Light-powered nano-organisms consume CO2, create eco-friendly plastics and fuels

University of Colorado at Boulder

University of Colorado Boulder Assistant Professor Prashant Nagpal Credit: Casey A. Cass

University of Colorado Boulder Assistant Professor Prashant Nagpal Credit: Casey A. Cass

University of Colorado Boulder researchers have developed nanobio-hybrid organisms capable of using airborne carbon dioxide and nitrogen to produce a variety of plastics and fuels, a promising first step toward low-cost carbon sequestration and eco-friendly manufacturing for chemicals.

By using light-activated quantum dots to fire particular enzymes within microbial cells, the researchers were able to create “living factories” that eat harmful CO2 and convert it into useful products such as biodegradable plastic, gasoline, ammonia and biodiesel.

“The innovation is a testament to the power of biochemical processes,” said Prashant Nagpal, lead author of the research and an assistant professor in CU Boulder’s Department of Chemical and Biological Engineering. “We’re looking at a technique that could improve CO2 capture to combat climate change and one day even potentially replace carbon-intensive manufacturing for plastics and fuels.”

The project began in 2013, when Nagpal and his colleagues began exploring the broad potential of nanoscopic quantum dots, which are tiny semiconductors similar to those used in television sets. Quantum dots can be injected into cells passively and are designed to attach and self-assemble to desired enzymes and then activate these enzymes on command using specific wavelengths of light.

Nagpal wanted to see if quantum dots could act as a spark plug to fire particular enzymes within microbial cells that have the means to convert airborne CO2 and nitrogen, but do not do so naturally due to a lack of photosynthesis.

By diffusing the specially-tailored dots into the cells of common microbial species found in soil, Nagpal and his colleagues bridged the gap. Now, exposure to even small amounts of indirect sunlight would activate the microbes’ CO2 appetite, without a need for any source of energy or food to carry out the energy-intensive biochemical conversions.

“Each cell is making millions of these chemicals and we showed they could exceed their natural yield by close to 200 percent,” Nagpal said.

The microbes, which lie dormant in water, release their resulting product to the surface, where it can be skimmed off and harvested for manufacturing. Different combinations of dots and light produce different products: Green wavelengths cause the bacteria to consume nitrogen and produce ammonia while redder wavelengths make the microbes feast on CO2 to produce plastic instead.

The process also shows promising signs of being able to operate at scale. The study found that even when the microbial factories were activated consistently for hours at a time, they showed few signs of exhaustion or depletion, indicating that the cells can regenerate and thus limit the need for rotation.

“We were very surprised that it worked as elegantly as it did,” Nagpal said. “We’re just getting started with the synthetic applications.”

The ideal futuristic scenario, Nagpal said, would be to have single-family homes and businesses pipe their CO2 emissions directly to a nearby holding pond, where microbes would convert them to a bioplastic. The owners would be able to sell the resulting product for a small profit while essentially offsetting their own carbon footprint.

“Even if the margins are low and it can’t compete with petrochemicals on a pure cost basis, there is still societal benefit to doing this,” Nagpal said. “If we could convert even a small fraction of local ditch ponds, it would have a sizeable impact on the carbon output of towns. It wouldn’t be asking much for people to implement. Many already make beer at home, for example, and this is no more complicated.”

The focus now, he said, will shift to optimizing the conversion process and bringing on new undergraduate students. Nagpal is looking to convert the project into an undergraduate lab experiment in the fall semester, funded by a CU Boulder Engineering Excellence Fund grant. Nagpal credits his current students with sticking with the project over the course of many years.

“It has been a long journey and their work has been invaluable,” he said. “I think these results show that it was worth it.”

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The new study was recently published in the Journal of the American Chemical Society and was co-authored by Yuchen Ding and John Bertram of CU Boulder; Carrie Eckert of the National Renewable Energy Laboratory; and Rajesh Bommareddy, Rajan Patel, Alex Conradie and Samantha Bryan of the University of Nottingham (United Kingdom).

From EurekAlert!

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83 thoughts on “Light-powered nano-organisms consume CO2, create eco-friendly plastics and fuels

  1. What’s one of the things greens hate most? Plastic. It’s right up there with oil and CO2. Now, how are the greens going to react to reducing CO2 but producing plastic.

    Prepare for exploding watermellons everwhere.

    • Perhaps the vegans will work it out first as their won’t be any vegies in the supermarket to wrap with all that plastic.

    • My first thought was what happens when these get out of the lab into lakes, rivers and seas everything’s going to be covered in this plastic film! Just imagine going for your morning swim and coming out wrapped in cling film.

      James Bull

  2. If it works, Nagpal may be able to end all life on EArth some day when his organism gets lose and eats every available molecule of CO2.

    What a great idea. NOT!

    Max

    • Good comments Max. Below is an excerpt from my soon-to-be-published paper:

      15. Atmospheric CO2 is not alarmingly high, it is too low for optimal plant growth and alarmingly low for the survival of carbon-based terrestrial life. The real danger is not too much CO2 – it is CO2 starvation. Over geologic time, CO2 is ~permanently sequestered in carbonate rocks.

      Plants evolved at atmospheric CO2 concentrations of 2000 ppm and greater, and many grow best at about 1200 ppm CO2 – about 3 times current levels. That is why greenhouse operators pump 1000-1200 ppm CO2 into their greenhouses.

      Major food crops (except corn) use the C3 photosynthetic pathway, and die at about 150 ppm from CO2 starvation – that is just 30 ppm below the minimum levels during the last Ice Age, which ended just 10,000 years ago – “the blink of an eye” in geologic time. Earth came that close to a major extinction event.

      During one of the next Ice Ages, unless there is massive human intervention, atmospheric CO2 will decline to below 150 ppm and that will be the next major extinction event – not just for a few species but for ~all complex terrestrial carbon-based life forms.

      Reference: “(Plant) Food for Thought”
      (first posted in January 2009 on wattsupwiththat.com, published on icecap.us in December 2014)
      by Allan MacRae, Dec 18, 2014
      http://icecap.us/index.php/go/new-and-cool/plant_food_for_thought2/

      Reference: “Should We Celebrate Carbon Dioxide?”
      by Patrick Moore, October 15, 2015
      https://www.thegwpf.org/patrick-moore-should-we-celebrate-carbon-dioxide/

      • It’s only the processes of ocean floor subduction into the mantle, which is so hot it decomposes the carbonates, and volcanoes venting the released CO2 back into the atmosphere, that make it possible for the earth to avoid CO2 starvation.

        • M wrote:
          “It’s only the processes of ocean floor subduction into the mantle, which is so hot it decomposes the carbonates, and volcanoes venting the released CO2 back into the atmosphere, that make it possible for the earth to avoid CO2 starvation.”

          Evidence shows that volcanic venting of CO2 over geologic time has not been sufficient to prevent the inexorable decline in atmospheric CO2 from several thousand ppm to several hundred ppm, as it is sequestered in thousands of feet of carbonates over vast areas. I suggest that CO2 sequestration is, in balance, pretty much a one-way street.

          It’s a question of magnitudes – my best guess is that CO2 sequestration is much larger than CO2 regeneration.

    • “Mutant 60: The CO2 Eaters”
      A sequel to a book I read as a kid! In that one it was a ‘brilliant’ idea to engineer a microbe that ate evil plastic.

    • It is unlikely (immpossible) that the organisms will produce the quantum dots. This is not a biological process so would be the limiting factor.

      Actually outside the resarch lab this would be tottaly impractcial as it would be vastly expensive and time consuming to make then insert the quantum dots into significant numbers of organisms to have any measured effect. The particles themselves would quickly shut down being surrounded by a sea of waste plastic that would quickly bury them and be complety impervious from breaking down by other organisms.

      It is a pie in the sky project which sounds all techy and revolutionary but is in fact very limited and hugely expensive.

      • You raise some good practical issues, adrian. From what I’ve seen of the paper, the work looks very innovative (not done reading yet).

        But you’re right, the quantum dots have to be prepared in a very precise way. They need to be finished with a two-layer coat of zinc sulfide (ZnS). Not one layer, not three.

        They then have to be coupled with the amino acid cysteine and injected into GMO bacteria that make a histidine-tagged version of the enzyme of choice (nitrogenase for ammonia production, hydrogenase for CO₂ reduction).

        The problem is making the huge batches of bacteria with the engineered quantum dots. It’s mostly done by exposure — the bacteria engulf the dots. But it’s got to be done. Even some small pond will require a huge number of functional bacteria to make any appreciable amount of product.

        The real problem may lay in the fact that the quantum dots are made of things like cadmium selenide (CdSe), indium phosphide (InP) and copper-zinc-tin-sulfide (CuZnSnS₃). All those materials get released into the environment. The CdSe and InP are serious environmental toxins.

        Every quantum dot is nano-grams, but when you’ve got billions of bacteria in a pond, you get grams of CdSe and InP eventually dropped into the bottom ooze. What happens to that? It’s a serious pollution hazard.

        If the quantum dot cum bacteria technology ever commercializes it will have to be undertaken in an isolation pond that can periodically be cleaned out. It will never go in someone’s backyard, or in the drainage ditch of some town. Not without producing a lot of sick bald people.

        Let me add that photosynthetic marine algae regularly make large oil slicks on the ocean surface, which consist of the lipids the algae make using sunlight and CO₂ (preceding quantum-dotted GMO bacteria technology by 3 billion years). No one ever sees anyone going out to skim those up for commercial exploitation.

        One could well dike off some sea water, spike it with the right algae, convince them to make a bank-rolling lipid slick, and head uptown in entrepreneurial triumph. No one does it. Mostly because the operation would generate negative income.

        So, while the scientific work is very good, the industrial prospects seem poor. Now, if the quantum-dotted bacteria would make antibiotic candidate molecules, you might have something.

      • Be thankful that most C4 plants are grasses, and there are no C4 trees! In the long term, C4 trees would have the potential to drive CO2 levels so low that C3 plants (most plants!) would be driven into extinction.

    • Exactly right, Max Porath, …… I had been composing a post expressing my fear of the danger if the modified “nanobio-hybrid organisms” (bacteria) figured out how to “copy” itself during reproduction.

      nanoscopic quantum dots, …… could be extremely dangerous and deadly if turned loose in earth’s environment.

    • Are there not CDC protocols for handling “nano” critters in research to avoid risk of danger and harm? Interesting that with the CO2 bugaboo, they don’t even contemplate that an out of control, runaway sequestration of CO2 could kill us all! From the press release they contemplate soil bacteria just needing the sun to shine on them to get to work. What about the possibility of plasticizing our agricultural soils. Now that would be worthy of naming the epoch Anthropocene.

    • Yeah. Exactly. Look at that verbiage.
      Quantum dots were going to do everything, and dice carrots too, when I was a grad student back in the 1990’s. Even the fellow students I knew in such research groups laughed at the hype. This seems no different except that they are now clearly going after “climate-change” funding as well as “nano-technology” funding.

      I mean, you have to laugh at the statement

      “..exposure to even small amounts of indirect sunlight would activate the microbes’ CO2 appetite, without a need for any source of energy or food to carry out the energy-intensive biochemical conversions.”

      So not only are they apparently going to make life forms more efficient at CO2 (or N2) fixation than that produced by a billion or so years of evolution, but they are going to do it without energy input, or at least more efficiently than current living systems? I don’t think so.

      Being generous, that maybe ought to be a spelling mistake or something ambiguous lost in translation by a journalist, but the tenor of the rest of the hype suggests otherwise.

      • You’re right, michael. I caught that, too.

        They implicitly assert a perpetual motion machine. Such is publicist enthusiasm.

    • But just imagine, walking around with a Scuba style tank and respirator mask that captures your CO2 at 40,000 ppm and converts it into biofuel for your car. The tanks store the fuel until you’re ready to empty them into your fuel tank.
      /sarc

  3. A really good idea. A sure way to make sure it works is to tell undergrad students it is possible to make beer this way. Guaranteed success!!

  4. “..By using light-activated quantum dots to fire particular enzymes within microbial cells, the researchers were able to create “living factories” that eat harmful CO2…”

    Harmful CO2? Yea, right.

  5. I see a sci-fi doomsday novel playing out from this.. Microbes escape holding pond… Weve lost containment… Propogating at enormous rate… Co2 levels in atmosphere dropping dangerously low… Etc etc…

      • Possible Austin Powers too. Mini Me steals the quantum dots and Fat Bastard uses them to create plastic food that never spoils.

      • Call M. Night Shyamalan. This can be a sequel to “Signs” and ‘The Happening’.

        When this kind of thing comes up, that old ad about Mazola margarine immediately shows up. “Don’t mess with Mother Nature! She’s cranky!!” (Lightning bolt and thunder!!!)

        Just to give you all a heads up on silliness, in the 1950s and early 1960s, the popular idea about producing enough food to feed the world’s population was to grow yeast in enormous vats and somehow turn it into edible fake ham. That was also the concept in 2001: A Space Odyssey, where one of the characters was handing out sandwiches on a trip in the lunar hovercraft to the site where the black tabulum was found.

    • Was about to post the same comment.

      “…that eat harmful CO2 and convert it into useful products such as biodegradable plastic, gasoline, ammonia and biodiesel.”

      Harmful CO2????
      This writer of this U-Reek-Alert clearly is just a journalism major with no clue how biology and photosynthesis drives every higher biological system on this planet.

      As for quantum dots collecting solar energy, I would suggest folks here at WUWT do some study on what real science knows about the Chlorophyll-A active center and how thousands of chlorophyll macromolecules interlock to form a multi-spectral antenna array to the active center where photons can be collected and the electrons moved to the active center for the efficient reduction of water to O2 and hydrogen plus 2 electrons.

      This is 2.5 Billion years of trial and error brought to likely perfection for the solar wavelengths we receive from our sun.

      Human made quantum dots “got nutin'” on 2.5 billion years of chlorophyll biology.

      • Yeah – I was thinking the same thing. The headline is describing blue.green algae and the polymer is cellulose. It seems a little silly to try to reinvent the wheel when it comes to things like nanomachines. Hell – we are nanomachines that just cooperate well.

      • Joel O’Bryan wrote, “This writer of this U-Reek-Alert clearly is just a journalism major…”

        Close. Even with no byline, it is easy to spot the work of “science journalists,” isn’t it?

        To find a version of this press release / story which mentions the author’s name, I google-searched for a snippet of text from the story, and and got over 2000 hits, and many other copies of it:

        https://www.google.com/search?q=%22nanobio-hybrid+organisms%22

        Here’s one with a pretty drawing.
        https://www.greencarcongress.com/2019/06/20190611-nanorg.html

        This shortened version includes a photo of “A gram of biodegradable plastic created by the nanobio-hybrid microbes.”
        https://www.rt.com/news/461615-nanobio-eco-friendly-plastics/

        Bingo. Here’s one that mentions the author’s name:
        https://www.sciencedaily.com/releases/2019/06/190611081905.htm

        The EurekAlert version calls him the CU “Media Contact.” (Is it customary to call the author of a press release the “media contact?”)
        https://www.eurekalert.org/pub_releases/2019-06/uoca-lnc061019.php

        Googling his name finds that he “is a science writer and beat contact at CU Boulder covering ecology, environmental science, technology, chemistry and engineering. Prior to joining CU, he worked for an outdoor lifestyle magazine and a non-fiction book publisher.”

        LinkedIn says he has an MS degree in “Science Writing,” from MIT:
        https://sciwrite.mit.edu/

        It’s a quickie one-year program. You can read about it here:
        http://scwritedev.online/curriculum-2/
        https://sciwrite.mit.edu/overview-3/

        The program has no prerequisite for a STEM background. “Applicants do not necessarily need to have science degrees [or] bench science experience… [but] They do need to have sharp writing skills…”

        The program doesn’t teach any science, either, but: “To provide a direct view of how science unfolds on a daily basis, the GPSW requires each student to spend a total of 12 hours in two of MIT’s hundreds of laboratories, then write profiles of each lab.”

        It could be worse; it could be PBS NewsHour. When they needed a “Reporter/Producer on Science and Climate Change,” they hired a pretty young thing with a fresh bachelor’s degree in feminist film criticism, and a senior honors thesis entitled, “Unzipping Gender.” They call her their “STEM Superstar.” In 2013 she reported that “90 percent of the mass” of the Greenland Ice Sheet had thawed, in a single month. (Brought to you by PBS — the same folks who assure us that “it’s okay to be smart.”)

        • Nice sleuthing out the author.
          The person who wrote, “By using light-activated quantum dots to fire particular enzymes within microbial cells, the researchers were able to create “living factories” that eat harmful CO2 and convert it into useful products such as biodegradable plastic, gasoline, ammonia and biodiesel.” cannot be an actual scientist. It was obvious he/she was scientifically illiterate.

          A real biochemist would never use the phrase “fire particular enzymes”.

          As for converting CO2 into ammonia… that clearly demonstrates an utter failure at basic 8th grade chemistry of the periodic table, much how nitrogen fixation occurs in biology.
          Any relevant use of this technology would clearly indicate a pathway to ethanol production as the useful end-product chemical fuel. But we have whole industries devoted to efficient and useful production of ethanol-based products for human consumption. That reality probably never crossed the writer’s little brain.

          • They forgot to include the ‘send it through the thermal neutron source‘ step. Otherwise known as “shazam!”

      • At least the li’l critters can tell the difference between the bad evil wicked not nice CO2s and the useful wonderful kind and generous CO2s.
        That’s more than I can do.

  6. Great! Perhaps if these nano dot infected microbes go viral we can have a planet covered with microbes instead of green plants. Microbial salad, anyone?

  7. Good grief, what is this, the script for a horror movie? Soylent Green II? Why take CO2 away from our brothers, the plants?

  8. Hey, I do believe I’ve heard of an organism that consumes CO2 and nitrogen, and with light produces a plastic-source material (cellulose) and fuel. I think it was called….a tree.

    • Ta da! It’s a race to the patent office, Len. Will you get there first? Don’t forget to bring a working model.
      ;o)

      Seriously, you may have plopped a fly slap dab in the middle of their ointment, depending on how they try to patent the idea.

      • Yes, H.R., good point. Indeed this may be an instance where modern academia, in the never-ending quest to discover something new and save the planet, somehow missed seeing the forest. Oddly however, it couldn’t have been for the trees.

        Too great a portion of life spent inside an ivy-covered ivory tower, possibly.

        • It’s likely nice work, Len, and worthwhile.

          It’s just the politically polluted times that has caused it to be misrepresented.

          Some useful technology may eventually come from it.

  9. Interesting, but only if they are price competitive with commercial
    processes. I note that many of the products made from CO2 would
    themselves produce CO2 when used, not good from the Greens point of view.

    MJE VK5ELL

    • Not much is needed, but quantum dots cost over $1,000,000/kg. I would imagine that at scaled they could be made more inexpensively, but I don’t think a doubling in bacteria production would justify the cost.

  10. An interesting research – an artificial photosynthesis, without chlorophyll. Including a speculation about practical applications. Sooner or later the researchers may discover algae.

  11. Well, I see this disaster coming: the microbe gets into the wild, turns our 80% nitrogen atmosphere into mostly ammonia, while at the same time killing all the plants on Earth by devouring all the CO2, leaving everything on Earth plastic-wrapped and dead from ammonia poisoning.

    It all sounds like a Michael Crichton novel.

  12. At some point they’ll be trying to find ways to get people to put more CO2 back in the atmosphere. The greenies will be wringing their hands and sobbing that the poor plants are going extinct because there won’t be enough CO2 in the atmosphere.

    • The deepest Greens believe that organic life is a cosmic mistake. They’d be quite happy for Gaia to become a sterile rock once more.

  13. There is no valid reason to try to reduce the amount of CO2 in the atmosphere so if the process costs anything more than you can get out of the products it is a poor commercial prospect.

  14. But if the gasoline and biodiesel so produced is burned, won’t it produce CO2?

  15. So a non-production artificial process duplicates a demonstrated and developed non-food capability of agriculture – as in canola, soy, and corn – at an unstated energy budge with undetermined side effects. Ain’t science fun? More grants!

    • I think its a good idea to definitely see if there is a mechanism to take advantage of more of the spectrum than photosynthesis can. There is a lot of energy that gets missed. I could imagine an eventual synthetic biological plant whose leaves are coal black and they grow a power socket. So investigating this stuff to get the basic science down is a good idea. I just hate that it all has to be couched in Global Warming bullshit.

  16. Maybe they can cure baldness with these nano watchamacallits! CO2 generated plastic hair that grows like the real stuff.

    Patent Pending!

    Hehehe

  17. This reminds me of a few months back, when Greta Thunberg had the UK’s and USA’s politicians in thrall and XR idiots were closing down the centre of London, the BBC interviewed a die-hard greenie who wanted all FF power and oil-based fuels to be banned. The BBC interviewer put it to the Greenie: ‘If I held in my hand a magic box which had a button on it that would immediately mitigate all CO² emissions and reduce the amount of CO² in the atmosphere to a satisfactory amount, would you press the button?”
    “Oh no”, came the reply. And that, my friends, is why we face economy-destroying tax levels. It’s not Green, it’s Red. To me, it’s a question that should be put to all Greenies.

  18. my issue as always with tech like this is the complete lack of control over it once it’s out in the wild.

    Nanobio tech is exceptionally dangerous in this context.

  19. How much energy is used to do this? I’m guessing more CO2 is used to do this than is sequestered…

  20. If this works on a commercial scale, the developers will have to fight the Climate Alarmunists.

    The Alarmunists don’t want any solution that doesn’t feature socialist leaders (which is them) at the helm, and the rest of us as slaves.

    This battle is totally political. Science is just another tool.

  21. This will go over like a skunk at a picnic with the global warming chicken little zealots. They will never agree to anything short than the goal of eliminating fossil fuels.

  22. We already have unique bioengineered nano machines that produce building materials, fuel, beauty, and food. They are called trees. They consume CO2 and are growing like crazy at 420 ppm.

    • Except what they’ve invented doesn’t work nearly as well as leaves, and is at least 10 orders of magnitude more expensive…no, make that 20 orders of magnitude more expensive…

      Can I get a big grant for engineering a stupid solution to a non-problem? Just a few million will be fine, thanks very much.

      • This has applications outside of our atmosphere.

        Imagine a small generator powered by propane that humidifies a chamber as well as improves the CO2 content of the air. Add some lighting and nutrients, instant grow house.

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