Microbes In Human Welfare

Lactic acid bacteria (LAB) convert milk into curd. These bacteria convert the lactose protein into lactic acid which causing the milk to coagulate and partial digestion of milk proteins to take place. This leads to increased vitamin B12 content.

The vitamins mentioned in the other options are not produced by lactic acid bacteria. Therefore, option c. vitamin B12 is the correct answer.

Anaerobic digesters are used in waste water treatment plants for the treatment of large quantities of sludge. They reduce the organic sludge as these digesters have microbes which digests the sludge and produces a mixture of gases like methane, carbon dioxide and hydrogen sulphide which are constituents of biogas.

Chemicals and oxidation ponds are not used in waste water treatment for large quantities of sludge. Flocs are microbial biomasses which causes flocculation. Therefore, option a. anaerobic digesters are mainly used for treating a large quantity of sludge and it is the correct answer.

Methanogenic bacteria are a group of bacteria which releases methane gas as a by-product. These bacteria are Aerobic bacteria and thus, requires oxygen.

Therefore, from the given options only activated sludge consists of anaerobic conditions and it can’t have methanogenic bacteria. So, option d. activated sludge is the correct answer.

A. Aspergillus niger – iv. Citric acid

Explanation:Aspergillus niger is a fungus which is commercially used for the production of citric acid. Citrate is converted to citric acid by Aspergillus niger.

B. Acetobacter aceti – iii. Acetic acid

Explanation: Acetobacter aceti is a bacteria which is used to convert ethanol into acetic acid.

C. Clostridium butylicum – ii. Butyric acid

Explanation: Clostridium butylicum is a bacteria which is used for the commercial production of butyric acid by metabolic engineering.

D. Lactobacillus – i. Lactic acid

Explanation: Lactobacillus is a group of bacteria which are used in the production of curd and yogurt from milk. They convert the lactose protein of the milk into lactic acid.

A. Statin - iii. Lowering of blood cholesterol

Explanation: Statins are a drug class which helps in lowering the blood cholesterol level by blocking a substrate known as HMG-CoA and reduces the blood cholesterol levels.

B. Cyclosporin A - iv. Immuno-suppressive agent

Explanation: Cyclosporin A is an immune-suppressive agent which can block the immune response in the body and it is widely used during organ transplant to avoid organ rejection.

C. Streptokinase - ii. Removal of clots from blood vessels

Explanation: Streptokinase is widely used as an anti-clotting agent. It can break down clots and prevent clot associated diseases like heart attacks.

D. Lipase - i. Removal of oil stains

Explanation: Lipase is an enzyme which can remove oil stains and also digests the fats in our digestive system.

During the primary treatment of waste water the removal of particles are carried out physically through the process of filtration and sedimentation. This process involves removal of stable particles.

Therefore, from the above options, only stable particles are removed during the processes involved in the primary treatment of waste water. The other options are incorrect as they are not removed during primary treatment of waste water. So, option b. stable particles is the correct answer.

Biological oxygen demand (i.e., BOD) is measured by the amount of oxygen that would be consumed when all the organic matter in one litre is oxidized by bacteria.

Thus, the BOD of waste water is estimated by measuring the amount of oxygen consumption. The other options are incorrect. So, option d. oxygen consumption is the correct answer.

Among the given options wine is the only alcoholic drink which doesn’t require distillation. It is produced by the alcoholic fermentation of fruits.

The other options require distillation to increase the alcohol content in alcoholic drinks. Thus, the correct option is a. Wine.

Indian Agricultural Research Institute (IARI) and Khadi & Village Industries Commission (KVC) promoted biogas production in the rural areas. The other options had no role in developing the technology of biogas production from cow dung in India. Thus, option c. Indian Agricultural Research Institute and Khadi & Village Industries Commission is the correct answer.

Trichoderma is a free-living fungus that is used effectively for plant disease management. It reduces or stops the pathogen attacks by various mechanisms such as enzyme secretion, competitive inhibition, and antibiosis. Trichoderma doesn’t kill insects or control butterfly caterpillars and they do not produce antibiotics.

Thus, option b. biological control of plant diseases is the correct answer.

Activated sludge flocs have bacteria which are aerobic (i.e., oxygen breathing) organisms. If oxygen availability to activated sludge is reduced then the center of flocs will become anoxic, which would cause death of bacteria and eventually break the flocs.

The other options are incorrect. Thus, option b. The center of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs is the correct answer.

Mycorrhiza is a fungus which helps plants in drawing more nutrients and water from the soil. It also increasesplant tolerance against unfavourable environmental conditions. But they DO NOT provide any form of resistance against insects.

Pseudomonas are gram-negative bacteria that are found in soil, plants, and humans. They are NOT a nitrogen-fixing organism. The other options are all nitrogen fixing organisms and can be found in a symbiotic relationship with plants.

The big holes in swiss cheese are made by a bacterium known as Penicillium shermani which consumes the lactose protein in the cheese to form lactic acid and also releases carbon dioxide(CO₂) and forms a gas bubble which bursts to create big holes in the swiss cheese.

The left after residue from methane production by cattle dung can be used as manure as it is very rich in nutrients like phosphorous. The other options are incorrect.

Methanogens are methane producing bacteria and they are anaerobic organisms. Therefore, they do not produce or require Oxygen. The other options are gases which methanogens produce.

Activated sludge should have the ability to settle quickly to pump it back rapidly from sedimentation tank to the aeration tank and using a small amount of the sludge as inoculum in the aeration tank and the part remaining in the anaerobic sludge digesters.

That’s why the activated sludge should have the ability to quickly settle.

A. Lady bird – iii. Aphids

Explanation: Lady bird is a red and black coloured beetle which feeds on small insects known as aphids. Ladybirds are natural bio controllers.

B. Mycorrhiza – iv. Glomus

Explanation: Glomus is a mycorrhizal fungus which forms a symbiotic relationship with the roots of the plants.

C. Biological control – ii. Trichoderma

Explanation: Trichoderma helps in controlling the plant diseases by various mechanisms such as enzyme secretion, competitive inhibition and antibiosis.

D. Biogas - i. Methano bacterium

Explanation: Methanogens are methane releasing bacteria.The main constituent of biogas is methane.

The big holes in ‘swiss cheese’ are made by a bacterium known as Penicillium shermani which consumes the lactose protein in the cheese to form lactic acid and also releases carbon dioxide(CO₂) and forms a gas bubble which bursts to create big holes in the swiss cheese.

Fermentors are large vessels which are used for the commercial production of fermented products (i.e., alcoholic beverages and antibiotics etc).They are used to grow micro-organisms necessary for fermentation. Fermentors provide adequate conditions like temperature and pH for the growth of micro-organism.

A microbe which is used in the production of statin is Monascuspurpureus. Statins lower the blood cholesterol level by blocking an enzyme known as HMG-CoA which stops the production of cholesterol and reduces the blood cholesterol level.

It is preferred to call secondary waste water treatment as biological treatment as it involves the use of micro-organisms for the treatment of waste water. The organic waste is degraded by the use of aerobic and anaerobic micro-organisms.

Nucleopolyhydro viruses (NPVs) are being used now a days as a biological pesticide to kill insects such as caterpillars and butterflies which damages the plants and crops. NPVs damages the midguts of the insects to kill them.

The discovery of antibiotics has helped mankind in the field of medicine by providing resistance against bacterial infections. Antibiotics either destroy the bacteria or slow down their effects in the body.

Distillation is required for producing certain alcoholic drinks because it increases the overall alcohol content in alcoholic drinks. The concentration of alcohol is increased from its original fermented concentration by the process of distillation.

The most important characteristic that Aspergillus niger, Clostridium butylicum, and Lactobacillus shareare that they all are micro-organisms which are involved in the production of various acids. i.e., Aspergillus niger is used for the production of citric acid, Clostridium butylicum is used for the production of butyric acid and Lactobacillus is used for the production of lactic acid.

If our intestine harbours microbial flora exactly similar to that found in the rumen of cattle then our digestive system would be able to digest cellulose and methane can be produced in our digestive system.

Two microbes that are useful in biotechnology are:

i) E.Coli: It is known as the biotech bacterium as it plays a significant role in gene technology as a model for testing protein functions and storing DNA sequences.

ii) Agrobacterium tumefaciens: It is widely used in plant biotechnology. It is used for DNA transfer between itself and the plant.

The source organism for ECORI, restriction endonucleaseis Escherichia coli (e.g., E.Coli). It is a gram-negative, rod shaped bacteria which is found in the intestines of warm blooded animals.

Bt cotton is a genetically modified (GM) crop. It produces an insecticide which makes the plantresistant to bollworm.

Blue green algae are not popular as biofertilizers as they produce slippery mucus and also cause algal bloom.

The species of Penicillium which produces Roquefort cheese is Penicillium roqueforti.

Ganga action plan involves the setting up of a large number of sewage treatment plants by the government. The states which are involved in Ganga action plan are Jharkhand, UP, Bihar, West Bengal.

Two industrially important enzymes are:

i) Lipase: It is used for the removal of oily stains from clothes and it is used widely in detergents.

ii) Amylase: It is used in the food and fermentation industry.

Cyclosporin A is an immune-suppressive agent produced by the Trichodermapolysporum funguswhich can block the immune response in the body and it is widely used during organ transplant to avoid organ rejection.

An example of rod shaped virus is Tobacco Mosaic virus which causes a disease known as a mosaic disease in tobacco leaves.

Methanogens are the group of bacteria found in both the rumen of cattle and sludge of sewage treatment. Methanogens release methane gas.

A microbe which is used for the production of Swiss cheese is Penicillium shermani which consumes the lactose protein in the cheese to form lactic acid and also releases carbon dioxide(CO₂) and forms a gas bubble which bursts to create big holes in the swiss cheese.

Flocs are the microbial biomass which gets together to act as a flocculant and causes a process known as flocculation.By this process, the microbial biomass metabolizes the organic waste and thus causes a decrease in the overall Biological Oxygen Demand (i.e., B.O.D) in the water.

Thus, flocs are important in the biological treatment of waste water as they help in reducing theBiological Oxygen Demand (i.e., B.O.D) in the water to make it less polluted and habitable for aquatic animals, reduces the pathogens and digests the organic waste.

The bacterium Bacillus thuringiensis helps us in controlling caterpillars of insects pests by producing a type of endotoxin in the midgut of the caterpillar after it gets ingested by the pest. The endotoxin then destroys the midgut lining and kills the caterpillars of insect pests.

Mycorrhiza is a fungus which helps the plants harbouring them in drawing more nutrients like phosphorous from the soil and transferring it to the Host plant and also helps the plants in drawing more water from the soil and increasesplant tolerance against unfavourable environmental conditions such as drought and salinity. In higher plants it also produces food and nourishment.

Cyanobacteria is considered to be useful in the paddy fields because it fixes the nitrogen from the atmosphere and provides organic matter which increases the fertility of the soil and helps in the overall development and growth of the plant.

Some examples are : Oscillatoria, Nostoc, Anabaena.

Penicillin was discovered by Alexander Fleming in 1921 by accident. Alexander Fleming once returned from a vacation to find that one of his staphylococcus culture plates had accidentally gotten contaminated with mould. The mould inhibited the growth of staphylococcus culture. This observation gave him an idea and the antibiotic was isolated from the fungus which was called Penicillium notatum.

Alexander Fleming discovered penicillin in 1921 but he was not credited for showing its role as an antibiotic.It was credited to Howard Florey and Ernst Chain. Their research enabled the testing and the production of penicillin on a commercial scale.

Bioactive molecules of fungal origin help in restoring the good health of humans as a number of bioactive molecules are significant in the medical treatment of humans. Some of the examples are:

i. Statins - Statins are a drug class which helps in lowering the blood cholesterol level by blocking a substrate known as HMG-CoA and reduces the blood cholesterol levels.

ii. Cyclosporin A – It is an immune-suppressive agent which can block the immune response in the body and it is widely used during organ transplant to avoid organ rejection.

iii. Streptokinase - Streptokinase is widely used as an anti-clotting agent. It can break down clots and prevent clot associated diseases like heart attacks.

iv. Lipase - Lipase is an enzyme which can remove oil stains and also digests the fats in our digestive system.

Enzymes like lipase and proteases are enzymes which plays an important role in detergents. They are added in detergent formulations to clean and remove oily stains from the clothes.

The source of these enzymes is produced from Xanthomonas for protease and Pseudomonas for lipases.

Biogas consists of three major constituent gases. Methane (CH₃) is present in about 60-70 % of the total volume , Carbon dioxide (CO₂) is present in about 30-40% of the total volume and Hydrogen sulphide is present in about 0.1% of the total volume. Other gases which are present in small quantities are Nitrogen (N₂), Carbon Monoxide (CO), Hydrogen (H₂) and Oxygen (O₂).

Methanogens are the organisms which are involved in biogas production. They are archaebacteria which release methane in the presence of low oxygen. An example of methanogens is Methanobacteriumbryantii.

Microbes helps in reducing the environmental degradation caused by chemicals. The bioremediation can be observed in agriculture. Biofertilizers consists of microbes which enrich the soil by fixing the nitrogen from the atmosphere. Some examples of such microbes are nostoc, rhizobium etc. Biopesticides are also used to kill pests by producing an endotoxin which is ingested by the pest and causes the midgut lining to get destroyed.

Microbes are also immensely used in waste water treatment by treating the organic waste with microbes which degrades the organic waste and reduces the biological oxygen demand (i.e., BOD). Thus, microbes help in reducing the environmental degradation caused by chemicals by replacing them as a better alternative which doesn’t harm the environment.

Broad spectrum antibiotics are a class of antibiotics which can be used for treating multiple bacterial infections. Their effects are not limited to treating a single bacterial infection and rather they are able to treat a wide number of different bacterial infections. Broad spectrum antibiotics can treat both gram-negative and gram-positive bacterial diseases.

An example of such an antibiotic is Ampicillin.

The viruses parasitising are known as bacteriophage. The bacteriophages attack the bacteria and they infect and replicate within the bacteria. They are made up of nucleic acid molecules which is surrounded by protein structure.

Bacterium Streptococcus produces an enzyme known as streptokinase is widely used as an anti-clotting agent. It can break down clots and prevent clot associated diseases like heart attacks.

Streptokinase combines with the plasminogen in the blood which forms an activator complex and it converts the plasminogen into plasmin. The plasmin is then able to degrade clot-bound fibrin.

Biofertilisers are used to provide additional supplement for increasing the nutrient content in the soil which helps in the overall development and growth of the plants.

For example rhizobium is used as a nitrogen fixing bacteria to fix atmospheric bacteria in the soil. Another example of biofertiliser is Nostoc a blue-green algae which increases the soil fertility and adds organic matter to the soil.

Aerobic degradation is more important than anaerobic degradation for the treatment of large volumes of waste waters rich in organic matter because:

i. The major part of the organic sludge is digested by the aerobic degradation of the waste water.

ii. After the aerobic degradation of the decomposers. They get separated along with the organic matter which is rich in nutrients.

iii. Biological oxygen demand (BOD) is reduced during the aerobic degradation which makes the water more suitable for aquatic organisms.

iv. The aerobic degradation produces sediments known as activated sludge which is introduced in anaerobic digesters and the activated sludge produces gases like methane (CH₃), carbon dioxide (CO₂), hydrogen sulphide (H₂S) which is the main constituents of biogas.

(a) The Ministry of Environment and Forests, Government of India has initiated two plans:

i. Ganga Action Plan

ii. Yamuna Action Plan

Both of these initiated plans involve the setting up of a large number of sewage treatment plants. Ganga and Yamuna are very important rivers in terms of flora, fauna and as a tourist and religious attraction spot. A large number of sewage treatment plants would treat the waste water which is polluted.

(b) The river Ganga is the largest river in India which covers a total distance of approximately 2520 Kms across India and Bangladesh and it provides the habitat for more than 140 different species of fish and about 90 different species of amphibians and many endangered species. It provides about 40% of the drinking water to India.

Thus, river Ganga serves as a major natural river and therefore the river requires to be free from pollution.

Diagrammatic sketch of biogas plant:

The main ideas behind the biological control of pests and diseases is that the population of pests is controlled by the introduction of natural predators of these pests in the environment. The natural predators of these diseases causing pests are to keep the population in control and protect the plants or crops from getting harmed.

Some examples are:

i. The Lady bird beetle is used to control the population of insects like Aphids.

ii. Nucleopolyhydro viruses (NPVs) are being used to kill insects such as caterpillars and butterflies which damages the plants and crops. NPVs damages the midguts of the insects to kill them.

(a) If a large volume of untreated sewage is discharged into a river then the Biological Oxygen Demand (BOD) will get higher which would lead to the death of organisms such as fishes due to low availability of oxygen in the water. Also, large volumes of untreated sewage in the water would cause water borne diseases like cholera and dysentery as people drink water directly from the river.

(b) Anaerobic sludge digestion is important in sewage treatments because it decreases the Biological Oxygen Demand (BOD) and the sludge digestion occurs in the presence of anaerobic bacteria and when the sludge is digested the anaerobic bacteria releases a mixture of gases like methane(CH₃), carbon dioxide(CO₂) and hydrogen sulphide(H₂S). These are the main constituents of biogas.

Thus, anaerobic sludge digestion is important as it not only helps in sewage waste water treatment and reducing the BOD levels to suitable levels for drinking and aquatic animals respiration but it also produces biogas.

Lactic acid bacteria (LAB) is widely used to ferment or culture food products. Lactic acid bacteria (LAB) is found in curd. It’s useful applications are:

i. The Lactic acid bacteria (LAB) is a type of bacteria whiczh can convert milk into curd by producing an enzyme called lactase. Lactase changes the milk protein lactose into lactic acid. The lactic acid produced coagulates the milk protein to convert it into curd.

ii. People who are allergic to lactose and suffer from a condition known as lactose tolerance. The bacteria is useful as it has the ability to remove or convert lactose.

iii. Lactic acid bacteria (LAB) increases the vitamin B₁₂ content.

iv. Lactic acid bacteria (LAB) is also present in our digestive system. It provides resistance to some pathogens in our digestive system.