cumA multicopper oxidase genes from diverse Mn(II)-oxidizing and non-Mn(II)-oxidizing Pseudomonas strains

A multicopper oxidase gene, cumA, required for Mn(II) oxidation was recentl y identified in Pseudomonas putida strain GB-I. In the present study, degen erate primers based on the putative copper-binding regions of the cumA gene product were used to PCR amplify cum4 gene sequences from a variety of Pse udomonas strains, including both Mn(II)-oxidizing and non-Mn(II)-oxidizing strains. The presence of highly conserved cumA gene sequences in several ap parently non-Mn(II)-oxidizing Pseudomonas strains suggests that this gene m ay not be expressed, may not be sufficient alone to confer the ability to o xidize Mn(II), or may have an alternative function in these organisms. Phyl ogenetic analysis of both CumA and 16S rRNA sequences revealed similar topo logies between the respective trees, including the presence of several dist inct phylogenetic clusters. Overall, our results indicate that both the cum A gene and the capacity to oxidize Mn(II) occur in phylogenetically diverse Pseudomonas strains.