| Autor: |
D.A. Cataldo, J.A. Duggin |
| Rok vydání: |
1985 |
| Předmět: |
|
| Zdroj: |
Soil Biology and Biochemistry. 17:469-474 |
| ISSN: |
0038-0717 |
| DOI: |
10.1016/0038-0717(85)90011-2 |
| Popis: |
Gas exchange rates over soils were measured in a closed, flowing-gas system. 14 CO was rapidly oxidized to 14 CO 2 with only a minor loss in atmospheric radioactivity. Incorporation of 14 C into the soil was slight and was via 14 CO 2 rather than 14 CO. CO oxidation was a microbial process and no oxidation occurred when soils had been autoclaved. The rate of CO depletion was concentration dependent and followed Michaelis-Menten kinetics. The rate constants K m and V max ranged from 18 to 51 μ 1 −1 CO and from 0.58 to 4.35 mg C kg −1 dry soil h −1 respectively. The maximum rate of reaction for Hubbard Brook soil was about an order of magnitude greater than any soil previously reported. The oxidation reaction was accompanied initially by a reduction in net soil respiration. This was then followed by a period of high respiration which continued until CO levels were reduced to about 5μll −1 . Thereafter respiration fell below the pretreatment rate and only returned to that rate 45 min after CO had been depleted from the atmosphere. The data suggest that at high CO concentrations (40–100 μll −1 CO) autotrophic carboxydobacteria comprise the main component of the CO-oxidizing population and, as the concentration declines towards ambient levels they are replaced by heterotrophic microorganisms possessing a cometabolic process. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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