Until now, the oxidation steps necessary for complete nitrification have always been observed to occur in two separate microorganisms in a cross-feeding interaction; here, together with the study by van Kessel et al., Daims et al. report the enrichment and characterization of Nitrospira species that encode all of the enzymes necessary to catalyse complete nitrification, a phenotype referred to as “comammox” (for complete ammonia oxidation).
- Holger Daims
- Elena V. Lebedeva
- Michael Wagner