Rebuilding marine biodiversity
Implementing CBD requirements to protect 30% of the global ocean will need to be informed by what interventions can address pressures on marine ecosystems to be successful.
Biological organisms may begin to provide new and better solutions to environmental problems, but wider use of bioengineering may raise ethical concerns with public perceptions unclear.
Biological organisms may begin to provide new and better solutions to environmental problems. These can range from exploiting a better understanding of interactions between organisms, such as developing synthetic gut microbiomes for livestock productivity,1 to using biotechnology to design innovations, such as enhancing photosynthesis to increase crop yields without increasing chemical inputs or land use.2 These innovations can be less energy intensive and environmentally harmful than existing approaches. For example, only 17.4% of the 53.6 megatonnes (Mt) of electronic waste produced globally in 2019 was recycled, with electronic waste projected to grow to 74.7 Mt by 2030.3 When it accumulates in landfill sites, toxic metals leach out. But the current technologies used for extracting and recycling e-waste metals often involve high temperatures and toxic chemicals.4 Industrial-scale trials are now underway to use microbes to extract metals from e-waste (‘bioleaching’).5
Contamination of the environment with highly persistent chemicals from industrial uses, consumer products and chemical weapons is difficult and costly to reverse.6,7,8,9,10 Research has shown microbes are an option for decontaminating soils and sediments, such as the identification of a bacteria-driven process that greatly decreases the toxicity of dioxins, chemicals that can cause a range of human health impacts. The process is quite slow, but could be enhanced to develop decontamination technologies.11 Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) are manufactured chemicals made up of a chain of linked carbon and fluorine atoms that do not degrade in the environment and accumulate in food chains.12 However, a wetland microbe has been shown to be capable of degrading two common types of PFAS when soils or sediments are acidic and iron rich.13 Researchers have also created a biosensor that attaches to a smartphone that uses genetically engineered bacteria to detect unsafe arsenic levels in drinking water.14 Although this is a major challenge in some regions,15 the biosensor has not yet been commercially developed due to the lack of a regulatory framework for such genetically engineered products. Some plants can accumulate high levels of heavy metals in their leaves, such as the 450 species that can accumulate nickel. Extracting this metal from such species is now being researched as a low impact form of mining (agromining), with the cropped plants burnt for energy and the metals extracted from the ash residue.16,17,18,19
The use of organisms could reduce the environmental impacts of production, lower costs and create products with their end of life in mind. For example, the two million tonnes of nylon polymer manufactured each year uses adipic acid, production of which involves emission of the greenhouse gas (GHG) nitrous oxide. Genetically modified bacteria have been used to convert plant waste into adipic acid without producing nitrous oxide, in a process that could be commercialised.20 Studies have also highlighted how different sustainable feedstocks can be used to create bioplastics, including biodegradable polyurethane foams made from algae oil, and biodegradable bioplastic derived from chitin in the pupa of black soldier flies fed on organic waste.21,22 Other materials made from organic wastes or organisms include leather substitutes derived from pineapple or apple waste,23 and a leather substitute created from fungal mycelium,24 with lower GHG emissions than leather from livestock or fossil fuel-based materials. Companies have also developed processes using microbes to reduce the carbon emissions associated with producing protein from animal feed, including directly using CO2 from industrial emissions,25 and using natural gas.26 Oils produced with yeasts from seaweed feedstocks in biorefineries could also have applications as an alternative to palm oil, with lower climate and biodiversity impacts.27,28 Although less well-developed, engineered living building materials (LBMs) use bacteria or biological materials to create self-healing properties that may reduce the need for repair of infrastructure in the future.29,30
Understanding the interactions between microorganisms and the environment could be used to reduce the impact of human activities. For example, plants interact with hundreds of thousands of microbes that are present on their surfaces or colonise plant organs, such as root bacteria and fungi, affecting a wide range of traits involved in plant growth and development and responses to adverse environmental conditions.31 Methods are being developed to understand these complex interactions,32,33 which could be enhanced to increase crop yields.34 A better understanding of the soil microbiome would improve predictions of their resilience under climate change,35,36,37 as well as practices for reducing soil GHG emissions arising from agriculture,38 such as seeding bacteria that reduce methane from waterlogged rice paddy soils,39 and nitrogen fixing genetically edited microbes as a replacement for nitrogen fertilisers.40 There is also increasing interest in improving the microbiome of marine plant and animal species that are important for forming habitats in coastal areas, such as sea grasses.41
Whether the cost of production when using biological organisms can be reduced. For example, polyhydroxyalkanoates produced by microbes are an alternative to polymers from fossil fuels, which make up around 5% of biodegradable plastics worldwide, but costs are too high for most sectors.42
The risk that our understanding of platforms (yeast, bacteria, plants or human cells) will remain insufficient to successfully produce at scale without significant investment in research.43
Knowledge remains limited, even for the more intensively researched human microbiome,44 and what constitutes a healthy plant or soil microbiome and how it behaves are only beginning to be explored.45
What ethical issues arise if applications of bioengineering increase across multiple areas?21
How to regulate the biosecurity risks arising from the dual-use nature of bioengineering technologies without creating high regulatory barriers for private investment in environmental applications.46
Why public perceptions tend to be positive in relation to using bioengineering, but are less clear for sectors such as agri-food, and whether it is likely to depend on social demographics and willingness to pay a premium for ethical goods.47
Early products from engineered biology are already starting to be placed on the market.48
Photo by Antoine GIRET on Unsplash
Implementing CBD requirements to protect 30% of the global ocean will need to be informed by what interventions can address pressures on marine ecosystems to be successful.
Climate change and poor management pose significant threats to soils and the services they provide; appropriate baselines and data need to be identified to assess changes in soil health.
Achieving environmental targets will involve changes in consumption at every level down to households and individuals, requiring effective measures to change consumer habits.