Sorting out complete ammonia oxidation: from ecophysiology to application

Abstract

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.