lecture 7 Flashcards
Genetic engineering definition
Genetic engineering is the act of modifying the genetic makeup of an organism. Modifications can be generated by methods such as gene targeting, nuclear transplantation, transfection of synthetic chromosomes or viral insertion. Selective breeding is not considered a form of genetic engineering.
Synthetic Biology
Synthetic biology is the design and construction of new biological parts, devices, and systems, and the re-design of existing, natural biological systems for useful purposes.
2 types of synthetic biology in agriculture
Agri-biotech investors and their affiliated scientists who consider agricultural biotechnology as a solution to food shortage, the scarcity of environmental resources and weeds and pests infestations
2) independent scientists, environmentalists, farmers and consumers who warn that genetically modified food introduces new risks to food security, the environment and human health such as loss of biodiversity; the emergence of superweeds and superpests; the increase of antibiotic resistance, food allergies and other unintended effects.
Application in agriculture
An important application of recombinant DNA technology is to alter the genotype of crop plants to make them more productive, nutritious, rich in proteins, disease resistant, and less fertilizer consuming. Recombinant DNA technology and tissue culture techniques can produce high yielding cereals, pulses and vegetable crops.
Application in medicine
Genetic engineering has been gaining importance over the last few years and it will become more important in the current century as genetic diseases become more prevalent and agricultural area is reduced. Genetic engineering plays significant role in the production of medicines.
Microorganisms and plant based substances are now being manipulated to produce large amount of useful drugs, vaccines, enzymes and hormones at low costs. Genetic engineering is concerned with the study (inheritance pattern of diseases in man and collection of human genes that could provide a complete map for inheritance of healthy individuals.
Gene therapy by which healthy genes can be inserted directly into a person with malfunctioning genes is perhaps the most revolutionary and most promising aspect of genetic engineering. The use of gene therapy has been approved in more than 400 clinical trials for diseases such as cystic fibres emphysema, muscular dystrophy, adenosine deaminase deficiency.
Energy production
Recombinant DNA technology has tremendous scope in energy production. Through this technology Ii is now possible to bioengineer energy crops or biofuels that grow rapidly to yield huge biomass that used as fuel or can be processed into oils, alcohols, diesel, or other energy products.
The waste from these can be converted into methane. Genetic engineers are trying to transfer gene for cellulase to proper organisms which can be used to convert wastes like sawdust and cornstalks first to sugar and then to alcohol.
Application to industries
Genetically designed bacteria are put into use for generating industrial chemicals. A variety of organic chemicals can be synthesised at large scale with the help of genetically engineered microorganisms. Glucose can be synthesised from sucrose with the help of enzymes obtained from genetically modified organisms.
Now-a-days with the help of genetic engineering strains of bacteria and cyanobacteria have been developed which can synthesize ammonia at large scale that can be used in manufacture of fertilisers at much cheaper costs. Microbes are being developed which will help in conversion of Cellulose to sugar and from sugar to ethanol.
Recombinant DNA technology can also be used to monitor the degradation of garbage, petroleum products, naphthalene and other industrial wastes.
For example bacterium pseudomonas fluorescens genetically altered by transfer of light producing enzyme called luciferase found in bacterium vibrio fischeri, produces light proportionate to the amount of its breaking down activity of naphthalene which provides way to monitor the efficiency of the process.
AGRICULTURE (5)
- development of crops with enhanced tolerance to field conditions, climate change
- Resistance to insect pests
- Herbicide tolerance
- Disease resistance
- Vitamin enrichment
Medicine
Hormones, eg. Insulin , human growth factor Monoclonal antibodies Vaccines Drugs Enzymes Gene therapy
Energy production
Bioengineer energy crops
Bioengineer bacteria to utilise cellulase and hemicellulast to generate biofuel from green waste eg
Algae for biofuels
Industry
Bacteria generate industrial chemicals on a large scale eg ammonia production
Bioremediation
Biosensors
Problems with TNT
The problems with TNT:
A synthetic chemical not found in nature
Toxic and causes cancer
Does not readily break-down in the environment
Plants have only a very limited ability to detoxify TNT (plants with the ability to degrade TNT have not been found)
A co-pollutant with RDX
Sticks to the soil, and does not wash easily into ground water
One way to think about TNT is as a kind of “toxic Velcro”. TNT binds tightly to the soil particles and is not readily washed through the soil. Particularly toxic to plants, the accumulating “toxic Velcro” reduces the ability of plants to establish and grow in the contaminated soil.
Munitions Pollution
Explosive compounds used in munitions are highly toxic
Production facilities and training ranges serve as the most common sites for contamination in soil, plants and groundwater
Main explosives in artillery, mortars and bombs are 2,4,6-trinitrotoluene (TNT) and Composition B (containing TNT and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX))
Problems with RDX
The problems with RDX:
A synthetic chemical not found in nature
Toxic
Does not readily break-down in the environment
Plants have only a very limited ability to breakdown RDX
A co-pollutant with TNT
Washes easily into ground water threatening drinking water supplies
A perhaps rather disgusting, but certainly memorable, way to remember the problem with RDX is that the effect of RDX in the soil is a little like the effect of a vindaloo curry on your digestive system: RDX rapidly travels through the soil!
Solution
Though the ability of microorganisms to breakdown a variety of xenobiotics has made the use of bioaugmentation seems promising, some studies reported that indigenous microbes frequently outcompete the foreign microbes, which results in limited successPlant-assisted degradation of xenobiotics through phytoremediation could offer an environmentally friendly, cost-effective technique for remediating explosive compounds. Certain plants have developed intricate detoxification systems to deal with explosives [2], which allow them to survive in areas with concentrations of these contaminants. Their root systems can take up the xenobiotics [2], while stabilizing the soils and minimizing the atmospheric release of contaminated dusts [6]. Plants offer additional benefits, as they could supply nutrients for the rhizosphere bacteria which may symbiotically aid in remediation, while the plants themselves would make monitoring of the site easier through tissue collection and even simple visualization [6]. The limitation of phytoremediation is that it is a time-consuming process. However, since explosive-contaminated sites are unusable, and given that such contamination usually covers large expanses of land, phytoremediation could be an appropriate technology for the remediation of explosive-contaminated sites [4].
