Enzymes – the solution to the plastic waste dilemma
The problem of plastic waste is becoming evident in almost all parts of the world. Some isolated initiatives aimed at replacing and recycling plastics are proving to be ineffective. German scientists are taking initiatives to destroy plastic in a new way. But that requires a temperature of 60–70 degrees Celsius.
The team of biochemist Christian Sonnendecker of the Leipzig University wants to use biotechnology to solve the plastic problem. Explaining the effort, Sonndecker said,
‘By observing nature, we are trying to replicate it. Nature uses enzymes to break down polymers. We are doing exactly that now.’
Christian and a colleague found the enzyme in a cemetery south of the city of Leipzig. It is found in compost. That enzyme actually decomposes the leaves that fall from the tree.
“A leaf has a layer of wax on it, called the cutin layer,” says Sonndecker. It is a type of polyester. It is a polymer whose structure is based on ester bonds, just like Polyethylene terephthalate (PET) plastic. Similar properties are also found in many bioplastics.
These enzymes are so nonspecific that they can recognize and process a wide range of polyester spectrum. It is also our advantage and fortune. Because, we have found an organic answer to the problem of plastic.
Christian Sonndecker is demonstrating by hand how quickly that enzyme can break down plastic. At a temperature of 60-70 degrees Celsius, the enzyme can completely break down the PET wrap in just one day. Then only the basic elements are left. The researchers were very happy to find the enzyme.
“We named it PHL Seven,” said Christian Sonnendecker. Ie polyester-hydrolase-lipsis. It is enzyme number 7 out of 9 that we have found. That was an enzyme with special power.
A 3d Replica of the enzyme was printed to make it visible. This makes its operation easier to understand. “This is the enzyme,” Sonndecker exclaimed confidently. Each ester bond in the PET chain is visible, i.e. the predetermined breaking point.
Now the enzyme comes to break down each ester bond. At the end of the process, basic ingredients such as terephthalic acid and ethylene glycol remain. New plastics can be made with them.
Sonnendecker’s team has gone one step further. They want to modify the enzyme’s DNA so that it can consume plastic more quickly. Several modified enzymes are being tested for that purpose. They want to select the most efficient enzyme by analyzing each one separately.
Technology and artificial intelligence are helping in that task. The researchers are working with biotechnologist Ronnie Frank. He said,
‘This time we want to apply our technology on a large scale. To that end, we developed a new prototype that can analyze nearly 100 enzyme samples.
At the same time, the upper layers can be measured. We can also train the AI by providing the necessary information. In this way, we can break down plastic by finding new and improved enzymes.
Researchers looking for super enzymes want to analyze hundreds of thousands of enzymes a day. They also have dreams of going one step further. “We want to eventually have more polyester on the market,” said Sonndecker. Because it is very easy to break them down using enzymes.
In this way we can create a truly effective circular economy. At the moment there is no arrangement for plastic-waste. As a result, we have no other option. Looking to the future, we want to do something to recycle plastic sustainably.
