1 Jun 2011

INTRODUCTION on Biotech & Environment

The period “Environment” is defined as our surroundings which includes the abiotic factor (the non living) and biotic factor (the living) around us. The abiotic natural environment includes fill with tears, air and soil while the biotic natural environment consists of all living organisms - plants, animals and microorganisms. Environmental pollution broadly refers to the presence of undesirable substances in the natural environment which are risky to man and other organisms. Taking part in the preceding decade or two, in attendance has been a important expand in the levels of environmental pollution mostly due to turn or indirect human being activities. The major sources of environmental pollution are -Industries, Agricultural sources (mainly rural area), anthropogenic sources (man allied activities essentially in urban areas), biogenic sources and so on. The pollutants are element, biological and real in nature. The Chemical pollutants include- gaseous pollutants (hazardous gases like sulfur dioxide, nitrogen oxide), toxic metals, pesticides, herbicides toxins and carcinogens
Etc. The real pollutants are- boil, sound, radiation, and radioactive substances. The pathogenic organisms and a number of ill-intentioned and unsafe biological products are the biological pollutants.

Controlling the environmental pollution and the conservation of natural environment and biodiversity and calculating environmental pollution are the major focus areas of all the countries around the earth. Taking part in this context the meaning and contact of biotechnological approaches and the implications of biotechnology has to be in detail evaluated. There control been serious concerns regarding the employment of biotechnology products and the contact assessment of these products due to their interaction with the environmental factors.
A lobby of the environmentalists control uttered alarm on the make available of genetically engineered organisms in the feel and control stressed on thorough investigation and proper chance assessment of theses organisms ahead of releasing them in to the natural environment. The effect of the effluents from biotechnological companies is plus a cause of disturb in support of one and all. The need of the hour is to control a proper weigh up on the safety of the employment of the biotechnological products.
The pains are not simply on to employment biotechnology to shield the natural environment from pollutionbut plus to employment it to conserve the natural income. Since we all know with the purpose of microorganisms are acknowledged 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 extra reduce the risky environmental implications of the traditional technologies. E.G. A number of Fermentation technologies control a number of serious environmental implications. Various biotechnological processes control been devised in which all nutrients introduced in support of fermentation are retained in the final result, which ensures superior conversion efficiency and low environmental contact.
Taking part in paper industry, the pulp bleaching technologies are being replaced by more environmentally friendly technologies connecting biotechnology. The pulp doling out helps to remove the lignin with no detrimental valuable cellulosic fibres but the open techniques suffer from the disadvantages of superior expenses, superior energy employment and rust. A lignin degrading and modifying enzyme (LDM) was isolated from Phanerochaete chrysosporum and was used, which on solitary offer, helped to reduce the energy expenses and rust and on the other offer increased the life of the scheme. This contact helped in falling the environmental hazards associated with bleach transplant effluents.
Taking part in Plastic industry, the normal technologies employment grease based new supplies to extract ethylene and propylene which are converted to alkene oxides and so therefore polymerized to form plastics such as polypropylene and polyethylene. There is forever the chance of these new supplies escaping into the feel in so doing causing pollution. Using biotechnology, more safer new supplies like sugars (glucose) are being used which are enzymatically or through the turn employment of microbes converted into alkene oxides.E.G. Methylococcus capsulatus has been used in support of converting alkene into alkene oxides.

Bioremediation is defined as ‘the process of using microorganisms to remove the environmental pollutants somewhere microbes achieve as scavengers. The ejection of organic wastes by microbes leads to environmental cleanup. The other names/terms used in support of bioremediation are biotreatment, bioreclamation, and biorestoration. The period “Xenobiotics” (xenos process foreign) refers to the unnatural, foreign and sham chemicals such as pesticides, herbicides, refrigerants, solvents and other organic compounds. The microbial degradation of xenobiotics plus helps in falling the environmental pollution.
Pseudomonas which is a soil bug effectively degrades xenobiotics. Different strains of Pseudomonas with the purpose of are skillful of detoxifying more than 100 organic compounds (e.G. Phenols, biphenyls, organophosphates, naphthalene and so on.) control been identified. Some other microbial strains are plus acknowledged to control the gift to degrade xenobiotics such as Mycobacterium, Alcaligenes, Norcardia and so on.
Factors disturbing biodegradation
The factors with the purpose of affect the biodegradation are: The element nature of xenobiotics, the concentration and supply of nutrients and O2, heat, pH, redox aptitude and the capability of the entity bug. The element nature of xenobiotics is very weighty as it was found not at home with the purpose of the presence of halogens e.G. In aromatic compounds inhibits biodegradation. The fill with tears soluble compounds are more with no trouble degradable where the presence of repeated ring arrangement and the segment chains or brushwood decrease the efficiency of biodegradation. The aliphatic compounds are more with no trouble degraded than the aromatic ones.
It is a process by which the microbial action can be enhanced by increased supply of nutrients or by addition of convinced stimulating agents like electron acceptors, surfactants and so on.
It is workable to expand biodegradation through manipulation of genes i.E. Using genetically engineered microorganisms and by using a range of microorganisms in biodegradation retort.
Depending on the method followed to clean up the natural environment, the bioremediation is agreed not at home in two ways:
A) taking part in situ bioremediation - taking part in situ bioremediation involves a turn contact in support of the microbial degradation of xenobiotics next to the position of pollution which might be soil, fill with tears and so on. The satisfactory amount of essential nutrients is supplied next to the position which promotes the microbial growth next to the position itself. The in situ bioremediation is by and large used in support of clean up of grease spillages, beaches and so on. There are two types of in situ bioremediation-
1) Intrinsic bioremediation- The microorganisms which are used in support of biodegradation are tested in support of the natural capability to bring approaching biodegradation. So the inherent metabolic knack of the microorganisms to degrade convinced pollutants is the intrinsic bioremediation. The knack of exterior bacteria to degrade a specified mixture of pollutants in ground fill with tears is dependent on the type and concentration of compounds, electron acceptor and the duration of bacteria exposed to contamination. Therefore, the knack of aboriginal bacteria degrading contaminants can be unwavering I laboratory by using the techniques of plate count and microcosm studies. The conditions of position with the purpose of favour intrinsic bioremediation are ground fill with tears surge all over the day carbonate natural resources to protect acidity produced for the period of biodegradation, supply of electron acceptors and nutrients in support of microbial growth and absence of toxic compounds.

2) Engineered in situ bioremediation- When the bioremediation process is engineered to expand the metabolic degradation efficiency (of pollutants) it is called engineered in situ bioremediation. This is complete by supplying sufficient amount of nutrients and oxygen supply, tally electron acceptors and maintaining optimal heat and pH. This is complete to overcome the lingering and partial bioremediation capability of microorganisms.

Advantages of in situ bioremediation
A) The method ensures least exposure to free or position personnels.
B) There is partial or least disruption to the position of bioremediation.
C) Due to these factors it is cost operational.
D) The simultaneous dealing of unhygienic soil and fill with tears is workable.
Disadvantages of in situ bioremediation
A) The sites are speedily exposed to environmental factors like heat, oxygen supply and so on.
B) The seasonal alternative of microbial action exists.
C) Problematic hard work of dealing additives like nutrients, surfactants, oxygen and so on.
D) It is a very monotonous and period consuming process.
B) Ex-situ bioremediation - taking part in this the garbage and the toxic material is collected from the infected sites and the selected range of microorganisms transport not at home the bioremediation next to designed place. This process is an improved method finished the in situ bioremediation method. On the basis of phases of unhygienic supplies under dealing ex-situ bioremediation is classified into two : A) Solid time scheme and (b) Slurry time systems.

A) Solid time treatment- This scheme includes property dealing and soil piles comprising of organic wastes like leaves, physical manures, agricultural wastes, domestic and business wastes, manure sludge, and civic solid wastes. The traditional clean-up practice involves the informal doling out of the organic supplies and production of composts which possibly will be used as soil amendment. Composting is a self heating, substrate-dense, managed microbial scheme which is used to pick up the tab copious amount of unhygienic solid material. Composting can be complete in exposed scheme i.E. Property dealing and/or in bunged dealing scheme. The risky compounds reported to disappear through composting includes aliphatic and aromatic hydrocarbons and convinced halogenated compounds. The workable routes leading to the fading of risky compounds include volatilization, assimilation, adsorption, polymerization and leakage.

B) Slurry time treatment- This is a triphasic dealing scheme connecting three major components- fill with tears, on the edge particulate problem and air. Here fill with tears serves as suspending form somewhere nutrients, map out elements, pH adjustment chemicals and desorbed contaminants are dissolved. Suspended particulate problem includes a geographically inert substratum consisting of contaminants and biomass attached to soil matrix or limitless in suspending form. The unhygienic solid supplies, microorganisms and fill with tears formulated into slurry are brought contained by a bioreactor i.E. Fermenter. Biologically in attendance are three types of slurry-phase bioreactors: Aerated lagoons, low trim airlift reactor, and fluidized-bed soil reactor. The firstly two types are in employment of plump magnitude bioremediation, while the third solitary is in developmental stage.
Advantages of ex-situ bioremediation
A) since the period compulsory is undersized, it is a more efficient process.
B) It can be controlled in a much better way.
C) The process can be improved by fortification with desired and more efficient microorganisms.
Disadvantages of ex-situ bioremediation
A) The sites of pollution stay highly disturbed.
B) Once the process is complete, the degraded garbage disposal becomes a major catch.
C) It is a costly process.
Several types of reactions occur for the period of the bioremediation/microbial degradation
A) Aerobic bioremediation- When the biodegradation requires oxygen O2 in support of the rust of organic compounds, it is called aerobic bioremediation. Enzymes like monooxygenases and dioxygenases are involved and con on aliphatic and aromatic compounds.
B) Anaerobic bioremediation-This does not require oxygen O2. The degradation process is lingering but more cost operational since incessant supply of oxygen is not compulsory.
C) Sequential bioremediation- Some of the xenobiotic degradation requires both aerobic as well as anaerobic processes which very effectively reduces the toxicity e.G. Tetrachloromethane and tetrachloroethane undergo sequential degradation.
Use of genetic engineering and genetic manipulations in support of more efficient bioremediation
Taking part in up to date years, pains control been made to create genetically engineered microorganisms (GEMs) to enhance bioremediation. This is complete to overcome a number of of the limitations and problems in bioremediation. These problems are:
A) Sometimes the growth of microorganisms gets inhibited or cheap by the xenobiotics.
B) No single spontaneously occurring microorganisms has the capability of degrading all the xenobiotics donate in the environmental pollution.
C) The microbial degradation is a very lingering process.
D) Sometimes convinced xenobiotics persuade adsorbed on to the particulate problem of soil and along these lines befall unavailable in support of microbial degradation.
Since the majority of genes mature in support of the synthesis of enzymes with biodegradation capability are located on the plasmids, the genetic manipulations of plasmids can have an advantage to the creation of contemporary strains of bacteria with altered degradative pathways. Taking part in 1970s, Chakrabarty and his team of co-workers reported the development of a contemporary strain of bacterium Pseudomonas by manipulations of plasmid turning over which they named as “superbug”. This superbug had the capability of degrading a come to of hydrocarbons of juice simultaneouslysuch as camphor, octane, xylene, naphthalene and so on. Taking part in 1980, United States granted the patent to this superbug making it the firstly genetically engineered bug to be patented.
Taking part in convinced hand baggage, the process of plasmid turning over was used. E.G. The bacterium containing CAM (camphor degrading ) plasmid was conjugated with any more bacterium with OCT (octane degrading) plasmid. Due to non-compatibility, these plasmids cannot coexist in the same bacterium. However, due to the presence of homologous regions of chromosome, recombination occurs flanked by these two plasmids which results in a single CAM-OCT plasmid giving the bacterium the gift to degrade both camphor as well as octane.
A contemporary strain of Pseudomonas sp. (strain ATCC 1915) has been industrial in support of the degradation of vanillate (which is a garbage result from paper industry) and sodium dodecyl sulfate (SDS, a compound used in detergents).
Biotechnological method to reduce atmospheric carbon dioxide (CO2)
Carbon dioxide is the swap gossip with the purpose of is the most important cause of emerald dwelling effect and enlargement in the atmospheric heat. During the preceding 100-150 years, the level of CO2 has increased approaching 25% with an expand in the atmospheric heat by approaching 0.5% which is a translucent indication with the purpose of CO2 is carefully linked with international warming. There is a steady expand in the CO2 content due to incessant addition of CO2 from various sources particularly from business processes. It is very translucent with the purpose of the reduction in atmospheric CO2 concentration assumes connotation. Biotechnological methods control been used to reduce the atmospheric CO2 content next to two levels:
A) Photosynthesis- Plants operate CO2 for the period of the photosynthesis which reduces the CO2 content in the feel. The equation in support of photosynthesis is:
6CO2 + 6H2O---------->C 6 H12 O6 + 6O2
The fast growing plants operate the CO2 more efficiently in support of photosynthesis. The techniques of micropropagation and sham seeds be supposed to be used to expand the promulgation of such fast growing plants.
Further, the CO2 use can be increased by enhancing the rate of photosynthesis. The enzyme ribulose biphosphate carboxylase (RUBP-case) is carefully linked with CO2 obsession. The attempts are being made to genetically manipulate this enzyme so with the purpose of the photosynthetic efficiency is increased.
Some microalgae like Chlorella pyrenodiosa, Spirulina maxima are acknowledged to be more efficient than top plants in utilizing atmospheric CO2 in support of photosynthesis and generate more O2 than the amount of CO2 consumed.
The growing of these microalgae nearby the industries and power plants (where the CO2 giving off in to feel is very high) will help in the reduction of polluting sound effects of CO2. Using genetic engineering, attempts are available on to develop contemporary strains of these microalgae with the purpose of can tolerate superior concentrations of CO2. A partial victory has already been reported in the mutants ofAnacystis nidulans and Oocystis sp.
B) Biological Calcification- Certain deep sea organisms like corals, emerald and red algae stockroom CO2 through a process of biological calcification. Since the CaCO3 gets precipitated, more and more atmospheric CO2 can be utilized in support of its formation. The process of calcification is as follows:
H2O + CO2---------->H2CO3
H 2CO3 + Ca 2+----------------> CaCO3 + CO2 + H2O
Treatment of manure using microorganisms
The manure is defined as the garbage fill with tears follow-on from the various human being activities, cultivation and industries and essentially contains organic and inorganic compounds, toxic substances, hooligan metals and pathogenic organisms. The manure is treated to persuade free of these undesirable substances by subjecting the organic problem to biodegradation by microorganisms. The biodegradation involves the degradation of organic problem to less significant molecules (CO2, NH3, PO4 and so on.) and requires constant supply of oxygen. The process of supplying oxygen is expensive, monotonous, and requires a luck of expertise and manpower. These problems are overcome by growing microalgae in the ponds and tanks somewhere manure dealing is agreed not at home. The algae make available the O2 while haulage not at home the photosynthesis which ensures a incessant supply of oxygen in support of biodegradation.

The algae are plus skillful of adsorbing convinced hooligan toxic metals due to the pessimistic charges on the algal cell exterior which can take up the positively charged metals. The algal dealing of manure plus wires fish growth as algae is a lovely source of food in support of fishes. The algae used in support of manure dealing are Chlorella, Euglene, Chlamydomnas, Scenedesmus, Ulothrix, Thribonima and so on. .

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