Plastic Fantastic: Green, Strong and Edible

Good news! I bet, we are close to inventing a new form of plastic that degrades better!

Note: The research study, on which the article below is based on, is not exactly new, dating from October 2023.

"... Currently, biodegradable plastics make up less than one-fifth of the total amount of plastic produced, and the processes needed to break them down are relatively cumbersome. ...

Seeking to create a composite plastic that would meet the needs of industry while also being environmentally friendly, the ... researchers decided to focus on commonplace, inexpensive source materials whose properties could be improved. They found that molecules of tyrosine – a prevalent amino acid that forms exceptionally strong nanocrystals – could be used as an effective component in a biodegradable composite plastic. After examining how tyrosine combines with several types of polymers, they chose hydroxyethyl cellulose, a derivative of cellulose, which is employed extensively in the manufacture of medicines and cosmetics.

On its own, hydroxyethyl cellulose is a weak material that disintegrates readily. To combine it with tyrosine, the two materials were mixed together in boiling water. When they cooled and dried, an exceptionally strong composite plastic was formed, made of fiber-like tyrosine nanocrystals that grew into the hydroxyethyl cellulose and integrated with it. ..."

Plastic Fantastic: Green, Strong and Edible - Chemistry | Weizmann Wonder Wander - News, Features and Discoveries "Weizmann Institute researchers have created a biodegradable composite material that might help battle the global plastic-waste crisis"

The gradual development of tyrosine nanocrystals in a hydroxyethyl cellulose solution

A 0.04-millimeter-thick strip of the new biodegradable plastic withstood a weight of 6 kilograms

New food packaging system reduces spoilage and contamination

Good news!

"... some 30-40 percent of America’s food supply ends up in landfills, mostly due to spoilage. At the same time, the World Health Organization estimates that foodborne illness from microbial contamination causes about 420,000 deaths per year worldwide. ...

Now, researchers ... have developed a biodegradable, antimicrobial food packaging system that does both. ...
he new food packing system has its roots in battlefield medicine. For more than a decade, Parker and his Disease Biophysics Group have been developing antimicrobial fibers for wound dressings. Their fiber manufacturing platform, known as Rotary Jet-Spinning (RJS), was designed specifically for the purpose. ...
The researchers dissolved the pullulan polymer in water and mixed it with range of naturally derived antimicrobial agents, including thyme oil, nisin, and citric acid.  ...

After seven days on a lab bench, 90 percent of unwrapped avocados were rotten while only 50 percent of avocados wrapped in antimicrobial pullulan fibers rotted.

The wrapping is also water soluble and biodegradable, rinsing off without any residue on the avocado surface. ..."

From the abstract:

"Food waste and food safety motivate the need for improved food packaging solutions. However, current films/coatings addressing these issues are often limited by inefficient release dynamics that require large quantities of active ingredients. Here we developed antimicrobial pullulan fibre (APF)-based packaging that is biodegradable and capable of wrapping food substrates, increasing their longevity and enhancing their safety. APFs were spun using a high-throughput system, termed focused rotary jet spinning, with water as the only solvent, allowing the incorporation of naturally derived antimicrobial agents. Using avocados as a representative example, we demonstrate that APF-coated samples had their shelf life extended by inhibited proliferation of natural microflora, and lost less weight than uncoated control samples. This work offers a promising technique to produce scalable, low-cost and environmentally friendly biodegradable antimicrobial packaging systems."

New food packaging system reduces spoilage and contamination – Harvard Gazette Inspired by battlefield medicine, scientists have developed an antimicrobial food wrap that reduces food waste and foodborne illness

High-throughput coating with biodegradable antimicrobial pullulan fibres extends shelf life and reduces weight loss in an avocado model (no public access)

Insights into plastic biodegradation: community composition and functional capabilities of the superworm microbiome in styrofoam feeding trials

Human ingenuity will easily and in time overcome the plastic trash/pollution issue! Here is another example!

From the abstract:

"Plastics are inexpensive and widely used organic polymers, but their high durability hinders biodegradation. Polystyrene, including extruded polystyrene (also known as styrofoam), is among the most commonly produced plastics worldwide and is recalcitrant to microbial degradation. In this study, we assessed changes in the gut microbiome of superworms (Zophobas morio) reared on bran, polystyrene or under starvation conditions over a 3 weeks period. Superworms on all diets were able to complete their life cycle to pupae and imago, although superworms reared on polystyrene had minimal weight gains, resulting in lower pupation rates compared to bran reared worms. ... Inferred microbial functions enriched in the polystyrene group included transposon movements, membrane restructuring and adaptations to oxidative stress. We detected several encoded enzymes with reported polystyrene and styrene degradation abilities, supporting previous reports of polystyrene-degrading bacteria in the superworm gut. By recovering metagenome-assembled genomes (MAGs) we linked phylogeny and functions and identified genera including Pseudomonas, Rhodococcus and Corynebacterium that possess genes associated with polystyrene degradation. ..."

Insights into plastic biodegradation: community composition and functional capabilities of the superworm (Zophobas morio) microbiome in styrofoam feeding trials | Microbiology Society

Credits: Johns Hopkins Bloomberg School of Public Health: Global Health NOW daily newsletter

Biodegradable Plastic to counter plastophobia

Human ingenuity can deal with any hysteric, irrational, and fabricated crisis like plastic pollution!

Do not vote for politicians who promise to prohibit or to make plastic artificially more expensive or to drastically regulate plastic! Don't be fooled!

See also my previous posts e.g. here, here

Here is more promising recent research on this topic:
A new technique could make some plastic trash compostable at home Embedding enzymes in the material causes it to rapidly break down without creating microplastics

Recycling single-use plastic with bacteria

Very recommendable! Trust in human ingenuity! For several decades, the populations in mostly Western countries were subjected to massive alarmism and false propaganda about single use plastic! 

To develop biodegradable forms of plastic is of course another alternative! I bet, we will also see breakthroughs in this area of research and engineering going forward!

"... Researchers from Ben-Gurion University of the Negev are looking into biodegradation by bacteria — a simpler and more environmentally friendly way to break down and recycle PET (polyethylene terephthalate) ... After several attempts, we saw a microorganism that grows and utilizes polyethylene as a carbon and energy source. These are the bacteria that can handle the polymers,” ... “We understood that in order for the bacteria to biodegrade the carbon bonds in the plastic polymers, it had to be grown in a carbon-free environment, so that the bacteria had no other choice but to consume the only available carbon in the plastic to survive,” ... We had to give them all kinds of additives, like sources of nitrogen and phosphorus to make it easier for them to perform decomposition" ... research team wound up discovering several types of bacteria capable of successfully biodegrading polyethylene microplastics in soil samples ... that within 30 days, 10 to 20 percent of the soil’s weight was lost just through the decomposition activity performed by the bacteria, which emitted carbon dioxide in the process of respiration ... biodegradation is much cheaper than thermal or chemical processes of recycling ..."

Recycling single-use plastic with bacteria - ISRAEL21c Collaboration between Israeli researchers and a Portuguese recycling company to develop a novel solution to the problem of disposable plastic.

Circe: Biodegradable plastic without the plants

Irrational plastophobia meets human ingenuity! How to address the manufactured plastic crisis!

Circe: Biodegradable plastic without the plants: Engineered microbes can produce biodegradable plastics at lower cost and environmental impact than plant-based plastics

‘A huge step forward.’ Mutant enzyme could vastly improve recycling of plastic bottles

Good news! Dedicated to all people afflicted with untreated plastophobia syndrome especially the believers of the environmentalism religion etc.! It is still in its infancy and bit slow, but this is only the beginning!

" ... Polyethylene terephthalate (PET) is one of the world’s most commonly used plastics, with some 70 million tons produced annually. ... In 2012, researchers at Osaka University found one such enzyme in a compost heap. That enzyme, known as leaf-branch compost cutinase (LLC), snips the bonds between PET’s two building blocks: terephthalate and ethylene glycol. ... The researchers then generated hundreds of mutant enzymes changing amino acids at the binding site and adding in heat-stabilizing ones. They then mass produced the mutants in bacteria and screened them to find efficient PET breakers. After repeating this process for several rounds, they isolated a mutant enzyme that’s 10,000 times more efficient at PET bond breaking than the native LLC. It also works without breaking down at 72°C, close to the temperature at which PET becomes molten.
In a small reactor designed to test the enzyme, the team found that it could break down 90% of 200 grams of PET in 10 hours."

‘A huge step forward.’ Mutant enzyme could vastly improve recycling of plastic bottles | Science | AAAS: Advance could prevent one of the world’s most common plastics from ending up in the landfill

"Researchers have engineered an enzyme that effectively breaks down the plastic PET into its constituent monomers. This could allow for more complete recycling of bottles and clothes. Research Article: Tournier et al."

"Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET)."

Podcast: A plastic-recycling enzyme, and supercooled molecules

An engineered PET depolymerase to break down and recycle plastic bottles | Nature: Present estimates suggest that of the 359 million tons of plastics produced annually worldwide1, 150–200 million tons accumulate in landfill or in the natural environment2. Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic, with almost 70 million tons manufactured annually worldwide for use in textiles and packaging3. The main recycling process for PET, via thermomechanical means, results in a loss of mechanical properties4. Consequently, de novo synthesis is preferred and PET waste continues to accumulate. With a high ratio of aromatic terephthalate units—which reduce chain mobility—PET is a polyester that is extremely difficult to hydrolyse5. Several PET hydrolase enzymes have been reported, but show limited productivity6,7. Here we describe an improved PET hydrolase that ultimately achieves, over 10 hours, a minimum of 90 per cent PET depolymerization into monomers, with a productivity of 16.7 grams of terephthalate per litre per hour (200 grams per kilogram of PET suspension, with an enzyme concentration of 3 milligrams per gram of PET). This highly efficient, optimized enzyme outperforms all PET hydrolases reported so far, including an enzyme8,9 from th

Plastic Munching Bacteria

Posted: 2/5/2017  Updated/revised: 5/23/2019, 12/9/2018

Update Of 5/23/2019

Another, recent article: These tiny microbes are munching away at plastic waste in the ocean

This article also stresses the destructive power of sunlight on plastic floating on body of water surface (emphasis added): “To conduct the study, researchers collected weathered plastic from two different beaches in Chania, Greece. The litter had already been exposed to the sun and undergone chemical changes that caused it to become more brittle, all of which needs to happen before the microbes start to munch on the plastic.”

Few articles about plastic actually mention this fact that exposure to sunlight already degrades plastic used for consumer products (e.g. polyethylene, polystyrene).

“The team immersed both [polyethylene, polystyrene] in saltwater with either naturally occurring ocean microbes or engineered microbes that were enhanced with carbon-eating microbe strains and could survive solely off of the carbon in plastic. Scientists then analyzed changes in the materials over a period of 5 months. Both types of plastic lost a significant amount of weight after being exposed to the natural and engineered microbes, scientists reported ...”

Update Of 12/9/2018

Meanwhile, more articles have been published about this subject:

1. Forscher entwickeln besseres Enzym gegen Plastikmüll – aus Versehen (German language; dated 4/17/2018)
2. Recycling hope for plastic-hungry enzyme (Dated 4/18/2018)

Both articles refer to a variant of a bacteria (Ideonella sakaiensis) that can break down PET plastic. Apparently, researchers were able to optimize the enzyme in the meantime. “The modified enzyme, known as PETase, can start breaking down the same material in just a few days.” (Source 2)

Plastics In The Cross Hairs Again

In case you had not noticed there is new environmental alarmism or hysteria going on about plastic contaminating oceans and ending up in the food chain. As usual the contamination claims are dramatically exaggerated. In past decades, many different attempts were made to malign plastics.

Trust In Human Ingenuity

I trust human ingenuity to handle such overblown concerns. Just read

Genetically Modified Bacteria Could Eat Away The World’s Massive Plastic Problem (dated 1/22/2017). The article is rather vague on specifics presumably to protect intellectual property rights. Here is the salient quote from the article (emphasis added): “Enter “Plasticure-BGU.” This invention would degrade the plastic and, as a byproduct of this process, will produce electricity by utilizing the energy released from PET’s bonds. …  using engineered enzymes and bacteria that could use plastic as a primary carbon source”

If I am not mistaken, humans also on the cusp of other solutions to the e.g. long recognized durability problem. I would bet humans soon will be capable of making plastic biodegradable, although previous attempts at that were not successful.

No To Statism

The usual recourse preferred by environmentalists to ban plastics outright should be rejected!