Synthetic biology can help control the growing global problem of plastic pollution by speeding up the natural decomposition process and making eco-friendly plastics to replace the current petroleum-based products, scientists say.
Bacteria and other microorganisms naturally degrade plastic waste, though the process is very slow and could take centuries, said Dr. Stephen Opiyo, research scientist at Ohio State University in the United States. Synthetic biology could greatly speed up the process by producing engineered enzymes that can degrade plastics efficiently while creating a new generation of truly disposable plastics.
In that way, the world would solve two problems related to climate change: taking carbon dioxide out of the air and making eco-friendly plastics, he said.
Some 99 percent of the plastic bags and containers on the market today are non-biodegradable and derived from climate-warming fossil fuels and petroleum.
Researchers have already isolated several different bacteria and fungi that can degrade plastics competently, Opiyo said.
“We just have to apply these microorganisms and carbon dioxide to scale up production of biodegradable plastics that, unlike non-biodegradable plastics, can decompose when disposed of,” Opiyo said.
Plastic pollution is increasingly turning into a global emergency. The United Nations Environment Program estimates that humans produce more than 300 million tonnes of plastic waste globally every year.
About 11 million tonnes of this waste ends up in oceans, harming and killing millions of birds and other wildlife each year, according to a 2020 report by the research arm of Pew Charitable Trusts. Without immediate and sustained action, this amount will nearly triple by 2040, to 29 million tonnes per year, the report said. That’s the same as dumping 110 pounds (50 kilograms) of plastic on every meter of coastline around the world.
“Only 9 percent of all plastic waste ever produced has been recycled,” according to the UN report. “About 12 percent has been incinerated, while the rest — 79 percent — has accumulated in landfills, dumps or the natural environment.”
The problem is worse in Africa, where rapid population growth and poor waste management practices generate tonnes of plastic waste every year. Though more than 30 African countries introduced polythene bans over the last 10 years to control the pollution, plastics continue to clog river basins, waterways and other drainage channels on the continent.
A number of countries across the globe have adopted measures to reduce plastic pollution, such as substituting plastic with paper and compostable materials, increasing demand for recycled plastics and instituting stronger regulations on production and consumption of plastics. But despite these conservation measures, they continue to generate tonnes of plastic waste.
University of Portsmouth Prof. Steve Fletcher, speaking at the launch of the Global Plastics Policy Center at the COP26 climate conference last month, highlighted how plastic pollution exacerbates the climate crisis and reduces the natural world’s resilience to cope with the effects of climate change.
Fletcher, the university’s director of Revolution Plastics, said the new policy center will assess over 100 global plastic policies to create a one-stop shop of good advice around plastic policy. The goal is to help find sustainable solutions to tackle plastic pollution around the world.
The center is designed to give governments and industry groups the evidence needed to make better decisions around plastic policies and bring an evidence-based approach to plastic policy-making, he said.
But Opiyo said the world needs to move away from petroleum-based plastics that are non-biodegradable, especially today when technologies are available to produce plastic that degrades upon disposal.
“With newer technologies, especially synthetic biology, we have a chance to produce plastic bags and other containers that will decompose when disposed of,” said Opiyo. “You just throw away the plastic and in three or four months it has decomposed.”
“We just need to stop production of non-biodegradable plastics, especially single-use non-biodegradable plastics, in favor of plastics that can actually decompose,” he continued. “When we stop production of non-biodegradable plastics, only the old plastics that have already been produced can remain. Then we can recycle them.”
The research scientist said he is using synthetic biology to develop a prototype to produce biodegradable plastics. The project should be ready in two years.
Dr. Arum Han, professor in the Department of Electrical and Computer Engineering at Texas A&M University, said synthetic biology enabled scientists to utilize microorganisms, fungi and bacteria to essentially break down plastic components more effectively.
Han said scientists could also utilize a mixture of different bacteria and fungi to improve the plastic degradation efficiency, mimicking how microbes work together to decompose complex materials in nature.
But there are challenges.
Many countries, especially in Africa, lack policies that can facilitate development of synthetic biology and govern usage of its applications or products.
Even countries like Sudan, Nigeria and Kenya, which have enabling legal frameworks for regulating related technologies such as genetic engineering, have yet to enact rules that are specifically meant for synthetic biology.
That’s not the only hurdle. Developing newer technologies also requires funding.
Thembeka Shongwe, a marine biologist in South Africa, told Global Citizen that it is very difficult to address plastic pollution on a continent where the majority of the population is lower and middle class and just trying to survive.
“Environmental issues need awareness and money,” she said. “We can make people aware of the impacts of plastic pollution, but if we can’t provide them with a free alternative we will never be able to solve environmental issues such as plastic pollution.”
But Opiyo said the countries just need the right mindset.
“The onus is on us scientists to show our leaders what these newer technologies can actually offer,” he said.
“We need to improve people’s awareness and perception of these technologies,” the scientist said. “When most of the public and our leaders understand what these technologies can offer, once we have the political will, everything else will start to fall in place.”
Image: A South African beach littered with plastic washed up by the sea. Photo: Shutterstock/Erlo Brown