Functionally redundant microbes can coexist by partitioning low-concentration substrates even though they compete for one dominant substrate. Thus, the ability to use the low-concentration substrate guanidine provides an additional niche for comammox

We are now attempting to isolate comammox bacteria from environmental samples using guanidine, as only one strain is currently available in pure culture. This seems particularly promising as none of the other nitrifier strains we tested could grow with guanidine.