Datensatz

Zusammenfassung

DNA encoding ammonia monooxygenase from two phylogenetically related
autotrophic nitrifying bacteria, Nitrosospira sp. AHB1 and Nitrosolobus
multiformis C-71, was amplified by PCR, The resulting products were
cloned into the vector pCR-Script, A continuous region of DNA of about
1.5 kb for strain AHB1 and 1.24 kb for N. multiformis C-71 was analysed.
These comprised the major part of the gene amoA encoding the active site
polypeptide and, directly downstream, the 5' portion of the amoB gene.
The identity values for these sequences at the amino acid level were
93.0% for amoA and 96.1% for amoB. The corresponding values for the
nucleic acid sequences were 86.7% and 88.8%, respectively. The identity
of the 16S rRNA gene of strain AHB1 to that of N. multiformis C-71 was
at least 98.5%. The different degree of sequence conservation between
the 16S rDNA and the genes encoding for ammonia monooxygenase
facilitates the application of the latter as a molecular tool for a
fine-scale differentiation of autotrophic nitrifying bacteria, at the
species or strain level, in both environmental and cultivation studies.