Fungi and bacteria digest plastic waste, or become a reality!

Beijing time on August 2, according to foreign media reports, imagine what it would be like to have a bunch of mushrooms popping out of a jar full of grains. Although mushrooms are very common, they are not particularly attractive or exciting. It was great to make that discovery in this particular experiment!

Because the fungus eats the plastic sponge used to fill the jars and then breaks it down like any other food, the goal of this research project was to evaluate some fungal strains for making bio-based insulation, but the hungry fungus was There have been breakthroughs in another direction -- the ability to ingest plastic matter ingeniously.

Biohm Biomanufacturing is currently working on developing this strain of fungus as a more effective digester, which may help us better deal with plastic waste.

It is no secret that dealing with single-use plastic waste is a serious environmental problem. According to statistics from Greenpeace, by 2015, the world had produced 6.3 billion tons of virgin plastic, of which only 9% were recycled, and the rest were incinerated Incinerate in furnace or discard.

However, the situation is gradually improving and currently more than 40% of plastic packaging in the EU has been recycled, with a target of reaching 50% by 2025. But some types of plastic, such as PET (polyethylene terephthalate), widely used in beverage bottles, are difficult to recycle through traditional methods, so might biology have the answer?

The researchers are currently testing the reaction of polyethylene terephthalate and polyurethane to the fungus. Put these plastic substances together with the fungus, and the fungus will eat the plastic, and as the fungus continues to multiply, it will produce more. fungi, and then people can make biomaterials from them, or animal feed, or antibiotics.

Scientists from the University of Edinburgh in the United Kingdom recently used Escherichia coli modified in the laboratory to extract molecules from ethylene terephthalate through a series of chemical reactions and convert them into terephthalic acid, which becomes vanillin, a culinary seasoning.

This research is still at a relatively early stage, and more work is needed to find ways to make the process more efficient and economically viable. This is a very exciting starting point, with future commercial applications possible after further improvements to the process.

Meanwhile, a research team at the Helmholtz Center for Environmental Research in Germany is using a bacterium originally discovered in a local garbage dump to break down polyurethane. The bacterium, called Pseudomonas, consumes about half of the plastic to increase its own biomass, with the rest converted into the form of carbon dioxide. Like other plastic-eating organisms, Pseudomonas uses enzymes to break down polyurethane, and the research team has now performed a genome analysis of the bacterium to identify the specific genes that encode these enzymes.

But some researchers question whether such technologies are commercially viable. Enzymatic or microbial conversion of PET to other components is a very interesting science that requires further exploration and analysis, however the technology will have to compete with mature commercial conversion technologies currently in widespread use with water-catalyzed systems.

At present, the best development on the road to commercialization may be a French company Carbios, which recently announced that it has produced the world's first food-grade PET plastic bottle made entirely of enzyme-recycled plastic. Unlike most recycling methods, the enzyme can also process colored PET material.

Based on this new technology, any kind of PET plastic waste can be recycled into any type of PET products, however, the cost of bottles manufactured in this way is almost twice that of conventional petrochemical production, despite this, the technology is still There is great potential to compete with the low cost of traditional plastic bottles.

Enzyme substances can be very useful because they are highly functional, and they can treat polluted environments, if the packaging is still dirty, and they don't use a lot of energy. In addition, enzyme substances can be scaled up and down very easily. The advantage of enzymes is that they can be composed of small units with a low carbon footprint, and they can be used in developing countries or in more remote areas.

However, this technology is not a panacea. Using this enzyme, PET bottles can be recycled to make new bottles. However, PET bottles are somewhat resistant to degradation by enzymatic substances, so an additional pretreatment must be introduced. mechanism that puts a lot of extra energy into melting the plastic and reducing theThe substance crystallizes, so that the plastic substance can be degraded using enzymes, but it does not make much sense from an economic point of view and a carbon footprint point of view.

While the situation may be improving now, the scope for enzymatic substance recovery is very limited. The latest technology that has been developed is used to completely degrade only two polyesters, which means that about 75 million tons of polyester can be degraded every year, and the global plastic production is about 350 million tons, so we still have a lot of work to do!