Q1. ________ is a substance obtained by microbial processing that functions as an artificial sweetener.
Xylitol is a substance obtained by microbial processing that functions as an artificial sweetener.
Updated on: 2026-03-31 | Author: Rahul Patil
Xylitol is a substance obtained by microbial processing that functions as an artificial sweetener.
Compressed yeast is used in the commercial bakery industry.
Rifamycin is a powerful antibiotic against treatment of tuberculosis.
Lactic acid is used in the production of vitamins.
Ethanol
Protease is used to produce vegetarian cheese.
False
Polylactic acid
The environmental role of microorganisms in pollution control:
Soil pollution caused due to chemical fertilizers can be prevented using microbial inoculants.
Bacteria which use sulphuric acid as a source of energy and can control soil pollution caused due to acid rain.
Geobacter converts salts of uranium into insoluble salts and thus prevents the mixing of these salts with ground water sources.
Microbes are also used in sewage treatment and clean technology.
In cities, sewage is carried to the processing unit and acted upon by microbial processes.
Microbes capable of decomposing any compound as well as destroying pathogens like those which cause cholera, typhoid, etc., are mixed with sewage.
Carbon compounds present in sewage are decomposed and gases like methane and CO2 are released.
Xenobiotic chemicals present in sewage are decomposed by phenol oxidizing bacteria.
The sludge that settles down can be used as fertilizer and the water released after microbial treatment can be treated and reused for different purposes, as it is environmentally safe.
Microbes are used for the production of many household items like idli, bread, vinegar and dairy products like cheese, yoghurt, butter, cream, etc., that are used on a daily basis.
Antibiotics such as penicillin, natamycin, etc. are produced using microbial fermentation.
Commonly used beverages like coffee, cocoa, wine and cider are produced by microbial fermentation of organic substrates.
Probiotics like yoghurt, kefir, sauerkraut, miso soup, etc. are produced by microbial fermentation.
Microbes are also used for the production of fuels, in pollution control and sewage management.
Plants
Plants have chloroplasts, whereas the rest of the organisms do not.
or
Bioinsecticides are made up of bacteria, viruses, and fungi.
Ice-cream
Pepsin
Khoa
Clostridium
Isomerase
Gaseous fuel : Coal gas : : Solid fuel : Coal
Biofuels are renewable sources of energy.
They are available in solid (dung, crop residue), liquid (vegetable oils, alcohol), and gaseous (gobar gas) forms.
Biofuels are easily available in sufficient amounts.
They are reliable fuels of the future.
They are pollution-free fuels.
Bread and other products produced using commercial yeast (baker’s yeast) are nutritious because compressed yeast used in the bakery industry contains various useful contents like carbohydrates, fats, proteins, various vitamins, and minerals.
Corrosion is a common problem in chemical industries. Using anticorrosive instruments increases the production cost. However, while using microbial enzymes costly anti-corrosive instruments are not required.
Microbial enzymes are active at low temperature, pH and pressure. Thus, they save energy.
Enzymes carry out specific processes due to which unnecessary byproducts are not formed. Thus, expenses on purification are minimized.
In microbial enzymatic reactions, elimination and decomposition of waste material is avoided and enzymes can be reused. Thus, microbial enzymes are eco-friendly.
Oil spills of rivers and oceans can be cleaned by bacteria such as Pseudomonas spp. and Alcanivorax borkumensis, that have the ability to destroy pyridines and other chemicals.
These hydrocarbonoclastic bacteria (HCB) decompose hydrocarbons and bring about the reaction of carbon with oxygen to form CO2 and water.
Thus, microorganisms are used to control the effects of sea oil spills.
Probiotics have got more importance in recent times due to the following reasons:
Probiotics are healthy foodstuffs which contain active bacteria such as Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, etc.
These microbes form colonies of useful microbes in the alimentary canal and maintain the balance of beneficial intestinal micro-organisms that help in digestion, and decrease the population of harmful microbes such as Clostridium.
They also improve resistance and lower the ill effects of harmful substances formed during metabolic activities.
When we take antibiotics, the useful microbes in the alimentary canal become inactive. These microbes can be made active by consuming probiotics.
Also, probiotics are used for treatment of diarrhoea and treatment of poultry diseases.
Landfill pits are lined with plastic sheets to prevent soil pollution caused by the leaching of toxic and harmful substances into the soil.
Role of microbes in land-filling for solid waste management:
Microbes present in soil and other top layers decompose the waste.
These microbes break down complex organic compounds into simpler inorganic substances and thus compost is formed after a few days.
These microbes also feed on the organic matter and free important minerals and nutrients like nitrogen, carbon, phosphorus, etc., that can be used to improve the fertility of soil.
Acid rain is rainwater containing harmful amounts of sulphuric acid and nitric acid.
Some species of bacteria like Acidiphilium and Acidithiobacillus ferrooxidans, use sulphuric acid as a source of energy.
Introduction of such bacteria in soil polluted by acid rain can make the soil fertile again.
Also, soil pollution occurring due to chemical fertilizers can be prevented due to use of these microbial inoculants.
Microbial enzymes are used instead of chemical enzymes in industries because:
Corrosion is a common problem in chemical industries. Using anticorrosive instruments increases the production cost. However, while using microbial enzymes costly anti-corrosive instruments are not required.
Microbial enzymes are active at low temperature, pH and pressure. Thus, they save energy.
Enzymes carry out specific processes due to which unnecessary byproducts are not formed. Thus, expenses on purification are minimized.
In microbial enzymatic reactions, elimination and decomposition of waste material is avoided and enzymes can be reused. Thus, microbial enzymes are eco-friendly.
Lactic acid : To impart acidity : : Beta carotene : Edible colour
Lactobacillus : Yoghurt : : Baker’s yeast : Bread
| Column A | Column B |
| 1) Aspartame | d) Sweetener |
| 2) Fermentation | a) Anaerobic respiration |
| 3) Niacin | b) Microbial restrictor |
| 4) Essence | c) Vanillin |
| Column A | Column B |
| 1) Baker’s yeast | b) Bread |
| 2) Sauerkraut | a) Probiotics |
| 3) Ligases | d) Microbial enzyme |
| 4) Penicillin | c) Antibiotics |
False
True
Azotobacter
Nowadays, probiotics are used for treatment of diarrhoea and treatment of poultry also.
The given figure represents the Modern landfill site
It is used for disposal of degradable waste in urban areas.
Methane gas is formed in landfill pits.
Microbes present in the soil decompose the waste resulting in the formation of methane gas.
i. In villages, domestic sewage is disposed of either in nearby soil or in biogas plants, whereas in cities, sewage is carried to a processing unit and acted upon by microbial processes.
ii. This sewage is acted upon by microbes that destroy the pathogens and decompose carbon and xenobiotic compounds in the sewage.
iii. The sludge that settles down in the process can be then used as fertilizer while the water released after microbial treatment is environmentally safe.
The fungus represented in the given figure is Aspergillus niger.
Sugar molasses, glucose and corn steep liquor is the source of these fungi.
Organic acids like citric acid and gluconic acid are obtained from this organism and used in commercial production.
Saccharomyces cerevisiae : Ethanol : : Aspergillus oryzae : Soya sauce
True
True
True
Sulphuric acid present in acid rain and materials coming out of mines causes metal erosion in statues, bridges and buildings.
Sulphuric acid is a source of energy for some species of bacteria like Acidiphilium spp. and Acidithiobacillus ferrooxidans.
These bacteria control soil pollution occurring due to acid rain.
Water soluble salts of uranium are present in the wastes produced during electroplating and in effluent released from atomic energy plant.
Geobacter prevent these salts from mixing with ground water by converting them into insoluble salts.
False
Vinegar means 4% Acetic acid.
Microbial inoculants are either sprayed on seeds before sowing them or can be released into plants.
Microbes in the inoculants, supply nutrients and help in plant growth. They also improve the quality of food.
A solution containing Azotobacter and artificial nitrogenase is used in organic farming.
Soil pollution caused due to chemical fertilizers can be prevented using such microbial inoculants.
Xanthan gum is added to impart thickness to instant soup.
The importance of probiotics to humans are as follows:
Probiotics are healthy foodstuffs which contain active bacteria such as Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, etc.
These microbes form colonies of useful microbes in the alimentary canal and maintain the balance of beneficial intestinal micro-organisms that help in digestion, and decrease the population of harmful microbes such as Clostridium.
They also improve resistance and lower the ill effects of harmful substances formed during metabolic activities.
When we take antibiotics, the useful microbes in alimentary canal become inactive. These microbes can be made active by consuming probiotics.
Also, probiotics are used for treatment of diarrhoea.
The use of antibiotics are as follows:
Many diseases of human and other animals have been controlled due to antibiotics obtained from different types of bacteria and fungi.
Antibiotics like penicillin, cephalosporins, monobactam, bacitracin, erythromycin, gentamycin, neomycin, streptomycin, tetracyclins, vancomycin, etc. are used against various strains of gram positive and gram negative bacteria.
Rifamycin is effective against tuberculosis.
Following are the products obtained through microbial fermentation:
Commonly used beverages like coffee, cocoa, wine and cider are produced by microbial fermentation of organic substrates.
Probiotics like yoghurt, kefir, sauerkraut, miso soup, etc. are produced by microbial fermentation.
Chemicals: Organic acids like citric acid, gluconic acid, lactic acid, itaconic acid.
Antibiotics like niacin and natamycin; artificial sweeteners like aspartame and xylitol; etc.
Fluoroacetamide-like chemicals are mixed with soil due to use of chemical pesticides and insecticides in the agricultural industry.
Methane, ethanol, hydrogen gas, etc. are fuels obtained by microbial processes.
Majority of these fuels can be obtained by anaerobic decomposition of waste products such as domestic waste, agricultural waste, etc.
Ethanol is a clean fuel which is obtained during the fermentation of molasses by Saccharomyces (yeast).
The fungus Aspergillus oryzae is used to make soy sauce by fermentation.
Geobacter convert uranium to its insoluble salts.
The process of dirt removal occurs even at low temperature due to mixing of enzymes with detergents.
Chemical insecticides are poisonous and enter the food web. They have many adverse effects on humans and the environment.
On the other hand, bacterial and fungal toxins which can destroy pests and pathogens can be directly integrated into plants with the help of biotechnology.
Being toxic to insects, they do not consume the plants.
Similar to bacteria, some species of fungi and viruses are useful as pesticides. e.g. Spinosad, a by-product of fermentation is a biopesticide.
Plants produce biomass by the process of photosynthesis in which solar energy is used to prepare carbohydrates and oxygen.
Biomass includes forest residues, crop residues, etc.
For production of biofuel, biomass is harvested and transported for threshing. The residue left after threshing contains cellulose, which is later on converted to glucose.
The glucose is then converted to liquid fuel through fermentation, which is used for different purposes.
Biofuels are renewable sources of energy.
They are available in solid (dung, crop residue), liquid (vegetable oils, alcohol) and gaseous (gobar gas) forms.
Biofuels are easily available in sufficient amounts.
They are reliable fuels of the future.
Bioinsecticides are insecticides derived from natural biological agents.
Bacterial and fungal toxins which can destroy pests and pathogens can be directly integrated into plants with the help of biotechnology.
Being toxic to insects, they do not consume the plants.
Similar to bacteria, some species of fungi and viruses are useful as pesticides.
e.g. Spinosad, a byproduct of fermentation is a biopesticide.
Landfill sites are located away from the residential area.
In this method of waste disposal, large pits are dug in an open area.
These pits are lined with plastic sheets to prevent soil pollution caused by the leaching of toxic and harmful substances into the soil.
The compressed degradable waste is dumped into the pit and covered with layers of soil, sawdust, leafy waste, specific biochemicals and sometimes the bioreactors are mixed for better aeration. This completely filled pit is sealed with soil slurry.
Microbes present in soil and other layers decompose the waste. As a result, best quality compost is obtained after few days which can be removed and such sites can be reused.
Corrosion is a common problem in chemical industries. Using anticorrosive instruments increases the production cost. However, while using microbial enzymes costly anti-corrosive instruments are not required.
Microbial enzymes are active at low temperature, pH and pressure. Thus, they save energy.
Enzymes carry out specific processes due to which unnecessary byproducts are not formed. Thus, expenses on purification are minimized.
In microbial enzymatic reactions, elimination and decomposition of waste material is avoided and enzymes can be reused. Thus, microbial enzymes are eco-friendly.
Microbial inoculants are produced by the process of fermentation and are either sprayed on seeds before sowing them or can be released into plants.
Microbes in the inoculants, supply nutrients and help in plant growth. They also improve the quality of food.
A solution containing Azotobacter and artificial nitrogenase is used in organic farming.
Soil pollution caused due to chemical fertilizers can be prevented using such microbial inoculants.
Probiotics are milk products containing active bacteria like Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidium, etc.
These bacteria maintain the balance of intestinal micro-organisms by increasing the population of microbes that help in digestion and decreasing the population of harmful microbes such as Clostridium.
They also improve resistance and lower the ill effects of harmful substances formed during metabolic activities.
When we take antibiotics, the useful microbes in the alimentary canal become inactive. These microbes can be made active by consuming probiotics.
Also, probiotics are used for the treatment of diarrhoea and treatment of poultry diseases.
Biofuel is produced in the process shown in the figure.
Solid fuels: Dung, crop residue
Liquid fuels: Vegetable oils, alcohol
Gaseous fuels: Gobar gas, coal gas
For the production of biofuel, the residue left after the threshing of biomass contains cellulose, which is converted to glucose. This glucose is then converted to liquid fuel through microbial fermentation, which is used for different purposes.
Yoghurt is a milk product produced with the help of Lactobacilli.