Role of microbes in our life

You might know microbes only for causing harm to human beings by causing diseases and making us ill.

But, the truth is microbes are also beneficial to us in a variety of ways. They help in preparation of several household products like curd, cheese and paneer, bread, cake, idli and dosa & industrial products Alcohols, acetic acid, antibiotics, beverages etc. They also help the environment acting as decomposers and biofertilizers. They play an important role in sewage treatment as well.

Uses of microorganisms

Some useful aspects of microorganisms are: 1. Food and beverage industry 2. Medicinal use 3. Increase soil fertility 4. Maintain clean environment 1.Food and beverage industry

Microbes are very useful in processing of may food items like curd, cheese, bread, idli, etc. are prepared by the process of fermentation. Fermentation is the process of conversion of sugar into an acid or an alcohol by the action of microorganisms.

 Microbes’ role in Curdling of milk # Curd: Microbes play a vital role in preparing curd from milk. Curd is formed by coagulation of a protein called casein which is present in the milk. Curd contains a bacterium, Lactobacillusis a friendly-bacterium and promotes curd formation by converting lactose sugar in milk into lactic acid. It treats & prevents diarrhoea, helps in food breakdown and absorption of nutrients. # Cheese and paneer:

The production of milk products such as cheese and paneer involves the use of bacteria like Lactobacillus and streptococcus.

# Bread:

Yeast is used as a raising agent in baking. Most commonly used yeast is Saccharomyces cerevisiae .It is due to the action of yeast that the dough rises, if you leave it for sometime adding yeast to it during kneading. Dough (Flour) contains carbohydrates. Yeast when added to it, converts carbohydrates into CO2. Due the formation of CO2, the dough rises. While preparing cake/ bread, the dough is baked. Once baked, the yeast dies. As a result, a soft and spongy baked product is formed.

# Idli and Dosa : Microbes also play a vital role in fermenting idli/dosa batter. Idli/ dosa batter contain Urad pulses. These Urad seeds contain Lactic Acid Bacteria (LAB). These bacteria lead to the formation of Lactic acid and CO2. Formation of Lactic acid gives a sour taste to the batter. Therefore, the batter should not be fermented for too long, else it might turn too sour.

# Alcoholic beverages: Yeast is also used in the production of alcoholic beverages such as wines and beers from fruit juices and barley by the process of fermentation. #Vinegar: Sugarcane juice is converted to vinegar (acetic acid) by the action of bacteria called Acetobacter. #Citric Acid: A fugus called Aspergillus is used to produce large quantities of citric acid which is used in soft drinks. #Sources of nutrients: Some algae like Chlorella and sea weeds are used as food in many countries. Chlorella is very rich in proteins and vitamins and seaweeds are rich source of minerals and all natural vitamins.

2. Medicinal use: Microbes’ role in i)preparation in Antibiotics

Microbes such as bacteria and fungi are also used in the preparation of medicines called antibiotics to kill or stop growth of the disease-causing microorganisms. Streptomycin, tetracycline and erythromycin are antibiotics which are used to treat several bacterial infections. Antibiotics are chemical substances that kill disease-causing microbes. It is quite interesting to find that there are some microbes which cause diseases; on the other hand, some other microbes help in preparation of antibiotics, and thus, cure diseases.

Alexander Fleming, a Scottish scientist discovered the first antibiotic & named it ‘Penicillin’.Penicillin discovery was ‘a chance’ discovery. Fleming was experimenting with Staphylococcus bacteria. A Petri dish (cell culture dish) had been left open by mistake, was found to be contaminated by blue-green mould. This visible mould growth inhibited bacterial growth around itself.

Fleming concluded that mould released a substance that inhibited bacterial growth. This substance was the antibiotic which was named ‘Penicillin’ after the mould Penicillium notatum

 Precautions for taking antibiotics: Antibiotics must be taken only when advised by a qualified physician. It should be taken when needed otherwise it becomes less effective for future use. Antibiotics if taken unnecessarily may kill the beneficial bacteria in the body. ii) Preparation in Vaccination Vaccination is a process in which vaccine is given to improve the immunity of the body against a specific disease. Vaccine is a biological preparation that resembles a disease-causing microbe. These vaccines are made up of dead or very weak microbes.

In vaccination, a memory of the disease-causing organism is created inside the body, so that the body can fight back any further attack of the same disease-causing organism. Vaccine is introduced into the body which resembles a disease-causing organism, at the same time, very mild to cause any harm to the body. The body produces Antibodies in response to the vaccine. These Antibodies fight any further attack of the Antigen.

Antigen refers to any foreign substance inside the body. These can be chemicals, micro- organisms (bacteria, virus etc), Toxins, Pollen etc. Antigens trigger immune system to produce antibodies. Antibodiesrecognize & neutralize pathogens. Each antibody binds to a specific antigen.

Vaccination has been a huge success. Diseases like small pox are eradicated. Many diseases like polio, tetanus, and measles have been reduced to a large extent. Vaccines are prepared against several infectious diseases like small pox, tuberculosis, cholera, hepatitis and polio.

Edward Jenner discovered the vaccine for smallpox in 1798. A worldwide campaign against smallpox has finally let to its eradication from most parts of the world. Pulse polio program is another mass immunization program to wipe out polio completely.

iii) Production of insulin Certain types of bacteria are used in producing insulin, a hormone used to treat diabetic patients whose body produces little or no insulin. Presence of bacteria in human body Bacteria such as lactobacillus, Acidophilus and Escherichia coli found in human intestine synthesise vitamin B complex which helps in digestion and absorption of food. They also help in destroying disease-causing microbes.

3. Increase soil fertility Nitrogen is an essential nutrient for all life forms to synthesise many components of their bodies such as proteins, chlorophyll, nucleic acids and vitamins. Microorganisms present in the soil help in the recycling of nitrogen in the environment. The microbes like Rhizobium, Nitrobacter and blue green algae help in fixing nitrogen from the atmosphere to enrich soil and to increase its fertility. These microbes are also called biological nitrogen fixers.

4. Maintain clean environment The microorganisms like bacteria and fungi, decompose biodegradable waste and help in recycling of nutrients to the environment. Decomposition is the Process in which complex organic matter is broken down into simpler forms. This process breaks down dead & decaying organic matter into simple inorganic forms.

Organisms which help in decomposition are termed as ’Decomposers’. Bacteria & Fungi are important Decomposers.

Decomposers help the environment to get rid of dead & decaying matter and also enrich the soil quality for better growth of plants.

 Bacteria are also used in decomposition of sewage.  Bacteria help in the breakdown of plants and animals waste to produce biogas, which can be further used as cooling gas.  The microorganisms like algae can carry out photosynthesis and produce oxygen and thus purifies air.