Eating ammonia in one go: these bacteria are good at it

Thursday 4 April 2024, 12:30 pm
PhD student
P. Blom. MSc.
Promotor(s)
dr. S. Lücker
Co-promotor(s)
dr. ing. M.A.H.J. van Kessel
Location
Aula

After more than a century of research, they were finally discovered: bacteria that eat ammonia completely. Prior to this, we only knew of bacteria that ate ammonia partially, with the leftovers being eaten by another bacterium. Until recently, much was still unknown about these newly discovered ammonia-eating bacteria: Where were they commonly found, and could they also be used for sewage treatment? As part of our research, we conducted a comparative analysis of methods for studying their natural distribution. Thanks to this knowledge, we knew in which sources the bacteria occur in large numbers, but in order to study them even better, we also had to be able to grow them. That is why we developed our own method of extracting these bacteria from these sources by specifically clicking luminescent molecules onto the bacteria, and then literally sorting them out on a minuscule scale. Thanks to this process of sorting and culturing, we found out how these bacteria compete with bacteria that only partially eat ammonia. Finally, with the knowledge obtained from these studies, we looked at whether we could also use these new bacteria to extract ammonia from sewage even more efficiently and under oxygen-free conditions. 

Pieter Blom was born in Rosmalen on 11 February 1995 and grew up in 's-Hertogenbosch, where he also obtained his pre-university qualification (VWO) at the Stedelijk Gymnasium.  At the University of Groningen, he enjoyed the Bachelor's programme in Life Science & Technology, but also sought and found more chemical in-depth knowledge by completing a Bachelor's programme in Chemistry. Pieter then decided to proceed at the interface of these two disciplines with a Master's programme in Molecular Biology & Biotechnology, also at the University of Groningen. The internships he completed on metabolic oscillations in baker's yeast in Groningen and on methane-eating volcanic bacteria at Radboud University played a key role in his development as a scientist. Building on this research, in November 2018, Pieter started his PhD research on recently discovered bacteria that can completely oxidise ammonia, known as comammox bacteria.