Scientists have created an enzyme that can increase the rate of plastic decomposition by six times. An enzyme found in garbage house bacteria that feed on plastic bottle diets has been used in combination with PETase to accelerate the decomposition of plastic.
Three times the activity of super enzyme
The team designed a natural PETase enzyme in the laboratory, which can speed up the decomposition of PET by about 20%. Now, the same transatlantic team has combined PETase and its "partner" (the second enzyme called MHETase) to produce even greater improvements: simply mixing PETase with MHETase can increase the rate of PET decomposition Double it, and design the connection between the two enzymes to create a "super enzyme" that triples this activity.
The team is led by the scientist who designed PETase, Professor John McGeehan, director of the Center for Enzyme Innovation (CEI) at the University of Portsmouth, and Dr. Gregg Beckham, a senior researcher at the National Renewable Energy Laboratory (NREL). In the U.S.
Professor McKeehan said: Greg and I are talking about how PETase erodes the surface of plastic, and MHETase further shreds it, so it is natural to see if we can use them together to mimic what happens in nature. "
Two enzymes work together
Initial experiments showed that these enzymes can indeed work better together, so the researchers decided to try to connect them physically, just like connecting two Pac-Man with a rope.
"A lot of work has been done on both sides of the Atlantic, but it is worth the effort-we are pleased to see that our new chimeric enzyme is three times faster than the naturally evolved independent enzyme, opening up new avenues for further development and improvement." McGeehan continued .
Both PETase and the newly combined MHETase-PETase can work by digesting PET plastic and restoring it to its original structure. In this way, plastics can be manufactured and reused endlessly, thereby reducing our dependence on fossil resources such as oil and natural gas.
Professor McKeehan used a synchrotron in Oxfordshire, which uses X-rays, which are 10 billion times stronger than the sun, as a microscope, enough to observe individual atoms. This allowed the research team to solve the 3D structure of the MHETase enzyme, thereby providing them with a molecular blueprint to begin designing faster enzyme systems.
This new research combines structural, computational, biochemical and bioinformatics methods to reveal molecular understanding of its structure and function. This research is a huge team effort involving scientists of all career stages.
