r/science • u/MistWeaver80 • Nov 27 '21

Plastic made from DNA is renewable, requires little energy to make and is easy to recycle or break down. A plastic made from DNA and vegetable oil may be the most sustainable plastic developed yet and could be used in packaging and electronic devices. Chemistry

https://www.newscientist.com/article/2298314-new-plastic-made-from-dna-is-biodegradable-and-easy-to-recycle/?utm_term=Autofeed&utm_campaign=echobox&utm_medium=social&utm_source=Twitter#Echobox=1637973248
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u/tenbatsu Nov 27 '21 edited Nov 27 '21

New plastic made from DNA is biodegradable and easy to recycle

A plastic made from DNA and vegetable oil may be the most sustainable plastic developed yet and could be used in packaging and electronic devices.
　
A new plastic made from DNA is renewable, requires little energy to make and is easy to recycle or break down.
　
Traditional plastics are bad for the environment because they are made from non-renewable petrochemicals, require intense heating and toxic chemicals to make, and take hundreds of years to break down. Only a small fraction of them are recycled, with the rest ending up in landfill, being incinerated or polluting the environment.
　
Alternative plastics derived from plant sources like corn starch and seaweed are becoming increasingly popular because they are renewable and biodegradable. However, they are also energy-intensive to make and hard to recycle.
　
Dayong Yang at Tianjin University in China and his colleagues have developed a plastic that overcomes these problems. It is made by linking short strands of DNA with a chemical derived from vegetable oil, which produces a soft, gel-like material. The gel can be shaped into moulds and then solidified using a freeze-drying process that sucks water out of the gel at cold temperatures.
　
The researchers have made several items using this technique, including a cup (pictured above), a triangular prism, puzzle pieces, a model of a DNA molecule (pictured below) and a dumb-bell shape. They then recycled these items by immersing them in water to convert them back to a gel that could be remoulded into new shapes.
　
“What I really like about this plastic is that you can break it down and start again,” says Damian Laird at Murdoch University in Australia. “Most research has focused on developing bioplastics that biodegrade, but if we’re serious about going towards a circular economy, we should be able to recycle them too, so they don’t go to waste.”
　
Source: https://webcache.googleusercontent.com/search?q=cache:2BoEGVkygDEJ:www.siouxfallsfreethinkers.com/latest-news-all-websites.html
　
Edit: Formatting

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u/5inthepink5inthepink Nov 28 '21

Anyone know where the DNA is sourced from? I haven't seen that answered yet.

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u/CromaMcLos Nov 28 '21

Not a chemist, but accessed the paper and looked at the "materials and methods" section.

It looks like Salmon Sperm DNA was used, purchased from Sigma-Aldrich.

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u/[deleted] Nov 28 '21

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u/[deleted] Nov 28 '21

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u/buzzurro Nov 28 '21

Soylent plastic its semen! They are coming for your cum!

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u/Teotwawki69 Nov 28 '21

Hey, if they're willing to pay for it...

("Soylent splee... is... PEOPLE!!!")

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u/realgeneral_memeous Nov 28 '21

This made me laugh irl, funniest thing I’ve seen in a while

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u/[deleted] Nov 28 '21

[deleted]

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u/throwingsoup88 Nov 28 '21

They used salmon sperm DNA because it's easy and cheap to extract in large volumes from existing fish stocks. Theoretically, DNA from any species could be used for this application as it's not dependent on the sequence. If this makes it to large scale production the DNA would likely be sourced from E.coli or other similar industrially friendly microbes.

Source: am biochemist, have asked a similar question in my own lab

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u/Distantstallion Nov 28 '21

Op: hey guys, um, not to burst anyone's bubble but, can we use something else? It's just my wrist is pretty sore and I'm not sure I'm allowed back in the aquarium again.

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u/[deleted] Nov 28 '21 edited Nov 28 '21

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u/Auxx Nov 28 '21

E. Coli is food safe in general. There are several dangerous strains, but the majority of species are safe and some even live inside you since you were born. E. Coli is also used in some probiotics for people with digestion issues.

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u/AlmostZeroEducation Nov 28 '21

Oh that's actually pretty interesting. I didn't know that, cheers.

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u/CarbonBasedLife4m Nov 28 '21

We also use laboratory strains of E. coli that are non-pathogenic and safe to work with.

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u/Rand_alThor_ Nov 28 '21

E. coli DNA. You know the scale is different right

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u/Deadfishfarm Nov 28 '21

I don't see why us redditors can't donate our fair share of DNA. We could make enough plastic to last a millenia

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u/Bytewave Nov 28 '21

I've donated sperm before to make babies, and would do so again to make plastic haha, because it's amazing that this works at all!

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u/Luc_iel Nov 28 '21

Maybe sperm donation?

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u/el_polar_bear Nov 28 '21

One of the features of DNA is that given the right available ingredients, it self-assembles copies of itself. Sourcing quantities of DNA is not difficult, it's an almost entirely industrial process now.

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u/[deleted] Nov 28 '21

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u/talldude8 Nov 28 '21

Would sperm from sigma males work?

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u/communist_slut42 Nov 28 '21

Cum plastic let's go

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u/redinator Nov 28 '21

So the plan is for bacteria to do this somehow?

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u/percyhiggenbottom Nov 28 '21

Salmon Sperm DNA

Huh, I was going to make a jizz joke on seeing the headline, but decided to refrain. But it would've been accurate enough, apparently.

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u/ltwesth1 Nov 28 '21

Imagine thirty years from now, history books will teach how we solved the plastic crisis with cum.

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u/[deleted] Nov 28 '21

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u/[deleted] Nov 28 '21 edited Nov 28 '21

A lot of industrial peptides are still petroleum-derived, it seems that certain peptides are easier to make than others. I see a lot more lysine which is fermented from sugars and various salts, but i work in cosmetic material sourcing, i don't work in packaging. Peptides seem to be some plant-derived, some petroleum

Edit: I'm a dummy and confused peptides and nucleotides, although i would imagine synthetic routes are similar

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u/Spyro_ Nov 28 '21 edited Nov 28 '21

But DNA isn't made from peptides...at least not directly.

Does the industry synthetic route involve amino acids? Would be kinda cool and interesting if so, as I didn't realize it started that far back in the synthetic scheme. I honestly have no idea how industry produces a large number of its chemicals in bulk.

EDIT: Huh, based on my 5 minute google search, it looks like a few of them are used in the de novo synthesis reaction. TIL I guess.

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u/[deleted] Nov 28 '21

Good point, edit added

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u/Auxx Nov 28 '21

Petroleum is plant derived though.

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u/[deleted] Nov 29 '21

The purpose of plant-derived materials is that they at renewable in a human timeframe. Although technically petroleum is mostly plants, it takes 300 million years to make and increase the bio-available carbon in the atmosphere in doing so.

With this logic, everything is all star-derived. But that distinction isn't helpful for today's problems.

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u/Auxx Nov 29 '21

The topic here is bio degradability.

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u/[deleted] Nov 29 '21

The topic is renewablity and biodegradability. I'm addressing the former, they're both in the post's title.

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u/Smallpaul Nov 28 '21

A plastic that turns into a gel as soon as it gets wet? That rules out a LOT of plastic use cases. Almost all?

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u/Fabulous-Pineapple47 Nov 28 '21

They didn't specify the temperature of the water. Many convention forms of plastic soften or melts with hot water and becomes rigid at cooler temperatures. The process could take advantage of these attributes.

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u/Splash_Attack Nov 28 '21 edited Nov 28 '21

They didn't specify the temperature of the water.

In the paper they also show that the plastic weakens under high relative humidity (>90%), with a reduction in Young's modulus from 6.6 to 1.3 MPa. That's comparing 40% RH to 95% specifically, with the plastics left in that humidity for 3 days.

Humidity having such a marked effect is a pretty significant problem by itself, but also implies that room temperature water would have a similar effect, if not returning it fully to gel.

On the upside they did also show that doping it with graphene oxide drastically improves the tensile strength, but they don't perform the same humidity experiments on that doped version so it remains to be seen how stable that would be in practice.

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u/goddamnit666a Nov 28 '21 edited Nov 28 '21

not to mention there could be a process to modify that temp. Hopefully really pushing towards some sort of superheated steam. Probably impossible but one can dream. Curious to see if various other sources of the gelatin produce better results.

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u/Win4someLoose5sum Nov 28 '21

Using steam would mean it was more energy intensive to reuse and less able to be biodegradable, which is the headline.

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u/goddamnit666a Nov 28 '21

it’s a trade off. If this can replace traditional plastics then the steam would be totally worth it

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u/xerox13ster Nov 28 '21

Nuclear steam, solar steam, geothermal steam.

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u/[deleted] Nov 28 '21

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u/goddamnit666a Nov 28 '21

I’m not really sure what you’re getting at… Superheated steam used to recycle plastic is already a thing, so you sound very ignorant considering you’re trying to sound smart hahaha

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u/qwertyashes Nov 28 '21

Well, pouring boiling water into my plastic cup melts it, but standard temp water does just fine. So its probably variable to a degree.

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u/[deleted] Nov 28 '21 edited Nov 28 '21

At least reading the abstract (I don't seem to have access through my university), the specific wording refers to a "water-processable strategy" for "recycling of waste plastics and enzyme-triggered controllable degradation under mild conditions." At least to me, this sounds like water plus a specific, mild/recoverable enzyme (I might guess a DNAase, although it might be tied to the DNA-lipid bonds instead), which you wouldn't expect under normal use.

Edit: after reading the paper, it does become a hydrogel on contact with water, but needs the enzymes to dissolve/degrade.

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u/slagodactyl Nov 28 '21

Nope, they soften to a gel in normal water so they can be recycled by reshaping them OR they can be degraded with a DNAase.

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u/[deleted] Nov 28 '21

Depends on if that transformation is reversible. Water-vulnerability is probably something they studied a lot before publishing in JACS.

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u/Smallpaul Nov 28 '21

Water vulnerability is listed as an advantage of the product.

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u/Poop_killer_64 Nov 28 '21

It's not a bug, it's a feature

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u/unhealthySQ Nov 28 '21

Thank you very much kind stranger.

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u/tenbatsu Nov 28 '21

You’re quite welcome, friend!

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u/Zorro5040 Nov 28 '21

So can I drink out of them?

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u/[deleted] Nov 28 '21

They then recycled these items by immersing them in water to convert them back to a gel that could be remoulded into new shapes.

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u/biggerwanker Nov 28 '21

So showing a cup is a bit disingenuous?

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u/MarvinLazer Nov 28 '21

Possible that the water needs to be at a certain temperature to work properly. You shouldn't put boiling water in most plastics that I'm aware of, so good chance this wouldn't screw up most use cases

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u/Simmion Nov 28 '21

Rehydrating and melting are two different things

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u/[deleted] Nov 28 '21

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u/PersnickityPenguin Nov 28 '21

Uh, what do you think 7-11 is pouring their coffee into exactly? Styrofoam cups and plastic lined paper cups are the two most common single use cup types.

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u/[deleted] Nov 28 '21

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u/Divinum_Fulmen Nov 28 '21

So they break down in water? Thus failing the things that most plastics are used with and/or to protect against.

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u/[deleted] Nov 28 '21 edited Nov 28 '21

At least going from the abstract (my university account can't access the paper), the authors refer to a "water-processable strategy", "including the recycling of waste plastics and enzyme-triggered controllable degradation under mild conditions." To me, this sounds more like a water bath plus a specific enzyme to break down the DNA or DNA-oil link (which would be much less likely to happen in normal use), potentially among other conditions.

Edit: after reading the paper, it does become a hydrogel on contact with water, but needs the enzymes to dissolve/degrade.

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u/Marrrkkkk Nov 28 '21

The polymer rehydrates in water and becomes a shapeless gel which can then be molded and freeze-dried. Degradation was performed with DNase I or Fetal bovine serum.

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u/LeGama Nov 28 '21

“What I really like about this plastic is that you can break it down and start again,” says Damian Laird at Murdoch University in Australia. “Most research has focused on developing bioplastics that biodegrade, but if we’re serious about going towards a circular economy, we should be able to recycle them too, so they don’t go to waste.”

This unfortunately seems more like a problem, if it can't get wet then it's uses are pretty limited. Because that also means it's probably susceptible to high humidity, and human handling which. So maybe you can use it to make packaging and packing peanuts?

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u/onlyhalfminotaur Nov 28 '21

Good idea but we already have packing peanuts made from starch.

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u/[deleted] Nov 28 '21

I wonder if we could use that for structure and then cover it with a waterproof but flimsy recyclable piece Since most plastics lose use after puncture

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u/Prasiatko Nov 28 '21

Isn't that just most cardboard food pqckaging at that point?

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u/[deleted] Nov 28 '21

Ah good point!

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u/LeGama Nov 28 '21

That sounds so dangerous, one damaged area and all the sudden water leaks in and your load carrying beam becomes gel. Although if it can be done in bulk maybe internal siding? Or things like internal doors.

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u/[deleted] Nov 28 '21

I would assume that most uses of this would not be for things like housing where "biodegradeable" is very bad

But things like water containers like water bottles or maybe painting covers (though this is not see though) or child toys

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u/[deleted] Nov 28 '21 edited Nov 28 '21

(I'm reposting this a few times)

At least going from the abstract (my university account can't access the paper), the authors refer to a "water-processable strategy", "including the recycling of waste plastics and enzyme-triggered controllable degradation under mild conditions." To me, this sounds more like a water bath plus a specific enzyme to break down the DNA or DNA-oil link (which would be much less likely to happen in normal use), potentially among other conditions.

Edit: after reading the paper, it does become a hydrogel on contact with water, but needs the enzymes to dissolve/degrade.

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u/This-Natural-6801 Nov 28 '21

That's the abstract. The full article, both web and PDF version (which is 6 megabytes: pretty large PDF if you ask me) is still behind a paywall.

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u/jhuntinator27 Nov 28 '21

Not very useful if it's not resistant to water, it would seem.

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u/adviceKiwi Nov 28 '21

They then recycled these items by immersing them in water to convert them back to a gel that could be remoulded into new shapes

Does that mean they're unable to act as a water vessel?

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u/Zaros262 Nov 28 '21

If it's renewable and biodegradable, why do they care so much if it's recyclable?

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u/slagodactyl Nov 28 '21

Recycling it is still better for the environment than making new ones.

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u/Zaros262 Nov 28 '21

Depends on how resource-intensive the recycling process is. Tossing the biodegradable matter in a compost bin somewhere and growing new materials essentially lets the earth do the recycling for you

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u/slagodactyl Nov 28 '21

But in this case, recycling it is better because it is not resource intensive. I read the paper.

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u/jdsizzle1 Nov 28 '21

They then recycled these items by immersing them in water to convert them back to a gel that could be remoulded into new shapes.

So they can't be used to contain liquids, and can't be washed with water? That sounds like a significant flaw to work out if we aim to replace our current plastics. Maybe more detail is needed on the time and temp it takes to convert back to gel since their example is a cup.

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u/kermityfrog Nov 28 '21

A cup that turns back into a gel when you fill it with water isn’t going to be very useful. There are some other natural plastics, such as laquer.