Nav: Home

Great potential in regulating plant greenhouse gas emissions

May 20, 2020

You cannot see them with the naked eye, but most plants emit volatile gases - isoprenoids - into the atmosphere when they breathe and grow. Some plants emit close to nothing; others emit kilograms annually.

Why are plant isoprenoid emissions interesting? Well, isoprenoids contribute immensely to the amounts of hydrocarbons released into the atmosphere, where they can be converted into potent greenhouse gases, affecting climate change. Actually, it has been estimated that short-chain isoprenoids account for more than 80% of all volatile organic compounds emitted from all living organisms, totaling about 650 million tons of carbon per year.

"We discovered a new way that plants regulate how much volatile isoprenoids they emit into the atmosphere, which had long been unknown. Some plants emit a lot, while very similar species don't emit them at all. This is interesting from a basic research point of view to better understand these emissions and how growing different plants might affect carbon cycling and impact greenhouse gases," says first-author behind a new study recently published in eLife, Senior Researcher Mareike Bongers from The Novo Nordisk Foundation Center for Biosustainability and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland.

Crops that emit a lot of isoprene are for example palm oil trees, spruce, which is grown for timber, and aspen trees, which are grown for timber and biofuel. With this knowledge, farmers could in principle optimise forest land and farming area by planting fewer high-emitter-plants and more zero-emitters.

"It should be said, though, that we do not know for sure that all effects of these emissions are bad, more research is needed on that. But what is clear is that many of the harmful effects of isoprenoid emissions happen when they react with common air pollutants, which affects greenhouse gas formation and air quality. Therefore, large plantations with high emissions are particularly troublesome in the vicinity of industrial or municipal air pollution. So, reducing pollution is another way to address the problem," says Mareike Bongers.

The researchers behind this study are now looking into the possibility of using this new knowledge in applied biotech. The researchers actually discovered the new regulatory mechanism, because they tried to engineer the bacterium E. coli to produce sought-after isoprenoids, which could replace many fossil fuel chemicals if they could be produced more cheaply.

So, while engineering plant genes into E. coli to improve isoprenoid production, the researchers became aware of the plant-based regulation mechanism. When E. coli was engineered with plant genes for an enzyme known as HDR, they produced two important chemicals in different ratios, and this influenced how much isoprene could be produced.

This revelation is very useful in applied biotech, because isoprenoids can be turned into products like rubber. GoodYear has already produced car tires made from bio-produced isoprene. Furthermore, the findings could also improve the production of monoterpene isoprenoids, which are excellent jet fuels because they are very energy dense.

"This is particularly interesting from a sustainability perspective, because it is not anticipated that airplanes can be fuelled from anything else than liquid fuels, as opposed to ground transportation, which could be electric," she says.

Finally, isoprenoids are also used as flavours and fragrances in perfumes and cosmetics, and they are very important as active compound in some drugs, for instance the anti-malarial drug artemisinin or taxadiene, from which the cancer drug Taxol is made.

Today, most labs and biotech companies that make isoprenoids use a pathway from yeast, since the achieved yields have been much higher than with E.coli. But the pathway used by E. coli and plants has a higher theoretical yield, meaning that more isoprenoids could theoretically be made from the same amounts of sugar in E.coli than in yeast. Therefore, trying to optimise E.coli for isoprenoid production makes good sense commercially.

The team compared eight different plant HDR genes and one cyanobacterial HDR gene in E.coli. The best result was obtained with genes from peach, poplar and castor bean. Since this was a proof of concept, the team only produced 2 mg isoprene per litre of cell broth. But with further engineering and fermentation optimization efforts, the researchers expect to improve isoprene production in E. coli using this system.

"We saw that choosing the right plant enzyme made a big difference for isoprene production in E. coli. So, our 'learning from nature' approach on how some plants became so good at emitting isoprenoids really helped us to design more efficient cell factories," she concludes.
-end-


Technical University of Denmark

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.