Bacteria Are My Employees

Ana Paulina López (ESR2)

As part of the Nowelties project, my main goal is to understand and enhance microorganisms’ potential to treat wastewater.

Why am I so interested in knowing more about this?

Most of the existing wastewater treatment plants include microorganisms because these marvelous bacteria, fungi, and protozoa use substances present in wastewater (that we consider contaminants) to grow, replicate, and continue with their life cycle. So, there is a win-win, we obtain cleaner water and they get constant “food”. However, some contaminants that are discharged in water due to human activities are not treated efficiently…and this is the case of many organic micropollutants (OMPs).

If we only understand why OMPs are resistant to biodegradation, we could try to provide what microorganisms need.

I like to think as if bacteria were employees, we need to provide them a nice working environment, some tools, and perhaps understand their limits and “preferences”. In this way, OMPs removal can be improved, for example by promoting a more diverse and old microbial community.

Particularly, I am focused on discovering why some OMPs persist in water even after improving the operational conditions of a biological treatment. One idea is that micropollutants could not be reached or detected by bacteria because they are adsorbed to other materials, and/or their concentrations in water are not enough to be up taken by microorganisms; in other words, OMPs are not bioavailable. And then, if bacteria cannot “eat” them, OMPs won’t be degraded.

· But is there a limit from where bacteria can start detecting and degrading them?

· How can we define this limit?

· Is this limit the same among different microorganisms?

· And what happens with diverse sorts of micropollutants?

These are some of the questions that I wish to answer with my research during the coming years.

Many times the answers are difficult to find. However, I will start my investigation with simple scenarios such as considering one type of bacteria at a time, exposing it to one OMP only, providing suitable environmental conditions…In summary, I will try to keep bacteria joyful and look for any detection limit.

Nevertheless, as these ideal conditions aren’t occurring in the environment, my research will expand to more realistic systems afterward.

Overall, I am glad to take part in unraveling the so-called black-box of microbial wastewater treatment.

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