Approaches To Genetic Engineering Bioremediation: Environment

The use of genetic engineering in bioremediation processes has grown significantly. In order to control and remove these toxins from hazardous places, genetically modified microbes are used. It would be economical and environmentally friendly to use genetically modified organisms for bioremediation. Different kinds of genetically modified bacteria have been produced using recombinant DNA and RNA technology, and these bacteria have been utilized to remove heavy metals and dangerous substances from contaminated areas. A symbiotic relationship between genetically modified bacteria and transgenic plants can increase the efficacy of bioremediation of contaminated sites. This calls for methods like phytoremediation and its variations. 

 

•    Recombinant DNA technology (rDNA technology) is a technique used in genetic engineering to alter the genetic make-up of a host organism.

 

•    It entails transferring isolated DNA from the donor organism to the host organism using a vector.

 

•    The ability of vectors to multiply within their hosts should prevent any genetic alterations from occurring.

 

•    Escherichia coli (E. coli) and Agrobacterium tumefaciens are two of the most widely utilized bacteria in genetic engineering studies, however many other bacteria are also used.

 

•    E. coli is one of the most often used microbes in the disciplines of biotechnology and genetic engineering.

 

•    E. coli can generate plasmid copies in a short amount of time and with great fidelity in vast numbers.

 

•    One instance of using E. coli in genetic engineering is the production of human insulin.

 

•    Agrobacterium tumefaciens, a naturally occurring microbe, may similarly infect plants and spread some of its own DNA. They can therefore be used to spread the target gene. 

 

•    When soil, air, or water are contaminated with harmful contaminants, phytoremediation procedures are utilized to clear them up.

 

•    The use of green plants, associated microbes, suitable soil amendments, and agronomic techniques is described as "the employment of green plants and associated microbes and appropriate soil amendments and agronomic techniques to either contain, remove, or render harmful environmental toxins harmless."

 

•    Numerous plants have proven their capacity to hyper accumulate poisons at toxic waste sites, including mustard, alpine pennycress, hemp, and pigweed.

 

•    The recovery of abandoned metal mine workings, the mitigation of ongoing coal mine emissions, and the reduction of contaminants in soils, water, and the air have all been accomplished through the use of phytoremediation.

 

•    Around the world, phytoremediation activities have lowered the levels of metals, pesticides, solvents, explosives, crude oil, and its derivatives. 

 

•    The process by which plants amass pollutants in their roots, shoots, or leaves above ground is known as phytoextraction/phytoaccumulation.

 

•    The roots concentrate nutrients in the biomass above ground of the plant after absorbing them from the soil or water.

 

•    Organisms with a high capacity for absorbing contaminants are called hyper accumulators.

 

•    The last twenty years or so have seen a remarkable rise in the use of phytoextraction. Phytoextraction is a typical method used to remove heavy metals and other inorganic materials.

 

•    At the time of disposal, contaminants are frequently concentrated in a much smaller amount of plant matter than they were in the original contaminated soil or silt.

 

•    In order to achieve a meaningful cleanup, the growth/harvest cycle must typically be repeated over numerous crops because a reduced level of pollutants remain in the soil after harvest. Following the operation, the soil is remedied. 

 

•    The process of converting organic contaminants from soil, sediments, or water into a more stable, risk-free, and immobile state is known as phytotransformation, sometimes known as phytodegradation.

 

•    The organic molecules are broken down by the enzymes secreted by the plant roots, which are then ingested by the plant and eliminated through transpiration.

 

•    The best organic contaminants for this technique are herbicides, trichloroethylene, and methyl tert-butyl ether.

 

•    Phytotransformation is the term describing the chemical alteration of ambient substances as a direct result of plant metabolism, and it frequently leads to their inactivation, degradation (phytodegradation), or immobilization (phytostabilization).

 

•    The metabolism of some plants, including Cannas, renders organic toxins, like pesticides, explosives, solvents, industrial chemicals, and other xenobiotic substances, non-toxic.

 

•    In other instances, microorganisms that live close to plant roots may metabolize these substances in soil or water.

 

•    Plants can control the mobility and migration of contaminated soil through a process known as phytostabilization.

 

•    Leachable substances create an unstable mass of plant from which poisons cannot re-enter the environment by becoming adsorbent and bonding with the structure of the plant.

 

•    The plant immobilizes pollutants by bonding them to soil particles, which reduces their availability for plant or human uptake.

 

•    Contrary to phytoextraction, phytostabilization focuses on securing pollutants in the soil close to the roots rather than in plant tissues.

 

•    Exposure lowers as pollutant bioavailability goes down.

 

•    A substance that triggers a chemical process and allows the heavy metal pollution to change into a less dangerous form can likewise be excreted by plants.

 

•    Stabilization lowers the bioavailability of the contaminant while also reducing erosion, runoff, and leaching.

 

•    An illustration of phytostabilization in action is the employment of a vegetative cover to stabilize and contain mining tailings.

•    Pollutants are broken down via rhizosphere activity, also referred to as phytostimulation or rhizodegradation.

 

•    This action is brought about by the presence of proteins and enzymes produced by plants or soil organisms like bacteria, yeast, and fungi.

 

•    These microorganisms may transform harmful pollutants like fuels and solvents into benign and unharmful byproducts.

 

•    Natural carbon-containing substances that are released by plants, such as sugar, alcohols, and acids, give microorganisms more food and stimulate their activity.

 

•    Better plant-microbe interactions in transgenic plants may increase production.

 

•    It would be easier for the plant to exude the natural compounds that fuel microbial activity.

 

•    Rhizofiltration is a process that filters water via a dense network of roots to remove dangerous pollutants and extra nutrients.

 

•    The roots can take up the pollutants or transfer them to them.

 

•    By planting directly in the contaminated region or by removing the contaminated water and sending it to these plants off-site, this technique is widely employed to clean up contaminated groundwater.

 

•    In either case, plants are often grown under controlled conditions in a greenhouse.

 

•    In wetlands and estuaries, pollution is reduced with this method.

 

•    A type of bioremediation called mycoremediation uses fungi to clean up a location.

 

•    It has been demonstrated that using fungi may efficiently and sustainably remove a variety of toxins from contaminated environments or wastewater.

 

• These contaminants include heavy metals, organic pollutants, textile dyes, chemicals and effluent from leather tanning, petroleum fuels, polycyclic aromatic hydrocarbons, pharmaceuticals and personal care items, pesticides, and herbicides in ecosystems on land, in freshwater, and in the ocean.

 

•    Enzymes and edible or therapeutic mushrooms are examples of remediation byproducts that can be important resources in and of themselves and increase the profitability of cleanup.

 

•    In extremely cold or radioactive environments, when traditional cleanup processes are either too expensive or impossible to use due to the harsh conditions, some fungi can assist with the biodegradation of contaminants.

 

•    Similar techniques include mycofiltration, which uses fungus mycelium to filter hazardous waste and pathogens from water in soil.

 

•    Fungal mycelium is said to use techniques like biosorption, bioaccumulation, and biodegradation to remove contaminants and xenobiotic.

 

•    It has been discovered that a number of fungus species have exceptional capacity to absorb and eliminate metals and other pollutants from waste and/or runoff water.

 

•    In addition to having a high biosorption capacity for metals like Cu, Zn, Fe, and Mn, fungi also have the power to transform drug resistance and degrade insecticides, whether they are living or in the form of dried biomass.

 

•    Maintain Fertility: By protecting the topsoil, it keeps the soil fertile.

 

•    Improve Soil Quality And Yield: Boost plant phytochemicals, soil fertility, and yield.

 

•    Prevents Metal Leaching And Soil Erosion: Plants are also helpful in preventing metal leaching and soil erosion.

 

•    Benefits of the bacteria used here include their ability to reduce BOD, manage smell, and stop the development of oil or grease in sewage/polluted water and sediments.

 

•    These microbial consortia are able to thrive in a wider variety of temperatures.

 

•    Low Powered Aerators: Because these strains maintain an appropriate level of dissolved oxygen (DO), high-powered aerators can be avoided or used less frequently.

 

•    Only biodegradable ingredients are permitted, therefore this disadvantage only applies to them.

 

•    Some people are worried that the biodegradation products would remain around longer or will be more dangerous than the parent chemical.

 

•    Treatment Time: It requires much more time than alternative treatments like pyrolysis or cremation.

 

•    Greater Operations: It is challenging to extrapolate results from bench- and pilot-scale experiments to full-scale field operations. 

 

Therefore, efforts in plant breeding and genetic engineering can be used to enhance or add to plants' existing natural phytoremediation capacities. Genes for phytoremediation can be derived from microorganisms or passed from one plant variety to another that is more suited to the environmental conditions at the cleanup site. When bacteria's nitroreductase gene was inserted into tobacco, for instance, the TNT clearance rate and tolerance to the deleterious effects of TNT rose. 

 

It has also been demonstrated that plants possess a system that enables them to thrive even in situations where the soil's pollution level is too high for untreated plants to survive. For instance, exogenous polyamines are organic, biodegradable compounds that enable plants to withstand pollution concentrations 500 times higher than those of untreated plants.