TRANSCRIPTION OF THE AMOC, AMOA AND AMOB GENES IN NITROSOMONAS-EUROPAEA AND NITROSOSPIRA SP, NPAV

Nitrifying bacteria such as Nitrosomonas europaea and Nitrosospira sp. NpAV use ammonia monooxygenase (AMO) for oxidation of their primary g rowth substrate, ammonia. Two polypeptides of AMO are coded for by con tiguous genes, amoA and amoB, which are preceded by a third gene, amoC . The amoCAB dusters are present in multiple copies in nitrifying bact eria of the beta subdivision. These bacteria also have one amoC copy t hat is not adjacent to a copy of amoAB. The seven known amoC genes in different nitrifiers code for similar polypeptides (> 68%), Reverse tr anscriptase-polymerase chain reactions and Northern blots indicated th at amoC from the amoCAB cluster is contained on a transcript with amoA B. Two other transcripts were detected with amo probes and may be a pr oduct of processing of the amoCAB mRNA or independent transcripts. (C) 1998 Federation of European Microbiological Societies. Published by E lsevier Science B.V. All rights reserved.