Can science solve the plastic glut?
A new program at Los Alamos National Laboratory holds promise
When an early form of plastic was discovered in 1869, it was hailed as an environmental breakthrough: a cellulose-based material that would save elephants and turtles from the lethal use of their tusks and shells in the production of ivory billiard balls and tortoiseshell hair ornaments.
While natural polymers like cellulose abound in nature, synthetic — or human-made — polymers are often derived from oil and gas products.
And there are thousands of possible variations of these long chains of molecules. Plexiglas, vinyl and PVC (polyvinyl chloride) pipes are examples of materials made from polymer chains.
Plastic production soared after World War II, with Saran wrap and Styrofoam emerging in the 1950s from the laboratories at Dupont. Today, solutions to plastic pollution reside, ironically, in similar research and development laboratories around the world.
Recently, Los Alamos National Laboratory announced a new consortium that will harness the technical and research capabilities of four Department of Energy research laboratories and four universities.
The program is being dubbed BOTTLE — calling to mind the ubiquitous plastic water bottle — and stands for Bio-Optimized Technologies to keep Thermoplastics out of Landfills and the Environment.
BOTTLE is a project of the
Bioenergy and Biome Group, part of the Bioscience Division at LANL, according to Taraka Dale, BOTTLE program lead for the lab
This program gives LANL an opportunity to expand ongoing partnerships as well as develop new collaborations with top-notch researchers,” Dale said in a prepared statement.
Two critical goals
The consortium will use a two-pronged approach to tackle plastics pollution.
Dale explained that approach by email.
“First, we aim to use biocatalysts to degrade existing plastic waste. Enzymes have been found to degrade some plastics, but they are slow. We will use our
Smart Microbial Cell Technology to help find new enzymes that degrade plastics faster.”
Biocatalysts can be cells or enzymes. And enzymes are special proteins that speed up many ordinary processes, such as digesting food or making cheese. (Lactase, for example, is an enzyme that helps us digest milk products. If our bodies don’t produce it, we can become lactose-intolerant.)
Once plastic is broken down, BOTTLE’s second goal is to rebuild more recyclable plastics.
Dale explained that the team “will engineer bacteria to take up these plastics degradation products and convert them to new molecules that will then be used as building blocks to make new polymers.”
Right now, there are reportedly more than a hundred companies with bioplastics already on the market. But a study published this year in the journal Environmental Pollution showed that some of these products, contrary to claims, do not readily breakdown in the environment.
What LANL brings to the table is a microbial cell technology, which, while not unique to the lab, is the best on the market, according to Dale.
“Our Smart Microbial Cell Technology will be used to find versions of the bacteria that make these building blocks (for better plastics) more effectively,” she said.
The current technology in plastic degradation research can only study tens of proteins at a time, whereas LANL’s technology can screen thousands of variants for plastic degradation at a time.
“This is orders-of-magnitude better and a real opportunity to accelerate the discovery process for new and better plastic degrading enzymes,” said Dale.
Enzymes that eat plastic
One of the first plastic-degrading enzymes was discovered in nature a mere four years ago.
In 2016 outside a plastic bottle recycling plant in Japan, a microbe that was mixed with contaminated sediment was doing something revolutionary: breaking down and consuming plastic.
Upon examination, Japanese researchers discovered not only a new bacterium to science — Ideonella sakaiensis — but also an enzyme (Ideonella PETase) the bacterium secreted that was responsible for breaking down the plastic.
It turns out, BOTTLE’s research will build directly from this discovery.
“The lead institution for BOTTLE, the National Renewable Energy Laboratory, has made major contributions to working with and improving Ideonella PETase,” said Dale.
LANL’s capabilities, according to Dale, will help advance this research by improving plasticdegrading enzymes from organisms and by building new and better ones.
Natural enzymes, for example, may not work fast enough or at the scale needed to tackle the plastics pollution problem. In 2018 alone, nearly 360 tons of it entered global markets. When China stopped accepting the world’s plastic in 2017, plastic recycling – even here in Taos – effectively ended.
The challenge for BOTTLE is to engineer biocatalysts with the best characteristics to degrade existing plastics as well as formulate more recyclable and degradable plastics for the future.
But might these new, lab-made “designer enzymes” end up harming the natural environment?
According to Dale, regulations are already in place that would prevent engineered bacteria from even making it into the environment.
“The vision is that we would use the engineered bacteria in a closed system designed for breaking down plastics. The systems would be similar to, and follow the same types of regulations, that other industries use when applying engineered organisms,” she said by email.
Role of private enterprise
Solving plastic pollution cannot come soon enough.
Landfills are filled with familiar plastic items ranging from birthday balloons to margarine tubs, soft drink bottles to beanbags, garden hoses to garden furniture.
And it can take 450 years for even the thin plastic in water bottles to naturally degrade; up to 1,000 years for other kinds of plastic.
Some 13 million metric tons of plastic end up in oceans each year, often turning up inside marine mammals and other organisms.
So-called “globe-trotting” microplastics, tiny bits of plastic fractured by sunlight and waves, are turning up in the Sahara Desert and Japan’s Mariana Trench, the deepest oceanic trench on the planet.
Dale pointed out that the ultimate goal is for private business to take what they develop and scale it up and make it global.
“We are actively discussing with companies how we can conduct our R&D in a way that will be useful to them in making their products more sustainable and environmentally friendly,” she said.
“Our part is to show that we can degrade plastics effectively and create new plastics in the laboratory, using approaches that industry will find feasible and cost effective and therefore want to use,” she added.
“This problem has been years in the making, and it will take years to solve,” she said. “However, the more people care about the problem, the better. And we should continue to press the companies who make our products to create environmentally friendly products and packaging.”