Uses of Bioremediation:
i. Breaking down impurities in water:
One of major water pollutants are hydrocarbons resulting from oil spills. When hydrocarbons or chlorinated solvents enter into the water from industries and oil wells without being treated, they contaminate water. With the use of bioremediation, biological agents like microbes or oil-eating bacteria are released into the water. These microbes break down the oil on water to create a thin layer. This thin layer spread on water is not harmful.
ii. Remedying air pollution:
Air pollutants are treated through bioremediation by creating microbial communities. These communities are spread over a solid surface and create multiple layers called biofilms. When microbes pass through these layers, they convert harmful chemicals into water and harmless gases.
iii. Treating chemical wastes:
Harmful agricultural and industrial wastes like DDT and organochlorines do not break down naturally. Tests are on to treat many of these wastes by using a variety of bacteria to break down the wastes.
iv. Clearing harmful metal wastes:
Bioremediation is also effective in treating heavy metal wastes that are very harmful for the food cycle. Organisms like algae, fungi or vascular plants which are found in water absorb the metals to a tolerable level. The growth can then be harvested to remove the metals from the environment.
v. Wetlands for acidification:
Acidic waters that come from activities like coal mining can be treated by creating artificial wetlands. Wetlands have living organisms like phytoplankton that eliminates acids by a natural process. This process can be used at the beginning of drainage of acids from a site. Wetland microbes reduce sulphate to sulphide and ferric iron to ferrous iron.
vi. Sewage treatment:
Sewage treatment involves break down of human wastes as well as metals. Microbes are used in the treatment of sewage to oxidize organic matter and to decrease the concentration of soluble compounds.
Genetically Engineered Herbicide-Resistant Plants
In the latest development in biotechnology, plants that are resistant to herbicides are being developed. Fertilizers, pesticides and herbicides are harmful to the growth of plants. Synthetic chemical herbicides are used to control weed growth that slower the rate of yield.
Herbicides kill all (or most) plants, and thus cannot be applied directly onto a field of crop plants. Such plants where a resistant gene is incorporated are known as genetically modified plants (GM) or transgenic plants. These resistant genes are isolated and incorporated to create resistance and to increase their nutritive value. Now, herbicide-resistant plants are being developed that do one of the following:
i. Produce a new protein to detoxify the herbicide, or
ii. Replace the protein of the plant that a herbicide destroys.
Some microorganisms present in the soil provide necessary nutrients to the available crop. With the use of biofertilizers, these microorganisms are activated to provide extra nutrients to the plants so that the seed, root and soil of the field they are applied to become more productive.
While synthetic inputs like chemical fertilizers are harmful to the crop, biofertilizers are safe for the crop, for the water and therefore, for human beings. Biofertilizers aid in enhancing crop yield by 20 to 30 per cent. Biofertilizers improve the quality of soil and restore the natural qualities of soil.
A number of biofertilizers are available. For example, to increase nitrogen content, Rhizobium is available for legume crops; Azotobacter and Azospirillum for non-legume crops. Blue-Green Algae and Azolla are used for low land paddy.
For phosphorus requirements, Phosphatika is used for plants along with Rhizobium, Azotobacter, Azospirillum and Acetobacter. Cellulolytic fungal culture, Phosphotika and Azotobacter culture are used to provide better manure.
Advantages of Biotechnology in Agriculture:
i. Since genetically engineered crops are pesticide resistant, they will not require pesticides to be used on them, making the crops safer for humans.
ii. With better varieties of crops available, these plants will also have better productivity.
iii. Genetically engineered plants are produced to have more nutritional value.
vi. Biotechnology helps provide improved crops to the developing countries. They are able to provide more nutrition to the population.
3. Genomic Revolution Biotechnology Applied to Human Beings:
The changing of DNA within the cells of an organism is known as gene therapy. Today, scientists are using gene therapies to cure deadly diseases such as cancer and to prevent many other diseases. Certain microorganisms are also being altered and modified, such as digestive enzymes, to provide better treatment to humans,
DNA testing of human and animal fossils has helped scientists to understand the origin of mankind. DNA finger printing is used for investigation purposes. Biotechnology has also been used to modify microorganisms such as E coli (or yeast) to prepare insulin (needed to treat diabetes) and antibiotics. Biotechnology has thus prepared human insulin from a non-human source.
Antibiotics such as penicillin and streptomycin are chemical substances secreted by living organisms, and are effectively used to treat many diseases. All these can be genetically manipulated to give higher yields and can be manufactured on commercial basis.
Vitamins are produced by microorganisms during their active growth phase. By using biotechnology, these compounds that contain vitamins can be stored
in cultures, and used commercially whenever required. Some examples are riboflavin (Vitamin Bi) and carotene (Vitamin A). Bj2 is another important vitamin produced by using biotechnological methods.
Biotechnology is also being used to make vaccines on a large-scale, such as hepatitis B vaccine.
Genetically engineered enzymes are being used to speed up processes in food and beverage industry, and to make amino acids which are used in medicine. The genetically engineered enzymes are being used in bio-detergents, to remove stains easily from fabrics.
When used in baby food, they help in easy digestion. They are used to make meat tender and also to clear fruit juices. Commercially produced yeast is used to make alcohol. Cheese is also being manufactured by genetic modification. Bio-yogurt contains extra bacteria which are not found in our digestive system.
Industries use bio-catalysts in their industrial processes. The bio-catalysts are designed to cause less pollution, and can be prepared at lower cost. Bio- fuels are produced by using microorganisms like bacteria in the absence of oxygen, and are eco-friendly. Bio-plastics being produced now are biodegradable by bacteria, and hence are eco-friendly.