Carbon monoxide (CO) is considered a highly poisonous gas often associated with tragic loss of life. Nonetheless, CO occurs naturally at relatively low concentrations in the atmosphere and in geothermal environments. Remarkably, certain bacteria, the CO oxidizers, thrive on CO using it as an important source of energy for their metabolism. Some CO-oxidizing bacteria can be found in soils, where their metabolism helps regulate CO concentrations in the atmosphere. Other CO-oxidizing bacteria occur in geothermal systems, such as hot springs and volcanic environments. These bacteria survive under harsh conditions, including high temperatures and low (acidic) pH. Little is known about these extremophiles, but they likely include many novel species, some of which might represent relatively ancient life forms.
Research conducted in the unique geothermal environments of Kilauea volcano (Hawai'i) and hot springs in Yellowstone and Lassen Volcano National Parks will establish the biodiversity of thermophilic oxygen-dependent CO oxidizers, discover new thermophilic CO-oxidizing species, and establish the factors that determine the geographic distribution of these organisms. Results of this study will create a new understanding of the evolutionary history of all oxygen-dependent CO-oxidizing bacteria and provide new insights that will aid research on CO oxidizers in soils and in the oceans.
