Researchers Engineer Bacteria To Produce Plastics (arstechnica.com) 39
An anonymous reader quotes a report from Ars Technica: [A] team of Korean researchers [describe] how they've engineered a bacterial strain that can make a useful polymer starting with nothing but glucose as fuel. The system they developed is based on an enzyme that the bacteria use when they're facing unusual nutritional conditions, and it can be tweaked to make a wide range of polymers. The researchers focused on the system bacterial cells use for producing polyhydroxyalkanoates (PHAs). These chemicals are formed when the bacterial cells continue to have a good supply of carbon sources and energy, but they lack some other key nutrients needed to grow and divide. Under these circumstances, the cell will link together small molecules that contain a handful of carbons, forming a much larger polymer. When nutritional conditions improve, the cell can simply break down the polymer and use the individual molecules it contained.
The striking thing about this system is that it's not especially picky about the identity of the molecules it links into the polymer. So far, over 150 different small molecules have been found incorporated into PHAs. It appears that the enzyme that makes the polymer, PHA synthase, only cares about two things: whether the molecule can form an ester bond (PHAs are polyesters), and whether it can be linked to a molecule that's commonly used as an intermediate in the cell's biochemistry, Coenzyme A. Normally, PHA synthase forms links between molecules that run through an oxygen atom. But it's also possible to form a related chemical link that instead runs through a nitrogen atom, like those found on amino acids. There were no known enzymes, however, that catalyze these reactions. So, the researchers decided to test whether any existing enzymes could be induced to do something they don't normally do. [...]
Overall, the system they develop is remarkably flexible, able to incorporate a huge range of chemicals into a polymer. This should allow them to tune the resulting plastic across a wide range of properties. And, considering the bonds were formed via enzyme, the resulting polymer will almost certainly be biodegradable. There are, however, some negatives. The process doesn't allow complete control over what gets incorporated into the polymer. You can bias it toward a specific mix of amino acids or other chemicals, but you can't entirely stop the enzyme from incorporating random chemicals from the cell's metabolism into the polymer at some level. There's also the issue of purifying the polymer from all the rest of the cell components before incorporating it into manufacturing. Production is also relatively slow compared to large-scale industrial production. The findings have been published in the journal Nature Chemical Biology.
The striking thing about this system is that it's not especially picky about the identity of the molecules it links into the polymer. So far, over 150 different small molecules have been found incorporated into PHAs. It appears that the enzyme that makes the polymer, PHA synthase, only cares about two things: whether the molecule can form an ester bond (PHAs are polyesters), and whether it can be linked to a molecule that's commonly used as an intermediate in the cell's biochemistry, Coenzyme A. Normally, PHA synthase forms links between molecules that run through an oxygen atom. But it's also possible to form a related chemical link that instead runs through a nitrogen atom, like those found on amino acids. There were no known enzymes, however, that catalyze these reactions. So, the researchers decided to test whether any existing enzymes could be induced to do something they don't normally do. [...]
Overall, the system they develop is remarkably flexible, able to incorporate a huge range of chemicals into a polymer. This should allow them to tune the resulting plastic across a wide range of properties. And, considering the bonds were formed via enzyme, the resulting polymer will almost certainly be biodegradable. There are, however, some negatives. The process doesn't allow complete control over what gets incorporated into the polymer. You can bias it toward a specific mix of amino acids or other chemicals, but you can't entirely stop the enzyme from incorporating random chemicals from the cell's metabolism into the polymer at some level. There's also the issue of purifying the polymer from all the rest of the cell components before incorporating it into manufacturing. Production is also relatively slow compared to large-scale industrial production. The findings have been published in the journal Nature Chemical Biology.
Advances on what has come before? (Score:1)
I was pretty sure I had read about this approach before and sure enough I found a paper from 1996... [sciencedirect.com]
It seems like this new approach is maybe a lot further along and more flexible though.
Re: Advances on what has come before? (Score:1)
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Oil is finite. Depending on how you slice it, there is only about 50 - 70 years left of provable reserves.
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I guess your first sentence is correct, everything is finite. But that 50-70 years is "light crude", which also gets pushed back every few years. All that means is that when this stuff runs out oil will get a bit more expensive, but not drastically so. There will probably be some geopolitical implications as well.
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There are waves of oil shale producers who go bankrupt every time there's a sustained drop in the price of a barrel of oil. Hard to find a concrete number on the cost, but it looks like production alone is $35 to $95 per barrel. The actual breakeven rates are typically around $50 to $60 per barrel, apparently. Currently, the price per barrel of light, sweet crude (which is what shale oil appears to be classified as) is around $67 per barrel. During COVID, it dropped through the floor.
Ultimately, it's not ab
The Plastic Centipede. (Score:3)
At this point lets just take the bacteria that digest plastic and feed their output into the holding tanks of these bacteria that make plastic and just turn it into a perpetual plastic machine.
Own Goal (Score:3, Insightful)
This reaction is pointing in the wrong direction.
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I have to disagree. Plastic is very useful stuff. That said, I'd like to see a lot less of it used, but it is still too useful to get rid of completely. Just get rid of like 99% of the disposable stuff, like stuffling plastic wrapped goods into a plastic bag.
So if we actually reach the point of not using oil and natural gas anymore, we'll still want to make plastic, and this will help with that.
In competition with oil (Score:5, Insightful)
"Production is also relatively slow compared to large-scale industrial production."
Best of luck to them but the problem is that they are in competition with oil refineries. Cracking oil into its various distillates results in about 10% light olefin gases such as ethylene, propylene, and butylene. A gigantic amount of oil gets refined and therefore a similarly large amount of olefin gases are generated. It is dirt cheap and it is feedstock for all kinds of virgin plastics. This is one reason why recycling plastics isn't economically viable.
It is great to see people developing non-fossil options that may be biodegradable, but it has to be extremely inexpensive and scale up to massive levels in order to make a difference.
basic economics (Score:2)
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We aren't on track to make the planet uninhabitable.
Completely uninhabitable, probably not. Sufficient to destroy all modern societies, maybe. As weather becomes more chaotic, food security decreases. We have no viable plan for protecting it.
I'm not a climate change denier [...] Siberia could become the next breadbasket to the world
You are a climate change denier, you just don't seem to know it. Tundra plus warming does not equal farmland.
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I'm not a climate change denier [...] Siberia could become the next breadbasket to the world
You are a climate change denier, you just don't seem to know it. Tundra plus warming does not equal farmland.
Your conclusion (that flyingfsck is a climate change denialist) does not follow from your premise (that flyingfsck is wrong about warmed-up tundra being arable).
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Your conclusion (that flyingfsck is a climate change denialist) does not follow from your premise (that flyingfsck is wrong about warmed-up tundra being arable).
In isolation, no. In a world where actions have reactions and he's been posting this shit for ages and has been told repeatedly that's not how anything works, yes he is.
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I tried to do the math on that once and came up with a range of more like 2000+ years. Not suffocating to death per se, but around where we could potentially actually die from the toxicity of the CO2. There were a number of unknowns that I had to estimate, so I could be way off (in both directions). It's bee a while. In any case, while I don't think it's as short as 100 years, we are headed roughly in that direction. Now, there are plenty of factors that could change and alter that, not to mention plenty of
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A bacterium, or enzyme that could effectively digest polymers in a heterogenous environment would go a long way towards solving our plastics problem. The problem with current processes is that they require extensive sorting and cleaning, which make destruction exceedingly expensive. Being able to seed the waste stream with them during processing and have measurable effects would b
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I'm thinking they have to feed a slurry of plastic through a fermentation vessel populated with their custom strain of E. coli
Amazing! (Score:1)
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We need the bacteria to digest plastic in our brains, before we all become RFK. Then we can proceed to create more plastic.
OH GOOD! (Score:3)
I was really worried we'd run out of microplastic pollution once we ran out of petroleum!
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Don't worry, this new bacterial plastic will promote gut health and nurture a healthy microbiome.
Bacteria printhead (Score:2)
What if this bacteria escaped into the wild (Score:2)
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You mean like the humans do?
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It's OK, it will be "green" plastic.
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Read the summary - it only creates and keeps the polymers if certain nutrients are missing, basically as a storage method. In the wild, it's likely that they would find those nutrients and break down their own polymers in order to undergo mitosis and reproduce like any bacteria.
Oh man (Score:1)
There are, however, some negatives. The process doesn't allow complete control over what gets incorporated into the polymer. You can bias it toward a specific mix of amino acids or other chemicals, but you can't entirely stop the enzyme from incorporating random chemicals from the cell's metabolism into the polymer at some level.
So now our plastics are gonna "hallucinate" too???
Lethal infection (Score:2)
Nothing really new (Score:2)
Grey goo (Score:2)
Some mad scientists never learn. (Score:2, Interesting)
Our modern society is built on, and requires, plastics. We use them for food safety, medicine, on ships, planes, cars, trains, medical devices, etc. Destroy the plastics and we become unsafe and society collapses.
So... along come some researchers who are so focused upon the supposed problems of plastics disposal that they decide to engineer a new creature that destroys plastics... what could POSSIBLY go wrong? . Where's the guarantee that such a thing would never escape the labs? Of course, in this case, t