Is Bioremediation the easy solution to human-caused pollution?

We have lots of important pollution issues all around us. It’s not a secret or something that just experts in the matter are aware of anymore. People are getting more worried about climate change and how we can try to fix our past (and present) mistakes with the environment.

To start off, the plastic problematic. We produce astonishing amounts of non-recyclable plastics yearly (381 million tons in 2017, at an increasing rate). Countries in the southeast of Asia take care of them, but usually not in the best ways. This problem arises from using very different plastics with very different recycling needs. When produced, they may even be mixed. We pay lots of money to these countries for taking care of our waste, but sometimes it’s impossible. From a practical scope, getting rid of the plastic in a non-environmental threatening way is not doable. Experts are very wary of this, pointing out that the properties that made us love plastics are also what causes them to be so dangerous. The only real solution should be cutting the use and production of plastics, especially disposable plastics.

We also have to take into account the sporadic oil spills that happen in all our oceans. These impenetrable black waves cover and suffocate everything that they touch.

Aside from hard to eliminate pollutants like plastic and oil spills, we also have other, less obvious substances, that obliterate ecosystems in the long run. Phosphorus and nitrogen compounds, spread by water contaminated by pesticides and organic wastes, can destroy whole ecosystems. As an example, the saltwater lagoon “Mar Menor” in Murcia, Spain. The pesticides and other wastes that have been flowing into the lagoon have killed the rich ecosystem there.

Bioremediation may be one way to solve these problems. It is currently the cheapest and the least harmful method of removing xenobiotics from the environment. Even though this is true, we usually find an accumulation in the environment of highly toxic and persistent compounds. This emphasizes the fact that the natural metabolic diversity of the autochthonous microbes is usually insufficient to protect the biosphere from human pollution. That is because these xenobiotics contain structural elements or substituents that do not occur in nature. Microorganisms have not evolved appropriate metabolic pathways for them. This avoids for natural occurring microorganisms to degrade the pollutants present at the time in the ecosystem.

Efficient degradation involves various factors, such as the bioavailability of the substrates, its diffusion into the cell and the actual presence of the microorganism. We require a combined approach to understand the bottlenecks of xenobiotics degradation. One option is genetic engineering, as it allows the creation of microorganisms that can degrade specific pollutants.

But approaches like these aren’t the definitive answer. One day we may be able to create microorganisms capable of degrading certain substances, but there’s always the biological factor. Some pollutants may be impossible to degrade through biological metabolic pathways. Some pollutants just are so hard to degrade that will take huge amounts of time. Of course, new advances may offer better solutions, but in the end it is up to us to avoid such harsh decline in the health of the environment.

We have to work hard at reducing the production of materials that aren’t needed and find alternatives if it may be toxic or harmful. We also have to avoid any possible environmental incidents. The UN pointed out in the sustainable development goals the need of a better relationship between humans and the planet. We have to ensure sustainable consumption and production patterns. Bioremediation isn’t the answer to all the environment needs. We have to take a step back and reflect on more sustainable, environmentally-responsible ways of living. Bioremediation isn’t going to solve all these problems.

Written by Oriol Bárcenas López