Celebrated annually on 10th November, the UNESCO World Science Day for Peace and Development aims at linking science more closely with society and underlines the importance and relevance of science in our daily lives. Marking this awareness day and touching on a relevant problem of our times, we are taking a look at bioremediation as a solution to manage plastic pollution.
Bioremediation is the process by which microorganisms remove pollutants in the environment. A basic example of bioremediation, that will be particularly familiar to gardeners, is composting, i.e. the use of a biological system of micro-organisms to break down contaminants in water or soil.
The deliberate introduction or stimulation (so called biostimulation) of these microorganisms in polluted sites has become a common practice over the past years. For example, fungi can be used to remove heavy metal pollutants from soil. Through this process, known as mycoremediation, fungi such as Aspergillus have been shown to be effective at reducing metals such as lead, mercury and arsenic in the environment in a sustainable, eco-friendly and cost-effective manner.
Single-use plastic & bioremediation
In recent years, the overuse of single-use plastics has been a high-priority topic. Examples of single-use plastic are carrier bags, drinks bottles and crisp packets. Single use plastics do not rot, like paper or food, so instead can hang around in the environment for hundreds of years and are contributing to a significant amount of non-biodegradable waste accumulating in landfills and in our oceans. In an article published by the BBC earlier this year, it is estimated that each year 400 million tonnes of plastic are produced and 40% of that is single-use – plastic we will only use once before it is binned.
A strong offender in this category is the styrofoam cup made of expanded polystyrene foam. These single-use cups are sometimes used only for seconds before being discarded and then take decades or even centuries to biodegrade. Furthermore, the production and incineration of styrofoam causes considerable environmental impact and contributes to global warming.
It is for this reason that bioremediation is so important. A recent journal article in IOP “Conference Series: Earth and Environmental Science” shows promising results of enhancing the rate at which polystyrene is degraded. Using Pestalotiopsis, a type of fungi, researchers were able to degrade styrofoam by 74.4% within 30 days (when in favorable conditions to the organism).
This and other research shows the potential for using microorganisms to degrade plastic waste. Instead of completely incinerating the waste, and therefore contributing strongly to climate change, plastics such as styrofoam can be partially decomposed by traditional methods and then treated using bioremediation.
Bioremediation may well be the way forward when the breaking point comes for our waste problem. The current solutions are not sustainable and with an ever-increasing population we may be relying more and more on our microscopic friends to help clean up our act.