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The use of genetic engineered organisms for pollution abatement. Genetically Modified Organisms. Ng yong chyn Tee jialeng Hidayat ariff. An abatement to air, water and soil pollution. Genetically Modified Food (GM Food). Ng yong chyn Tee jialeng Hidayat ariff. What is GM Food?.
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The use of genetic engineered organisms for pollution abatement Genetically Modified Organisms Ng yongchyn Tee jialeng Hidayatariff
An abatement to air, water and soil pollution Genetically Modified Food (GM Food) Ng yongchyn Tee jialeng Hidayatariff
What is GM Food? GM Food – food that have had their genes modified to be resistant against insects that may do harm to them, thus reducing the amount of insecticides and pesticides used. Ng yongchyn Tee jialeng Hidayatariff
Advantages of GM Food • Pharmaceutical benefits, vitamin-enhanced grains, and those with amino acids and other nutritional features. • Increases drought and extreme-temperature tolerance • Resistance to a variety of pests and diseases • Increase the amount of food for the world so as to ensure that sufficient food is available. • Reduce the number of herbicides used to control weeds, facilitating minimum tillage or no-tillage farming, reducing soil erosion and surface water contamination. Ng yongchyn Tee jialeng Hidayatariff
Disadvantages of GM Food • Environmental implication: “Bt” corn is resistant to corn borers attack, but there are concerns that a Bt-resistant borer may develop. • ‘Super weeds’ might develop a resistant against herbicides. • GMO crops may also cross breed with some other closely related species, leading to transgenic pollution. • Loss of genetic resources due to accidental cross breeding. Ng yongchyn Tee jialeng Hidayatariff
Ng yongchyn Tee jialeng Hidayatariff
GM Food in the United States Case Study Ng yongchyn Tee jialeng Hidayatariff
Ng yongchyn Tee jialeng Hidayatariff
Ng yongchyn Tee jialeng Hidayatariff
Advantages of GM Food • As of 2000, 68% of such crops come from the U.S. • Soybeans and corn in U.S. make out 82% of all GM crops harvested in 2000, in which 74% were modified for herbicide tolerance, 19% with insect pest resistance, and 7% with both herbicide tolerance and pest tolerance. • Acreage of GM crops has increased from approximately 4.3 million acres in 1996 to 109 million acres • Pesticide and herbicide decreased, resulting in increase of yields. Ng yongchyn Tee jialeng Hidayatariff
Ng yongchyn Tee jialeng Hidayatariff
Disadvantages of GM Food • “Transgenic” pollution – Crops pollinated with biotech genes can lose their organic status if they have been cross polluted. • Dangerous on countries that rely highly on agriculture (with most countries pledging against GM food). • Health effects of consumption and at what dose is unknown. • Create a class of insects resistant to it. • Low reduction in terms of use of pesticides – only by 2.5%. Ng yongchyn Tee jialeng Hidayatariff
Phytoremediation • Phytoremediation, able to clean up transgenic pollutants. • Few methods to phytoremediation: - Phytovolatilization Plants take up contaminants from soil and release them as volatile form into the atmosphere through transpiration - Phytodegradation Complex organic pollutants are degraded into simpler molecular and incorporated into plant tissues to aid plant growth. - PhytoextractionUse of plant to take up metal contaminants from soil through the absorption by plant roots. Ng yongchyn Tee jialeng Hidayatariff
Phytovolatilization • Contaminants move to the leaves and volatilize into the atmosphere. It is changed and modified along the way. Water travels from the roots to the leaves along the vascular system of the plant. Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • No plants even to this date; are found with natural ability to • accumulate • or degrade mercury. • Transgenic plants are developed to remove mercury How? • (Mer B) and (Mer A) are enzymes in bacteria • Responsible for the process, • Converts organic mercury to elemental mercury that is less toxic. Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • Mer B converts • organic mercury (CH3Hg) to ionic mercury Hg (II), • Mer A then reduced • ionic mercury Hg (II) to the volatile elemental mercury Hg (0) • Genes were introduced in • Arabidopsis thaliana plant. • Yellow Poplar plant • Eastern cottonwood, Populus deltoids Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • Result : • Able to grow on up to 10μM methyl mercury concentrations, • 40-times higher than the maximum concentration tolerated by WT seedlings • 10-times higher concentrations than plants that express MerB alone • Combining gene resulted in more efficient detoxification of organomercurial compounds than did merB alone Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • Results: • Transfer of Mer A producing gene to Yellow Poplar plant • Ability to volatilize 10 times more mercury than control plants. Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • Eastern cottonwood, Populus deltoids • Another candidate plant used for Phytoremediation. • Modified with Mer A gene. • Transgenic shoots • Grew normally on a medium with 25μM Hg(II) • A concentration which killed wild-type shoots. • In addition, the transgenic plant • Produced up to 4 times more elemental mercury Hg (0) than wild-type plants. • Evidently shows that the plants are capable of transforming mercury to its less toxic form more efficiently. Ng yongchyn Tee jialeng Hidayatariff
Brief Case Study • Another experiment is carried out in polluted soil • With mercuric ion at a toxic concentration of 400 ppm Hg (II). • By 2 weeks, • All non-transgenic plant had died • While the transgenic cottonwoods were still alive. Ng yongchyn Tee jialeng Hidayatariff
Phytodegradation • Enzymes in plant roots break down (degrade) organic contaminants. The fragments are incorporated into new plant material. Ng yongchyn Tee jialeng Hidayatariff
Case Study • Trinitrotoluene (TNT) • One of the most persistent and dangerous explosives. • The use and disposal of TNT has • Resulted in the contamination of many sites. • While many plant species that are able to break down TNT in their own tissue, not many can last long in TNT contaminated site. • Affects their growth and development. Ng yongchyn Tee jialeng Hidayatariff
Case Study • Entereo cloaca, a soil bacterium • was able to utilize ester explosive as its source of nitrogen. • Enzymes produced by this bacterium are • PETN reductase and Nitro-reductase. • Both enzymes degrade TNT into less harmful product. Ng yongchyn Tee jialeng Hidayatariff
Case Study • The genes expressing the production of these 2 enzymes are introduced into the plant, • Tobacco (Nicotiana tabacum) • When exposed to 0.25 mM TNT • Wild type plant became chlorotic and lose mass • Transgenic plant continue to grow • The transgenic plant are • more resistant to TNT. • metabolized TNT at far greater rate than the control plants. Ng yongchyn Tee jialeng Hidayatariff
Plants absorb contaminants through system of roots • Store them in roots • Or transport them up into the stems and leaves • It will carry on absorbing contaminants until it is being harvested Ng yongchyn Tee jialeng Hidayatariff
Phytoextraction • After the plants are allowed to absorb the contaminants for some time, they are harvested to either be • Disposed by incineration • Or be composted to recycle metals. • After the harvest, • Soil contain a lower concentration of contaminant. • This growth and harvest cycle is repeated for a number of times to achieve a considerable clean up. • After the process, remediated soil can be put into other beneficial uses. Ng yongchyn Tee jialeng Hidayatariff
Transgenic Plant on Phytoextraction • A problem in the use of hyperaccumulator • Do not have enough biomass • & growth rate to be applied in large scale practices. • To resolve this, Phytoextraction can be further improve by • Transferring genetic traits from hyper-accumulator into plants that has high biomass and growth rate. • In this way, • plants with high biomass and growth rate • will also have the ability to take up high quantity of metals. Ng yongchyn Tee jialeng Hidayatariff
Transgenic Plant on Phytoextraction • E.g. Poplar and willow • do not accumulate metals to high concentration. • However, they are still effective remediators • because of their deep root system • and biomass. • Hence, they are excellent candidate to be genetically engineered to have traits of hyper-accumulators. Ng yongchyn Tee jialeng Hidayatariff
Conclusion • While genetically modified food is known as a way to reduce the amount of pesticides and herbicides that are used in order to abate pollutions like air and water, there is always a slight chance that their might be transgenic plants that may be spun out of this genetically engineering crops. Ng yongchyn Tee jialeng Hidayatariff
Conclusion • Phytoremediation, on the other hand, uses transgenic plants to control land pollution, should there be more than the required amount of heavy metals present in the soil Ng yongchyn Tee jialeng Hidayatariff
Want to know more? • http://knowhowtogmo.wordpress.com/ • Includes pollution abatement for Eutrophication, CO2 Emission and more details on what you have seen today. Ng yongchyn Tee jialeng Hidayatariff
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