Carbon monoxide-oxidizing bacteria occur commonly in natural systems and are ecologically important. They play numerous roles in biogeochemical cycles, and a significant role in the budget of atmospheric CO. Nonetheless, CO oxidizers are poorly represented in cultures. A total of twelve isolates are found in at least two major phylogenetic lineages of the Bacteria (Proteobacteria and Firmicutes), however they may be even more widely distributed based on recent studies using molecular approaches to address diversity (King, in press-a; Dunfield and King, 2003; Nanba et al, submitted).

The Kilauea Volcano Microbial Observatory will emphasize isolation of CO oxidizers in various lava and tephra deposits and from roots of pioneering plants that colonize new sites. Particular emphasis will be placed on isolating representatives of groups distantly related to known CO oxidizers.