Carbon Monoxide Metabolism in Roadside Soils

AUTOR(ES)

Spratt, Henry G.

RESUMO

Air-dried soils which were equilibrated under relative humidities greater than 93% or moistened with liquid water showed marked increases in their capacities to oxidize CO to CO2. Liquid water addition in excess of saturation resulted in lower CO oxidation rates, reflecting the limited diffusion of CO through the aqueous phase. After 35 days' storage under 100% relative humidity, the capacity for CO oxidation decreased to 21% of the value observed with a freshly collected sample. Incubation of this stored soil under an atmosphere containing 200 ppm of CO (250 mg/m3) for 21 days resulted in a sevenfold increase in CO oxidation. A correlation was noted between the CO oxidative activity and the history of previous exposure of soils to high ambient levels of CO. The organisms responsible for CO oxidation apparently comprise a small fraction of the microbial population in the soils. With a roadside soil the oxidation of CO provided the driving force for the assimilation of CO2. The stoichiometry of the oxidative and assimilatory reactions in soil was in the range of values reported from laboratory studies with CO chemoautotrophs (carboxydobacteria). It is proposed that the population and activity of CO-oxidizing microorganisms increase in response to increasing levels of CO in the environment.

Documentos Relacionados

• Attributes of Atmospheric Carbon Monoxide Oxidation by Maine Forest Soils†
• Microbial metabolism of carbon monoxide in culture and in soil.
• Recovery of energy metabolism in rat brain after carbon monoxide hypoxia.
• Carbon monoxide metabolism of the methylotrophic acidogen Butyribacterium methylotrophicum.
• Heme Oxygenase-1/Carbon Monoxide: From Metabolism to Molecular Therapy