from the waste water before it is made available for human use. It cannot be discharged into natural water bodies like river directly. It is treated in sewage treatment plants.
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| Sewage treatment plant |
There are three processes includes in the sewage treatment.
1. The primary treatment is a physical process and remove large pieces of floating debris, oily substances, etc. through filtration and sedimentation.
2. Secondary treatment is biochemical process. The primary effluent is passed to the large aeration tanks. Here it is constantly agitated mechanically and air is pumped into it. Due to this vigorous growth of useful aerobic microbes into flocs (flocs are the masses of bacteria associated with fungal filaments to form mesh like structures) take place. These microbes consume the major part of the organic matter in the effluent as they grow. Due to this Biological Oxygen Demand of the effluent is significantly reduced.
3. Once the Biological Oxygen Demand of waste water is reduced, it is passed into a settling tank. Here the bacterial flocs are allowed to sediment. The sediment is called activated sludge. Small part of this is passed back into aeration tank and the major part is pumped into large tanks called anaerobic sludge digesters.
In these tanks anaerobic bacteria grow and digest the bacteria and fungi in the sludge. During this digestion gases such as methane, hydrogen sulphide, CO2 are produced that form gases. Effluent from these plants are released in natural water bodies like rivers and streams.
2. Microbes in Industrial production:
A) Production of alcoholic beverages:
Alcoholic beverages includes liquors like wine, Beer, and whisky etc. products.
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| Microorganisms in alcoholic beverages |
A number of strains of the yeast, Saccharomyces cereviaiae var. ellipsoideus are used in industrial production of wine. Different flavors of wine are obtained by using different fruit juices.
Beer is obtained from fermented grains, mostly barley. Suitable strains of S. cerevisiae are used for fermentation. It is produced through various steps like malting, mashing and fermentation. It is allowed to stand for a few days. Then it is clarified, carboxylated, filled in bottles, packed and marketed. Wine and beer are produced without distillation.
Whisky is obtained by fermenting mixed grains of corn, wheat barley, etc. The product of fermentation is then distlled.
B) Gibberellin Production:
Gibberellins are a group of growth hormones mainly produced by higher plants and fungi to promote growth by stem elongation. The first gibberellin was isolated by two Japanese scientists Yabuta and Sumiki in 1938 from rice seedlings infected with the fungus Gibberella fujikuroi. Gibberellin have many practical applications. They are used to induce parthenocarpy in apple, pear etc. They are used in breaking dormancy and inducing flowering also.
C) Dairy industry:
We know that, different products are obtained from milk in dairy industry using microbial species. Examples: Cheese, buttermilk, panner, yoghurt etc. Species of Streptomyces, penicillium and Lactobacillus are commonly employed.
Curd and buttermilk were produced using lactic acid bacteria. Cheese too is a product of fermentation by fungi.
D) Enzyme production:
Enzymes are biocatalysts which either initiate or accelerate all biochemical processes in living organisms. A number of hydrolytic enzymes that degrade starch, proteins, fats and pectin into simple compounds are known.
Examples:
Enzyme name Microbial source
1. Invetase enzyme - Saccharomyces cerevisiae
2. Pectinase - Sclerotiana libertine
3. Lipase - Rhizopus spp
4. Cellulase - Trichoderma konigi
E) Organic acid fermentation:
A number of organic acids are obtained by fermentation using various microbes.
Organic acid Microbial source
1. Citric acid - Aspergillus Niger
2. Gluconic acid - Aspergillus Niger
3. Fumaric acid - Rhizopus arrhizus
4. Acetic acid - Acetobacter aceti
F) Vitamin Production:
Vitamins are complex organic compounds required in very small quantities for normal growth and development of the body. They include vitamins A, B, C, D, E, and K. They may be water soluble (vitamins B and C) or fat soluble (vitamins A, D, E and K). All the vitamins are not produced in human body. Therefore, they are to be consumed through food or tablets.
Vitamins name Microbial source
1. Vitamin B2 - Neurospora gossypii
-Eremothecium ashbyi
2. Vitamin B12 - Pseudomonas denitrificans
3. Vitamin C - Aspergillus Niger
G) Antibiotic production:
Antibodies are the substances produced in small amounts by certain microbes to inhibit the growth of other microbes. They may be anti-fungal or anti-bacterial in nature.
Antibiotic produced Microbial source
1. Chloromycetin - Streptomyces venezuelae
2. Erythromycin - Streptomyces erythreus
3. Penicillin - Penicillium chrysogenum
4. Streptomycin - Streptomyces griseus
Many deadly diseases such as plague, whooping cough, diphtheria and leprosy, which used to kill millions all over the world can be now controlled by antibiotics.
3. Microbes in Biogas production:
We know that, Biogas contains methane gas. Methane gas is domestic as well as industrial fuel. It is a non-conventional and renewable source of energy and obtained by microbial fermentation.
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| Biogas plant |
Biogas production by microbes is a complex process and involves several anaerobic microbial species growing in marshy places, organic sediments and in the rumen (part of stomach) of ruminant animals. Plant wastes and animal wastes are commonly used for biogas generation. It includes domestic waste, agricultural waste, agro-industrial waste, municipal waste, forestry waste, etc. The biogas contains about 50-80% methane, 15-45% CO2 and other gases in traces. It's chemical composition depends upon the nature of the waste material used and prevailing environmental conditions.
Biogas production involves 3 major processes:
1. Anaerobic digestion or hydrolysis,
2. Acetogenesis or Acidogenesis and
3. Methanogenesis.
The anaerobic digestion occurs by certain anaerobic bacteria like species of Clostridium, Pseudomonas, etc. In this process complex insoluble polymers are converted to simple soluble monomers with the help of bacterial hydrolytic enzymes. These monomers are further converted into organic acids, chiefly acetic acid by enzymes of Acidogenic bacteria. Finally, acetic acid is transformed to biogas by the enzymes of methanogenic bacteria. These bacteria include species of Methanococcus and Methanobacillus.
Advantages of Biogas :
1. It is a cheap, safe and renewable source of energy.
2. It can be used for domestic lighting, cooking, street lighting as well as small scale industries.
3. It burns with blue flame and without smoke.
4. It helps to improve sanitation of the surrounding.
5. It is eco-friendly and does not cause pollution and imbalance of the environment.
6. It can be easily generated, stored and transported.
The biological agents which can be used to kill or check the proliferation of disease causing agents are called biopesticides. Use of micro organisms or biological methods for controlling plant diseases and pests is called Biocontrol. Use of chemical pesticides and insecticides is effective but these chemicals are toxic and extremely harmful to human beings, domestic animals and useful pollinators. Moreover they pollute our environment. Therefore use of chemical pesticides should be minimum.
In modern agriculture microbes are used for controlling pests. These microbes are either pathogens or predators or the parasites on the pests. An example of microbial biocontrol agent is Bacillus thuringiensis. Dried spores of B. thuringiensis are mixed with water and sprayed onto vulnerable plants such as cotton, brassicas etc. when insect larvae eat the leaves, they get killed as toxins are released in their gut by the bacteria.
Four groups of biocontrol agents are known. They are bacteria, fungi, protozoans and viruses.
Pathogen Host range
Bacteria:
1. Bacillus Caterpillars larvae of thuringiensis Aedes, black flies, some adult beetles, wax moths, etc.
Fungi:
1. Beauveria Aphids, mealy bugs, bassiana mites, white flies,etc.
Protozoans:
Nosema locustae Grasshoppers, caterpillars, some corn-borers and crickets.
Viruses:
1. Nucleopolyhedrovirus caterpillars Gypsy moths and or NPV
Microbes are used as herbicides also. Many dicot herbs grow in the field of cereals as weeds and these weeds can be killed by certain microbes.
Dhokla, Jalebie are common Indian delicacies. A number of microbes are involved in their production through the process of fermentation. The use of microbes in food production is almost as old as human civilization.
The dough of dhokla is prepared by mixing gram flour (besan) with butter milk. The lactobacilli bring about the fermentation process. Many species of bacteria and yeast are useful in making idli and dosa. The bubbles of CO2 trapped in glutein make idlies puffy. The microorganisms like species of Bacillus, Candida and Saccharomyces are involved in this process.
2. It can be used for domestic lighting, cooking, street lighting as well as small scale industries.
3. It burns with blue flame and without smoke.
4. It helps to improve sanitation of the surrounding.
5. It is eco-friendly and does not cause pollution and imbalance of the environment.
6. It can be easily generated, stored and transported.
4) Microbes as Biocontrol agents:
The biological agents which can be used to kill or check the proliferation of disease causing agents are called biopesticides. Use of micro organisms or biological methods for controlling plant diseases and pests is called Biocontrol. Use of chemical pesticides and insecticides is effective but these chemicals are toxic and extremely harmful to human beings, domestic animals and useful pollinators. Moreover they pollute our environment. Therefore use of chemical pesticides should be minimum.
In modern agriculture microbes are used for controlling pests. These microbes are either pathogens or predators or the parasites on the pests. An example of microbial biocontrol agent is Bacillus thuringiensis. Dried spores of B. thuringiensis are mixed with water and sprayed onto vulnerable plants such as cotton, brassicas etc. when insect larvae eat the leaves, they get killed as toxins are released in their gut by the bacteria.
Four groups of biocontrol agents are known. They are bacteria, fungi, protozoans and viruses.
a) Microbial pesticides and their host range:
Pathogen Host range
Bacteria:
1. Bacillus Caterpillars larvae of thuringiensis Aedes, black flies, some adult beetles, wax moths, etc.
Fungi:
1. Beauveria Aphids, mealy bugs, bassiana mites, white flies,etc.
Protozoans:
Nosema locustae Grasshoppers, caterpillars, some corn-borers and crickets.
Viruses:
1. Nucleopolyhedrovirus caterpillars Gypsy moths and or NPV
Microbes are used as herbicides also. Many dicot herbs grow in the field of cereals as weeds and these weeds can be killed by certain microbes.
5) Microbes in household production:
Dhokla, Jalebie are common Indian delicacies. A number of microbes are involved in their production through the process of fermentation. The use of microbes in food production is almost as old as human civilization.
The dough of dhokla is prepared by mixing gram flour (besan) with butter milk. The lactobacilli bring about the fermentation process. Many species of bacteria and yeast are useful in making idli and dosa. The bubbles of CO2 trapped in glutein make idlies puffy. The microorganisms like species of Bacillus, Candida and Saccharomyces are involved in this process.
So, this are the 5 Uses of Microorganisms in different ways.