BIOTECHNOLOGY AND ITS APPLICATIONSFlame Institute

Study of use of living organisms and the substances produced due to their activities is called biotechnology.

Mostly micro-organisms are used in many industries as alcohol, enzymes, vaccines, vitamins, antibiotics, organic acids, etc. So biotechnology is controlled use of microbes for benefit of human beings. In this science, principles of biochemistry, molecular biology and microbiology are mostly used. Some important examples of biotechnology products are :

Alcohol : It is the result of yeast fermentation, which is the incomplete oxidation of complex organic compounds with the help of enzymes produced by yeast (Invertase and Zymase)

In the middle of the 19^th century, Louis Pasteur reported that alcohol, beer and butter milk are the result of yeast fermentation. Yeast fermentation is the basis of baking as well as brewing industries, besides preparation of fermented foods like idli, dosa etc.

Types of yeasts

(1) Baker’s yeast : These include the selected strains of Saccharomyces cerevisiae and Torulopsis utilis grown on molasses. They are available in the form of powder or cakes. These yeasts have ability to ferment the sugar in the dough. The carbon dioxide produced during fermentation is responsible for the leavening (i.e., raising the dough). Both CO₂ and alcohol escape during baking so that the bread and other baked products become porous and soft. The baker’s yeast is manufactured by growing the ‘stock’ strain on molasses and then collected after centrifugation and washing. These are used to flavour the food, as nutrient ingredients, to ferment and raise dough in bread making (leavening agent).

(2) Brewer’s yeast : Brewing industry produces alcoholic beverages of several types depending upon the fermenting agent and the medium. Fermenting agents are Saccharomyces cerevisiae, S. sake, S. ellipsoidens (wine yeast) and S. pireformis (ginger yeast) is a saprophytic unicellular ascomycetes fungus. Molasses is dark coloured syrup left after extraction of sugar. It still contains 30% sucrose and about 32% invert sugar (mixture of glucose and fructose).

Some other common products of yeast fermentation are :

Beer : It is produced from Hordeum vulgare (barley) malt and alcohol content is 4-8%.

Wine : Produced from grapes by fermentation and alcohol content is 10-20%.

Brandy : Produced by distillation of wine and alcohol content is 43-57%.

Gin : Produced from fermented European rye, i.e., Secale cereale.

Rum : Produced from molasses of sugarcane and alcohol content is 40%.

Industrial production of alcohol : Although industrial fermentations to produce alcohol are performed almost exclusively with S. cerevisiae, the bacterium Zymomonas mobilis is a potentially useful organism for the commercial production of alcohol. Zymomonas can permit glucose, fructose and sucrose, thus producing relatively high yields of alcohol.

Organic acids : Microbes are useful in the manufacture of a number of organic acids as follows :

(1) Acetic acid (Vinegar) : It is most important acid being produced by two step fermentation of sugarcane juice by yeast and Acetobacter aceti bacteria.

(2) Lactic acid : It was the first organic acid to be produced from microbial fermentation of lactose (milk sugar). Fermenting agents are bacteria, e.g., Streptococcus lactis and Lactobacillus and Fungi, e.g., Rhizopus. Lactic acid is used in confectionery, fruit juices, essence, pickles, canned vegetables and fish products.

(3) Citric acid : It is obtained by the fermentation of sugar syrup by Aspergillus niger and Mucor species. It is used in dyeing, engraving, medicines, flavouring and preservation of food and candies.

(4) Gluconic acid : This acid is produced, during glucose oxidation by most Aspergillus sps. and many species of other fungal genera like Penicillium, Mucor, Fusarium, Pullutaria, etc.

It is used in pharmaceuticals, food, infant feed, detergent textile, leather, photographic and concrete industries.

(5) Fumaric acid : This is obtained by the activity of Rhizopus nigricans on sugar.

Enzymes : The term ‘enzyme’ was coined by William Kuhne in 1876. Buchner (1897) found that living cells of yeast are not required for alcoholic fermentation, but their extract also causes fermentation. In dialysis process, which is used to remove small molecules from enzymes. Enzymes are the organic substances which enhance the rate of biochemical reactions (without themseleves undergoing any change). Enzymes are also called biological catalysts or biocatalysts. Enzymes can also be used outside the cell to catalyse some specific biochemical reactions to manufacture many industrial products. Out of total over 2200 enzymes known today, only a few are used in industries, medicines and food.

Enzymes obtained by microbial activity

(1) Proteases or proteolytic enzymes : Obtained from Aspergillus oryzae and Bacillus subtilis and are used in detergents to remove some proteinaceous stains on clothes.

(2) Amylases : Obtained from Bacillus subtilis, Aspergillus niger, A. oryzae etc., and are used in beer and bread making. Also used for softening starched clothes.

(3) Lactase : Obtained from Saccharomyces fragilis and Torula cremoris. Lactases convert lactose (milk sugar) into lactic acid which is responsible for coagulation of milk protein (casein).

(4) Rennin (Rennet) : Danish chemist Christian Hensen (1874) first obtained it from calf stomach and used for cheese formation.

(5) Invertase : Obtained from Saccharomyces cerevisiae and is used to prevent sandiness in dairy products.

(6) Pectinases : Obtained from Aspergillus lucherisis and used for destruction of penicillin action.

(7) Cellulase : Obtained from Myrothecium verrucaria and used in production of dextrin and fructose.

Role of enzyme in medicine

(1) Thrombin : Obtained from beef plasma and is used for blood clotting in surgical operations.

(2) TPA (Tissue Plasminogen Activator) : This enzyme is specifically used in heart patients to dissolve blood clots. Some enzymes are also used to modify protein molecules. Pig insulin has been converted to human insulin (or humulin) by the action of enzymes.

(3) Papain : This protein digesting enzyme obtained from latex of papaya, is used for making meat tender.

(4) Protein modifying enzymes : Some enzymes are known to modify proteins for human used e.g., conversion of pig insulin into human insulin and called Pseumcelin.

Vitamins : Vitamins are the organic compounds provided to the body with diet and are required for some biochemical processes in very small amounts. First vitamin was discovered by Casimir Funk in (1911) when he succeeded in isolating vitamin B₁(thiamine), the deficiency of which causes beri beri. This discovery was followed by the discovery of vitamin A by Mc Collum, vitamin D by Mellanby and vitamin C by Albert Van Szent Gyorgy. The first vitamin which was produced during fermentation was vitamin C. This fermentation was carried out by using a wild bacterium. Some important examples of microbes-produced vitamins are :

(1) Riboflavin (Vit. B₂) : It is synthesized for industrial purposes by fermentation with a filamentous yeast, Ashbya gossypii. It was produced for the first time in 1938 using the microbial fermentation. The main sources of Vit. B₂ are cereals, yeast, leafy vegetables, milk etc. It is precursor of FMN and FAD. Which act as coenzymes for dehydrogenases enzymes. It is a bitter, crystalline, odourless, yellowish brown substance essential for the growth and reproduction in animals.

(2) Cobalamine/Cyanocobalamin (Vit. B₁₂) : This vitamin is of animal protein origin like liver, meat, fish. It is not present in vegetarian diet and its deficiency causes pernicious anemia. This vitamin was isolated for the first time in 1948 from liver extract and as a by product during production of antibiotics by fermentation. The first commercial fermentation production of vitamin B₁₂ was as a by products of fermentation for streptomycin and acetone-butanol fermentation. Nowadays this vitamin is being produced by fermentation using Pseudomonas denitrificans, Bacillus coagulans, B.megatherium and propionic acid bacteria, i.e., Propionibacteria.

(3) Ascorbic acid (Vitamin C) : It is produced by a complicated modification of glucose by different species of Acetobacter. Acetobacter is helpful in dehydrogenation of
D-Sorbital and its conversion to L-Sorbose. The lattes is precursor of vitamin (or L-ascorbic acid).

Dextrins : These are soluble polysaccharides formed by simple sugars through the agency of micro-organisms like Leuconostoc mesenteroides bacteria or its enzyme called dextran sucrose. Fermentation is allowed to proceed till dextrins are obtained. Dextrans represent the 6-10% solution of dextrins. It is used in plasma transfusions.

Tissue culture : This is also a latest method of crop improvement. Besides also used in manufacture of antibiotics, alkaloids and dyes (like Shikonin, a red dye used in silk-industry and in treatment of burns is obtained from culture of cells of Lithospermum root).

Antibiotics : These are the substances of microbial origin and having antimicrobial activity or these are the chemical substances secreted by one micro-organism, which inhibit or check the growth of other micro-organisms. Antibiotics are secondary metabolites and therefore, medium is so selected that the organism is diverted to its secondary metabolism.

First antibiotic discovered was Penicillin (wonder drug), from Penicillium notatum by Sir Alexander Fleming (1928). However the term “antibiotic” was given by Waksman (1942). Waksman himself discovered two antibiotics i.e., Actinomycin (1941) and Streptomycin (1942). Main sources of antibiotics are fungi, bacteria and actinomycetes and about 7,000 antibiotics are known at this time. There are two main groups of antibiotics :

(1) Broad spectrum antibiotics are those which inhibit the growth of many pathogenic species, differing from one another in their structure.

(2) Narrow spectrum antibiotics are those which inhibit the growth of a specific pathogenic species. Different antibiotics have different modes of action, e.g., by destruction of cell membrane, inhibition of cell wall synthesis or checking protein synthesis or inhibition of nucleic acid synthesis.

Table : 10.11-1 Antibiotic produced by micro-organisms

Antibiotic	Microbial source	Action	Discovery
Penicillin	Penicillium notatum and P. chrysogenum	Inhibits growth of Pneumococcus, Streptococcus, Gonococcus; cure gonococal infection, rheumatic fever, pneumonias diseases.	Sir Alexander Flemming (1928)
Streptomycin	Streptomyces griseus	Active against acid-fast and Gram-negative bacilli, cure pulmonary tuberculosis, may injure 8^th cranial or auditory nerve.	Waksman (1942)
Chloromycetin (Chloramphenicol)	S. Venezuelae	Broad spectrum against bacterial and rickettsial infections, viral psittacosis.	Burkholder et.al. (1947)
Tetracyclines
Chlorotetracyclin (Aureomycin)	S. aureofaciens	Broad spectrum against Gram-negative organisms; cure rickettsia and some viral diseases.	Duggar (1950)
Oxytetracycline (Terramycin)	S. rimosus	Broad spectrum against bacteria, rickettsia, spirochetes, some viruses typhoid and amoebiasis; non-toxic.	Discovered in 1950
Tetracycline (Archomycin)	S. taxas (soil)	Resemble the spectrum of chlorotetracycline.
Dimethyl chlorotetracycline	S.aureofaciens’s mutant	More effective against bacterial and streptococal infections.
Macrolides
Erythromycin	S. erythraeus	Bacteriostatic to Gram-positive and some Gram-negative organisms that are resistant to penicillin; non-toxic.	Clerk (1953)
Gentamycin	Micromonospora purpurea	Effective against gram (+) bacteria.
Carbomycin	S. halstedii
Ravomycin	S. ambofaciens
Antifungal
Viridin	Gliocladium virens	Antifungal.
Nystatin	S. noursei	Used adjunct to tetracyclines.	Hazen and Brown (1953)
Griseofulvin	Penicillium griseofulvum	Inhibits growth of most of the fungi but not of bacteria; used in ringworm treatment.
Hamycin	S. Pimprei	Fungal infection like thrush.	Hindustan Antibiotics, Poona
Actinomycetin	Actinomycetes	Some saprophytic bacteria can kill Anthrax bacterium	Pasteur and Jaubert (1877)
Miscellaneous
Vancomycin (Ristocetin)	S. Orientalis	Range of activity is similar to penicillin	Discovered in 1957
Novobiocin (Cathomycin)	S. Spheroides	Antimicrobial spectrum resembles penicillin.	Discovered in 1950, 1956
Tyrothrycin	Bacillus brevis	Antibacterial, inhibits Gram-positive bacteria and cocci.	Dubois (1939)
Polymyxin A,B,C & D	Bacillus Polymyxa	Intestinal antiseptic; toxic.	Discovered in 1947
Neomycin	Streptomyces fradiae	Resembles streptomycin; but toxic to kidneys and ear.	Discovered in 1946, 1950
Viomycin	S. puniceus
Farmycetin	S. decaris
Cycloserine	S. orchidacens
Azaserine	S. fragilis	Cure leukemia; toxic to glossitis.	Moore et al (1954)
Actinomycin C & D	S. chrysomallus	Used in the treatment of willm’s tumor, embryonic tumor of kidney in children.
Fumagillin	Aspergillus fumigatus	Bacterial and wide range, spectrum includes Salmonella and Shigella sps.

Steroids : Steroids are high molecular weight complex crystallisable fatty compounds. Which are having one 5-carbon ring and three 6-carbon rings. Steroids are of wide distribution in both plants and animals. Cholesterol is one of the most important steroids of animals, which is a precursor of animal hormones (steroid hormones) like progesterone and oestrogen (female sex hormones) and testosterone (male sex hormone).

Steroids are nowadays used as valuable drugs, e.g., in treatment of hormonal disturbances, for suppressing immune response in auto immune diseases, used in formation of birth control pills or contraceptive pills (oestrogens and progesterones) and anit-inflammatories.

Rhizopus stolonifer is capable of hydroxylation, necessary for steroid synthesis. (Murray and Peterson, 1950).

Progesterone is precursor of 4 different useful steroids and the micro-organisms used in this conversion are Rhizopus arrhizus, R. stolonifer (R. nigricans), Curvularia lunata (all fungi) and a bacterium Streptomyces argenteolus.

Vaccines : The vaccines are preparations of infectious or toxic agents that have been altered so as not to cause disease. It is injected into an antibody producing organism to produce immunity in the body against diseases. The process of inoculation of vaccine is known as Vaccination and Louis Pasteur (1850) is responsible for understanding the basis of vaccination and immunization. (Edward Jenner 1790, however made earlier studies in relation to smallpox). A vaccine contains either weakened (polio, smallpox and measles vaccines) or even killed pathogens (typhoid vaccine) which have still antigens to induce antibody production. In some cases (like botulism and tetanus), toxins produced by pathogens serve as vaccines. A large number of vaccines (called first generation vaccines) against different viral and bacterial diseases have been produced.

In recent years, some new vaccines called second generation vaccines and third generation vaccines have been developed. Second generation vaccines produced by recombinant DNA technology or genetic engineering, e.g., vaccines are for Herpes virus and Hepatitis B. Third generation vaccines are produced synthetically or are synthesized vaccines, e.g., for feline leukemia virus and foot and mouth disease virus.

Insulin : It is a hormone secreted by b-cells of islets of langerhans of pancreas in human body. Insulin is a hormone of protein nature (51 amino acids), made of 2 polypeptide chains having 21 and 30 amino acids respectively and joined by disulphide bonds. Deficiency of this insulin leads to a disease called diabetes mellitus. Insulin supplied from outside can cure this disease.

Sharpy-Shafer (1916) proposed that diabetes is due to failure pancreas to secrete a chemical named insulin. Banting and Best (1921) first of all isolated insulin from dog’s pancreas and used it for curing diabetes patients. Insulin is now obtained from pancreas of slaughtered pigs and cattle. This insulin slightly differs from man’s insulin and effectively controls diabetes.

By using genetic engineering or recombinant DNA technology, insulin producing genes from human beings have been transferred into E.coli bacteria, which produce insulin called ‘Humulin’ for clinical use. This type of synthetic insulin was produced by an American pharmaceutical firm Eli-Lily on July 5, 1983.

Monoclonal antibodies : Monoclonal antibodies (Mabs) are the specialized antibodies, which are specific to only one type of antigen. Antibodies are produced in lymph nodes, spleen and liver. Antibodies are often required for research in medicine. The concept of monoclonal antibodies was put forward by Georges Kohler and Cesal Milstein in 1974 and these antibodies are produced outside the body by hybrid cell culture technique, known as Hybridoma technology. For this technology Kohler and Milstein were awarded Nobel Prize in 1984. Lymphocytes and myeloma cells fuse together to form hybridoma cells (by somatogamous fusion).

These hybridoma cells have capacity of antibody production (of lymphocytes) and rapid cell division (of cancer cells). These hybridoma cells in cultural conditions produce large quantities of specific and pure (monoclonal) antibodies, which are separated and used in cure of different diseases.

Yoghurt : Yoghurt is a form of sour milk. It is a special diet, which is prepared by fermentation of concentrated milk first with Lactobacillus bulgaricus and Streptococcus thermophilus at 40–46°C for 4 hrs. and then fermentation with yeast. America produces 75 Lac kg of yoghurt yearly.

Interferons : Interferons (antiviral proteins) were produced by Charles Weismann of Zurich University through recombinant DNA technology in E. coli in 1980.

Amino acids : An important basic amino acid, lysine is produced from diaminopimelic acid (constituent of cell wall of bacteria, e.g., E.coli) by activity of bacterium Enterobacter aerogens.

Cheese : Danish chemist Christian Hensen (1874) first obtained Rennet from calf stomach and used for cheese formation.

It is made by separating casein and fat of milk form the liquid. About 400 kinds of cheese are known which can be made from many types of milk (goats, cows, buffaloes or camels) by employing microbes under favourable conditions.

Cheese are following types

(1) Ripened Cheese : Blocks of cottage cheese are salted and placed in brine solution for a few days. Pressing helps in removing whey. Salting removes moisture and checks growth of microbes. The salt is now wiped and the cheese allowed to ripen for 1-16 months. Ripening is carried out with the help of different strains of bacteria and fungi. Roquefort Cheese, Camembert Cheese, Limburger Cheese, Swiss Cheese. Temperature is kept low during ripening. It provides a particular consistency and flavour to the cheese.

(2) Unripened/Cottage Cheese : Pasteurised skimmed milk is inoculated with cheese culture. Within 1-2 hours, rennet is added. Formerly, stomach of sheep and goat (lining has rennin) or sap of fig trees (enzyme ficin) was used. Fruit extract of Withania coagulans is also effective. Curd is placed in cloth lined porous containers for draining the whey. The left out solidified material is called cottage cheese. It can be consumed as such. Whey contains lactic acid, lactose and minerals.

(3) Soft cheese has moisture content of more than 40%.

(4) Hard cheese has lower moisture content (39% or less)

(5) Processed cheese is formed by melting, blending and emulsifying one or more types of cheese.

(6) Raw Cheese : Milk is curdled with the help of cheese culture Streptococcus lactis, S. cremoris, Leuconostoc citrovorum, etc. Curd is heated gently to separate cheese from liquid called whey. Any liquid left in cheese is allowed to drain by hanging it in cloth. It is salted and mixed with cream for marketing. Raw cheese has short shelf life.

Butter : Butter contains 80% fat, 2-6% lactose and proteins and often 2% salt. Butter is made by churning cream until the fatty globules of butter separate from the liquid buttermilk. The cream is inoculated with mixed cultures of Streptococcus lactis,
S. diacetylactic and species of Leuconostoc citrovorum and L. dextranicum.

Biosynthesis of somatostatin : This hormone is secreted from front lobe of pitutary gland. It is made up of 191 amino acid units. Ross isolated first this hormone. The individual suffers dwarfness due to its deficiency. The gene or DNA of this hormone is introduced in E.coli, near the gene which codes for
b-galactosidase.

? The concept of alcoholic fermentation dates back to 6000 BC.

? Streptomyces griseus. Produces 41 different types of antibiotics.

? Saccharomyces piriformis. Ginger Beer Yeast.

? Bacillus subtilis. Forms 60 types of antibiotics.

? Christian Hansen (1874). First to purify an enzyme, rennet.

? Selman Abraham Waksman (1888-1973). First to obtain antibiotics from Streptomyces (e.g., streptomycin), coined the term antibiotic and got Nobel Prize in 1952.

? Babes (1855). First demonstrated antibiosis. Concept was propounded by Paul Vuillemin (1889).

? In 1998 Eli Lilly and Ranbaxy launched diabetic drugs like Humapen, Humalog and protein kinase C.

? Sabin et al prepared oral vaccine known as oral polio vaccine (OPV).

? Non rabies zone in India is Lakshadweep.

Biotechnology and it’s application

When and where first time word “biotechno logy’‘ was used

(a) In 1950 in England (b) In 1960 in Holand

In olden days cheese was prepared by [BVP 2003]

(a) Aspergillus (b) Rennet enzyme

Who first realized the use of yeast in fermentation

(a) Christian Hansen (b) Louis Pasteur

Beer is obtained by the fermentation of seeds of

(a) Hordeum vulgare (b) Rice

Wine is prepared by fermentation of grape juice by

(a) Bacillus liquifaciens

(b) Penicillium roqueforti

(d) Streptococcus aureus

Curding of milk takes place by [CPMT 1991]

(a) Streptococcus lactis

(b) Streptococcus thermophillus

(d) All the above

In India, first time an international meeting on biotechnology was held in

(a) 1986 (b) 1987

Lactic acid is produced by

(a) Lactobacillus bulgaricus (b) Streptococcus lactis

Who coined the term ”antibiotics” [BHU 1985]

(a) Flemming (b) Florey

Lal Bahadur Shastri biotechnological centre is in

(a) Bombay (b) Calcutta

Which protein production was successfully introduced in coli

(a) Interferon (b) Xanthotoxin

Vinegar is produced from sugars with the help of

[MP PMT 1992; CPMT 1993]

(a) Lactobacillus (b) Acetobacter

First antibiotic isolated was [BHU 1983]

(a) Terramycin (b) Neomycin

Yeast is used in the production of

[BHU 1983; AFMC 1984; MP PMT 1990; CBSE PMT 1998]

(a) Ethyl alcohol (b) Acetic acid

Which micro-organism is used in the formation of cheese

[MP PMT 1989]

(a) Streptococcus (b) Aspergillus

Streptomycin was first isolated in 1944–45 by

[CPMT 1982, 84, 85; BHU 1986; MP PMT 2002, 03]

(a) Leeuwenhoek (b) Burkholder

What is interferon

(a) A type of plasmid (b) A type of protein

In the production of leavened bread, the following is used

[CPMT 1985]

(a) Bacterium (b) Yeast

Biotechnology is the modern branch of biology which deals with

(a) Genetic engineering (b) Biochemistry

Micro-organism used in the production of yoghurt is

(a) Salmonella sp.

(b) Lactobacillus bulgaricus

(d) Both (b) and (c)

For the manufacture of gluconic acid and citric acid, which of the following micro-organism is used [CPMT 1998]

(a) Lactobacillus bulgaricus (b) Acetobacter sp.

Raw cheese is known as

(a) Blue cheese (b) Cottage cheese

In the formation of ascorbic acid, the micro-organism used is

(a) Acetobacter (b) Streptomyces sp.

Sex hormone is a

(a) Fat (b) Protein

Streptomycin is produced by or from which micro-organism streptomycin is prepared

[DPMT 1982; MP PMT 1997, 2001,04; CPMT 2004]

(a) Streptomyces venezuelae (b) Streptomyces griseus

Chloramphenicol and erythromycin (broad spectrum antibiotics) are produced by [AFMC 1986]

(a) Streptomyces (b) Nitrobacter

Terramycin is obtained from [CPMT 1988; MP PMT 1995]

(a) Streptomyces venezuelae

(b) Streptomyces aureofaciens

(d) Streptomyces griseus

Penicillin was discovered by

[CBSE PMT 1988, MHCET 2001; Orisa JEE 2005]

(a) Waksman (b) Dubois

The enzyme diastase was identified by [RPMT 1987]

(a) S.A. Waksman (b) A. Fleming

Enzymes can be immobilised by [Bihar MDAT 1988]

(a) Cross-linking enzyme molecules

(b) Covalently attaching to a solid support

(d) All the above

Germinating barley seeds are employed in the preparation of

[EAMCET 1987]

(a) Cheese (b) Wine

Torulopsis utilis is [MP PMT 1988]

(a) A food yeast

(b) Employed for synthesis of citric acid

(d) Micro-organism that yields third generation vaccines

Dextran is used in [CPMT 1987]

(a) Bleeding (b) Blood preservation

Utility of fungi for steroid conversion was demonstrated by

[EAMCET 1988]

(a) Pasteur and Jaubert (b) Kohler and Milstein

Humulin is [AMU 1989; CBSE PMT 1999]

(a) A form of chitin (b) A powerful antibiotic

Rennet is used in [Bihar MDAT 1987; MP PMT 2002]

(a) Fermentation (b) Cheese making

Which of the following established the scientific basis of vaccination [RPMT 1985]

(a) Louis Pasteur (b) Edward Jenner

Hybridomas are employed for

[AIIMS 1986; MP PMT 2003]

(a) Synthesis of antibiotics

(b) Killing cancer cells

(d) Production of somatic hybrids

Cells obtained from cancerous tumours are known as

[AIIMS 1985]

(a) Hybridomas (b) Myelomas

Kohler and Milstein developed biotechnology for the production of [CBSE PMT 1989; MP PMT 2002]

(a) Myelomas (b) Steroid conversion

Which of the following organic acids was produced by fermentation [Bihar MDAT 1989]

(a) Oxalic acid (b) Lactic acid

Most of the Eubacteriales antibiotics come from

[RPMT 1989]

(a) Bacillus (b) Rhizobium

Vitamin B₁₂ is produced directly during the course of fermentation by [AFMC 1986; MP PMT 2002]

(a) Ashbya gossypii

(b) Rhizopus stolonifer

(d) Propioni bacteria

The process which the yeast cells perform is called

[DPMT 1992]

(a) Transpiration (b) Pastuerization

Sir Alexander Fleming extracted penicillin from

[MP PMT 1993]

(a) Penicillium citrinum

(b) Penicillium notatum

(d) Bacillus brevis

Which of the following is not an antibiotic [MP PMT 1993]

(a) Griseofulvin (b) Cephalosporin

Which one of the following pairs is not correctly matched

[MP PMT 1993]

(a) Plasmid Small piece of extrachromo- somal DNA in bacteria

(b) Interferon An enzyme that interferes with DNA replication

(d) Myeloma Antibody–producing tumor cells

Conversion of sugar into alcohol during fermentation is due to the direct action of [MP PMT 1992, 94]

(a) Temperature

(b) Micro-organisms

(d) Zymase

Cheese and Yoghurt are products of the process

[MP PMT 1994, 2003]

(a) Distillation (b) Pasteurization

Streptomycin is used to cure the diseases caused by the bacteria [MP PMT 1994]

(a) Gram-positive

(b) Gram-negative

(d) Both gram-positive and gram-negative

Yeast in an important source of [CPMT 1993]

(a) Vitamin C (b) Vitamin B

The antibiotic “chlorellin” is extracted from the genus

[CPMT 1994]

(a) Chlamydomonas (b) Chlorella

The organism used for alcohol fermentation is

[CBSE PMT 1995]

(a) Penicillium (b) Pseudomonas

Citric acid is produced by [CBSE PMT 1995, 98]

(a) Aspergillus niger (b) Streptococcus lactic

Antibiotics are produced by [MDAT Bihar 1995]

(a) Mucor (b) Penicillium

Use of living organisms or their substances in industrial processes is called

(a) Microbiology (b) Biotechnology

Sodium chloride is added during preparation of cheese as it

(a) Gives flavour

(b) Controls moisture

(d) Controls moisture and gives flavour

Rennin used in cheese industry is

[MP PMT 1995; BVP 2002]

(a) Antibiotic (b) Alkaloid

Which one of the following is not used in the production of yoghurt [MP PMT 1995, 97, 2002]

(a) Streptococcus lactis

(b) Streptococcus thermophilus

(c) Lactobacillus bulgaricus

(d) Acetobacter aceti

A compound which is produced by an organism and inhibits the growth of other organisms is called

[MP PMT 1995; AFMC 1996]

(a) Antigen (b) Antibody

Which of the following enzyme is secreted by yeast, responsible for fermentation

(a) Enolase (b) Dehydrogenase

Which one of the following is used in the baking of bread

[MP PMT 2004]

(a) Rhizopus stolonifer

(b) Zygosaccharomyces octosporous

(d) Saccharomycodes ludwigii

Chloromycetin is produced by

(a) Bordetella pertusis (b) Streptomyces venezuelae

The phenomenon of antibiotic was discovered by

(a) Fleming (b) Pasteur

Rennet enzyme was purified by

(a) A. Flemming (b) S.A. Waksman

Which of the following enzymes are used for converting corn starch into high fructose syrup

(a) Glucoisomerases (b) Glucoamylases

Which of the following participates in the manufacturing of dextrans

(a) Lactobacillus (b) Leuconostoc

Steroids are used in

(a) Birth control

(b) Treatment of hormonal balance

(d) All of these

Vaccine for small pox was developed by

(a) Cesor Milstein (b) Louis Pasteur

Which of the following is used in biotechnology

(a) Cattle (b) Yeast

Woodruf (1941) were responsible for the isolation of

(a) Neomycin (b) Actinomycin

Waksman got Nobel Prize for the discovery of

(a) Chloromycetin (b) Neomycin

nif genes occur in [MP PMT 1996]

(a) Rhizobium (b) Penicillium

Neomycin is extracted from [EAMCET 1993]

(a) Streptomyces griseus

(b) Streptomyces venezuelae

(d) Streptomyces rimosus

Interferons are [CBSE PMT 1996]

(a) Antiviral proteins

(b) Complex proteins

(d) Anti–cancer proteins

Antibiotics are [MP PMT 1996]

(a) Herbicides (b) Pesticides

The drug streptomycin inhibits the process of

[MP PMT 1996]

(a) Procaryotic translation (b) Eucaryotic translation

An antiviral chemical produced by the animal cell is

[MP PMT 1996]

(a) Virion (b) Interferon

Anand Chakrabarty has used biotechnology for

(a) Production of insulin

(b) Removal of oil pollution

(d) Production of relaxin

Streptococcus thermophilus and Lactobacillus bulgaricus are being used for the production of [MP PMT 1997]

(a) Cheese (b) Yoghurt

Which of the following is an antifungal antibiotics

(a) Penicillin (b) Cephalosporin

From which of the following LSD is obtained

(a) Mucor (b) Spirogyra

Which of the following antibiotics is found to be most effective against mycoplasma

(a) Penicillin (b) Streptomycin

Which one of the following systems commonly used in alcoholic fermentation

(a) Bacterial system (b) Algal system

Milk is converted into curd (yoghurt) by biological activity of

(a) Algal cells (b) Fungal cells

Cheeses are usually classified on the basis of

[MP PMT 1997]

(a) Texture (b) Flavour

Which one of the following is used in the manufacture of alcohol [MP PMT 1997]

(a) Bacteria (b) Water molds

Antibiotics are mostly obtained from

[MP PMT 1997; AIEEE 2003]

(a) Fungi (b) Actinomycetes

Penicillin is obtained from [MP PMT 1997]

(a) Aspergillus fumigatus

(b) Penicillium chrysogenum

(d) Streptomyces griseus

The name of drug used in cancer treatment produced by biotechnology is [MP PMT 1998]

(a) Interferon (b) HGH

The main technique involved in agricultural biotechnology is called [MP PMT 1998]

(a) Tissue culture (b) Transformation

The new strain of bacteria produced by biotechnology in alcohol industry is [MP PMT 1998]

(a) Escherichia coli

(b) Saccharomyces cerevisiae

(d) Pseudomonas putida

Important objective of biotechnology in agriculture section is

[MP PMT 1998]

(a) To produce pest resistant varieties of plant

(b) To increase the nitrogen content

(d) To increase the plant weight

Yeast is an important source of [MP PMT 1999]

(a) Vitamin C (b) Riboflavin

Saccharomycetes cerevisae is [MP PMT 1999]

(a) Akaryote (b) Prokaryote

Antibiotic flavicin is obtained from [MP PMT 1999]

(a) Aspergillus flavus (b) Aspergillus clavatus

Which of the molecules listed below is a product of fermentation of glucose by yeast [MP PMT 1999]

(a) (C₆H₁₀O₅)n (b) C₂H₅OH

The micro-organism grown on molasses and sold as a food flavouring substance is [MP PMT 1999]

(a) Sacchromycetes (b) Rhizopus

Due to which of the following organism, yield of rice is increased [CBSE PMT 1999]

(a) Anabena (b) Bacillus popilliae

Alcoholic beverages are obtained with the help of

[Karnataka CET 1998]

(a) Penicillium (b) Yeast

Immobilised enzymes are generally used for bioreactors in

[AIIMS 2001]

(a) Batch process (b) Digestive process

Cheese is prepared from [MP PMT 2001]

(a) Lactobacillus

(b) Streptococcus

(d) Streptococcus and Lactobacillus

Streptomyces fradiae produces [MP PMT 2001]

(a) Erythromycin (b) Neomycin

The vaccine of Hepatitis-B is a [DPMT 1988; MP PMT 2003]

(a) First generation vaccine

(b) Interferon

(d) Third generation vaccine

Ethyl alcohol is commercially manufactured from

[BHU 2004]

(a) Wheat (b) Grapes

Which one of the following is used in the baking of the bread [MP PMT 2004]

(a) Rhizopus stolonifer

(b) Zygosaccharomyces

(d) Saccharomycodes ludwigii

Antibiotics occur from [MP PMT 2004]

(a) Medicines (b) Toxins

Dough kept overnight in warm weather becomes soft and spongy because of [CBSE PMT 2004]

(a) Cohesion

(b) Osmosis

(d) Fermentation

Which one of the following pairs is not correctly matched

[CBSE PMT 2004]

(a) Spirulina – Single cell protein

(b) Rhizobium – Biofertilizer

(d) Serratia – Drug addiction

Which one of the following is the correctly matched pair of a product and the microorganism responsible for it

[AIEEE 2004]

(a) Ethyl alcohol – Yeast

(b) Acetic acid- Lactobacillus

(d) Curd – Azotobacter

Ergot, which is an important source of a drug is obtained from [AIEEE 2004]

(a) Agaricus (b) Claviceps

Which of the following organism is useful in the preparation of roquefort cheese [BHU 2004]

(a) Mucor (b) Rhizopus

Streptococcus is employed in the manufacturing of

[BVP 2004]

(a) Wine (b) Bread

Which raw material is used in fermentation

[Orissa JEE 2005]

(a) Starch in vegetables (b) Starch in cereals

Butter is produced from [Manipal 2005]

(a) Propanoic acid (b) Butyric acid

Which row material is used in farmentation process of making beer [Orissa JEE 2005]

(a) Buffer needed to control pH

(b) Batch and feed possible

(d) Easy in process sampling

The bread is soft and porous when the yeast cells are mixed in the lump of wheat flour because [CPMT 1976]

(a) Yeast produce benzoic acid

(b) Evolution of CO₂ makes the bread spongy

(d) Yeast produces acetic acid and alcohol which give softness to the bread

Broad spectrum antibiotic is that which [AMU 1985]

(a) Acts on both pathogens and hosts

(b) Acts on all bacteria and viruses

(d) Is effective in very small amounts

Antibiotics inhibit the growth of or destroy

[Bihar MDAT 1988]

(a) Bacteria and fungi

(b) Bacteria and viruses

(d) Bacteria, fungi and viruses

The fruit juices turn bitter in taste if they are kept in open place for some time, because of [CPMT 1977]

(a) Bacteria of the atmosphere react with the juice

(b) Fermentation of the juice by yeast

(d) All the above three statements are correct

Most of the micro-organisms which produce antibiotics live in the soil because

(a) Darkness favours synthesis of antibiotics

(b) By the phenomenon of antibiosis, their growth, nutrition and survival value are enhanced in competitive world of microflora of the soil

(d) No one easily misuse their antibiotics

The prerequisites for biotechnological production of antibiotics is [MP PMT 1998]

(a) To search an antibiotic producing microorganism

(b) To isolate the antibiotic gene

(d) All of the above

Hybridomas are the result of fusion of

(a) Male reproductive cells

(b) Female reproductive cells

(d) Abnormal antibody producing cells with myeloma

Trichoderma reesei is being used for the

(a) Industrial production of cellulase

(b) Biological control of plant diseases

(d) Industrial production of amylase

Hybridoma cells are [CBSE PMT 1999]

(a) Nervous cells are

(b) Hybrid cells resulting from myeloma cells

(d) Product of spore formation in bacteria

Read the assertion and reason carefully to mark the correct option out of the options given below :

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

(e) If the assertion is false but reason is true

Assertion : Yeasts such as Saccharomyces cerevisiae are used in baking industry.

Reason : Carbon dioxide produced during fermentation causes bread dough to rise by thermal expansion. [AIIMS 2003]

Assertion : The kneaded flour shows leavening, when yeast is added to it.

Reason : Enzymes secreted by yeast cause leavening.

Assertion : Curdling is required in the manufacture of cheese.

Reason : Lactic acid bacteria and rennet is used for the purpose.

Assertion : Enzymes application in industry is enhanced by its immobilization.

Reason : Immobilization provides protection to enzymes without affecting their activity.

Assertion : Extraction and purification of enzymes is laborious and expensive.

Reason : Protein engineering can be used to produce enzymes at large scale.

Assertion : The antibodies separted from serum are homogenous.

Reason : Monoclonal antibodies are homogenous immunological reagents.

Assertion : Vitamins is found in cereals, green vegetables, brewer’s yeast, egg white, milk and liver.

Reason : It can be commercially produced by some yeasts.

Assertion : Acetic acid is prepared by acetic acid bacteria.

Reason : Alcoholic fermentation and the conversion of alcohol to acetic acid are aerobic processes.

Assertion : Interferons are effective against viruses.

Reason : Proteins which can be synthesized only by genetic engineering are effective against viruses.

Biotechnology and it’s application

1	c	2	b	3	b	4	d	5	c
6	d	7	c	8	d	9	d	10	c
11	a	12	b	13	c	14	a	15	d
16	d	17	b	18	b	19	d	20	d
21	c	22	b	23	a	24	d	25	b
26	a	27	c	28	d	29	d	30	d
31	c	32	a	33	c	34	c	35	d
36	b	37	a	38	c	39	b	40	c
41	b	42	a	43	d	44	c	45	b
46	c	47	b	48	d	49	c	50	d
51	b	52	b	53	d	54	a	55	b
56	b	57	b	58	c	59	d	60	c
61	c	62	c	63	b	64	d	65	d
66	d	67	b	68	d	69	c	70	c
71	b	72	c	73	a	74	c	75	a
76	d	77	a	78	b	79	b	80	b
81	c	82	d	83	c	84	c	85	d
86	d	87	c	88	d	89	b	90	a
91	a	92	c	93	a	94	b	95	d
96	a	97	b	98	a	99	a	100	b
101	d	102	d	103	b	104	c	105	d
106	a	107	a	108	d	109	d	110	a
111	b	112	d	113	c	114	b	115	b
116	c

Critical Thinking Questions

1	b	2	c	3	d	4	b	5	b
6	d	7	c	8	a	9	b

Assertion and Reason

1	a	2	a	3	b	4	a	5	b
6	e	7	b	8	c	9	c

Biotechnology and it’s application

(b) In old days, cheese was prepared by using the enzyme “rennet” from the lining of stomach of sheep and goat.
(b) In the middle of the 19th century, Louis Pasteur reported that alcohol, beer and butter milk are the result of yeast fermentation.
(d) Lactic acid is produced from microbial fermentation of lactose (milk sugar). Fermenting agents are bacteria, e.g., streptococcus lactis and Lactobacillus and fungi, e.g., Rhizopus.
(d) The term ‘antibiotic’ was given by Waksman (1942).
(a) Interferons (antiviral proteins) were produced by Charles Weismann through recombinant DNA technology in E. coli in 1980.
(b) Vinegar is most important acid being produced by two step fermentation of sugarcane juice by yeast and Acetobacter bacilli bacteria.
(c) First antibiotic isolated was panicillin (wonder drug), from Penicillium notatum.
(a) Yeast is used in the industrial production of ethanol (alcohol). When yeast is added to sugar solution, it causes fermentation and forms alcohol.
(d) Lactic acid bacteria acts on lactose which present in milk and converts it into cheese.
(d) S.A. Waksman (1944) discovered streptomycin from the bacterium Streptomyces griseus.
(b) Interferon is a protein which is released by host cells when a virus enters the cell.
(d) Biotechnology includes use of living organisms or substances obtained from them, in industrial processes. It is an integrated use of different disciplines like microbiology, biochemistry and chemical engineering.
(d) Yoghurt is a form of sour milk. It is a special diet, which is prepared by fermentation of concentrated milk first with Lactobacillus bulgaricus and Streptococcus thermophilus at 40–46°C for 4 hrs.
(c) Gluconic acid is produced, during glucose oxidation by most Aspergillus sps. and citric acid is obtained by the fermentation of sugar syrup by Aspergillus niger.
(b) If cheese is used as a unripened stage, it is called cottage cheese.
(a) Ascorbic acid (vitamin C) is produced by a complicated modification of glucose by different species of Acetobacter.
(d) Steroid hormones are of wide distribution in both plants and animals. Cholesterol is one of the most important steroids of animal, which is precursor of animal hormones (steroid hormones) like progesterone and oestrogen (female sex hormones) and testosterone (male sex hormone).
(b) Streptomycin is produced from Streptomyces griseus. Streptomycin inhibits the bacterial protein synthesis by affecting 30S subunit of ribosome.
(a) Chloramphenicol is obtained from Streptomyces venezuelae (Ehrlic et. al, 1947) and erythromycin obtained from Streptomyces erythraeus (Clerk, 1953)
(d) Alexander Flemming (1929) discovered the antibiotic penicillin and showed its effectiveness against many disease producing bacteria.
(d) By cross linking enzyme molecules or by covalently attaching them to a solid support or by entrapping them in gel, metabolic activities of enzymes are stopped.
(c) Beer is produced from Hordeum vulgare (barley seed) malt and alcohol content is 4-8%.
(a) Common food yeast is Torulopsis utilis. It is cultured over molasses and starchy materials like Potato at 5 PH.
(c) Dextran is a complex polysaccharide and dextran plays an important role in plasma transfusions.
(c) Rhizopus Stolonifer is capable of hydroxylation, necessary for steroid synthesis, (Murray and Peterson 1950).
(d) The first commercial example of enzyme modification of a protein for human use is the conversion of pig insulin to human insulin called “humulin”.
(b) Rennet is obtained from calf stomach and used in the preparation of cheese.
(a) The process of inoculation of vaccine is known as vaccination and Louis Pasteur (1850) is responsible for understanding the basis of vaccination.
(c) Monoclonal / Magic antibodies are pure antibodies against a particular which are obtained through Clonal culture of hybridoma.
(c) In biotechnology monoclonal antibodies (Mabs) are the specialize antibodies, which are specific to only one type of antigen. The concept of monoclonal antibodies was put forward by Georges kohler and Cesal Milstein in 1974.
(b) First organic acid (lactic acid) to be fermented, which obtained by the activity of a number of bacteria like Streptococcus lactis, Lactobacillus delbreukii, and Rhizopus fungus.
(a) Bacillus eubacteriales / simple bacteria is main source (about 70%) of antibiotics production and 30% antibiotics produced from pseudomonas.
(d) This Vitamin is now being produced during fermentation by Propioni bacteria (bacteria which synthesize propionic acid) and certain strains of Pseudomonas.
(c) Yeasts are cultured on the nutrient medium generally of on fermentation.
(b) First antibiotic penicillin from blue – green fungus Penicillium notatum in agar – agar medium, contributed by Sir Alexander Flemming in 1928.
(b) Interferons antiviral proteins were produced by “Charles Weismann” (1980) by recombinant DNA technology in E. coli.
(c) Cheese and yoghurt is nutritive product of milk which formed by fermentation process.
(d) Brewing industry produces alcoholic beverages of several types depending upon the fermenting agent and the medium. Fermenting agents are Saccharomyces cerevisiae, S. sake, S. ellipsoidens (wine yeast) and S. pireformis, (ginger yeast).
(a) Citric acid produced by aerobic fermentation of sucrose in beet molasses by Aspergillus niger fungus.
(d) Because Acetobacter aceti is used in the production of vinegar.
(c) Invertase enzyme is obtained from Saccharomyces cerevisiae and is used to bread baking is also called baker’s yeast.
(b) Chloromycetin / Chloramphenicol obtained from Streptomyces venezuelae which is broad spectrum against bacterial and viral psittacosis. It discovered by Ehrlic et. al. (1947)
(d) Rennet enzyme was purified 1st time Christian Hensen (1874) from calf stomach and used for cheese formation.
(b) Sucrose by activity of Leuconostoc mesenteroides bacteria, gives rise to a complex polysaccharide called dextran.
(d) Steroids are fatty compounds, reported Murrey and Patterson (1950). Which used for hormonal imbalance, birth control Pills, antifertility properties and immune responses.
(c) The process of inoculation of vaccine is known as vaccination and Edward Jenner 1790 however made earlier studies in relation to smallpox.
(c) Waksman (1942) got nobel prize for the discovery of two antibiotics i.e., Actinomycin and Streptomycin.
(a) ‘nif‘ is nitrogen fixation genes and occur in Rhizobium.
(c) Neomycin obtained from Streptomyces fradiae. It against acid-fast and gram negative bacilli but toxic to kidneys and ear.
(a) Interferons are active proteins (Antiviral proteins) that are effective against most viruses.
(d) Antibiotics are the substances which are produced by micro-organism for killing or inhibiting the growth of micro-organism.
(b) Yoghurt / yogurt produced by curdling of milk with the help of Streptococcus thermophilus and Lactobacillus bulgaricus at 40–46°C for four hours.
(c) Griseofulvin is source of Penicillium griseofulvum. It is antifungal in nature, especially for ringworm.
(c) Alcohol is the result of yeast fermentation, which is the incomplete oxidation of complex organic compounds with the help of enzymes (Invertase and Zymase) produced by yeast.
(d) Antibiotics are obtained from lichens, fungi, eubacteria, actinomycetes.
(b) Penicillin is obtained from Pinicillium notatum and Pinicillium chrysogenum. (Sir Alexander fleming 1928)
(a) The tissue culture is a latest method of crop improvement. Besides also used is manufacture of antibiotics, alkaloids and dyes.
(b) Riboflavin (Vit. B₂) is synthesized for industrial purposes by fermentation with a filamentous yeast, Ashbya gossypii.
(b)
(d) Immobilisation of enzymes is the process of fixing enzyme to or enclosing it in a solid support so as to protect it from deactivation and attack from proteases, maintain enzyme purity, ability to recover it after reaction and perform continuous reaction.
(d) Cheese is prepared from milk with the help of Streptococcus lactis, S. Cremoris, Leuconostoc citrovorum, Lactobacillus sp. etc.
(b) Neomycin obtain from Sterptomyces fradiae which acts against gram negative bacilli and some Gram positive bacteria.
(c) Second generation vaccines are produced by recombinant DNA technology or genetic engineering e.g., vaccine for Herpes virus and Hepatitis – B.
(d) Sugarcane (Saccharum officinarum) is the main source of commercial ethyl alcohol. Source is extracted from the juice of sugarcane as a commercial product, but this leaves a syrup called molasses which contains glucose and fructose. Ethanol is produced by the fermentation of molasses by using yeast Saccharomyces cerevisiae.

Critical Thinking Questions

(b) Selected strains of Saccharomyces are used as Baker’s yeast. It is available as powder or cake. The same is added to flour during kneading. Yeast secretes amylase (Changes some starch to maltose), maltase (maltose to glucose) and Zymase (glucose to ethyl alcohol and ). The dough swells up or leavens. Leavened dough is baked. Both alcohol and evaporate. The bread becomes soft and porous.
(c) It is an antibiotic which can kill or destroy a number of pathogens that belong to different groups with different structure and wall composition.
(d) Clinically, an antibiotic is a substance proudced by a micro-organism which in low concentration inhibits the growth and metabolic activity of pathogenic organisms without harming the host.
(c) Lymphocytes cells are mixed with myeloma cells (tumour cells isolated from cancer of bone marrow). Lymphocytes and myeloma cells fuse together to form hybridoma cells. These hybridoma cells have capacity of antibody production and rapid cell division.
(b) A myeloma is a type of cancer associated with abnormal production of irregular antibodies. It occurs in antibody producing cells that have lost their normal control. Clones of the hybrid cell resulting from artificial fusion of a normal antibody producing B cell with myeloma cell are called hybridomas.

Assertion and Reason

(a) Bakers yeast (saccharomyces cerevisiae) is added to flour during kneading. Yeast secretes enzymes like amylase (change some starch to maltose), maltose (maltose to glucose) and zymase (glucose to ethyl alcohol and ). Leavened dough is baked and both alcohol and The bread becomes soft and porous.
(a) A small quantity of yeast is added to wheat flour. The same is kneaded. The kneaded flour is kept at a warm temperature for a few hours. It swell up. The phenomenon is called leavening. Leavening is caused by secretion of three types of enzymes by yeast. They are amylase, maltase and zymase.
(b) The manufacture of cheese requires two main steps curdling and the ripening. Curdling the milk proteins forms a solid material from which the liquid is drained away. The curdling process may be exclusively microbiological, since acid production of lactic acid bacteria is sufficient to coagulate milk proteins. However an enzyme known as rennin (extracted from the stomachs of calves or rennet) which curdles milk is often used for this purpose.
(a) An immobilized enzymes is physically entrapped or covalently bonded by chemical means to an inert and usually insoluble matrix, where it can act upon its natural substrate. The matrix is usually a high molecular weight polymer such as polyacrylamide, cellulose, starch, glass, beads, etc. Because of its binding with a matrix the immobilized enzyme has better stability in many cases. Efficiency of immobilized enzyme is better. The enzyme can be recovered at the end of the reaction and can be used repeatedly.
(b) Although thousands of proteins have been characterized in prokaryotes and eukaryotes, only few became commercially important. This is due to the high cost of isolating and purifying enzymes in sufficient quantities. Through recombinant DNA technology, a protein can be obtained in abundant quantity the objectives of protein engineering are to create superior enzymes to catalyze production of high value specific chemicals and to produce enzymes for large scale use.
(e) From hyperimmunized animals, the blood serum may be taken and antibodies may be isolated from this serum. However, the antibodies, whenever separated from serum after induction due to an antigen, are usually heterogenous, because the cells keep on producing a variety of antibodies. Monoclonal antibodies (Mabs), on the other hand are homogeneous immunological reagents of defined specificity so that these can be utilized for diagnosis and screening with ease and certainty.
(b) Besides cereals, green vegetables, brewer’s yeast, egg white, vitamin is also produced by intestinal bacteria. The vitamin was first obtained in 1938 using wild strain of mould Ashbhya gossypii. Vitamin is essential for normal growth and reproduction in a number of laboratory animals.
(c) Acetic acid is prepared from fermented alcohols with the help of acetic acid bacteria, Acetobacter aceti. Alcoholic fermentation is anaerobic process but the conversion of alcohol to acetic acid is aerobic one.
(c) Interferons are proteins that are effective against most viruses. They are naturally produced by virus infected cells. The proteins interact with adjacent cells and make them resistant to virus attack. Now interferons are also being manufactured through genetic engineering.