Biotechnology is the field of science that involves the use of biological systems, living organisms, or their derivatives to make products useful for mankind. Biotechnology helps us address many problems such as infectious diseases, improving food quality, fossil fuel shortage, etc. As the population is increasing and natural resources are decreasing, biotechnology helps us find alternative sources. Biotechnology plays a crucial role in meeting our everyday life requirements. Biotechnology has been providing services in almost every field like healthcare, food industry, winemaking, dairy products, textile industry, and bioremediation for a long time. Today, when the whole world is suffering from COVID-19, biotechnology is playing an important role in vaccine production.
Biofuels are derived from biomass like plant, animal waste, and algae material. With the increase in fuel prices and depletion of fossil fuels, biofuel production through bitechnology can play a crucial role. Biofuels act as a renewable source of energy and are environmental friendly as they prevent green house gas emission. Examples of biofuel are ethanol, biodiesel, and biogas.
Ethanol is a colourless liquid biofuel produced by the fermentation of starch present in crops like maize, sugarcane etc. Brazil and the United States are the main producers of ethanol. The United States uses food grains with high sugar content like sugarcane, barley, and sorghum as feed stocks for making ethanol. In US, 10 % ethanol is used in blend with gasoline to form ‘gasohol,’ a mixture of petrol and ethanol used as fuel in internal combustion engines.
Biodiesel is a domestically produced biofuel manufactured from vegetable oils, animal fats, etc. It helps in clean-burning of fuel and acts as renewable substitute for petroleum diesel. Using biodiesel in vehicles reduces environmental pollution, thus it improves air quality. Biodiesel is made through a process called transesterification of trigylcerides present in the fatty acids. Transesterification of vegetable oil by ethanol produces biodiesel and glycerine. In some countries like india, biodiesel is produced from the seeds of Jatropha plant.
Biogas is produced by degradation of agriculture, plant and animal wastes, and sewage or municipal waste, by certain bacteria called methanogens. Biogas is a renewable source of energy, and it is a mixture of gases like methane, carbon dioxide, and others. Biogas is mostly used in rural areas for cooking, and in compressed form, it can be used as vehicle fuel.
2. Dairy Products
Biotechnology has a wide application in dairy, and we owe to biotechlogy for our favourite dairy products like cheese and yogurt. Cheese is formed by lactic acid fermentation of milk. Milk contains water (85%), fat, carbohydrates (lactose), and protein (casein & whey). Cheese is formed by separating milk into solid curd and liquid whey by acidification of milk or by adding rennet. Certain bacteria like lactobacilli or streptococci families convert milk sugar (lactose) to lactic acid and thus lower the milk pH. This is called acidification of milk; it kills the harmful bacteria present in the milk. This helps to separate the milk into curd and liquid whey. Rennet is an enzyme which helps in the coagulation of casein protein. This separates the solid curd and the liquid whey. Liquid whey is then removed, and the curd is then salted and shaped. Rennet is a set of enzymes present in the stomach of ruminant mammals. Chymosin (protease) is the key enzyme, which curdles the casein protein in milk.
3. Bakery Products
Bread is one of the most common foods consumed by human in everyday life. Do you know what makes the bread soft and fluffy? Bread is formed by making dough using flour, water, yeast and sugar. Amylase present in the moist dough breaks down the starch (amylase or amylopectin) present in the flour and releases maltose and sucrose. Yeast is a type of fungus, which feeds on sugar for energy. Yeast present in the dough contains maltase, which breaks the maltose into glucose through aerobic respiration but soon runs out of oxygen and switches to anaerobic respiration. In anaerobic respiration, it breaks down the sugar and produces CO2 and ethanol. These CO2 molecules get trapped in the gluten molecules, resulting in fluffiness of the dough. The dough is then heated, which kills the yeast and evaporates the ethanol. Saccharomyces cerevisiae is the yeast species that is used to make bread, it is also known as baker’s yeast.
4. Lactose-free Milk
Lactose is a sugar naturally present in milk. It has smaller units called glucose and galactose. Lactose breaks down in our gut by the enzyme lactase. Some people cannot digest lactose and are lactose intolerant as they lack the enzyme lactase in their body. In such people, lactose remains as such in the gut and causes symptoms like nausea, bloating, cramps, etc. Thanks to biotechnology lthat has provided us the lactose free milkin the market. Such milk is pre-treated with lactase enzyme. This causes lactose to breakdown into glucose and galactose. This enzyme is produced in yeast called Kluyveromyces. Lactose free milk consist of single unit glucose and galactose, which are more soluble in water than lactose and can be easily absorbed by the gut.
5. Alcohol Production
Biotechnological process alcoholic fermentation, achieved by certain bacteria and yeast, is widely used to produce alcohols. Raw materials for alcohol production are starch crops like barley, wheat, rice sugarcane or maize. Fermentation is a process in which yeast converts sugar into alcohol (ethanol) and carbon dioxide (CO2). In the presence of oxygen, yeast breaks down glucose (sugar) molecules into two molecules of pyruvic acid and releases carbon dioxide and water as by products. These two molecules of pyruvic acid are then reduced into ethanol and CO2 under anaerobic conditions. Some bacterial species like Zymomonas mobilis can also perform alcoholic fermentation. Alcohol fermentaion by yeast Saccharomyces cerevisiae is very common and well known, but Z. Mobilis is also used as a starter for ethanol production in industries. Wines are formed through the fermentation of grapes (Vitis vinifera). Wine making involves two main biotechnological processes, alcoholic fermentation and malolactic fermentation. In alcoholic fermentation, sugar present in fruits is converted into ethanol and CO2 follwoing which most red wines undergo malolactic fermentation by lactic acid bacteria, Oenococcus oeni. This process converts the malic acid (harsh tasting) into creamier lactic acid and also raises the pH. This is necessary for deacidification and flavour modification of the wine.
6. Skin Care Products
Biotechnology has played an important role in cosmetology and aesthetic medicines. Botox is one of the prominent examples of biotechnology products in everyday life. Botox is a protein produced by the bacteria Clostridium botulinum. It paralyzes nerve cells, thereby reducing the wrinkles on face. Hylauronic acid is also a very important ingredient in anti aging skin care. It is naturally present in the human body. In laboratory, hyaluronic acid is formed by fermentation of glucose by certain bacteria like Streptococcus zooepidemicus, Escherichia coli, and Bacillus subtilis under right temperature and pH.
7. Detergent enzymes
Conventional detergents have been over shadowed by detergent enzymes, a product of biotechnology. These detergents contain enzymes like proteases, lipases, and amylases, which help in removing the stains of blood, oil, etc.
8. Genetically Modified (GM) Crops
Biotechnology plays an important role in improving natural fibres like cotton, wool silk, etc. It also helps in improving yield and quality of crops production by making pest or herbicides resistant crops. Genetically modified foods are produced by introducing changes in their DNA by genetic engineering. Some examples of GM food are Bt crops, golden rice, etc.
Bt crops are genetically modified to contain a specific gene of a bacterium, Bacillus thuringiensis (Bt). This gene leads to the formation of a toxin in the leaves. When a pest feeds on Bt crops, the toxin (Cry protein) present in plant cells crystallizes the pest’s digestive system and kills the pest. This protein has no harmful effect on humans. This toxin is lethal to several insects like butterflies, moths, skipper flies, beetles, etc. Examples of BT crops are corn and cotton.
Golden rice is genetically altered variety of rice (Oryza sativa). In this, multi-gene biochemical pathway is integrated in the genome of rice through genetic engineering. This pathway results in the production of beta-carotene, a precursor of vitamin A. When metabolized by humans, it produces vitamin A. Golden rice has been engineered to overcome vitamin A deficiency in developing countries. Deficiency of vitamin A can cause night blindness and corneal scars or permanent blindness.
9. Dye Manufacturing
Shikonin is an example of naturally occurring naphthoquinone. It is found in the dried root of the plant Lithospermum erythrorhizo. They are used as natural colorants in cosmetic, food, and textile industries. Biotechnology also helps in the production of anthraquinone dyes. These dyes can be extracted from various fungi like trichoderma, aspergillus, and curvularia strains. Examples of anthraquinones biodyes are CI disperse blue 7 and CI acid green 28. Anthraquinones are organic compounds produced by plants and fungi; these dyes are less expensive and very eco friendly.
10. Paper Industry
Paper is formed by extracting cellulose from woods and converting it into pulp. The purpose of pulping is to free the cellulose fibres from lignin and other impurities present in the wood. Biotechnology allows the pulping of cellulose by a specific lignin degrading fungi, this method of pulping is called biopulping. Many harmful chemicals are replaced by enzymes used in pulp processing. Pulps are usually brown in colour due to the presence of lignin, and to make them lighter in colour, biobleaching is done. Initially, chlorine was used for bleaching the pulp, but due to its adverse affects on environment, it now has been replaced by enzymes like xylanase. Biobleaching agent Xylanase is produced by Trichoderma asperellum (fungus), it helps in the hydrolysis of hemicelluloses (xylan) present in the pulp. Biobleaching is cost effective and prevents the formation of harmful by products. It also improves the texture and strength of paper.
Environmental pollution is a major global concern, but with the emerging bioremediation technology, we can easily control the damaging effects of pollutants. Bioremediation is a process in which microbes are used to degrade the toxic substances present in contaminated groundwater or soil and convert them into non toxic substances.
Applications of Bioremediation
- It helps in cleaning of blood and body fluids at crime scenes. Initially bleach or ammonia were used as a cleaning agents but now enzyme cleaners (proteases, lipases, etc.) are used to get rid of harmful substances like blood that might posses health risks like HIV or hepatitis.
- Chemical pesticides and industrial wastes can contaminate the soil and underground water by releasing toxic substances into the soil. Through Bioremediation, microbes can utilize these chemical contaminants in the soil as their energy source. They metabolize these contaminants through oxidation-reduction reactions and produce energy.
- Bioremediation can also help in controlling oil spills in the marine ecosystem. Oil spills can harm sea animals and also make sea food unsafe to consume. Bioremediation can help to control the hazardous effects of oil spills in two ways.
Bioaugmentation: The insertion of a small amount of oil-degrading microbes into an affected area.
Biostimulation: Stimulating the growth of oil degrading microbes by the addition of nutrients. This increases the rate of degradation by microbes like bacteria and fungi.
12. Production of Antibiotics
Antibiotics are one of the very common examples of biotechnology products. They are non-protein molecules produced by microorganism that live in the soil. Antibiotics are produced as secondary metabolites by many species of bacteria such as Streptomyces, Bacillus, and Penicillium (fungi). Antibiotics play an important role in combating infectious diseases in humans and animals. Antibiotics can be divided into two broad categories based on their mode of action, bactericidal (kills the bacteria) and bacteriostatic (stalls bacterial growth). Penicillin was the first antibiotic discovered by Alexander Fleming.
Why do microorgaicms produce antibiotics?
Several microbes in the soil like bacteria and fungi produce antibiotics as a defence mechanism against other microbes living in the same vicinity. Due to heterogeneous nature of soil, different microorganisms dwell in it. These different microbes fight for their survival and successful reproduction, and hence they produce antibiotics to inhibit the growth of other microbes. Soil microorganisms ate the main source for the production of antibiotics.
13. Vaccine Production
Biotechnology has played a significant role in production of vaccines against various deadly diseases. Vaccines are made of dead or inactive pathogens, one of its surface proteins or toxins produced by pathogens. Vaccination triggers our immune system, resulting in the production of antibodies. These antibodies circulate in blood for a long time as memory antibodies, and if the said pathogen invades in future, the memory antibodies fight against it.