Most adults probably have an idea of what a bacterium is, but it is far from everyone who is aware of how many wild things bacteria are actually capable of! You have probably heard of 'good' bacteria in the gut that make up our gut flora. Furthermore, food items that can promote the growth of good bacteria or contain bacteria that help with the overall function of the intestine - A good example is yogurt. But have you heard of bacteria that can help us in the fight against plastic pollution? This blog post will make you wiser on the bacteria able to degrade one of the most controversial, overproduced and difficult to degrade materials of our time; plastic.
There are bacteria all around us, and inside us for that matter, and scientists keep finding new species of bacteria. Bacteria are special in many ways, and throughout history there are countless examples of humans exploiting and further developing bacterial processes to our advantage, e.g. in food production. The different species of bacteria are uncommonly different; where they live, how they look and where they get their energy from. And this is where it gets really interesting; it has recently been discovered that some bacteria have developed the ability to degrade plastic!
It may be hard to believe, but plastic is actually made from natural organic materials - Paradoxically, however, it is difficult to degrade in nature. This is due to the chemicals added during production of the thousands of different types of plastics that exist. In general, plastic can be divided into two main groups: 1) Thermoplastic, which can become soft when heated and hard when cooled; and 2) hardened plastic, which can never become soft after it is formed. In the group of hardened plastics, the most common-known type of plastic is Polyethylene Terephthalate, probably better known by its abbreviation PET. PET is, among other things, polyester, if we talk about textiles, but also covers plastic bottles, containers and packaging.
It is PET that scientists have discovered can be used as a source of carbon, by a bacterium with the tongue-twisting name: I. sakaiensis - We allow ourselves to call it I.sak. for convenience. I.sak. can for example utilize PET plastic bottles as a carbon source, and the really interesting thing is that I.sak. have not always been able to do this! PET plastic was not used until the 1970s, so it is only recently, seen with evolutionary glasses, I.sak. has developed the ability to absorb and degrade PET quite naturally, as an energy source. More specifically, I.sak uses. two enzymes for this process, and researchers are of course extremely interested in them, as they can contribute to understanding and optimizing plastic-degrading enzymes in the future.
How can we as a society benefit from this discovery in our sometimes unmanageable struggle to reduce the global amount of plastic waste in nature? Well, bacteria are a natural, and very important, part of the planet's many circuits, eg. the Nitrogen Cycle, where organic and inorganic substances are broken down and taken up again and again in nature. Plastic has also become a ubiquitous component in nature, whether we like it or not, and it is due to this fact that it is extremely interesting that bacteria like I.sak. really rapidly (again, seen with evolutionary glasses) has become able to degrade and utilize the otherwise difficult-to-degrade material plastic.
Whether or not the enzymes that make I.sak. able to degrade PET, are able to degrade other types of plastics as well, is still uncertain, but there is no doubt that this is an area of research with an enormous potential to contribute with sustainable solutions to the global problem of plastic pollution, both in relation to actively removing plastic from nature, but also more proactively as an integrated part of future waste management.
