A chemical substance produced by certain microorganisms that kills or inhibits the growth of disease-causing microorganisms is called an antibiotic.
Definitions [5]
Define the following term
Zymology
Zymology is an applied science which deals with the biochemical process of fermentation and its practical uses.
Define the following term
Antibiotics
Antibiotics are chemical substances produced by microorganisms which can kill or retard the growth of other disease causing microbes even in low concentration. Antibiotic means “against life”.
Define the following terms
Superbug
"Superbug" is a term used to describe strains of bacteria that are resistant to the majority of antibiotics commonly used today.
Define bioherbicides.
Bioherbicides are living creatures such as microbes, fungi, insects, or other pathogens that are employed to restrict the population of undesired plants in agricultural fields, ponds, lakes, and so on.
Definition: Antibiotic
Key Points
Key Points: Microbes in Household Products
| Product | Micro-organisms Used | Function |
|---|---|---|
| Curd | Lactobacillus (LAB) | Converts milk into curd, increases vitamin B₁₂ |
| Butter | Streptococcus cremoris, Leuconostoc dextranicum | Gives flavour and aroma |
| Yogurt | Lactobacillus bulgaricus, Streptococcus thermophilus | Ferments milk at 40°C |
| Cheese | Streptococcus lactis, Leuconostoc, fungi | Curdling and ripening of cheese |
| Swiss Cheese | Propionibacterium shermanii | Produces CO₂, forms holes |
| Roquefort Cheese | Penicillium roqueforti | Ripening and flavour |
| Camembert Cheese | Penicillium camemberti | Soft texture and taste |
Key Points: Microbes in Industries
- Bio-active Compounds — Streptokinase (Streptococcus) = clot buster; Statins (Monascus purpureus) = lowers blood cholesterol.
- Antibiotics — Penicillin (Penicillium chrysogenum), Streptomycin (S. griseus), Erythromycin (S. erythreus), Oxytetracycline (S. aurifaciens), Bacitracin (Bacillus licheniformis).
- Alcoholic Beverages — Yeast (Saccharomyces cerevisiae) ferments cereals/fruit juices. Distilled = Whisky, Brandy, Rum; Non-distilled = Wine, Beer. Fenny = Goa's cashew wine.
- Organic Acids — Citric & Gluconic acid (Aspergillus niger), Acetic acid/vinegar (Acetobacter aceti), Fumaric acid (Rhizopus arrhizus).
- Vitamins — B₂ (Neurospora gossypii), B₁₂ (Pseudomonas denitrificans), Vitamin C (Aspergillus niger).
- Industrial Enzymes — Invertase (S. cerevisiae), Lipase (Candida lipolytica), Cellulase (Trichoderma konigii), Pectinase (Aspergillus niger).
- Gibberellins — Isolated from fungus Gibberella fujikuroi; ~15 types; used for parthenocarpy, seed dormancy breaking, flowering induction & enlarging grape fruits.
Key Points: Microbes in Sewage Treatment
- Sewage = 99.5–99.9% water + 0.1–0.5% organic/inorganic matter + microbes (bacteria, viruses, fungi, algae, etc.)
- Preliminary Treatment — Bar screens remove large solids; Grit Chamber removes sand & stones.
- Primary Treatment — Sedimentation tank settles suspended solids; reduces coliform bacteria. Removes ~50–70% solids.
- Secondary Treatment — Aerobic bacteria decompose organic matter in aeration tanks; lowers BOD by 70–80%.
- Tertiary Treatment — Anaerobic bacteria digest sludge in sludge digesters; disinfection improves water quality.
- Chlorination — Kills remaining pathogenic bacteria before water release.
- Disposal — Treated water → natural water bodies; digested sludge → proper disposal/manure.
Key Points: Microbes as Biocontrol Agents
- Meaning — Biocontrol agents are microbes that control pests by causing disease, competing with, or killing them, reducing dependence on chemical pesticides.
- Biopesticides — Safer, eco-friendly alternative to chemical pesticides. Key agents: Bacillus thuringiensis (Bt) → caterpillars, beetles; Beauveria bassiana → aphids, mites, white flies; Nosema locustae (protozoa) → grasshoppers, crickets; NPV & Granulovirus → gypsy moths, ants, wasps.
- Bacillus thuringiensis (Bt) — Dried spores mixed with water and sprayed on plants to kill butterfly caterpillars. Most widely used bacterial biocontrol agent.
- Trichoderma — A fungus that acts as a biocontrol agent specifically against soil-borne fungal plant pathogens.
- Microbial Herbicides — Phytophthora palmivora → milkweed; Alternaria crassa → water hyacinth; Fusarium spp. → most weeds; Pseudomonas, Xanthomonas, Agrobacterium → several weeds.
- Insects as Herbicides — Tyria moth controls Senecio jacobeae weed; Cactoblastis cactorum controls cacti weeds.
Key Points: Types of Biocontrol Agents
| Category | Biocontrol Agent | Target / Use |
|---|---|---|
| Insects | Ladybird beetle | Controls aphids |
| Insects | Dragonfly | Controls mosquitoes |
| Viruses | Baculoviruses (NPV) | Control insect pests like bollworm |
| Bacteria | Bacillus thuringiensis | Controls insect pests and mosquito larvae |
| Bacteria | Agrobacterium radiobacter (K-84) | Controls crown gall disease |
| Bacteria | Pseudomonas sp. | Controls fungal disease (damping off) |
| Fungi | Trichoderma sp. | Controls many plant diseases |
| Fungi | Beauveria, Metarhizium, Verticillium | Control insect pests |
| Fungi | Aschersonia aleyrodis | Controls whiteflies |
Key Points: Microbes as Biofertilizers
- Biofertilizers are living micro-organisms that improve soil fertility by increasing the availability of nutrients to plants.
- They are eco-friendly alternatives to chemical fertilizers, which degrade soil quality and reduce microbial life.
- Nitrogen-fixing microbes such as Rhizobium, Azotobacter, Azospirillum, and Frankia convert atmospheric nitrogen into usable forms.
- Legume–Rhizobium symbiosis forms root nodules that fix large amounts of nitrogen and enrich the soil for subsequent crops.
- Azolla–Anabaena symbiosis and cyanobacteria are widely used in paddy fields and significantly increase rice yield.
- Mycorrhiza (fungus–root association) enhances absorption of phosphorus and other minerals and protects plants from pathogens.
- Phosphate-solubilizing bacteria and fungi convert insoluble phosphates into forms available to plants.
- Biofertilizers improve crop yield, reduce fertilizer requirement, and help in sustainable agriculture and soil conservation.
Key Points: Vaccine Production
- Vaccines produced using recombinant DNA technology are called recombinant or subunit vaccines, such as the hepatitis-B vaccine.
- These vaccines may be protein vaccines (using specific antigens) or DNA vaccines that induce an immune response.
- Examples include hepatitis-B vaccine produced in yeast, rotavirus, dengue, HPV vaccines, and plant-based edible vaccines.
Key Points: Applications of Biotechnology in Health and Medicine
- Biotechnology has wide applications in healthcare, agriculture, industry, the environment, and genomics.
- In healthcare, it provides diagnostic and therapeutic solutions such as stem cell therapy, genetic counselling, DNA fingerprinting, and gene probes.
- Human insulin is produced using recombinant DNA technology by inserting insulin genes into bacteria like E. coli.
- Biotechnology helps in the production of vaccines using weakened or modified microorganisms to provide immunity against diseases.
- Advanced vaccines include recombinant vaccines, DNA vaccines, and plant-based (edible) vaccines.
- Oral and “melt-in-the-mouth” vaccines are modern innovations that are easy to administer and cost-effective.
- Biotechnology has significantly helped in controlling diseases like smallpox and polio and is advancing towards treating major diseases like cancer.
Key Points: Genetically Engineered Insulin
- Earlier insulin was obtained from animals, which caused allergic reactions and could not meet large-scale demand.
- Recombinant DNA technology enabled large-scale production of human insulin, first produced in 1983 as Humulin®.
- Human insulin consists of two polypeptide chains (A and B) that are produced separately in E. coli using plasmid vectors.
- The purified A and B chains are joined by disulphide bonds to form active human insulin.
Key Points: Microbes in Production of Biogas
- Biogas is a fuel gas rich in methane, produced by anaerobic microbial activity on organic waste.
- Methanogens (e.g., Methanobacterium) anaerobically digest cellulosic material and produce methane, CO₂ and H₂.
- These microbes occur naturally in sewage sludge and in the rumen of cattle, aiding cellulose digestion; cattle dung is therefore used for biogas production.
- Biogas plants use dung slurry in anaerobic tanks to generate gas for cooking and lighting, while the leftover slurry serves as a good fertiliser.
Key Points: Microbes in Sewage Treatment
| Stage / Aspect | Process Involved | Role of Microbes | Result |
|---|---|---|---|
| Sewage | Municipal wastewater containing organic matter and pathogens | Naturally present microbes | Highly polluting if untreated |
| Primary Treatment | Physical removal by filtration and sedimentation | No active microbial role | Removes debris and forms primary sludge |
| Secondary Treatment | Aeration to promote microbial growth | Aerobic bacteria and fungi form flocs | Reduces BOD significantly |
| Activated Sludge | Settling of microbial flocs | Bacteria reused or digested | Part recycled, part sent to digesters |
| Anaerobic Digestion | Sludge broken down in digesters | Anaerobic bacteria | Produces biogas and treated effluent |
Important Questions [86]
- Name the Group of Bacteria Involved in Setting Milk into Curd. Explain the Process They Carry in Doing So. Write Another Beneficial Role of Such Bacteria.
- Name the Microbes that Help the Production of the Following Product Commercially: Citric Acid
- Answer the Following Question: Why Does 'Swiss Cheese' Develop Large Holes?
- State the most important contribution of the following microbes for human welfare: Monascus purpureus
- State the medicinal value and the bioactive molecules produced by Penicillium notatum, Monascus purpureus and Trichoderma polysporum.
- Why are the fruit juices bought from market clearer as compared to those made at home?
- Name the Microbes that Help the Production of the Following Product Commercially: Penicillin
- Name the drug a patient who has undergone a successful organ transplant, has to take all his/her life.
- Answer the following question based on Meselson and Stahl's experiment on E. coli : Write the name of the chemical substance used as the only source of nitrogen in the experiment.
- State the medicinal value and the bioactive molecules produced by Trichoderma polysporum.
- State the medicinal value and the bioactive molecules produced by Monascus purpureus.
- State the most important contribution of the following microbes for human welfare: Trichoderma Polysporum
- Name the Microbes that Help the Production of the Following Product Commercially: Statin
- Given below are the list of the commercially important products and their source organisms. Select the option that gives the correct matches. List A List B S No. Bioactive Products
- Name the source of streptokinase. How does this bioreactor molecule function in our body?
- Study the given diagram of the Sewage treatment Plant (S.T.P.) and answer the question that follows:
- Answer the Following Question. Secondary Treatment of the Sewage is Also Called Biological Treatment. Justify this Statement and Explain the Process.
- Answer the Following Question. What Are 'Flocs', Formed During Secondary Treatment of Sewage?
- Answer the Following Question. What Are ‘Flocs’, Formed During Secondary Treatment of Sewage?
- Explain the Different Steps Involved During Primary Treatment Phase of Sewage.
- Explain the Function of “Anaerobic Sludge Digester” in a Sewage Treatment Plant.
- Distinguish Between the Roles of Flocs and Anaerobic Sludge Digesters in Sewage Treatments.
- What are flocs with respect to sewage treatment?
- Explain the Process of Secondary Treatment Given to the Primary Effluent up to the Point It Shows Significant Change in the Level of Biological Oxygen Demand (Bod) It
- Explain the process of sewage water treatment before it can be discharged into natural water bodies.
- Describe how do 'flocs' and 'activated sludge' help in Sewage Treatment.
- Can we use slurry of human excreta instead of cowdung slurry to produce biogas in a typical biogas plant? Support your answer giving reasons.
- How Do Methanogens Help to Generate Biogas?
- Answer the Following Question. Write Any Two Places Where Methanogens Can Be Found.
- What Are Methanogens?
- Answer the Following Question. Write Any Two Places Where Methanogens Can Be Found.
- Name the Animals in Which Methanogens Occur and the Role They Play There.
- State the difference in organic farmers approach from that of conventional pest control methods.
- How do organic farmers control pests? Give two examples.
- Name and explain the type of interaction that exists in mycorrhizae and between cattle egret and cattle.
- State the Medicinal Value and the Bioactive Molecules Produced by Streptococcus, Monascus and Trichoderma.
- Name the Bioactive Molecules Produced by Trichoderma Polysporum and Monascus Purpureus.
- How Do Mycorrhizae Act as Biofertilizers? Explain.
- Given below is a list of six micro-organisms. State their usefulness to humans. (a) Nucleopolyhedrovirus (b) Saccharomyces cerevisiae (c) Monascus purpureus (d) Trichoderma polysporum
- Mention One Advantage and One Disadvantage to a Farmer Who Uses Them.
- Name the type of association that the genus Glomus exhibits with higher plants.
- Explain the significant role of the genus Nucleopolyhedrovirus in an ecological sensitive area.
- Why are baculoviruses considered good biocontrol agents?
- Name a genus of fungi that forms a mycorrhizal association with plants.
- Name a genus of baculovirus.
- Organic Farmers Prefer the Biological Control of Diseases and Pests to the Use of Chemicals for the Same Purpose. Justify
- Give an example of a bacterium, a fungus and an insect that are used as biocontrol agents.
- How Does the Activity of Each One of the Following Help in Organic Farming? Mycorrhiza
- Many members of genus Glomus form a mycorrhizal association with plants. Elaborate how is this association beneficial to the plants.
- Organic farmer use Trichoderma as biological control agents. Explain.
- Organic farmer use Baculovirus as biological control agents. Explain.
- Give an example of a genus of virus used as narrow spectrum insecticidal biocontrol agent. How does its use serve as an aid in overall integrated pest management programme?
- How Does the Activity of Each One of the Following Help in Organic Farming? Cyanobacteria
- Your Advice is Sought to Improve the Nitrogen Content of the Soil to Be Used for Cultivation of a Non-leguminous Terrestrial Crop. (a) Recommend Two Microbes that Can Enrich the Soil with Nitrogen.
- How does the application of cyanobacteria help improve agricultural output?
- How does the application of the fungal genus, Glomus, to the agricultural farm increase the farm output?
- Farmers are often suggested to use the following organism in their crop land so as to improve the soil fertility. Explain. Rhizobium
- Farmers are often suggested to use the following organism in their crop land so as to improve the soil fertility. Explain. Anabaena
- Explain the Interrelationship Between Organic Farming and Biofertilizers, with the Help of Any Three Suitable Examples.
- Give an example of a genus of fungi that forms mycorhizal association with plants. How does the plant derive benefits from this association?
- Describe the role of primers.
- Describe the role of bacterium Thermus aquaticus in carrying the process of polymerase chain reaction.
- State the Cause of Ada Deficiency in Humans.Mention a Possible Cure for a Ada Deficiency Patient.
- Eli Lilly's contribution for diabetic patients through r-DNA technology has been overwhelmingly accepted. Explain how?
- Give a Schematic Representation of the Transformation of a Pro-insulin into Insulin.
- State the role of C-peptide in human insulin.
- Recombination DNA−technology is of great importance in the field of medicine. With the help of a flow chart, show how this technology has been used in preparing genetically engineered human insulins.
- C-peptide of human insulin is ______.
- Suggest Any Two Possible Treatments that Can Be Given to a Patient Exhibiting Adenosine Deaminase Deficiency.
- Expand the Given and Mention One Application of Each: PCR
- Write the Function of Adenosine Deaminase Enzyme.
- A cell-free method of amplifying DNA first developed in the mid 1980's revolutionised the field of biotechnology, Name the method and explain the basic steps of the technique involved.
- How does a gene therapy involving direct modification of the cells, in order to achieve a therapeutic goal is used in the treatment of ADA deficiency? Explain.
- A host cell must be made competent, before it is able to receive an rDNA. Justify.
- How did an American Company, Eli Lilly use the knowledge of r-DNA technology to produce human insulin?
- Why Do Children Cured by Enzyme-replacement Therapy Adenosine Deaminase Deficiency Need Periodic Treatment?
- Explain how recombinant human insulin was prepared in 1983 by Eli Lily an American company.
- Explain Enzyme – Replacement Therapy to Treat Adenosine Deaminase Deficiency. Mention Two Disadvantages of this Procedure.
- Describe the Steps that Are Followed During Secondary Treatment of Sewage.
- Why Does Bt Toxin Not Kill the Bacterium that Produces It, but Kill the Insect that Ingests It?
- Answer the Following Question. Describe the Roles of Heat, Primers, and the Bacterium Thermus Aquaticus in the Process of Pcr.
- Answer the Following Question. Explain the Various Steps Involved in the Production of Artificial Insulin.
- What is Gene Therapy? Name the First Clinical Case in Which It Was Used.
- Write Any Two Biochemical/Molecular Diagonostic Procedures for Early Detection of Viral Infection. Explain the Principle of Any One of Them.
- Expand the Given and Mention One Application of Each: Elisa
- Describe the role of high temperature.
Concepts [9]
- Microorganisms (Microbes) and Microbiology
- Microbes in Household Products
- Microbes in Industrial Products
- Microbes in Sewage Treatment
- Microbes in Production of Biogas
- Microbes as Biocontrol Agents
- Microbes as Biofertilizers
- Applications of Biotechnology in Health and Medicine
- Overview of Microbes in Human Welfare
