ENVIRO PIGS
In order to address the pollution problems caused by runoff from animal operations, mainly because of the presence of phosphorous, a new series of Yorkshire pigs are being engineered.
Firstly, the main problem is that animal operations produce manures that are rich in phosphorous content. This leads to run off containing phosphorous which are retained in oceans deltas, rivers, and lakes. This results in algae blooms as the phosphorous acts as a fertilizer and sparks off the rapid growth of algae. This finally causes the formation of dead zones. Dead zones are basically areas in water which are incapable of supporting aquatic life. This is so the algae used up most of the dissolved oxygen available in the water, hence rendering the aquatic life unable to undergo respiration.
The Enviro pig, or Franken pig, is engineered as by decreasing the amount of phosphorous in animal waste scientists hope to decrease the incidence of dead zones around the world. This particular type of pig only emits of up to 35% of phosphorous in their feces and urine as compared to their normal Yorkshire counterparts. This is so as they are engineered to create their own enzyme, phytase, to break down phosphorous. Normal pigs need phosphorous in their daily food as this element is responsible for the formation of teeth, bones and cell walls as well as in a variety of cellular and organ functions. Hence, farmers provide the pigs with ingested phytase with the intent of helping the pig to break down phosphorous found in their daily food like corn or barley. However, the ingested phytase are not as effective as compared to the naturally formed phytase, hence a large percentage of the element still gets flushed out of the pigs. This in turn pollutes the environment by causing water pollution through the means of creating dead zones.
For decades, researchers and scientists have struggled to find the enzyme needed for animals to break down phosphorous but finally this elusive enzyme was found in the genome of the bacterium E Coli. To make sure this modification works for mammals, the E Coli genes are paired with a DNA mouse promoter. The DNA mouse promoter is a section of DNA that encourages the replication of a specific segment, in this case is the bacterial genes. Researchers then injected microscopic fertilized pig embryo with the mixture. This is basically how an Enviro pig comes about. They have the ability to produce their own phytase to break down phosphorous in their food and they are also able to absorb more of the element hence producing cleaner wastes.
This series of Franken pigs not only addresses environmental issues but also societal challenges in pig farming. This is so as there is no more need for farmers to supplement their pigs with ingested phytase, hence this reduces the overall costs of pig farming. However, this Enviro pig is still currently in the researching and testing process and is yet to pass safety tests with U.S food and drug administration. So far no transgenic food has been approved for consumption and this pig might not be in the market anytime sooner as these tests might take years to overcome.
If this particular breed of pigs is passed fit for consumption, there might be a leap in this aspect of genetic engineering as more animals would be able to create their own enzymes to break down elements which would cause pollution when excreted. This would lead to greener animal operations and hence a greener Earth.
Tuesday, July 27, 2010
Disadvantages of chemical addition in treating pollution
Why microorganisms are nowadays frequently used instead of chemicals to bioremediate pollution?
Microorganisms (primarily bacteria and fungi) are nature's original recyclers. Their capability to transform natural and synthetic chemicals into sources of energy and raw materials for their own growth suggests that expensive chemical or physical remediation processes might be replaced with biological processes that are lower in cost and more environmentally friendly.
Scenario 1: Metal Removal in Fluid Environment Using Chemical Treatment
Disadvantages:
• Corrosive chemicals are required for use (sulfuric acid, sodium hydroxide).
• Chemical treatment is very sensitive to changes in emulsifier (surfactant) chemistry.
• Specialized instruments are required (pH meter).
• Instruments require frequent calibration (pH meter).
• Chemical changes and/or meter malfunctions can result in poor water quality without notice.
• Balancing chemical reactions, at times, can be more an art than a science.
• Synthetic fluids cannot be effectively treated by this method.
• The basic concepts of this method are abstract and are not easily understood by persons without some chemistry background.
Scenario 2: Disinfection in Water Treatment
Disadvantages:
Excess chlorine in water can combine with organic material in the water to form substances such as trihalomethanes, which can cause liver, kidney, or central nervous system problems, and are linked to an increased risk of cancer over a lifetime exposure.
Scenario 3: Pre-tanning processes of Leather Processing
Disadvantages:
Chemicals such as lime, sodium sulphide, and caustic soda are introduced in soaking, dehairing, bating, degreasing and offal treatment. The tannery effluents are released into the rivers and streams contaminating with the toxic chemicals. Therefore, leather industry contributes to one of the major industrial pollution problems facing countries such as India.
Microorganisms (primarily bacteria and fungi) are nature's original recyclers. Their capability to transform natural and synthetic chemicals into sources of energy and raw materials for their own growth suggests that expensive chemical or physical remediation processes might be replaced with biological processes that are lower in cost and more environmentally friendly.
Scenario 1: Metal Removal in Fluid Environment Using Chemical Treatment
Disadvantages:
• Corrosive chemicals are required for use (sulfuric acid, sodium hydroxide).
• Chemical treatment is very sensitive to changes in emulsifier (surfactant) chemistry.
• Specialized instruments are required (pH meter).
• Instruments require frequent calibration (pH meter).
• Chemical changes and/or meter malfunctions can result in poor water quality without notice.
• Balancing chemical reactions, at times, can be more an art than a science.
• Synthetic fluids cannot be effectively treated by this method.
• The basic concepts of this method are abstract and are not easily understood by persons without some chemistry background.
Scenario 2: Disinfection in Water Treatment
Disadvantages:
Excess chlorine in water can combine with organic material in the water to form substances such as trihalomethanes, which can cause liver, kidney, or central nervous system problems, and are linked to an increased risk of cancer over a lifetime exposure.
Scenario 3: Pre-tanning processes of Leather Processing
Disadvantages:
Chemicals such as lime, sodium sulphide, and caustic soda are introduced in soaking, dehairing, bating, degreasing and offal treatment. The tannery effluents are released into the rivers and streams contaminating with the toxic chemicals. Therefore, leather industry contributes to one of the major industrial pollution problems facing countries such as India.
GM Products: Benefits and Controversies
Benefits
• Crops
o Enhanced taste and quality
o Reduced maturation time
o Increased nutrients, yields, and stress tolerance
o Improved resistance to disease, pests, and herbicides
o New products and growing techniques
• Animals
o Increased resistance, productivity, hardiness, and feed efficiency
o Better yields of meat, eggs, and milk
o Improved animal health and diagnostic methods
• Environment
o "Friendly" bioherbicides and bioinsecticides
o Conservation of soil, water, and energy
o Bioprocessing for forestry products
o Better natural waste management
o More efficient processing
• Society
o Increased food security for growing populations
Controversies
• Safety
o Potential human health impacts, including allergens, transfer of antibiotic resistance markers, unknown effects
o Potential environmental impacts, including: unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity
• Access and Intellectual Property
o Domination of world food production by a few companies
o Increasing dependence on industrialized nations by developing countries
o Biopiracy, or foreign exploitation of natural resources
• Ethics
o Violation of natural organisms' intrinsic values
o Tampering with nature by mixing genes among species
o Objections to consuming animal genes in plants and vice versa
o Stress for animal
• Labeling
o Not mandatory in some countries (e.g., United States)
o Mixing GM crops with non-GM products confounds labeling attempts
• Society
o New advances may be skewed to interests of rich countries
Directly taken from http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
• Crops
o Enhanced taste and quality
o Reduced maturation time
o Increased nutrients, yields, and stress tolerance
o Improved resistance to disease, pests, and herbicides
o New products and growing techniques
• Animals
o Increased resistance, productivity, hardiness, and feed efficiency
o Better yields of meat, eggs, and milk
o Improved animal health and diagnostic methods
• Environment
o "Friendly" bioherbicides and bioinsecticides
o Conservation of soil, water, and energy
o Bioprocessing for forestry products
o Better natural waste management
o More efficient processing
• Society
o Increased food security for growing populations
Controversies
• Safety
o Potential human health impacts, including allergens, transfer of antibiotic resistance markers, unknown effects
o Potential environmental impacts, including: unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity
• Access and Intellectual Property
o Domination of world food production by a few companies
o Increasing dependence on industrialized nations by developing countries
o Biopiracy, or foreign exploitation of natural resources
• Ethics
o Violation of natural organisms' intrinsic values
o Tampering with nature by mixing genes among species
o Objections to consuming animal genes in plants and vice versa
o Stress for animal
• Labeling
o Not mandatory in some countries (e.g., United States)
o Mixing GM crops with non-GM products confounds labeling attempts
• Society
o New advances may be skewed to interests of rich countries
Directly taken from http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
Engineered bacteria to convert carbon dioxide into liquid fuel
Introduction
Global warming is becoming a major concern for environmentalists and the general public. On the other hand, the power plants and factories need to continue their operations in order to meet the demands of the growing population. This goes to show that greenhouse gases will still be generated and emitted to the environment. Thus, pollutants such as carbon dioxide, nitrous dioxide, ozone will absorb and re-emit the infrared radiation back to the atmosphere.
However, a recent study made by a team from University of California-Los Angeles (UCLA) Henry Samueli School, Engineering and Applied Science, has produced a promising solution to the problem.
In December 2009, the research was published in an online journal Nature Biotechnology. The team applied the fundamentals of recombinant DNA technology to genetically modify a cynobaterium. The genetically modified bacterium has the ability to consume carbon dioxide and produce isobutanol. Isobutanol is a liquid fuel and can be a gas alternative to automobiles. The process will only require sunlight as the main source of energy. This is to ensure that the cynobacterium will photosynthesize the carbon dioxide.
Process
Steps taken:
1. Constructing the bacterium
2. Gas extraction
3. Chemical catalysis process
Constructing the bacterium
The cynobacterium, Synechoccus elongatus, is altered to possess carbon dioxide fixing enzyme (RuBisCO) and other genes. This step is carried out to ensure that the genetically modified bacterium has the desired characteristics. The strain has the ability to uptake carbon dioxide and sunlight to produce isobutyraldehyde gas.
Genetically modified cynobacterium + Carbon dioxide + Sunlight → Isobutyraldehyde gas
Gas extraction
The isobutyraldehyde gas can easily be extracted because it has a low boiling point and high vapor pressure.
Chemical catalysis process
After extraction, chemical catalysis process will help convert isobutyraldehyde gas to isobutanol or other petroleum-based products. This process is inexpensive and easier as compared to allowing the gas to directly produce isobutanol.
Isobutyraldehyde gas → Isobutanol + Petroleum based products
Advantages
There are several advantages of this new method. Firstly, it ensures a cleaner and greener economy in a long run. This is true because it recycles carbon dioxide. This reduces the amount of greenhouse gases produced as a result of burning fossil fuels. In other words, the method is reducing the rate and minimizing the impacts of global warming.
In addition, the energy requirement is minimal and clean. Solar energy is needed for the cynobacterium to convert carbon dioxide into liquid fuel, which can then be supplied to automobiles. Solar energy is a green form of technology and can be powered by natural sunlight.
Furthermore, it provides an alternative to biofuels(plants, algae, cellulosic biomass). The only difference between the two methods is in one of the steps towards fuel refinement. The new method allows operators to skip biomass deconstruction. It is believed that biomass deconstruction is an expensive process. Therefore, it is evident that the method is more efficient and cost effective.
Disadvantages
In any technology or process, there are advantages and disadvantages. Similarly, this new method has its flaws. On the contrary, there is still room for improvement. As the method is new, it will need further study to emphasize its capability to reduce greenhouse gases and produce liquid fuels. In depth studies will enhance rate and yield of production. The team will need to consider the following factors namely the efficiency of light distribution (photosynthesis) and cost reduction of the bioreactor.
Application
In the future, the bioreactor can be constructed next to power plants. The gases emitted from the stack can be captured before the plume disperses into the atmosphere. Furthermore, the captured gas can be recycled by converting it to liquid fuel. The production of liquid fuel will be an additional benefit to the power plant. It can be used within the premises or sold to external companies.
Evaluation
The above process is supported by the U.S Department of Energy. This implies that the government is keen in venturing into the technology. It is interesting to see that even a pollutant can be a resource with the assistance of technology. The future for this technology is bright and promising. Time will tell whether this technique will be effective in controlling the rate of greenhouse gas emissions into the atmosphere and in slowing down the rate of global warming.
Global warming is becoming a major concern for environmentalists and the general public. On the other hand, the power plants and factories need to continue their operations in order to meet the demands of the growing population. This goes to show that greenhouse gases will still be generated and emitted to the environment. Thus, pollutants such as carbon dioxide, nitrous dioxide, ozone will absorb and re-emit the infrared radiation back to the atmosphere.
However, a recent study made by a team from University of California-Los Angeles (UCLA) Henry Samueli School, Engineering and Applied Science, has produced a promising solution to the problem.
In December 2009, the research was published in an online journal Nature Biotechnology. The team applied the fundamentals of recombinant DNA technology to genetically modify a cynobaterium. The genetically modified bacterium has the ability to consume carbon dioxide and produce isobutanol. Isobutanol is a liquid fuel and can be a gas alternative to automobiles. The process will only require sunlight as the main source of energy. This is to ensure that the cynobacterium will photosynthesize the carbon dioxide.
Process
Steps taken:
1. Constructing the bacterium
2. Gas extraction
3. Chemical catalysis process
Constructing the bacterium
The cynobacterium, Synechoccus elongatus, is altered to possess carbon dioxide fixing enzyme (RuBisCO) and other genes. This step is carried out to ensure that the genetically modified bacterium has the desired characteristics. The strain has the ability to uptake carbon dioxide and sunlight to produce isobutyraldehyde gas.
Genetically modified cynobacterium + Carbon dioxide + Sunlight → Isobutyraldehyde gas
Gas extraction
The isobutyraldehyde gas can easily be extracted because it has a low boiling point and high vapor pressure.
Chemical catalysis process
After extraction, chemical catalysis process will help convert isobutyraldehyde gas to isobutanol or other petroleum-based products. This process is inexpensive and easier as compared to allowing the gas to directly produce isobutanol.
Isobutyraldehyde gas → Isobutanol + Petroleum based products
Advantages
There are several advantages of this new method. Firstly, it ensures a cleaner and greener economy in a long run. This is true because it recycles carbon dioxide. This reduces the amount of greenhouse gases produced as a result of burning fossil fuels. In other words, the method is reducing the rate and minimizing the impacts of global warming.
In addition, the energy requirement is minimal and clean. Solar energy is needed for the cynobacterium to convert carbon dioxide into liquid fuel, which can then be supplied to automobiles. Solar energy is a green form of technology and can be powered by natural sunlight.
Furthermore, it provides an alternative to biofuels(plants, algae, cellulosic biomass). The only difference between the two methods is in one of the steps towards fuel refinement. The new method allows operators to skip biomass deconstruction. It is believed that biomass deconstruction is an expensive process. Therefore, it is evident that the method is more efficient and cost effective.
Disadvantages
In any technology or process, there are advantages and disadvantages. Similarly, this new method has its flaws. On the contrary, there is still room for improvement. As the method is new, it will need further study to emphasize its capability to reduce greenhouse gases and produce liquid fuels. In depth studies will enhance rate and yield of production. The team will need to consider the following factors namely the efficiency of light distribution (photosynthesis) and cost reduction of the bioreactor.
Application
In the future, the bioreactor can be constructed next to power plants. The gases emitted from the stack can be captured before the plume disperses into the atmosphere. Furthermore, the captured gas can be recycled by converting it to liquid fuel. The production of liquid fuel will be an additional benefit to the power plant. It can be used within the premises or sold to external companies.
Evaluation
The above process is supported by the U.S Department of Energy. This implies that the government is keen in venturing into the technology. It is interesting to see that even a pollutant can be a resource with the assistance of technology. The future for this technology is bright and promising. Time will tell whether this technique will be effective in controlling the rate of greenhouse gas emissions into the atmosphere and in slowing down the rate of global warming.
Monday, July 26, 2010
Poplar Tree
Trees with rabbit genes accelerate cleaning of soil
In a recent study, Sharon Doty, of the University of Washington, Seattle have developed transgenic poplars with an enhanced uptake and metabolism of toxic volatile pollutants. In doing so, they have delivered a technology that is likely to lead to the wider application of phytoremediation in the field.
Poplars use an enzyme called cytochrome P450 to break down contaminants. Mammalian cytochrome P450 has been used in the past to create GM plants that can detoxify herbicide-treated fields.
Although poplars already naturally remove contaminants from the environment, the rabbit liver enzyme speeds up the process.
Tests on six-inch tall GM poplar cuttings which had a gene from a rabbit inserted into them showed that they could remove up to 91% of a chemical called trichloroethylene(TCE) from the water used in their feed. This chemical, used as an industrial degreaser and one of the most common contaminants of ground water, was broken down by the plants into harmless byproducts more than 100 times faster than by unaltered plants. Trichloroethylene is turned into a harmless salt, water and carbon dioxide.
After Dr Doty's team inserted the gene into the tree from a rabbit they also produced P450, but at a much faster rate. Ultimately, the scientists would like to manipulate the plant's own genes to achieve the same goal.
The engineered trees were capable of the enhanced metabolism of five volatile toxic compounds: TCE, vinyl chloride, carbon tetrachloride, chloroform and benzene.
ADVANTAGES/DISADVANTAGES
In comparison with other clean-up technologies, phytoremediation has potentially many advantages, including low installation and maintenance costs, less disruption of the environment and other beneficial side effects such as carbon sequestration and biofuel production. However, phytoremediation also suffers from several limitations, among which the most commonly evoked are the slow rate of removal, incomplete metabolism and potential increase in bioavailability of toxic contaminants. Indeed, in the absence of significant detoxification, parent compounds and toxic metabolites can accumulate inside plant tissues and eventually return to the soil or volatilize into the atmosphere.
RESEARCH
Among the different transgenic clones tested, the most efficient one, line 78, expressed CYP2E1 at a 3.7- to 4.6-fold higher level and exhibited the highest level of TCE metabolism (>100-fold higher than in non-transgenic controls). When cultivated in hydroponic solution spiked with toxic compounds, line 78 was capable of extracting 90% of TCE (compared with 3% extracted by non-transgenic controls), 99% of chloroform (compared with 20% by controls) and 92–94% of carbon tetrachloride (compared with 20% by controls). Enhanced metabolism of organic pollutants in transgenic plants is associated with a faster uptake, which can be explained by a steeper concentration gradient inside plant tissues. Transgenic plants were also shown to remove volatile compounds from contaminated air at a higher rate than non-transgenic controls: 79% of TCE (none removed by controls), 49% of vinyl chloride (compared with 29% by controls) and 40% of benzene (compared with 13% by controls).
Figure 1. Phytoremediation involves several processes:
Resources:
http://news.nationalgeographic.com/news/2007/10/071015-plants-toxic.html http://www.guardian.co.uk/environment/2007/oct/16/gmcrops http://www.iasvn.org/uploads/files/phyto-transgenic_0626083555.pdf
In a recent study, Sharon Doty, of the University of Washington, Seattle have developed transgenic poplars with an enhanced uptake and metabolism of toxic volatile pollutants. In doing so, they have delivered a technology that is likely to lead to the wider application of phytoremediation in the field.
Poplars use an enzyme called cytochrome P450 to break down contaminants. Mammalian cytochrome P450 has been used in the past to create GM plants that can detoxify herbicide-treated fields.
Although poplars already naturally remove contaminants from the environment, the rabbit liver enzyme speeds up the process.
Tests on six-inch tall GM poplar cuttings which had a gene from a rabbit inserted into them showed that they could remove up to 91% of a chemical called trichloroethylene(TCE) from the water used in their feed. This chemical, used as an industrial degreaser and one of the most common contaminants of ground water, was broken down by the plants into harmless byproducts more than 100 times faster than by unaltered plants. Trichloroethylene is turned into a harmless salt, water and carbon dioxide.
After Dr Doty's team inserted the gene into the tree from a rabbit they also produced P450, but at a much faster rate. Ultimately, the scientists would like to manipulate the plant's own genes to achieve the same goal.
The engineered trees were capable of the enhanced metabolism of five volatile toxic compounds: TCE, vinyl chloride, carbon tetrachloride, chloroform and benzene.
- trichloroethylene(TCE)- commonly used as an industrial solvent & it is one of the most common contaminants of ground water
- Vinyle chloride- used to make plastic. It is highly toxic, flammable and carcinogenic.
- Carbon tetrachloride- Exposure to high concentrations of carbon tetrachloride (including vapor) can affect the central nervous system, degenerate the liver and kidneys and may result (after prolonged exposure) in coma and even death. Chronic exposure to carbon tetrachloride could result in cancer.
- Chloroform – a byproduct of disinfection of drinking water. chloroform vapors depress the central nervous system.
- Benzene- carcinogenic, may cause death in high level breathing.
ADVANTAGES/DISADVANTAGES
In comparison with other clean-up technologies, phytoremediation has potentially many advantages, including low installation and maintenance costs, less disruption of the environment and other beneficial side effects such as carbon sequestration and biofuel production. However, phytoremediation also suffers from several limitations, among which the most commonly evoked are the slow rate of removal, incomplete metabolism and potential increase in bioavailability of toxic contaminants. Indeed, in the absence of significant detoxification, parent compounds and toxic metabolites can accumulate inside plant tissues and eventually return to the soil or volatilize into the atmosphere.
RESEARCH
Among the different transgenic clones tested, the most efficient one, line 78, expressed CYP2E1 at a 3.7- to 4.6-fold higher level and exhibited the highest level of TCE metabolism (>100-fold higher than in non-transgenic controls). When cultivated in hydroponic solution spiked with toxic compounds, line 78 was capable of extracting 90% of TCE (compared with 3% extracted by non-transgenic controls), 99% of chloroform (compared with 20% by controls) and 92–94% of carbon tetrachloride (compared with 20% by controls). Enhanced metabolism of organic pollutants in transgenic plants is associated with a faster uptake, which can be explained by a steeper concentration gradient inside plant tissues. Transgenic plants were also shown to remove volatile compounds from contaminated air at a higher rate than non-transgenic controls: 79% of TCE (none removed by controls), 49% of vinyl chloride (compared with 29% by controls) and 40% of benzene (compared with 13% by controls).
Figure 1. Phytoremediation involves several processes:
pollutants in soil and groundwater can be taken up inside plant tissues (phytoextraction) or adsorbed to the roots
(rhizofiltration); pollutants inside plant tissues can be transformed by plant enzymes (phytotransformation) or can volatilize into the atmosphere
(rhizofiltration); pollutants inside plant tissues can be transformed by plant enzymes (phytotransformation) or can volatilize into the atmosphere
(phytovolatilization);pollutants in soil can be degraded by microbes in the root zone (rhizosphere bioremediation) or incorporated in soil material (phytostabilization)
EVALUATION
Overall, the technology is very efficient for treating any contaminated sites. Transgenic poplars are much better than normal poplars since they enhance the uptake and metabolism of organic pollutants. Despite being a slow process, the transgenic poplars are fast growing thus increasing efficiency. Trangenic poplars have low installation and maintenance cost. Moreover, it is a good source for paper/ wood manufacturing and also good biomass. Eventhough gene pollution may occur, poplar trees can grow several years without flowering. As such, the tress could be harvested before their seeds germinates and spread their genes.
Resources:
http://news.nationalgeographic.com/news/2007/10/071015-plants-toxic.html http://www.guardian.co.uk/environment/2007/oct/16/gmcrops http://www.iasvn.org/uploads/files/phyto-transgenic_0626083555.pdf
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