Earth’s biodiversity is declining at an unprecedented rate. 1 million species face extinction in the next decades if the current trajectory continues1. Synthetic biology as a potential tool to preserve biodiversity and restore natural ecosystems. Research into how synthetic biology can help is at an early stage, but if the risks to altering nature are properly handled, it could help to clean polluted waters, control invasive species and reverse changes to natural ecosystems10.
Synthetic biology is defined as a collection of technologies that allows us to make precise alterations to the genes of organisms, in other words, applying engineering principles to DNA. DNA is the hereditary material found in the cells of almost every organism, including humans. Humans have been manipulating the DNA of plants and animals for millennia, by selectively breeding plants and animals with desirable features. But the recent development of gene editing tools like the CRISPR-Cas 9 make it possible to edit DNA, faster and more efficiently than ever before3. The usual process is to identify gene sequences that give organisms certain traits, and then insert them into other microorganisms so that they produce the desired proteins or functions. But some also go further and create completely new biological organisms and systems.
Synthetic biology is already used for important applications like sustainable production of bioenergy, materials, drugs and food and is often imperative for reducing emissions. Technology to capture CO2 from industrial emissions and transform it to fuels and chemicals by using microorganisms for carbon recycling is one interesting example4.
But in order to reach the UN SDGs we need to go further than reducing emissions: we also need to restore ecological balance and remove pollution and plastic waste from our industrial processes and other human activities. Advances in synthetic biology will be part of the solution to some of the most severe threats to the environment including reducing chemical and plastic pollution, recycling CO2 from the atmosphere and protecting against biodiversity loss.Reducing pollution naturally
It is well known that many microbes can naturally decontaminate soil or water. In a process called bioremediation, microbes use pollutants as energy to break down organic compounds and absorb unwanted inorganic substances from the environment. Synthetic biology is used to enhance these capabilities by creating gene-modified microorganisms that can be used to restore the balance of nature in the wake of pollution incidents5. As an example, much research is underway to identify how bacterial enzymes with the ability to degrade PET-plastic (a significant pollutant in many environments6). These microorganisms can be used as part of the process at recycling sites or introduced into polluted environments to degrade unwanted plastics.
Synthetic biology is also used to capture CO2 from the atmosphere and convert it into usable products by genetically modifying CO2-fixing organisms. One interesting example is how bacteria fed with CO2 can produce proteins to replace fish in fishmeal7. As a result, synthetic biology could help reduce CO2 in the atmosphere while also reducing the need for fish.
Another example is the creation of synthetic jellyfish that can break down and absorb toxic chemicals when they are released into marine environments after toxic spills8. As the jellyfish are designed to avoid replication and can be programmed to “die” after a certain time, they can be released into the environment in immense numbers, perform their job and disintegrate and disappear from the ecosystem. The technology to design such synthetic organisms (biomimetic multicellular structures) is still under development, but it has significant potential in the future clean-up of polluted marine ecosystems.Preserving biodiversity
Synthetic biology can also be used to preserve biodiversity by strengthening organisms’ resilience to external threats. Genetic modifications to living organisms and the use of ‘gene drives’ and can help us preserve biodiversity caused by threats to the ecosystems.
A gene drive is a natural phenomenon that changes the odds of inheriting genes. This means that a gene can be inherited at a frequency above the usual 50% such that the gene drive element can spread through populations without providing a fitness advantage. Engineered gene drive systems can be used to provide bias inheritance throughout a population to drive local extinction, for example, by distorting the sex ratio. This is often considered to be a more humane way of managing invasive populations in order to protect the endangered species. However, this approach presents several important risks, including the possibility of genetic spread to other species and populations9.Coral bleaching
Pollution and warmer oceans have resulted in extensive coral bleaching. Coral bleaching, or whitening of coral, is a result of the loss of a coral’s symbiotic algae or the degradation of the algae’s photosynthetic pigment. Such bleaching destroys coral reefs, the most biologically diverse ecosystem in the ocean and an essential habitat for many species of fish and invertebrates10. Current conservation efforts have been insufficient to prevent further bleaching. Scientists are testing how to edit genes in corals, not to make them heat resistant, but to learn more about the species’ ability to handle stress in the environment, which can aid conservation efforts more indirectly11.Invasive species
Another threat to biodiversity is the transfer of species from one area or ecosystem to another12. This is often caused by ships, air travel and other forms of long-distance transport which inadvertently transport organisms and introduces them to new environments. Without natural enemies, these organisms can breed excessively and displace or destroy other species or ecosystems.
Rodents are one of the most common invasive species, disrupting natural habitats, contributing to serious species decline and the extinction of native species. A possible solution to invasive rodents could be to use a variant of the so called “gene drive”.Opportunities and market impacts
The potential impact of synthetic biology is vast. Over the last 15 years, there has been a five-fold growth in companies with public and private investment in this technology with investment figures approaching US $10 billion over this period. By 2022, the global market for these technology applications is projected to reach US $13.9 billion9 and are likely to grow even further towards 2030. Investments in environmental applications is, however, orders of magnitude lower than their biomedical and demand-driven counterparts but is expected to grow as the need to respond to environmental effects becomes more urgent in the next decade. Investments and advancements in synthetic biology is mainly taking place in the Western world.Risks and uncertainties
Synthetic biology is controversial as it involves the intentional modification of nature. We do not have the full picture of its potential and associated risks. It is also criticised for undermining the goals of conservation by taking the focus away from the root cause of the problem: human activities.
Risk assessments are challenging, requiring the evaluation of the complex dynamics of the ecosystem One major risk from synthetic biology is that introduction of genetically modified organisms into the environment as part of crops, bioremediation or bio-control measures lead to a reduction of global biodiversity. Another important risk is that it can increase global inequality by exploitation of genetic resources by producing synthetic versions of natural products threatens fair-use of natural resources and lack of income for small-scale farmers who grow the natural products13. On the technical side, scaling the technology from the research lab to use on an industrial scale represents a huge unknown. Towards 2030, significant efforts will be put into solving these challenges.
There also needs to be an equal focus on developing governance methods and research guidelines to promote the ethical and responsible use of synthetic biology. The current lack of such governance is one of the main barriers for large-scale implementation of this technology.
Main author: Marte Rusten
Contributor: Sharmini Alagaratnam
Editor: Ellen Skarsgård
- Komor AC, Badran AH, Liu DR. CRISPR-Based Technologies for the Manipulation of Eukaryotic Genomes. Cell. 2017 Apr 20;169(3):559. doi:10.1016/j.cell.2017.04.005. PubMed: 28431253.
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- Phillip A. Cleves, Marie E. Strader, Line K. Bay, John R. Pringle, Mikhail V. Matz (2018) Proceedings of the National Academy of Sciences CRISPR/Cas9-mediated genome editing in a reef-building coral DOI: 10.1073/pnas.1722151115
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