10.1
Introduction
From curd, bread and kanji to genetic engineering and recombinant DNA technology.
Biotechnology
Explore how humans use microorganisms, cells and genetic information to produce useful products in food, agriculture, medicine, industry and environmental protection—and examine the safety, equity and ethical questions that follow.
10.2
Traditional vs Modern
Natural microbial processes compared with deliberate genetic modification.
10.3
Microbes as Tools
Why bacteria, yeast and fungi are useful biotechnology organisms.
10.4
Daily-Life Applications
Agriculture, medicine, food processing, bio-enzymes and environmental protection.
10.5
Bioreactors
Fermenters, controlled growth, sterilisation, sensors and microbial growth phases.
10.6
Ethical Issues
Safety, gene flow, super-bugs, patents, biopiracy, access and fairness.
Chapter Roadmap
Start with everyday biotechnology.
Curd, bread and fermented drinks show that humans have long used microbial activity.
Curd, bread and fermented drinks show that humans have long used microbial activity.
Move from natural processes to genetic engineering.
Modern biotechnology deliberately modifies genetic material to obtain desired traits or products.
Modern biotechnology deliberately modifies genetic material to obtain desired traits or products.
Apply the technology.
GM crops, human insulin, fermented foods, bio-enzymes, bioremediation and biofuels show the breadth of biotechnology.
GM crops, human insulin, fermented foods, bio-enzymes, bioremediation and biofuels show the breadth of biotechnology.
Scale it up.
Bioreactors provide controlled conditions for large-scale microbial production.
Bioreactors provide controlled conditions for large-scale microbial production.
Ask the ethical questions.
Biotechnology can bring benefits while creating biosafety, ecological, economic and access concerns.
Biotechnology can bring benefits while creating biosafety, ecological, economic and access concerns.
10.1 Introduction to Biotechnology
Biotechnology refers to the judicious use of living organisms, such as microbes, or their cellular components, to produce substances beneficial to humans. It has developed from simple food fermentation to sophisticated genetic engineering.
Biotechnology: The use of living organisms, microorganisms or
their cellular components to produce useful substances or achieve useful outcomes for humans.
Human beings have used biotechnology for centuries through selective breeding and fermentation for products such as cheese, beer and wine. Today, microbes are also exploited to produce antibiotics, enzymes, improve food nutrition, make biofuels and develop eco-friendly products.
Genetic modification / genetic engineering / recombinant DNA technology
The chapter describes a modern branch in which genes can be taken from one organism and inserted into another to obtain a desired altered gene. Such technology can enhance production of enzymes, antibiotics, vitamins, hormones such as insulin, and other industrially significant substances.
Figure 10.1: Recombinant DNA Technology: Target gene is cut with restriction enzymes, ligated into a bacterial plasmid vector, and expressed inside host cells.
Major colour-coded areas of biotechnology
| Category | Area covered in the chapter |
|---|---|
| Blue Biotechnology | Marine and freshwater organisms; seafood supply, regulation of water-borne diseases and development of new drugs. |
| Green Biotechnology | Improvement of nutritional quality, quantity and eco-friendly products; transgenic plants for productivity and disease resistance. |
| Red Biotechnology | Medical biotechnology for products such as insulin, enzymes, antibiotics and vaccines. |
10.2 Traditional vs Modern Biotechnology
Traditional biotechnology includes simple processes used since ancient times and relies on natural microbial activity—for example, making wine, baking bread and brewing beverages.
Modern biotechnology uses scientific knowledge and molecular techniques to deliberately modify genetic material. The chapter describes gene transfer as cutting a specific gene from one organism and inserting/pasting it into another.
| Traditional Biotechnology | Modern Biotechnology |
|---|---|
| Uses natural microbial processes. | Uses molecular/genetic techniques. |
| Used since ancient times. | Developed with modern scientific technology. |
| Examples: curd, bread, wine and fermented beverages. | Examples: insulin production using bacteria; disease-resistant crops. |
| Limited control over the biological process. | Greater control over the desired genetic trait/process. |
| Does not involve deliberate gene transfer. | Involves genetic modification / gene transfer. |
Core distinction: Traditional biotechnology mainly harnesses
naturally occurring biological processes; modern biotechnology deliberately manipulates genetic
material or biological systems to achieve a chosen outcome.
10.3 Microbes as Tools in Biotechnology
Microorganisms such as bacteria, yeast and fungi are widely used in biotechnology.
Easy to growThe chapter notes that bacteria can double
their population in about 20 minutes.
Simple nutrientsThey need basic nutrients such as sugar and
nitrogen for growth.
Little spaceMillions of bacteria can be grown in a
relatively small space.
DNA manipulationTheir DNA can be manipulated to obtain
desired products or traits.
Self-replicating DNATheir genetic material can replicate as
cells multiply.
Industrial usefulnessThey can produce food products,
enzymes, medicines and other useful substances.
10.4 Applications of Biotechnology in Daily Life
The chapter identifies crop production and agriculture, medicine and health care, food processing, bio-enzymes for household cleaning, and environmental protection as major application areas.
10.4.1 Crop Production and Agriculture
Genetic engineering of crop plants can enhance stress tolerance, insect resistance, viral resistance, productivity and nutritional value. A gene is a segment of DNA that codes for specific proteins. Biotechnology can manipulate genes of interest to create recombinant DNA and genetically modified plants.
10.4.1.1 Pest-resistant crops — Bt crops
Bt toxin: A protein from the soil bacterium Bacillus
thuringiensis. The chapter states that it has insecticidal properties and targets larvae of
moths, butterflies and cotton bollworms.
1. Source
Bacillus thuringiensis naturally produces a protein toxic to certain insects.
Bacillus thuringiensis naturally produces a protein toxic to certain insects.
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2. Gene isolation
The toxin gene is identified and isolated.
The toxin gene is identified and isolated.
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3. Gene insertion
The toxin gene is inserted into plant DNA, such as cotton or corn.
The toxin gene is inserted into plant DNA, such as cotton or corn.
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4. Expression
The plant produces the protein in its leaves and stems.
The plant produces the protein in its leaves and stems.
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5. Pest protection
When a target pest feeds on the plant, the toxin enters its gut and kills it, reducing the need for chemical pesticides.
When a target pest feeds on the plant, the toxin enters its gut and kills it, reducing the need for chemical pesticides.
10.4.1.2 Improving Nutritional Quality — Golden Rice
Golden Rice is described as a genetically modified crop designed to produce high levels of beta-carotene, a precursor to vitamin A. The chapter presents it as a bio-fortified crop intended to help address vitamin A deficiency.
| Stage | Golden Rice example from the chapter |
|---|---|
| Problem | Normal rice is a good energy source but lacks vitamin A. |
| Process | Genes from maize and a soil bacterium are inserted into rice. |
| New ability | The modified rice produces beta-carotene. |
| Visible result | The grains develop a golden-yellow colour. |
| Intended benefit | The body can convert beta-carotene into vitamin A. |
10.4.2 Medicine and Health Care — Recombinant Human Insulin
The chapter uses human insulin production in bacteria as an example of genetic engineering. The overall idea is to give bacteria the genetic instructions needed to synthesise human insulin.
DNA Isolation
The human insulin gene is cut from human DNA using restriction enzymes, leaving compatible “sticky ends”.
The human insulin gene is cut from human DNA using restriction enzymes, leaving compatible “sticky ends”.
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Preparing the Plasmid
A bacterial plasmid is cut open using the same restriction enzymes, creating matching sticky ends.
A bacterial plasmid is cut open using the same restriction enzymes, creating matching sticky ends.
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Ligation
DNA ligase joins the human insulin gene to the plasmid, forming a recombinant plasmid.
DNA ligase joins the human insulin gene to the plasmid, forming a recombinant plasmid.
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Transformation
The recombinant plasmid is inserted into a bacterium, usually E. coli.
The recombinant plasmid is inserted into a bacterium, usually E. coli.
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Mass Production
Engineered bacteria are grown in a fermenter and express the insulin protein.
Engineered bacteria are grown in a fermenter and express the insulin protein.
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Extraction and Purification
The insulin is collected and purified for safe use.
The insulin is collected and purified for safe use.
10.4.3 Food Processing
Biotechnology supports large-scale production of fermented foods such as yoghurt, cheese, probiotics, buttermilk, idli, dosa and dhokla. The chapter notes that controlled microbial action can improve taste, nutrition such as probiotics for gut health, added vitamins and shelf life. Lactobacillus and yeasts are among the selected microorganisms used.
10.4.4 Bio-Enzymes — Household Cleaning
Bio-enzymes are natural proteins derived from microbes such as bacteria and fungi. The chapter highlights proteases, amylases and lipases.
| Enzyme | Target described in the chapter | Example use |
|---|---|---|
| Proteases | Proteins | Stain and laundry cleaning |
| Amylases | Starch-related food residues | Detergents and dishwashing products |
| Lipases | Fats / grease | Cleaning greasy stains |
These enzymes can work at low temperatures, saving energy and reducing reliance on harsh chemicals. The chapter also describes their use in drain openers to break down organic clogs.
10.4.5 Environmental Protection
BioremediationMicrobes, engineered bacteria or fungi break
down pollutants such as oil spills, heavy metals and pesticides.
PseudomonasThe chapter gives Pseudomonas bacteria as an
example of organisms that can degrade hydrocarbons from industrial waste.
BiofuelsMicrobial fermentation converts biomass into
renewable fuels such as ethanol, biodiesel or biogas.
10.5 Bioreactors: Powering Large-Scale Biotechnology Applications
Fermenters, also called bioreactors, are large vessels used to grow microorganisms under controlled conditions so that desired products can be produced efficiently. The chapter gives capacities of up to 100,000 litres and describes glass or steel vessels.
Fermenter / Bioreactor: A large controlled vessel in which
microorganisms are grown in nutrient medium to produce useful products on a large scale.
Why sterilisation matters
Fermenters must be sterilised before use so unwanted microorganisms do not contaminate the nutrient-rich culture.
10.5.1 Parts of a Fermenter
| Part | Function |
|---|---|
| Stirrer / Impeller | Agitates and mixes the broth so cells receive nutrients and oxygen. |
| Sparger | Provides aeration into the tank for microbes that require aerobic respiration. |
| Cooling jacket | Controls temperature by surrounding the tank with cooling water when microbial growth produces heat. |
| pH sensors | Monitor pH; the system can add a base when the broth becomes too acidic. |
10.5.2 Fermentation Process
Preparation of Culture Medium
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Sterilization of Medium and Equipment
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Preparation of Pure Microbial Culture (Inoculum)
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Growth of Microorganisms in a Fermenter under Controlled Conditions
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Extraction and Purification of Product
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Treatment and Disposal of Waste Materials
10.5.3 Growth of Microorganisms in a Fermenter
Microbial growth does not occur at a constant rate. The chapter describes a growth curve with four phases:
| Phase | What happens |
|---|---|
| Lag phase | New inoculum adapts to the environment; also called acclimatization phase. |
| Log phase | Cells divide at the optimal rate, causing rapid population growth and maximum product formation; also called exponential phase. |
| Stationary phase | Nutrients begin to deplete and metabolic waste builds up. New cells are produced while an approximately equal number die. |
| Decline / Death phase | Toxic waste becomes too high and the population decreases. |
Continuous Culture System
To avoid the decline phase, the chapter describes a continuous culture system:
- Nutrient replenishment: fresh medium is continuously added.
- Waste removal: an equal volume of spent broth is removed.
- Steady state: conditions keep microorganisms in the productive log phase.
- Automatic buffering: sensors detect pH and temperature changes and corrective action can be taken.
10.6 Ethical Issues in Biotechnology
10.6.1 Safety — Super-bugs and Ecological Imbalance
Engineering a microbe or modifying a plant introduces a new variable into an ecosystem. The chapter highlights several possible unintended consequences.
Gene flowA modified gene could move into wild plants
through cross-pollination, potentially producing difficult-to-control traits such as a
resistant “super-weed”.
Non-target organismsA toxin intended for a pest might
affect beneficial insects such as bees or butterflies and disrupt food webs.
Evolutionary pressurePests may evolve resistance to toxins
in GM crops, creating “super-bugs” that are harder to control.
10.6.2 Equity — The Global “Biotech Divide”
Patent controlPatents may restrict seed saving or access to
biological processes and products.
BiopiracyUnethical or unlawful appropriation/commercial
exploitation of biological materials native to a country without fair compensation.
Health accessExpensive biotechnology products may not reach
poorer or middle-income populations, potentially widening inequality.
Four Ethical Principles
| Principle | Meaning in the chapter |
|---|---|
| Beneficence | Doing good. |
| Non-maleficence | Do not harm. |
| Autonomy | Freedom of choice. |
| Justice and Fairness | Consider equitable distribution of benefits, risks and opportunities. |
Think like a biotechnology decision-maker: A useful technology should
be evaluated not only by what it can do, but also by its possible ecological risks, safety
requirements, access, fairness and effects on society.
Check Your Understanding — Solutions Hidden
Attempt each question first. Click Show Solution to reveal the answer.
1. Define biotechnology. Explain how microorganisms act as
“life’s engineers” giving two examples.
Biotechnology is the judicious use of living organisms such as microorganisms,
or their cellular components, to produce substances beneficial to humans. Microorganisms act as
“life’s engineers” because humans can harness their natural processes or modify them to make
useful products. Examples include curd formation using microbial action and
production of insulin using genetically engineered bacteria.
2. Differentiate between traditional biotechnology and modern
biotechnology using suitable examples.
Traditional: uses natural microbial processes and has been
practised since ancient times; examples include curd, bread, wine and fermented beverages.
Modern: uses scientific and molecular techniques to deliberately modify genetic
material; examples include bacterial insulin production and disease-resistant crops.
3. Why are fermenters used instead of open containers for
industrial production of useful substances? Give any two reasons.
Fermenters provide controlled conditions for microbial growth
and help maintain sterility, reducing contamination. They also allow control of
factors such as mixing, oxygen supply, temperature and pH and enable large-scale production.
4. Explain the importance of maintaining sterility inside a
fermenter. What problems may arise if sterility is not maintained?
Sterility prevents unwanted microorganisms from entering the nutrient-rich
culture. If contamination occurs, unwanted microbes may compete for nutrients, alter the culture
conditions, reduce product quality or interfere with the desired microbial process.
5. Study the diagram of a fermenter in the chapter. A) Identify
any two parts responsible for maintaining microbial growth. B) What is the function of the stirrer?
C) Why is oxygen supply important in some fermenters?
A) Any two: stirrer/impeller, sparger, cooling jacket, pH
sensors. B) The stirrer mixes the broth so cells receive nutrients and oxygen.
C) Oxygen is important for microorganisms that require aerobic respiration; the
sparger supplies air into the tank.
6. Data: 0 h=20, 2 h=30, 4 h=70, 6 h=140, 8 h=145, 10 h=140, 12
h=90. (a) During which time period does rapid microbial growth occur? (b) Identify the stationary
phase. (c) Suggest one reason why the population decreases after a certain time.
(a) The fastest increase occurs from 2–6
hours, with the sharpest rise between 4 and 6 h. (b) Approximately
6–10 hours is the plateau/stationary region, with the population around
140–145. (c) Nutrient depletion and accumulation of metabolic/toxic waste can
cause the population to decline.
7. Microbes are used in food production, medicine and
environmental protection. Analyse how biotechnology helps improve human life using any three
examples.
Examples: food—controlled fermentation produces yoghurt,
cheese, idli, dosa and other foods; medicine—engineered bacteria can produce
human insulin; environment—microorganisms can help degrade pollutants through
bioremediation or convert biomass into biofuels. These applications improve food availability,
health care and environmental management.
8. A scientist wants to produce insulin using bacteria. Explain
how modern biotechnology makes this possible. Why has traditional biotechnology not achieved this?
The human insulin gene is isolated using restriction enzymes, inserted into a
bacterial plasmid, joined by DNA ligase to form a recombinant plasmid, and introduced into
bacteria such as E. coli. The bacteria are grown in a fermenter, where they express
insulin, which is then extracted and purified. Traditional biotechnology relies mainly on
natural microbial processes and does not provide deliberate recombinant gene transfer, so it
cannot give bacteria the specific human insulin instructions in this way.
9. Biotechnology has helped increase food production, but some
people have ethical concerns regarding GM crops. Evaluate both advantages and concerns.
Advantages: GM crops can provide insect resistance, disease
resistance, improved productivity, stress tolerance and enhanced nutritional quality.
Concerns: gene flow to wild plants, effects on beneficial organisms, evolution
of pest resistance, patent/seed-control issues and unequal access may create ecological or
social problems.
10. Design a simple biotechnology product that can help solve an
environmental problem in your community. Describe the microorganism or enzyme, the problem it solves
and how it benefits society.
Sample design: a microbial organic-waste treatment system
using suitable decomposer microorganisms to break down biodegradable waste.
Problem: accumulation of organic waste. Microorganism:
decomposer bacteria/fungi selected for safe waste degradation. Benefit: reduces
waste volume and supports cleaner waste management. The exact organism and operating conditions
would need proper local scientific and safety evaluation.
11. Which is an example of traditional biotechnology? (a) insulin
using bacteria (b) curd from milk (c) disease-resistant crops (d) gene transfer.
Answer: (b) Preparation of curd from milk.
12. Which microorganism is commonly used in bread making? (a)
Bacteria (b) Virus (c) Yeast (d) Algae.
Answer: (c) Yeast.
13. Which condition is necessary for proper functioning of a
fermenter? (a) Contamination (b) Controlled temperature (c) Open environment (d) Absence of
nutrients.
Answer: (b) Controlled temperature. Temperature is one of the
conditions that must be controlled for microbial growth.
14. Genetic engineering mainly involves: (a) Mixing different
foods (b) Transfer of genes between organisms (c) Increasing natural microbial growth (d) Removing
microorganisms from food.
Answer: (b) Transfer of genes between organisms.
15. During which phase do microorganisms show maximum growth? (a)
Lag (b) Log (c) Stationary (d) Death.
Answer: (b) Log phase. This is the exponential phase, when
cells divide at their optimal rate and population growth is rapid.
16. Assertion: Sterility must be maintained inside a fermenter.
Reason: Contamination by unwanted microorganisms can reduce product quality. (a) Both true and R
correctly explains A (b) Both true but R not explanation (c) A true, R false (d) A false, R true.
Answer: (a). Both statements are true, and unwanted microbial
contamination can interfere with the desired culture and reduce product quality, explaining why
sterility must be maintained.
17. Assertion: Modern biotechnology allows production of insulin
using bacteria. Reason: Modern biotechnology involves genetic modification techniques. (a) Both true
and R correctly explains A (b) Both true but R not explanation (c) A true, R false (d) A false, R
true.
Answer: (a). Both statements are true, and genetic
modification/recombinant DNA techniques provide the mechanism for giving bacteria the genetic
instructions needed to produce human insulin.
Worksheets
Practice sheets for traditional vs modern biotechnology, genetic engineering, GM crops, insulin production, fermenter parts, growth curves and ethical reasoning will be added here.
Coming SoonQuick Revision
| Concept | Remember |
|---|---|
| Biotechnology | Judicious use of living organisms, microbes or cellular components to produce useful substances. |
| Traditional biotechnology | Natural microbial processes; curd, bread, wine and other fermentation. |
| Modern biotechnology | Scientific/molecular techniques including deliberate genetic modification and gene transfer. |
| Blue biotechnology | Marine and freshwater organisms and related applications. |
| Green biotechnology | Agriculture, nutrition, productivity, disease resistance and eco-friendly products. |
| Red biotechnology | Medical biotechnology, including insulin, antibiotics, vaccines and enzymes. |
| Useful microbes | Bacteria, yeast and fungi are easy to grow and can be used to produce useful substances. |
| Bt crops | Use a Bt toxin gene from Bacillus thuringiensis to protect plants against certain insect pests. |
| Golden Rice | GM rice producing beta-carotene, a precursor to vitamin A. |
| Insulin production | Restriction enzyme → plasmid → ligation → transformation → fermenter → extraction/purification. |
| Food processing | Fermented foods include yoghurt, cheese, probiotics, buttermilk, idli, dosa and dhokla. |
| Bio-enzymes | Proteases, amylases and lipases help break down proteins, starch-related residues and fats. |
| Bioremediation | Microbes break down pollutants such as oil-related hydrocarbons and other contaminants. |
| Biofuels | Microbial fermentation can produce ethanol, biodiesel or biogas. |
| Fermenter | Large controlled vessel for growing microorganisms and producing useful products. |
| Stirrer | Mixes broth so cells receive nutrients and oxygen. |
| Sparger | Provides aeration. |
| Cooling jacket | Helps control temperature. |
| pH sensor | Monitors pH and enables corrective action. |
| Lag phase | Microorganisms adapt to the new environment. |
| Log phase | Rapid/exponential growth and maximum product formation. |
| Stationary phase | Nutrients decline and waste accumulates; growth and death become approximately balanced. |
| Death phase | Toxic waste becomes too high and population declines. |
| Continuous culture | Fresh nutrients enter and spent broth leaves, helping maintain a productive steady state. |
| Safety concerns | Gene flow, non-target effects and evolutionary resistance. |
| Equity concerns | Patent control, biopiracy and unequal access to biotechnology benefits. |
| Ethical principles | Beneficence, non-maleficence, autonomy, justice and fairness. |
High-yield chain: Gene of interest → restriction enzyme → plasmid →
DNA ligase → recombinant DNA → transformed bacterium → fermenter → product → purification.
Chapter Test
A dedicated mixed test covering biotechnology applications, genetic engineering, fermenter operation, growth phases and ethical reasoning will be added here.
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