Biotechnology, as you would have learnt from the

previous chapter, essentially deals with industrial scale

production of biopharmaceuticals and biologicals using

genetically modified microbes, fungi, plants and animals.

The applications of biotechnology include therapeutics,

diagnostics, genetically modified crops for agriculture,

processed food, bioremediation, waste treatment, and

energy production. Three critical research areas of

biotechnology are:

(i) Providing the best catalyst in the form of improved

organism usually a microbe or pure enzyme.

(ii) Creating optimal conditions through engineering for

a catalyst to act, and

(iii) Downstream processing technologies to purify the

protein/organic compound.

Let us now learn how human beings have used

biotechnology to improve the quality of human life,

especially in the field of food production and health.

12.1 BIOTECHNOLOGICAL APPLICATIONS IN

AGRICULTURE

Let us take a look at the three options that can be thought

for increasing food production

(i) agro-chemical based agriculture;

CHAPTER 12

BIOTECHNOLOGY AND ITS

APPLICATIONS

12.1 Biotechnological

Applications in

Agriculture

12.2 Biotechnological

Applications in

Medicine

12.3 Transgenic Animals

12.4 Ethical Issues

2022-23

op gh

for increasing food production

(i)

agro-chemical based agriculture;

202

2-2

Biotechnology, as you would have learnt from the

evious chapter

, essentially deals with industrial scale

production of biopharmaceuticals and biologicals using

genetically modified microbes, fungi, plants and animals.

The applications of biotechnology include therapeutics,

diagnostics, genetically modified crops for agriculture,

ocessed food, bioremediation, waste treatment, and

energy production. Three critical research areas of

biotechnology are:

(i)

Providing the best catalyst in the form of improved

organism usually a microbe or pure enzyme.

(ii)

Creating optimal conditions through engineering for

a catalyst to act, and

(iii)

Downstream processing technologies to purify the

protein/organic compound.

Let us now learn how human beings have used

biotechnology to improve the quality of human life,

especially in the field of food production and health.

GRICULTURE

Let us take a look at the three options that can be thought

12.1

Biotechnological

Applications in

Agricultur

12.2

Biotechnological

ications i

Medici

Transgenic Anima

12.4

Ethical Issues

208

BIOLOGY

(ii) organic agriculture; and

(iii) genetically engineered crop-based agriculture.

The Green Revolution succeeded in tripling the food supply but yet

it was not enough to feed the growing human population. Increased yields

have partly been due to the use of improved crop varieties, but mainly

due to the use of better management practices and use of agrochemicals

(fertilisers and pesticides). However, for farmers in the developing world,

agrochemicals are often too expensive, and further increases in yield with

existing varieties are not possible using conventional breeding. Is there

any alternative path that our understanding of genetics can show so that

farmers may obtain maximum yield from their fields? Is there a way to

minimise the use of fertilisers and chemicals so that their harmful effects

on the environment are reduced? Use of genetically modified crops is a

possible solution.

Plants, bacteria, fungi and animals whose genes have been altered by

manipulation are called Genetically Modified Organisms (GMO). GM

plants have been useful in many ways. Genetic modification has:

(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).

(ii) reduced reliance on chemical pesticides (pest-resistant crops).

(iii) helped to reduce post harvest losses.

(iv) increased efficiency of mineral usage by plants (this prevents early

exhaustion of fertility of soil).

(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’

enriched rice.

In addition to these uses, GM has been used to create tailor-made

plants to supply alternative resources to industries, in the form of starches,

fuels and pharmaceuticals.

Some of the applications of biotechnology in agriculture that you will

study in detail are the production of pest resistant plants, which could

decrease the amount of pesticide used. Bt toxin is produced by a

bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has

been cloned from the bacteria and been expressed in plants to provide

resistance to insects without the need for insecticides; in effect created a

bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and

soyabean etc.

Bt Cotton: Some strains of Bacillus thuringiensis produce proteins that

kill certain insects such as lepidopterans (tobacco budworm, armyworm),

coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis

forms protein crystals during a particular phase of their growth. These

crystals contain a toxic insecticidal protein. Why does this toxin not kill

the Bacillus? Actually, the Bt toxin protein exist as inactive protoxins but

once an insect ingest the inactive toxin, it is converted into an active form

of toxin due to the alkaline pH of the gut which solubilise the crystals.

The activated toxin binds to the surface of midgut epithelial cells and

2022-23

BIOLOG

(ii)

organic agriculture; and

(iii)

genetically engineered crop-based agriculture.

The

Green Revolution

succeeded in tripling the food supply but yet

it was not enough to feed the growing human population. Increased yields

have partly been due to the use of improved crop varieties, but mainly

due to the use of better management practices and use of agrochemicals

mers in the developing world,

A’

of toxin due to the alkaline pH of the gut which solubilise the crystals.

The activated toxin binds to the surface of midgut epithelial cells and

202

2-2

220088

(fertilisers and pesticides). However

, for far

mers in the developing world

agrochemicals are often too expensive, and further increases in yield wi

existing varieties are not possible using conventional breeding. Is ther

any alternative path that our understanding of genetics can show so th

farmers may obtain maximum yield from their fields? Is there a way t

minimise the use of fertilisers and chemicals so that their harmful effect

on the environment are reduced? Use of genetically modified crops is

possible solutio

Plants, bacteria, fungi and animals whose genes have been altered

mani

lation are called

Genetically Modified Organisms

(

GMO

). G

plants have been useful in many ways. Genetic modification has

(i)

made crops more tolerant to abiotic stresses (cold, drou

t, salt, heat)

(ii)

reduced reliance on chemical pesticides

est-resistant crops).

(iii)

ed to reduce post harvest losses.

(iv)

increased efficiency of mineral usage

plants (this prevents ear

exhaustion of fertility of soil).

(v)

enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘

A’

enriched rice.

In addition to these use

GM has been used to cr

eate tailo

-mad

plants to supply alternative resources to industries, in the form of starche

fuels and pharmaceuticals.

Some of the applications of biotechnology in agriculture that you wi

study in detail are the production of pest resistant plants, which cou

decrease the amount of pesticide used. Bt toxin is produced by

bacterium called

acillus

huri

iens

(

for short). Bt toxin gene ha

been cloned from the bacteria and been expressed in plants to provid

resistance to insects without the need for insecticides; in effect created

bio-

sticide. Exa

les are Bt cotton, Bt corn, rice, tomato,

tato a

soyabean etc.

Bacillus thuringiensis

produce proteins th

kill certain insects such as lepidopterans (tobacco budworm, armyworm)

coleopterans (beetles) and dipterans (flies, mosquitoes).

B. thuringiens

forms protein crystals during a particular phase of their growth. Thes

crystals contain a toxic

insecticidal protein

. Why does this toxin not ki

? Actually, the Bt toxin protein exist as inactive

protoxins

once an insect ingest the inactive toxin, it is converted into an active for

209

BIOTECHNOLOGY AND ITS APPLICATIONS

create pores that cause cell swelling and lysis and eventually cause death

of the insect.

Specific Bt toxin genes were isolated from Bacillus thuringiensis and

incorporated into the several crop plants such as cotton (Figure 12.1).

The choice of genes depends upon the crop and the targeted pest, as

most Bt toxins are insect-group specific. The toxin is coded by a gene

cryIAc named cry. There are a number of them, for example, the proteins

encoded by the genes cryIAc and cryIIAb control the cotton bollworms,

that of cryIAb controls corn borer.

Figure 12.1 Cotton boll: (a) destroyed by bollworms; (b) a fully mature

cotton boll

(b)

(a)

Pest Resistant Plants: Several nematodes parasitise a wide variety of

plants and animals including human beings. A nematode Meloidegyne

incognitia infects the roots of tobacco plants and causes a great reduction

in yield. A novel strategy was adopted to prevent this infestation which

was based on the process of RNA interference (RNAi). RNAi takes place

in all eukaryotic organisms as a method of cellular defense. This method

involves silencing of a specific mRNA due to a complementary dsRNA

molecule that binds to and prevents translation of the mRNA (silencing).

The source of this complementary RNA could be from an infection by

viruses having RNA genomes or mobile genetic elements (transposons)

that replicate via an RNA intermediate.

Using Agrobacterium vectors, nematode-specific genes were

introduced into the host plant (Figure 12.2). The introduction of DNA

was such that it produced both sense and anti-sense RNA in the host

cells. These two RNA’s being complementary to each other formed a double

stranded (dsRNA) that initiated RNAi and thus, silenced the specific mRNA

2022-23

BIO

TEC

HNO

LOG

Y A

ITS

PLI

CAT

ION

create pores that cause cell swelling and lysis and eventually cause death

of the insec

Specific Bt toxin genes were isolated fr

Bacillus thuri

iensis

and

incorporated into the several crop plants such as cotton (Figure 12.1).

The choice of genes depends upon the crop and the targeted pest, as

most Bt toxins are insect-group specific. The toxin is coded by a gene

cells. These two RNA’s being complementary to each other formed a double

stranded

(

dsRN

that initiated RNAi a

nd thus, silenced the specific mRNA

a a

202

2-2

220099

gr p sp y ge

cryIAc

named

cry

. There are a number of them, for example, the proteins

encoded by the genes

cryIAc

and

cryIIA

control the cotton bollworms,

that of

cryIAb

contr

ols cor

n bor

Figure 12.1

Cotton boll: (a) destroy

eded

by boll

(

b)b)

ly mature

))

(a(a))

Pest

Resistant Plants

Several nematodes parasitise a wide variety

plants and animals including human beings. A nematode

Meloidegyne

incognitia

infects the roots of tobacco plants and causes a great reduction

in yield. A novel strategy was adopted to prevent this infestation which

was based on the process of

RNA interference

(RNAi). RNAi takes place

in all eukaryotic organisms as a method of cellular defense. This method

involves silencing of a specific mRNA due to a complementary dsRNA

molecule that binds to and prevents translation of the mRNA (silencing).

The source of this complementary RNA could be from an infection by

viruses having RNA genomes or mobile genetic elements (transposons)

that replicate via an RNA intermediate.

Using

Agrobacteriu

vectors, nematode-specific genes were

introduced into the host plant (Figure 12.2). The introduction of DNA

was such that it produced both sense and anti-sense RNA in the host

ll The t RNA’s being pl ta t ch th f d double

210

BIOLOGY

of the nematode. The consequence was that the parasite could not survive

in a transgenic host expressing specific interfering RNA. The transgenic

plant therefore got itself protected from the parasite (Figure 12.2).

Figure 12.2 Host plant-generated dsRNA triggers protection against nematode infestation:

(a) Roots of a typical control plants; (b) transgenic plant roots 5 days after deliberate

infection of nematode but protected through novel mechanism.

(a) (b)

12.2 BIOTECHNOLOGICAL

APPLICATIONS IN MEDICINE

The recombinant DNA technological processes have made immense impact

in the area of healthcare by enabling mass production of safe and more

effective therapeutic drugs. Further, the recombinant therapeutics do not

induce unwanted immunological responses as is common in case of

similar products isolated from non-human sources. At present, about

30 recombinant therapeutics have been approved for human-use the

world over. In India, 12 of these are presently being marketed.

12.2.1 Genetically Engineered Insulin

Management of adult-onset diabetes is possible by taking insulin at

regular time intervals. What would a diabetic patient do if enough

human-insulin was not available? If you discuss this, you would soon

realise that one would have to isolate and use insulin from other animals.

Would the insulin isolated from other animals be just as effective as

that secreted by the human body itself and would it not elicit an immune

response in the human body? Now, imagine if bacterium were available

that could make human insulin. Suddenly the whole process becomes

so simple. You can easily grow a large quantity of the bacteria and make

as much insulin as you need.

Think about whether insulin can be orally administered to diabetic

people or not. Why?

2022-23

BIOLOG

of the nematode.

The consequence was that the parasite could not survive

in a transgenic host expressing specific interfering RNA. The transgenic

plant therefore got itself protected from the parasite (Figure 12.2).

(a(a

))

(b(b

))

Think about whether insulin can be orally administered to diabetic

people or not. Why?

202

2-2

221100

Figure 12.2

Host

lant

-g

enerated dsRNA tri

ececec

on a

infestation:

(a) Roots of a typical control pla

s;s;

(

t t

nic plant

ys after deliberate

infection of nematode but pr

d d

h no

meme

(a(a

))

(b(b

))

12.2 B

GICA

ONS

EDICINE

The recombinant DNA technological processes have made immense impa

in the area of healthcare by enabling mass production of safe and mo

fective therapeutic drugs. Further

efef

, the

ecombinant therapeutics do n

induce unwanted immunological responses as is common in case o

similar products isolated from non-human sources. At present, abou

30 recombinant therapeutics have been approved for human-use t

world over

. In India

12 of these

e pr

esently being marketed.

ically Engineered Insulin

Management of adult-onset diabetes is possible by taking insulin a

regular time intervals.

What would a diabetic patient do if enou

human-insulin was not available

? If you discuss this, you would soo

realise that one would have to isolate and use insulin from other animal

ould the insulin isolated fr

om other animals be just as ef

fective

efef

that secreted by the human body itself and would it not elicit an immu

response in the human body

Now, imagine if bacterium were availab

that could make human insulin. Suddenly the whole process become

so simple. Y

ou can easily gr

ow a lar

ge quantity of the bacteria and ma

as much insulin as you need.