Structure of the guanidinase enzyme of the comammox species Nitrospira inopinata, which converts guanidine into urea. The presumed entrance to a tunnel leading to the active site is highlighted in the left image. In the right section, the tunnel is shown as a green line and guanidine as a stick model. The structure was elucidated by the team led by Kristina Djinović-Carugo. © Kristina Djinović-Carugo/University of Vienna
An international research team led by the Centre for Microbiology and Environmental Systems Science (CeMESS) at the University of Vienna has discovered that comammox bacteria, first identified by them in 2015, can grow using guanidine, a nitrogen-rich organic compound, as their sole energy and nitrogen source. This unique ability opens new avenues for targeted cultivation of these enigmatic microbes and could also provide a key to reducing agricultural nitrous oxide emissions. The research findings were recently published as an article in the prestigious journal Nature.
This unexpected finding revealed a fourth growth substrate for ammonia oxidizers and offers new insights into niche partitioning of nitrifiers, opportunities for targeted isolation of comammox microbes, and opportunities for a more sustainable agriculture.
This study led by the DOME nitrification group involved many members of the FWF Cluster of Excellence Microplanet at CeMESS as well as scientists from the UFZ in Leipzig and Aalborg University.
This work is part of Microplanet Work package 4.3.