Good morning students. Today I will be starting a new course on biochemical engineering.
The name itself indicates that it has got a bio and chemical engineering. Now, if we
see the definition; it is a branch of chemical engineering or biological engineering that
mainly deals with the design and construction of most processes that involves the biological
organism. Now, this is the course which will be jointly taken by professor Saikat Chakraborty
from chemical engineering department and me, professor Rintu Banerjee from agricultural
and food engineering engineering department.
At the outset let me tell you the course content of this particular subject. Now, if we see
the subject biochemical engineering; we can find that this subject includes basics of
biology, overview of biotechnology, diversity in microbial cells, cell constituents, chemicals
for life. It also have that kinetics of enzyme catalysis, immobilized enzymes, major metabolic
pathways that mainly includes the bioenergetics and different biosynthetic pathways, microbial
growth kinetics, design analysis and stability of bioreactors, kinetics of receptor ligand
binding, receptor mediated endocytosis, regulation of gene expression and different biological
product synthesis in the living cell and the strategy for their separation.
So, we will also learn the recovery and bio separation of the biological products. So,
this is the total course content of this particular course.
Now, as I have already defined you this biochemical engineering; it has got distinctly two part
that is, the biological portion and the chemical engineering. Now, if we see the total syllabus
or if we define this particular subject as it is a fusion of biology and chemical engineering
where the principles and techniques of chemical engineering are applied to enhance the product
formation from the biological system or the living system.
In this particular course I will be mainly concentrating towards the biology part.
Now, as biology, biochemical engineering the biology is the integral part I will be mainly
covering the fundamentals of biology and biotechnology. Now, here this particular knowledge, this
topic will include the fundamental knowledge of biology and then what is the difference
between biology and biotechnology. I’ll try to emphasis emphasize upon this particular
thing. Then, we will gradually proceed to the microbial world. As you know, cells are
the basic unit of life, from cells tissues are formed and from tissues different organs
which perform different activities of the living system.
We will also learn that how cell functions and what are the different characteristics
of the cell along with the different structure and function of the cell organelles. We will
also concentrate on the macro molecules present in the living cell which includes carbohydrate,
lipid, protein, nuclic acid and so on. Enzymes are the biocatalysts which are present in
any living cell and they catalyze the different biological function. We will also learn something
on the enzymes. We will also study the bioenergetics and different metabolic pathways which are
playing a very important and significant role in any living system.
We’ll also learn the synthesis of different biological product formation within the cell
and what are the strategies which one can adopt for maximum recovery of the yield and
we will also study some of those strategies along with few examples. Now, for this portion
what I will be covering you can refer any standard book say, that Lehninger principle
of biochemistry by Nelson and Cox, you can also study biochemistry by Stryer, microbiology
by Pelczar, cell biology by Coen and Coen D Robertis. So, these are some of the books
which you can refer. Any standard book can also be referred for these topics which I
will be covering.
Now, to start with I have told you that I will be giving you the fundamentals of biology
and biotechnology. Some ideas to start with, let us start with biology. Biology is a Greek
word which means bios is life and logos means study. So, biology can be defined as that
branch of science which deals with the study of the living things.
So, if we see obviously that terminology which is coming to this picture is the living thing.
So, how one can differentiate the living system from the non living system? There are certain
characteristics which are present in the living system and are not present in the non living
such as locomotion, growth, respiration, reproduction, metabolism and so on. So these are the some
activities which are performed by the living system or living cell.
Now, the other features of the living system are; they have the high degree of chemical
complexity and they are microscopic organization. A living system can extract transformed and
can use energy from the environment. It has got the capacity for precise self replication
and self assembly. Mechanism for sensing and responding to the alteration to their surroundings
is also one of the characteristics of life. Defined functions for each of their component
and regulated interactions among them are also the activities of living system. If we
see the life system, evolution is one of such phenomena which is very common in the life
system.
Now, if we differentiate the living and non living as I have already mentioned by having
some of the characteristics which I have already mentioned, we can easily differentiate the
non living from the living system. Virus is one of such particle which is controversial
in nature. Now, if we see the virus says we can find that, this virus behaves as a non
living particle as long as it is outside of the living cell. As soon as, it comes in contact
with the living host cell it performs certain activities through which the scientist they
are compelled to think that yes, virus is a living organism. But, it is true that virus
is an obligatory, obligate intra cellular parasite. For its normal behavior it needs
host cell. So if we see the living living cell, living
system then cell is a basic unit of the living system. If we classify the cells it can be
broadly classified into two major groups; one is called a prokaryotic cell, another
is the eukaryotic cell. Prokaryotic cells are the primitive or it does not have the
well defined nucleus which is covered by the nuclear membrane. That means pro means the
primitive, karyon means nucleus. That means it has got the the nucleus which is very primitive
in nature. Where as in case of eukaryotes, we can find that it is it has a well defined
nucleus along with a nucleus membrane. And this is called the true nucleus eu means true,
karyotes means nucleus. So this way we can differentiate prokaryotes and eukaryotes.
Now, as I have already mentioned you that, the evolution is one of the indication of
life system. So, when all the micro organisms were studied, it it has been classified into
different kingdom. We take a five kingdom classification is one of the most popular
classification of the living organism where it starts from monera which is the prokaryotic
unicellular cells. Mainly it performs its normal activity nutrition and other activities
through absorption or it can photosynthesize. It is either motile or non motile and mostly
the reproduction is through asexual means. Little bit developed species are called protists.
Protists are the eukaryotic unicellular or multicellular organism. It either take its
food or nutrition through absorption or it can ingest or it can photosynthesize if any
such pigmentation is there. Its main reproduction is either through sexual means or by asexual
means. If we further classify this protest, depending upon its development, this protist
can be once again classified into fungi plant and animal.
If we see the fungal classification, we can find that it is eukaryotic, multicellular
organism. It can absorb, it is non motile and mostly it performs its activity through
sexual means. In case of plants, it is also eukaryotic multicellular. But, in plant one
particular organelle is present called chloroplast and for which it is it can perform, it can
synthesize its own food through photosynthesis phenomena. It is mainly non motile and reproduction
is sexual means. Then, coming to this animal world we can divide it is the eukaryotic multicellular
organism. It mainly ingest the food and it is motile in nature and reproduction is through
sexual means.
Now, if we further go for this classification of three developed eukaryotic species; fungi,
plant and animal, we can further classify this fungi into different groups like; ascomycetes,
basidiomycetes and deuteromycetes. So, depending upon its development this this
fungi are further categorized into different groups.
The next is the plant kingdom. Now, when we are coming to this plant kingdom these eukaryotic
organisms can be divided into two groups based on the nature of the flowering. Now one group
is called cryptogamia or the non flowering plant, another group is called the phanerogamia
which is the flowering plant. Now, depending upon the nature of the flowering pattern,
it has been divided further into different classes. Now, in some, this in in case of
this flowering plant it is divided into three major part; one is called monocotyledons,
monocotyledons another is that dicotyledons and another is the gymnosperm. Monocotyledons
are those groups of plant which during germination, it produce only the one cotyledons are coming
from this embryo. And this is the parallel venation plant and any type of grass, grasses
belonging to this particular, belongs to this particular group the parallel venation.
Whereas in case of dicotyledons, it is the two cotyledons are coming that means a pair
of cotyledons are coming and depending upon its arrangement it is further divided into
polypetalae, gamopetalae and monochlamydeae. Now, these are the sub classes of this particular
flowering plant. The group of plants which do not contain any seed coat are coming under
the group called gymnospermae. Now, in most of the cases it has been seen that that many
of the students they do not understand the meaning of the terminologies and that is the
reason they do not feel interest on this particular subject.
So, I am trying to give you the meaning of this groupism; how it has been classified
so that you’ll understand the basics and the evolution how these plants are evolved.
Now, coming to the animal world; the animal world has been divided into two major group
depending upon the presence of back bone. That is the spinal cord. The group of organism
animals which are having this backbone are called chordates. Those which which are without
backbone are the non chordates.
So, if we further classify this animal world the non chordates can be further divided into
several phylum like protozoa, porifera, coelenterate, ctenophore, platyhelminthes, aschelminthes,
annelid, arthropoda, mollusca’s and echinodermata. So, some of the examples what in daily life
we are coming across belonging to the without backbone animals are amoeba, paramecium, sponges,
coral, sea pens, jelly fish, flatworm, round worm, pin worm, earth worm, cockroaches, snails,
octopus, star fish, sea cucumber etc etc. Those group of creature which do not possess
the backbone.
If we further classify the chordates, the organism which are having the backbone, it
can be further classified into different phylum; Pisces or the fish are one of such group which
are having backbone and it has got the fins for swimming. It has got streamlined body
and gills are present in this type of creature. Now, if we see little developed animals which
is called the amphibians. Amphibians can can be there it either it can survive in water
or in land. And it possess the lungs and it has also got heart which is three chambered.
Reptiles are those groups of creature which are also having three chambered hearts. Their
limbs are not highly modified.
And coming to the little more evolved species belongs to this phylum Aves. They have the,
this Aves means it is birds. They have the bones which are hollow in nature. It possess
feather, it can fly and they have the four chambered heart. Then the most developed species
in this world are the mammals. The mammals are the most evolved, they have the mammary
gland, their limbs are highly modified and they have the most developed brain and that
is the reason why the mammals, the Homo sapiens are considered to be the most developed species
in this world, in this universe. Now, once again the enter animal kingdom can
be divided into two major groups depending upon its nature, its certain character. Some
group including the non chordates to up to this reptile are called cold blooded animal
and Aves and mammals are considered as the warm blooded animals. Now, these are the certain
classification what I wanted to give you to to make you understand that how the living
cells are developed and and now I will be going for the transition phase of biology
and biotechnology. How to define and how biological activities are different from that of the
biotechnological activities.
If we see, I, we have already learnt about the biology and we have learned that what
is biology and how biological specimens are. Now, what are the specimens which are coming
under this living system? Now when we are defining this biotechnology, it is the fusion
of two terminologies one is the biology, another is the technology. Now, biology is the, biotechnology
is the technology based on biology especially when used in agriculture, food, medicine,
pharmaceutical, environment and any other field. The united nation convention or biological
diversity has come up with one of the most important definition of biotechnology as it
is the means where the technological application that uses biological system that is the living
organism or derivatives thereof to make or modify the products or processes for specific
use. Biotechnology has been defined by many other
ways; one of such definition is that it is the application of scientific and engineering
principles to the processing of materials by biological agent to provide goods and services.
It is the science of the future that will attract interest of many people and will bring
about a big revolution in the lives of people and will show human how to live even comfortable
life with lesser stress.
So these are the definition of biotechnology. Now, if we see the biotechnological activities
we can find that most often these fields are overlapping to each other. Now, any of the
activities say for example, environment, food, pharmaceuticals, industrial or agricultural
biotechnology if we see that, we will find that none of these disciplines are independent.
They have certain connection with each other for which we can tell that these fields are
highly interdisciplinary in nature. Say for example, plant biotechnology. This plant biotechnology
has got direct connection with agriculture; it has got direct connection with food, pharmaceuticals.
Similarly, animal biotechnology has got direct relation with agriculture. It has got direct
relation with food, pharmaceutical, microbes, plant. Microbial biotechnology has got the
connection with agricultural, food, pharmaceuticals and if we see, we can find that each of the
disciplines are overlapping to each other.
So, in other word what we can tell is that, biotechnology is an interdisciplinary science
where we are mostly concerned with a applied aspect. That is with the living cell engineering
studies are to be carried out. Thus biology and biotechnology are interrelated with each
other. But, at the same time they are different. Now how they are different? Suppose, a person
is working with some living system which has got immense application in future, in prolong
after development it has got, it may have got immense application that particular work
will not come under the activities of biotechnology. Rather, it will be a bioscience work. Similarly,
when a product or process is in the in the transition phase from laboratory to pilot
scale, pilot scale to commercial scale when any such engineering aspect or scaling of
studies are carried out for any product formation or improvement of yield or improvement of
productivity then only, we can consider that type of activities as biotechnological activities.
So, we cannot avoid the scientific development or bioscience activities from the biotechnological
work. Different disciplines which can actively involve in such activities are microbiology,
chemistry, biochemistry, genetics, molecular biology, immunology, cell biology and so on.
Any basic biological science subjects can be considered as the basic subject of biotechnological
activities. Similarly, the branches of engineering which can be can given their very important
participation are the process engineer, chemical engineering and biochemical engineering disciplines.
So, this is the branch of where the biologist and engineer should go together to make a
process or product economically viable.
Now, if we classify this biotechnology; now a day’s many of you have come across the
terminologies like red biotechnology, green biotechnology, white biotechnology and so
on. So, what are those biotechnologies? Red biotechnologies are the pharmaceuticals biotechnology
or you can consider this this branch as the, which has got direct connection with the health
care activities. Green biotechnology is otherwise known as plant biotechnology or agricultural
biotechnology. Food biotechnology is also a part of this type of biotechnological activities.
White biotechnology is the industrial biotechnology. Whatever may be the branches; whether it is
white, green or red any scientist and engineers they have the direct role on the product and
process improvement and optimization.
Thus, in a nutshell we can tell that whatever may be the living system irrespective of the
sources, whether it is the animal source, whether it is a microbial source, that microbial
sources may be also the bacterial source or the fungal source it can be the plant source.
Whatever may be the product formation, if we are going for the biotechnological activities
may be depending upon the nature of the living system; we have we will have to study the
product formation in a different way and it can have direct application in a food sector,
pharmaceutical environment and agriculture. So, whatever may be the sources has got the
direct applications to all those disciplines which has got direct link with the mankind.
Now, let us come one by one and I will give you some example to make you understand that
what is biotechnology, how a scientist can contribute and what is the role of any engineer
like you to take part in this process product formation.
Now, the examples, this plant biotechnology are the insect protected plants, herbicide
tolerant plant, disease resistant plant, improved improved food and crop quality.
Let me come one by one to each of these. Now, when you’re talking about this insect protected
plant what we are doing? We are introducing a specific gene into the genetic makeup of
a plant and that plants are able to continuously produce the protein to protect them from the
harmful insect bite. Say for example, b t toxin.
Now, b t toxin is one of the toxin which is produced by the bacillus thuringiensis. It
is a bacterial toxin protein. If we that gene to any plant system, that plant will be continuously
producing that particular protein and when any insect will come and attack that plant
because of the presence of that toxin inside the plant that pest will die. So, this inbuilt
protection offers the farmer an alternative to the use of chemical pesticide. That means
in built the toxins are there which when it comes in contact with the pest, pests are
taking care of automatically. So obviously the farmer need not have to spray
that chemical pesticide. What is actually happening if chemical pesticide application
is getting reduced? Due to the decreased uses of the chemical pesticide, beneficial bacteria
which are present can survive. In turn it helps the harmful insect plant. It maintains
or improves the crop yield. It reduces the exposure of farmer to the chemical pesticide,
soil can be protected, less exposure of good ground water, water and chemical insecticide
is also there and lower level of fungal toxin sprayed by the insect damage.
So, these are this is one of such example. If we see the another example that is the
herbicide tolerant plant. Now, when we when we are talking about this
herbicide tolerant plant; the farmers they fight against weeds by tilling using herbicide
or through a combination of these methods. Tilling exposes the valuable topsoil to wind
and water erosion and has serious long term consequences for the environment. Environmentally
conscious farmer try to reduce the tilling and limit the use of chemical herbicides.
What can be done if the the introduction of gene to the plant that confer the tolerance
to a specific herbicide can be done? A farmer can apply this herbicide in judicious amount
to control the weeds without destroying the crop. This technology allows the grower to
apply herbicide only when the presence of weeds is required. A practice which is generally
there is called the integrated pest management. It may also result in the increased use of
environmentally favorable herbicide and reduce the use of tilling.
Another approach is the disease resistant plants. Plant diseases like which include
the fungal and viral diseases can devastate both the yield as well as the crop quality.
To minimize the economic loss resulting from the plant diseases, farmer often plant more
than what they are expected to harvest. This increases in both the ways; the cost, the
fuel cost, water, fertilizer and everything is getting increased. In addition, farmers
use chemical insecticide to destroy pest such as aphids which carry the viral diseases.
Now, by introducing a small part of DNA from the virus into the genetic makeup of the plant,
the scientists are developing the crop that have in built immunity to such type of viral
diseases. This allows reduced dependence on chemical input and improves both the productivity
and crop quality.
So, these are some of the techniques. Now, what are the input food which is already available
with us. By introducing a gene through the genetic modification, beneficial changes has
already been made in some of the crops which include consistentantly high yielding oil
palm, potatoes and tomatoes with a higher content of solid making the plant more suitable
for food processing. Tomatoes or squash and potatoes with high level of nutrients such
as vitamin A C and E are already available.
Corn and soya beans containing high level of essential amino acids, potatoes with higher
level of essential amino acids, oil seed with lower level of saturated fat, garlic cloves
with more allicin which help in lowering the cholesterol level. Strawberries with increased
level of natural agents which are being studied and it has got some positive effect which
help in fighting against cancer. Slow ripening of tomatoes, crop that can grow in very cold
temperature and animal feed crops with improved level of protein content are already been
there in the market. Some work is already being done.
I will be talking to you now about another area of biotechnology which is called food
biotechnology. And genetically modified food is one of such example of food biotechnology.
Now, if we see the genetically modified food, it is of course, a controversial topic as
far as today’s world is concerned. It has got ethical concern and if we see the genetically
modified food, we can find that the exotic species can also be explode explored. Now,
suppose if, this type of attempt can be taken, suppose mango is available in summer. Instead
of getting it only in summer season, if we can get, if we can develop some species of
mango which can produce such mangoes throughout the year and if such type of attempt can be
done then how nice it will be. Those who are liking mangoes I am just telling for example,
it may be applicable for any type of any variety of vegetable or fruits which are seasonal
in nature. Now, it may be also applicable for the exotic
species to, now this is one aspect of genetically modified food. Now, very recently that genetically
engineer bringer brinjal has come to the market. Now, I am not telling that yes whether it
is good or bad. But, what I am telling, this is one type of modifications which are there.
Now, the scientist or the biochemical engineer can also participate actively in the area
of processing. Now, when the normal cereals and pulses are getting processed; irrespective
of its sources whether it is genetically modified or not but, through biotechnological activities
one can go for the better polishing technology which may retain the more and more amount
of nutrients. That means, nutrient quantity retaining of the nutrient quantity in that
cereals and pulses can be improved with the modern processes, modern processing technology,
biotechnological applications.
Another area is the environment. Biotechnology can also be applied equally to the environment.
A number of microorganisms that have been isolated, genetically isolated and genetically
modified which have the capacity of bioremediation of solid as well as liquid waste. Biodegradation,
bioaccumulation, bioaugmentations are some of the important strategical issues which
are generally used for taking care of such type of pollutants. Bioremediation is also
carried out with the help of enzymes which biodegrade and mineralize the pollutants of
environment.
Now these types of technologies are also applied to the animal system too. Now when we’re
talking about the tools in biotechnology, then we can find that genetic engineering
is one of such important tool which is playing an active role as far as today’s biotechnology
is concerned. Now, this particular tool can be applied to any branches of the living cell;
may be plant, may be animal or microbes. Through this technique we can go for the better improvement
of yield. This is one way of modification. As I have already mention you in my earlier
few slides, that when starting this lecture I have already mentioned you that evolution
is one of the indication of life. Now, in any living system the improvement
on evolution is naturally taking place. Now, when such type of changes is taking place,
sometimes the microbes which are present in this universe are automatically getting mutated.
And sometimes we are identifying some of those important microorganisms which are present
in our surroundings for better yield and those microorganisms are called the hyperactive
microorganism. By isolating that type of microorganism, we can also go for the product process development.
And whatever may be the activities which what I am talking about are coming under the umbrella
of biosciences. Now, when such type of developments are going on in the laboratory these are coming
under the banner of bioscience.
Now, if we see the different biological or technological products, it can be divided,
it can be distinctly classified into two major group; one is called the low value high volume
product, another is the high value low volume product. Now, here the low value high volume
means, here the volume of this particular product what we are manufacturing is in huge
quantity. Let us take one example that ethanol from lignocellulosics. It is the second generation
biofuel. It has got huge demand as far as today’s world is concerned.
Now, what we will be doing with this ethanol? We will be using this ethanol as the petroleum
substitute. And when we are talking about this ethanol then, we are handling the raw
material which are lignocellulosics in nature and these lignocellulosics what we are getting
is a huge amount of lignocellulosics. And from here, the ethanol which we are getting
it is also high volume. Huge quantity of ethanol we are producing but, its value is not that
high, if we see another system which is the high value and low volume. Now, in this system
what we have seen that, it is the very costly product and its volume is in a very, very
small quantity. That means, this product is produced in the living cell in a minute quantity
but, its value is very high. Say for example, taxol. Taxol is a secondary metabolite which
is produced in a very, very low quantity. And it is in the tune of microgram level and
it is present in the plant cell and if we want to go for the production of such type
of product obviously our attempt will be of what type? Then, what we are going handling
we are adopting the process for handling a huge quantity of biomass.
So, this is the reason why these types of information are very, very essential for all
of you. For those who are studying engineering, for them this information’s, why this biological
information the information of cell and its constituent is so much important. If you know,
the behavior of the cell characteristics of the cell it will be very easy for you to design
a reactor. Now, say for example, if we are taking a plant cell, if we are taking any
microbial cell, if we are taking any animal cell obviously the reactor design will not
be same as plant cell has got cell wall, microbial cell also has cell wall but, animal cell they
do not have any cell wall. They have the cell membrane. Obviously the reactor what we will
be using for microbial culture will not be the same for the plant cell culture; will
not be the same for animal cell. So, this type of information, then another
information which is very, very important is that what type of product we are producing?
Is it intra cellular or extra cellular? So, such type of information are very, very important
and through this particular this information the biological information what I will be
giving I think you will you can enrich yourself to understand the living system the living
cell and its behavior. So, with this I am concluding my today’s
lecture in the nest class I will be talking to you about a tiny particle which cannot
be seen without microscope, in our naked eye. So, that type of organisms coming to a particular
group, of a it is it is a part of the prokaryotic organism and I will be talking to you about
that type of micro creature in my next class. Thank you very much.