Researchers Engineer Bacteria To Produce Plastics (arstechnica.com) 27
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)
Re: (Score:2)
Oil is finite. Depending on how you slice it, there is only about 50 - 70 years left of provable reserves.
The Plastic Centipede. (Score:2)
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.
Re: (Score:2)
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)
Re: basic economics (Score:1)
Re: (Score:2)
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.
Re: (Score:2)
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).
Re: (Score:2)
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.
Amazing! (Score:1)
Re: (Score:3, Interesting)
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!
Re: (Score:2)
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)
Re: (Score:3)
You mean like the humans do?
Re: (Score:2)
It's OK, it will be "green" plastic.
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)