In the past decade or two, there has been a significant increase in the levels of environmental pollution mostly due to direct or indirect human activities. The major sources of environmental pollution are -Industries, Agricultural sources (mainly rural area), anta reporting SOUrces (man related activities mainly in urban areas), boogieing sources etc. The pollutants are chemical, biological and physical in nature. The Chemical pollutants include- gaseous pollutants (hazardous gases like sulfur dioxide, nitrogen oxide), toxic metals, pesticides, herbicides toxins and carcinogens Etc.
The physical pollutants are- heat, sound, radiation, and radioactive substances. The pathogenic organisms and some poisonous and dangerous biological products are the biological pollutants. Controlling the environmental pollution and the conservation of environment and biodiversity and controlling environmental pollution are the major focus areas of all the countries around the world. In this context the importance and impact of biotechnological approaches and the implications of biotechnology has to be thoroughly evaluated.
There have been serious concerns regarding the use of biotechnology products and the impact assessment of these products due to their interaction with the environmental actors.
A lobby of the environmentalists have expressed alarm on the release of genetically engineered organisms in the atmosphere and have stressed on thorough investigation and proper risk assessment of theses organisms before releasing them in to the environment. The effect of the effluents from biotechnological companies is also a cause of concern for everyone. The need of the hour is to have a proper debate on the safety of the use of the biotechnological products.
The efforts are not only on to use biotechnology to protect the environment from pollution also to use it to conserve the natural resources. As we all know that microorganisms are known natural scavengers so the microbial preparations (both natural as well as genetically engineered) can be used to clean up the environmental hazards. Development of alternate cleaner technologies using biotechnology Biotechnology is being used to provide alternative cleaner technologies which will help to further reduce the hazardous environmental implications of the traditional technologies. E. G. Mom Fermentation technologies have some serious environmental implications. Various biotechnological processes have been devised in which all nutrients introduced for fermentation are retained n the final product, which ensures high conversion efficiency and low environmental impact. In paper industry, the pulp bleaching technologies are being replaced by more environmentally friendly technologies involving biotechnology. The pulp processing helps to remove the logging without damaging valuable celluloses fibers but the available techniques suffer from the disadvantages of high costs, high energy use and corrosion.
A logging degrading and modifying enzyme (LED) was isolated from Phonetician chromosome and was used, which on one hand, helped to reduce the energy costs and corrosion and on the other hand increased the life of the yester. This approach helped in reducing the environmental hazards associated with bleach plant effluents. In Plastic industry, the conventional technologies use oil based raw materials to extract ethylene and propylene which are converted to alkaline oxides and then popularized to form plastics such as polypropylene and polyethylene.
There is always the risk of these raw materials escaping into the atmosphere thereby causing pollution. Using biotechnology, more safer raw materials like sugars (glucose) are being used which are enigmatically or through the direct use of microbes converted into alkaline oxides. . G. Meticulously capsular has been used for converting alkaline into alkaline oxides. Integration of biological steps in pulping process leading to logging degradation Premeditation Premeditation is defined as ‘the process of using microorganisms to remove the environmental pollutants where microbes serve as scavengers.
The removal of organic wastes by microbes leads to environmental cleanup. The other names/terms used for premeditation are obtainment, proclamation, and overestimation. The term “Secessionist” (xenon means foreign) refers to the unnatural, foreign and synthetic chemicals such as suicides, herbicides, refrigerants, solvents and other organic compounds. The microbial degradation of secessionist also helps in reducing the environmental pollution. Pseudonymous which is a soil microorganism effectively degrades secessionist. Different strains of Pseudonymous that are capable of detoxifying more than 100 organic compounds (e. . Phenols, phenyl, archaeopteryx’s, naphthalene etc. ) have been identified. Some other microbial strains are also known to have the capacity to degrade secessionist such as Mycobacterium, Allegiances, Inorganic etc. Factors affecting biodegrading The factors that affect the biodegrading are: the chemical nature of secessionist, the concentration and supply Of nutrients and 02, temperature, pH, redo potential and the capability of the individual microorganism. The chemical nature of secessionist is very important because it was found out that the presence of halogens e. G. N aromatic compounds inhibits biodegrading. The water soluble compounds are more easily degradable whereas the presence of cyclic ring structure and the length chains or branches decrease the efficiency of biodegrading. The aliphatic compounds are more easily degraded than the aromatic ones. Visualization It is a process by which the microbial activity can be enhanced by increased supply of nutrients or by addition of certain stimulating agents like electron acceptors, surfactants etc. Pigmentation It is possible to increase biodegrading through manipulation of genes I. E. Sing genetically engineered microorganisms and by using a range of microorganisms in biodegrading reaction. Depending on the method followed to clean up the environment, the premeditation is carried out in two ways: A) In situ premeditation – In situ premeditation involves a direct approach for the microbial degradation of secessionist at the site of pollution which could be soil, water etc. The adequate amount of essential nutrients is supplied at the site which promotes the microbial growth at the site itself. The in situ premeditation is generally used for clean up of oil spillages, beaches etc.
There are two types of in situ premeditation- 1) Intrinsic premeditation- The microorganisms which are used for biodegrading are tested for the natural capability to bring about biodegrading. So the inherent metabolic ability of the microorganisms to degrade certain pollutants is the intrinsic premeditation. The ability of surface bacteria to degrade a given mixture of pollutants in ground water is dependent on the type and concentration of compounds, electron acceptor and the duration of bacteria exposed to contamination.
Therefore, the ability of indigenous bacteria degrading contaminants can be determined I laboratory by using the techniques of plate count and microcosm studies. The conditions of site that favor intrinsic premeditation are ground water flow throughout the year carbonate minerals to buffer acidity produced during biodegrading, supply of electron acceptors and nutrients for microbial growth and absence of toxic impounds. 2) Engineered in situ premeditation- When the premeditation process is engineered to increase the metabolic degradation efficiency (of pollutants) it is called engineered in situ premeditation.
This is done by supplying sufficient amount of nutrients and oxygen supply, adding electron acceptors and maintaining optimal temperature and PH. This is done to overcome the slow and limited premeditation capability of microorganisms. Advantages of in situ premeditation a) The method ensures minimal exposure to public or site personnel. B) There is limited or minimal disruption to the site Of premeditation. C) Due to hose factors it is cost effective. D) The simultaneous treatment of contaminated soil and water is possible.
Disadvantages of in situ premeditation a) The sites are directly exposed to environmental factors like temperature, oxygen supply etc. B) The seasonal variation of microbial activity exists. C) Problematic application of treatment additives like nutrients, surfactants, oxygen etc. D) It is a very tedious and time consuming process. B) Ex-situ premeditation – In this the waste and the toxic material is collected from the polluted sites and the selected range of microorganisms carry out the premeditation at designed place. This process is an improved method over the in situ premeditation method.
On the basis of phases of contaminated materials under treatment ex-situ premeditation is classified into two : a) Solid phase system and (b) Slurry phase systems. A) Solid phase treatment- This system includes land treatment and soil piles comprising of organic wastes like leaves, animal manures, agricultural wastes, domestic and industrial wastes, sewage sludge, and municipal solid wastes. The traditional clean-up practice involves the informal processing of the organic materials and production of composts which may be used as soil amendment.
Composting is a self heating, substrate-dense, managed microbial system which is used to treat large amount of contaminated solid material. Composting can be done in open system I. E. Land treatment and/or in closed treatment system. The hazardous compounds reported to disappear the rough composting includes aliphatic and aromatic hydrocarbons and certain halogenated compounds. The possible routes leading to the disappearance of hazardous compounds include balkanization, assimilation, adsorption, popularization and leaching.
B) Slurry phase treatment- This is a Triassic treatment system involving three ajar components- water, suspended particulate matter and air. Here water serves as suspending medium where nutrients, trace elements, pH adjustment chemicals and desorbed contaminants are dissolved. Suspended particulate matter includes a biologically inert substratum consisting of contaminants and biomass attached to soil matrix or free in suspending medium. The contaminated solid materials, microorganisms and water formulated into slurry are brought within a fabricator I. E. Fermented.
Biologically there are three types of slurry-phase fabricators: aerated lagoons, low shear airlift reactor, and fulfilled-bed soil reactor. The first two types are in use of full scale premeditation, while the third one is in developmental stage. Advantages of ex-situ premeditation a) As the time required is short, it is a more efficient process. B) It can be controlled in a much better way. C) The process can be improved by enrichment with desired and more efficient microorganisms. Disadvantages Of ex-situ premeditation a) The sites of pollution remain highly disturbed. ) Once the process is complete, the degraded waste disposal becomes a major problem. C) It is a costly process. Several types of reactions occur during the premeditation/microbial gradation a) Aerobic premeditation- When the biodegrading requires oxygen 02 for the oxidation of organic compounds, it is called aerobic premeditation. Enzymes like anonymousness and disadvantages are involved and act on aliphatic and aromatic compounds. B) Anaerobic premeditation-This does not require oxygen 02. He degradation process is slow but more cost effective since continuous supply of oxygen is not required. C) Sequential premeditation- Some of the xenophobic degradation requires both aerobic as well as anaerobic processes which very effectively reduces the toxicity e. G. Treacherousness and tetrachloride’s undergo sequential degradation. Use of genetic engineering and genetic manipulations for more efficient premeditation In recent years, efforts have been made to create genetically engineered microorganisms (GEMs) to enhance premeditation.
This is done to overcome some of the limitations and problems in premeditation. These problems are: a) Sometimes the growth Of microorganisms gets inhibited or reduced by the secessionist. B) NO single naturally occurring microorganisms has the capability of degrading all the secessionist present in the environmental pollution. C) The microbial gradation is a very slow process. D) Sometimes certain secessionist get adsorbed on to the particulate matter of soil and thus become unavailable for microbial degradation.
As the majority of genes responsible for the synthesis of enzymes with biodegrading capability are located on the plasmids, the genetic manipulations of plasmids can lead to the creation of new strains of bacteria with different degradation pathways. In sass, Charitably and his team of co-workers reported the development of a new strain of bacterium Pseudonymous by manipulations of plasmid transfer which they named as “superb”. This superb had the pap ability of degrading a number of hydrocarbons of petroleum simultaneousness as camphor, octane, Selene, naphthalene etc.
In 1980, united States granted the patent to this superb making it the first genetically engineered microorganism to be patented. In certain cases, the process of plasmid transfer was used. E. G. The bacterium containing CAM (camphor degrading ) plasmid was conjugated with another bacterium with COT (octane degrading) plasmid. Due to non-compatibility, these plasmids cannot coexist in the same bacterium. However, due to the presence of homologous regions of DNA recombination occurs between these two lassies which results in a single CAM-COT plasmid giving the bacterium the capacity to degrade both camphor as well as octane.
A new strain of Pseudonymous SP. (strain ATSC 1915) has been developed for the degradation Of ventilate (which is a waste product from paper industry) and sodium decoded sulfate (SD, a compound used in detergents). Biotechnological method to reduce atmospheric carbon dioxide (CA) Carbon dioxide is the gas that is the main cause of green house effect and rise in the atmospheric temperature. During the past 100-150 years, the level of CA has increased bout 25% with an increase in the atmospheric temperature by about 0. % which is a clear indication that CA is closely linked with global warming. There is a steady increase in the CA content due to continuous addition of CA from various sources particularly from industrial processes. It is very clear that the red action in atmospheric CA concentration assumes significance. Biotechnological methods have been used to reduce the atmospheric CA content at two levels: a) Photosynthesis- Plants utilize CA during the photosynthesis which reduces the CA content in the atmosphere.
The equation for photosynthesis is: sunlight CA + 6 HUH 06 + 602 Chlorophyll The fast growing plants utilize the CA more efficiently for photosynthesis. The techniques of misappropriation and synthetic seeds should be used to increase the propagation of such fast growing plants. Further, the CA utilization can be increased by enhancing the rate of photosynthesis. The enzyme ribose phosphate carboxylic (RUB-case) is closely linked with CA fixation. The attempts are being made to genetically manipulate this enzyme so that the photosynthetic efficiency is increased.
Some micromanage like Chloral oppressions, Spiraling maxima are known to be more efficient Han higher plants in utilizing atmospheric CA for photosynthesis and generate more 02 than the amount of CA consumed. The growing of these micromanage near the industries and power plants (where the CA emission in to atmosphere is very high) will help in the reduction of polluting effects of CA. Using genetic engineering attempts are going on to develop new strains of these micromanage that can tolerate high concentrations of CA. A limited success has already been reported in the mutants of Inactions undulant and Society SP. ) Biological Calcification- Certain deep sea organisms like corals, Rene and red algae store CA through a process of biological calcification. As the Cacao gets precipitated, more and more atmospheric CA can be utilized for its formation. The process of calcification is as follows: H2O + CA—- – H CHIC ca 2+- –> cacao + CA + H2O Treatment of sewage using microorganisms The sewage is defined as the waste water resulting from the various human activities, agriculture and industries and mainly contains organic and inorganic compounds, toxic substances, heavy metals and pathogenic organisms.
The sewage is treated to get rid of these undesirable substances y subjecting the organic matter to biodegrading by microorganisms. The biodegrading involves the degradation Of organic matter to smaller molecules (CA, NH, POP etc. ) and requires constant supply of oxygen. The process of supplying oxygen is expensive, tedious, and requires a lot of expertise and manpower. These problems are overcome by growing micromanage in the ponds and tanks where sewage treatment is carried out.
The algae release the 02 while carrying out the photosynthesis which ensures a continuous supply of oxygen for biodegrading. The algae are also capable of adsorbing certain heavy toxic metals due to the active charges on the algal cell surface which can take up the positively charged metals. The algal treatment of sewage also supports fish growth as algae is a good source of food for fishes. The algae used for sewage treatment are Chloral, Euglena, Chlamydeous, Condescends, Ultrix, Attribution etc.
Role of biotechnology in restoration of degraded lands The arbitration and increased human activity has led to degradation of habitats. The restoration of the degraded lands can be carried out by using biotechnology which involves the manipulations of biological systems. This estimation could be carried out by the following biotechnological methods: a) use of misappropriation and myocardial for reforestation One of the approaches to tackle this problem is to develop strong and superior species which have the capability to grow well on degraded lands.
This can be done by using mass multiplication which involves starting aseptic culture, multiplication of shoot using shoot apical merits or buds, rooting of in vitro formed shoots, transfer, acclimatization and adaptation of misappropriated platelets in the field. Using this methodology an estimated 500 million plants of diverse nature have been produced. Mechanized, which are symbiotic non-pathogenic associations between plant roots and fungi, improves the seedling survival and growth by enhancing uptake of nutrients and water. They also lengthen the root life and provide protection against the pathogens.
A list of fungi which can efficiently form mechanized has been prepared. These fungi can be used as inoculate which are applied to roots of seedlings, to allow formation of mechanized. The experimental infection of misappropriated plants during rooting increases their survival chances in the field, which is very important in case of plantations on degraded lands. ) Improvement of soil infertility through the use of nitrogen fixing bacteria, Rhizome in association with leguminous trees and Frankie in association with non leguminous species.
Biotechnological methods are being developed to help the non-leguminous plants to survive under adverse conditions such as low nutrient supply. There are about 160 species of angiosperms, which are known to form nitrogen fixing root nodules with the stationmasters bacteria belonging to the genus Frankie which is being used for this purpose. Frankie helps in nitrogen fixation in non-leguminous plant species therefore it an be used for land reclamation through reforestation due to high biomass production with out the need of expensive nitrogen fertilizers. ) Development of plants tolerant to biotic stress which can be grown on degraded lands The techniques like tissue culture and genetic engineering are being used to develop plants resistant to biotic stresses e. G. Salinity, acidity, aluminum toxicity etc. The cell lines which exhibit resistance to salt stress are selected and then used for plantation on degraded lands. E. G. Brassier SSP. , Citrus uranium, Inactions tobacco etc. Research is going on to understand he molecular basis of salt tolerance and to isolate genes responsible for this attribute so that salt tolerant plants can be developed using genetic engineering.
In vitro selection for tolerance to biotic stress like aluminum toxicity has been successful in certain plant species e. G. Tomato, rice, barley, rice and wheat. “Trickle” which is a man made synthetic crop has been found suitable for growing on acid soils, dry and sandy soils, on alkaline and calcareous soils and on mineral deficient and high boron soils especially in countries like Kenya, Ethiopia, Ecuador, Mexico, Brazil etc. In China, a number f new stress resistant varieties of rice, wheat and tobacco have been developed using anther culture. ) Use of selected and engineered microbes for removal and recovery of strategic and precious metals from contaminated degraded lands. The domestic and industrial effluents often contain harmful heavy metals. These heavy metals cause soil contamination when these effluents are used for irrigation purposes. The biotechnological methods and procedures are being developed to prevent the contamination by these heavy metals and also restore the contaminated soils. This involves the selective use of engineered microbes. Plasmids have been constructed which can enhance the recovery of gold from reactionaries ores, by Tabulations foreordains.
Gendarme lucid which is a wood rotting unglamorous , is a highly potential absorbent material for heavy metals and thus can be used to control contamination by heavy metals. The metal pollution occurs through several processes. As the living organisms including man are constantly exposed to metals, they accumulate by a process referred to as ‘fasciculation. ‘ The continuous exposure and accumulation of a given metal leads to increase in it’s concentration which is referred to as ‘pontification;. Pontification occurs through food chain and the man gets the maximum impact due to it’s being on top of the food chain.
The ‘ventilation’ is carried out by microorganisms in the soil and water and involves the process of transfer of methyl groups from organic compounds to metals. Some phytoplankton’s (plants that float freely on water surface) and some benthic (plants attached to some substratum at the bottom of aquatic bodies) microorganisms can take up the metals from the waste water ponds. These natural vicegerents not only control the water pollution by absorbing metals but also contributes in the recovery of industrially important metals from the effluents.
The microorganisms like algae can absorb metals form the fresh water e. G. Chloral vulgarism takes up copper, mercury, uranium. Certain fungal species like Rhizomes, Espadrilles, Penicillin, Neurosurgeon are good absorbers of heavy metals like lead, mercury etc. Some of the bacterial species are capable of accumulating metals on cell walls such as E. Coli can take up mercury while Bacillus circulars can accumulate copper. The mechanism of metal scavenging by these microorganisms is very complex and involves multiple steps.
Some of the microorganisms fasciculate these metals on their cell walls whereas some there have the capacity to transport these metals to intracellular and intracellular free space and cellular organelles. In certain cases some of the metals occur as immobilizers metal containing crystals e. G heavy metal complexes of calcium oxalate crystals. Some of the fungal and algal species synthesize metal binding proteins or peptides. ‘Photochemical’ is an ubiquitous metal chelating protein present in all plants and acts as a common buffering molecule for the homeostasis of metals.
It is rich in cytosine and can form salt metal complexes through sculptural (SSH) groups. Due to this property, photochemical can be used as a biometry for metal pollution detection. The mechanisms involved in the removal of metals by microorganisms are: adsorption, complication, precipitation and balkanization. The process of adsorption involves the binding of metal ions to the negatively charged cell surfaces of microorganisms. The process of complication leads to production of organic acids e. G. Citric acid, oxalic acid, cloning acid, lactic acid, malice acid etc. Which chalet the metal ions. In precipitation, the metals are precipitated as hydroxides or sulfates by some bacteria such as which produce ammonia, organic bases or HAS. E. G. Desultoriness and Dessertspoonfuls transform SIS to HAS which promotes extracurricular precipitation of insoluble metal sulfides. Kielbasa arrogates detoxifies cadmium sulfate which precipitates on cell surface. Balkanization involves bacteria that causes mutilation Of Hag+ and converts to timely mercury which is a volatile compound.
Whole cell of Bacillus subsists have been shown to reduce gold from AAU+ to Au O through extracurricular enzymatic beatifications. Under anomic environment, sulfate- reducing bacteria (Desultoriness) oxidize organic matter using sulfate as an electron acceptor. In yeast, Chromosomes accessories removal of metals is done by their precipitation as sulfides e. G. Cue+ is precipitated as Cuss. Several technologies for metal removal have been commercialese and employed are given below: – ATOMICALLY process: The advance Mineral Technology (AT M) Inc. U. S. A. ) developed a waste water treatment process with Bacillus SP. immobilizers and pre-treated in caustic solution. It is specific for metal actions in the order: Cue+ ; Zen+ ; CDC+ = NIH+ ; Pub+. – Alligators process: Everybody systems, Inc. (U. S. A) developed this proprietary based material which consists Of several hypes of living and non living algae. The algal cultures are immobilizers in silica gel in the form of beads and description of metals is carried out. Premeditation of coal wastes through VAMP fungi: Selected VAMP fungi are introduced through plants in coal mine areas where it was found that VAMP fungi improved the growth and survival of desirable re-vegetation species e. G. Red maple, maize, alfalfa etc. – BIO-FIXITY process: The bureau of Mines (U. S. A) developed this process that consists of biomass immobilizers in polystyrene. It consists of thermally killed biomass of Sphagnum pat moss, algae, yeast, bacteria and/or aquatic flora. The beads are suitable for practical application in stirred tank reactor, fixed and fulfilled-bed columns. ) Use of biotechnology in the conservation of biodiversity The extinction of wild species due to the destruction of habitats and ecosystems has raised serious concerns about the biodiversity in general. Biodiversity provides genes from wild species for biotechnology exercises and experiments hence biotechnology and biodiversity are interrelated. Besides taking steps to minimize and regulate the factors responsible for causing loss of biodiversity, efforts are on to develop the techniques of conservation of diversity. One of the methods involves the establishment of ‘gene banks” leading to “in situ conservation and ex situ conservation.
The in situ conservation involves the conservation of plants and animals in their natural habitat and ecosystems. The ex situ conservation includes conservation of species away from their habitats. The ex situ conservation uses sample populations and establishes the “gene banks” which includes resource centers, zoos, botanical gardens, national parks, culture collection centers etc. Biotechnology offers special methods to conserve both animal and plant emetic resources especially in the conservation of endangered plant species.
The tissue culture method is being used to multiply an endangered plant species. The method of embryo transfer and artificial insemination is used for the multiplication of endangered animal species. Use of biotechnology in reducing the use Of chemical pesticides, herbicides and fertilizers I A lot of debate is going on the overuse of chemical herbicides, pesticides and fertilizers. They become an environmental hazard because they undergo degradation by microorganisms and ultraviolet light which releases toxic Heimlich in the environment.