Synthetic Biology: The Future of Bioremediation
In 2012, the World Health Organization “reported that an estimated 12.6 million people died as a result of living or working in an unhealthy environment.” Pollution has grown rapidly in recent years, largely due to ever-increasing urbanization and industrialization coupled with unsafe farming practices. However, several areas impacted by environmental degradation, such as soil, groundwater, and sediment, are often ignored by the general public. Therefore, the severe toxicity and contamination occurring just below the surface remains a mystery to most.
The primary sources of land pollution are oil, heavy metals, solvents, pesticides, and other synthetic products and dyes. These contaminants pose significant problems to both groundwater and soil, as mentioned earlier. Soil pollution is linked with biodiversity loss, disruption to microbial communities, and reduced crop yields. Additionally, groundwater pollution is associated with widespread health problems, such as hepatitis and dysentery, for humans. Heavy metals are also water pollutants, leading to cancer if consumed in high concentrations. Therefore, scientific efforts to find an inexpensive, effective, and adaptable solution to soil and groundwater pollution led to the development of bioremediation.
Bioremediation is a process that utilizes living microorganisms, such as microbes and bacteria, to remove contaminants and pollutants from soil and groundwater. The microorganisms used are capable of converting toxins into small amounts of water or harmless gases. This process can be conducted both “in situ,” in the contaminated site, or “ex situ,” outside the contaminated site. Ex situ bioremediation requires the removal of contaminated soil from the ground to an alternative site where the process can then successfully occur. This is necessary if low temperatures or dense soil hinder the bioremediation process in situ.
This has become a favored tool for environmental scientists as it hosts various advantages over other clean-up processes. Firstly, bioremediation minimizes damage to ecosystems as it can largely occur underground. Other cleanup processes generally require excavation or extraction, both of which disrupt the natural ecosystem. Additionally, the process is relatively cheap as minimal tools, labor, and equipment are necessary. This makes bioremediation sustainable for the Environmental Protection Agency (EPA), which manages large national clean-up initiatives, and smaller organizations and businesses.
As bioremediation is used to clean real-world contamination issues, such as oil spills, industrial waste sites, and hazardous chemical deposits, several methods have been developed. All types fall under two primary categories, intrinsic or extrinsic. Intrinsic bioremediation utilizes the ability of native organisms to mitigate pollution, relying on only naturally-developed species within the environment. Conversely, extrinsic bioremediation achieves cleaner soil and groundwater through the introduction of foreign agents. As this form involves additions to the environment, it is generally a faster and more controlled process. However, intrinsic bioremediation is more affordable, making the decision between the two forms complex.
This article is primarily focused on extrinsic bioremediation, as many scientists have explored the use of synthetic microorganisms to expedite the cleanup process. Exploring synthetic biology for bioremediation became a goal of environmentalists due to the specific conditions necessary for bioremediation to be effective. The cleanup site needs a combination of the right temperatures, proper nutrients, optimal pH levels, and additional factors. If these are not met, the process can be severely delayed or in some cases, completely ineffective. This led to a synthetic approach as the production of microorganisms capable of performing under sub-par conditions is easier than altering the conditions themselves.
The creation of synthetic biology requires changing the genetic codes of organisms. To do so, scientists stitch together long strands of DNA, which are then inserted in the organism’s genome. The strands of DNA inserted can be based on genes found in other organisms or lab-based designs. Therefore, organisms with entirely novel traits can be produced. This process is largely reliant on modern technology, including devices for DNA sequencing and genetic engineering. As such, it is often compared to “genome editing.” However, greater stretches of DNA are changed in synthetic biology, making it a slightly different process.
There are several modern-day examples of successful genetic modifications in the field of bioremediation. By editing enzymes in Ideonella Sakaiensis, a strain of bacteria, scientists improved its ability to decompose polyethylene terephthalate (PET), a common plastic used in the textile industry. Through CRISPR technology, 300 genes were eliminated and replaced in Pseudomonas, another strain of bacteria, to improve its decomposition of chlorinated pollutants. More recently, the genes responsible for decomposing explosive chemicals have been engineered into rhizosphere-colonizing bacteria, allowing bioremediation to occur effectively in military sites. Ultimately, synthetic biology is rapidly changing how scientists approach bioremediation. These changes will only increase as improvements are made in the field of biotechnology, with technological advancements at the forefront of genetic modification.
However, this increased reliance on synthetic microorganisms has raised several ethical questions. A major concern raised by philosophers is the implications of synthetic biology on the natural order. If human beings can change or create life, some fear the preservation of nature will be ignored in an attempt to promote human interests. This struggle between the natural world and the man-made one is only amplified as synthetic technology improves, creating great fears for a potential future in which a majority of organisms are lab-made. Still, the greatest ethical question posed by scholars surrounding genetic modification is: When will we draw the line? Should we preserve the imperfections and inadequacies of natural life or strive for perfection and efficiency? Which organisms should modifications impact and which should be protected from any changes? If we are able to change all that we want in microorganisms, what are the implications for humans and larger organisms? All of these questions surround the field of synthetic biology, creating a large ethical dilemma surrounding its application in modern life. Therefore, this connects modern bioremediation to a widespread academic and moral conflict that must be addressed before improvements to the field can be made.
Additionally, there are key environmental implications of synthetic biology that make its implementation in bioremediation questionable. This debate seems counterintuitive considering the goal of synthetic microorganisms is to improve environmental conditions. However, it is the very release of these organisms that poses environmental harm. They can alter local ecosystems, posing threats to native plants and organisms. Some scientists have even argued that they could become invasive species in certain communities, threatening biodiversity and lowering resources. Another environmental factor to consider is the use of synthetic biology for bioterrorism. As the field develops, synthetic biology could be used to create nefarious biological weapons that could harm plants, animals, and humans. This possibility could pose widespread environmental harm, therefore contradicting the original purpose of the technology itself. As such, the microscopic alterations used for bioremediation must be considered in the overall context of synthetic biology’s environmental implications.
Overall, the use of synthetic biology in the field of bioremediation has limited environmental pollution in soil and groundwater while also increasing the effectiveness of this process. Its modern applications have only increased with the growth of biotechnology. However, its ethical and environmental implications must be considered as scholarly debate grows. This field will continue to intrigue the public as it develops in the upcoming years, paving the way for new environmental preservation methods in a world of synthetic production.
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