KINGSTON, R.I. – Aug. 21, 2023 – Researchers at the University of Rhode Island have developed a computational model of a single-celled organism known as Pyrococcus furiosus, or P. furiosus, to better understand and predict how the organism reacts in certain situations. P. furiosus is a hyperthermophilic microorganism—which means it can survive and thrive in extreme temperatures. Well known and studied for years, P. furiosus has been genetically engineered to produce a variety of chemicals and fuels, including ethanol, yet there is still much that is not known about its metabolic capacity. The results of the study were recently published in the academic journal Applied and Environmental Microbiology.

The model, which was tested and confirmed by team members at the University Georgia and North Carolina State University, examined how the organism responds when cultivated and manipulated in different settings—including open and closed systems. The model is important in predicting these types of reactions because while a closed system may be more efficient in producing more ethanol and losing less hydrogen, the reality is that producing in a closed system is not only less safe, but more cost prohibitive.

With the use of open system bioreactors more commonly used in industrial practices, the model makes it possible to determine how best to manipulate the system to achieve maximum efficiency.

“The model proved to be very effective at both predicting the growth of the organisms as well as the production of the bioproducts,” said senior author and project lead Ying Zhang, a URI associate professor of cell and molecular biology. “It has been an extremely useful approach in helping us to sort through different scenarios and propose more promising approaches for experimental follow up.”

“One of the advantages of the model is the ability to try out multiple configurations on a computer without having to invest the time to do it experimentally,” said Jason Vailionis, Ph.D. graduate student in evolution and marine biology and the study’s lead author. In a matter of days, the team was able to simulate more than 60 genome mutation scenarios using the model—which would have taken months to years to re-create experimentally.    

The model enables researchers to propose newer strategies utilizing P. furiosus to more efficiently create ethanol—the advantage being that as a hyperthermophilic organism, it is better able to withstand the high temperatures produced in existing biosystems. While current systems are effective at producing ethanol, they rely primarily on mesophilic organisms. These organisms are best able to survive only at more moderate temperatures. When temperatures rise, they cease ethanol production.

“With increased interest in genetically modifying organisms to make fuels and manufacturing chemicals, there are many labs right now trying it on a lot of different systems, but very, very few actually manage to break that hurdle of making it economically viable,” said Vailionis. “So, the hope is with some of the modeling methodology that we’re putting forth in this paper—with hyperthermophiles, which haven’t been used very frequently—we can help reach that point where an alternative bio-based chemical production can be a viable competitor.”

“The potential is there,” added Zhang. “While more research is needed, models such as these are an important step toward more efficient production pipelines and reduced dependence on fossil fuels.”