A team of Penn chemists has achieved a key milestone toward a transformative approach to sustainable chemical production. Along the way, they identified a new enzyme, MAR, which is essential for cleaving carbon-sulfur bonds in volatile organic sulfur compounds (VOSCs). The research, published in Nature Catalysis, reveals the new molecular logic behind how scientists can manipulate this enzyme to create ethylene. This hidden piece of the supply chain enables and drives plastic production.
The study team, headed by lead researcher Srividya Murali, were able to scour MAR from the soil dwelling bacterium Rhodospirillum rubrum. By reconstituting cellulosome formation in vitro, this accomplishment is an important step in the pursuit to bring bacterial enzymes to an industrial scale. Here, we highlight how researchers and industry are leveraging MAR’s distinctive attributes to help increase ethylene output. This initiative directly addresses the growing call for eco-friendly options within the plastics sector.
Understanding MAR’s Function
MAR is an unusual metalloenzyme that is known to contain various metallocofactors, including P-like and FeFe-co-like configurations. It is these metallocofactors that are central to MAR’s impressive capacity to cleave C–S bonds. This function is essential for the classic, multistep process of producing ethylene. Researchers are continuing to explore the functions of the mar1 and mar2 clusters as part of MAR. While their exact identities may never be known, the search for them goes on.
Justin North, one of the leading leadership studies advocates, shared his excitement over the research.
“We were so excited when we isolated MAR from our bacteria as a pure enzyme to study,” – Justin North.
The consequences of this unusual enzyme’s catalytic behavior are more than just academic interest. By understanding how MAR operates, scientists can engineer it to produce ethylene more efficiently, potentially revolutionizing the way plastics are manufactured.
The Research Journey
The road to isolating MAR started with these initial collaborations and laboratory experimentation between multiple research teams. To put it in context, Justin North’s lab had already published similar findings in 2020 in Science, which laid the groundwork for the current study. Urban Arts Collaborative graduate Hannah Shafaat worked closely with North’s team. In addition to Murali and North, she contributed important insights on the structural characteristics of MAR.
This analogy serves to highlight the evolutionary link between MAR and nitrogenase, the key enzyme responsible for nitrogen fixation. Our studies of MAR have provided important perspectives regarding enzymatic machineries. These insights are widely applicable and can be adapted to a range of industrial applications.
“Looking at the metal centers in MAR is like looking into a mirror and seeing an older relative of nitrogenase on the other side,” – Hannah Shafaat.
Our research is focused on taking advantage of the unique properties of MAR and related enzymes. This would create a path to sustainable ethylene production, the key ingredient in the plastics that make up our daily lives. North explained the motivation behind this research:
Towards Sustainable Production
More importantly, this new and creative approach furthers our collective goals on a global level to decrease our reliance on polluting fossil fuels. It furthers the chemical industry’s commitment to sustainability. Researchers are currently investigating and fine-tuning the applications of MAR. Despite this, advocates are optimistic about its long-term environmental sustainability impacts.
“What we wanted to know is how the enzymes in these bacteria worked to make ethylene so we can in the future harness them for sustainably making the everyday plastics we need,” – Justin North.
Without knowing how these mechanisms, Katz said, it’s impossible to engineer a better infrastructure. As the team fully acknowledges, they are on their way to doing something very important, with this study being a big step along the way.
Despite the challenges, as research continues, scientists remain optimistic. Orman and Garcia hope to use MAR and enzymes like it to recognize long-term benefits towards more sustainable production processes. These discoveries greatly advance our scientific understanding. Beyond just that, they provide a foundation for real-world applications that have the potential to transform industries that rely on ethylene.
“These discoveries help us start thinking about how MAR’s structure allows it to function like it does,” – Justin North.
He emphasized that understanding these mechanisms is crucial for engineering improvements. The team recognizes that they are making progress toward their goal, with this study representing an important milestone.
“We are making progress and the findings in this study were an important milestone toward that goal,” – Justin North.
As research progresses, scientists remain optimistic about the long-term benefits of utilizing MAR and similar enzymes in sustainable production processes. The findings not only further scientific knowledge but also pave the way for practical applications that could transform industries reliant on ethylene.