Prevalence of nitrous oxide reducing capacity in denitrifiers from a variety of habitats
- 23 Downloads
A total of 81 strains isolated by T. N. Gamble from soils from eight countries, fresh water lake sediments and nitrified poultry manure were examined for their ability to grow on N2O as their electron acceptor, as well as for their tendency to produce N2O from NO 3 − in the absence and presence of acetylene. Seventy-seven of the 81 strains were confirmed as denitrifiers. Fifty-nine of the 77 strains grew on N2O, while 12 strains produced N2O but could not utilize it. Six strains reduced NO 3 − to N2 but could not grow on N2O, suggesting that even if N2O is always an intermediate product of denitrification, it is not always a freely diffusible intermediate. The organisms, however, would consume N2O that accumulated early in growth and accumulated N2O in the presence of acetylene. Thus the total number of N2O users was 65 strains or 83% of the total tested. This implies that the N2O reducing capacity of denitrifiers occur widely in nature. A high proportion ofPseudomonas fluorescens biotype II reduced N2O. The accumulation of N2O from NO 3 − in the presence of acetylene provides strong evidence that N2O is generally an intermediate in denitrification as well as provides additional support for the usefulness of this chemical as a general inhibitor of N2O reduction.
Key wordsAcetylene inhibition Denitrifiers Electron acceptor Incubation Nitrate Nitrous oxide Nitrogen
Unable to display preview. Download preview PDF.
- 1.Delwiche C C 1956In Inorganic Nitrogen Metabolism. Eds. E D McElroy and B Glass. pp 233–256, John Hopkins, Baltimore.Google Scholar
- 3.Focht D D 1974 The effect of temperature, pH and aeration on the production of N2O and gaseous N — a zero — order Kinetic model. Soil Sci. 118, 173–179.Google Scholar
- 5.Garcia J L 1974 Reduction de loxyde nitroux dans les sols de rizieres du Senegal measure de lactivite denitrificans soil. Biol. Biochem. 6, 79–84.Google Scholar
- 6.Martin J K 1975 Comparison of agar media for counts of viable soil bacteria. Soil Biol. Biochem. 7, 401–402.Google Scholar
- 8.Payne W J 1973 Reduction of N2O by Microorganisms. Bacterial. Rev. 37, 409–452.Google Scholar
- 9.Sacks L E and Baker H A 1952 Substrate oxidation and nitrous oxide utilization in denitrification. J. Bacterial 64, 247–252.Google Scholar
- 10.Smith M S Firestone J K and Tiedje J M 1978 The acetylene inhibition method for short-term measurement of soil denitrification and its evaluation using Nitrogen — 13. Soil Sci. Soc. Am. J. 42, 611–615.Google Scholar
- 11.Stanford G, Legg J O, Dzienia S and Simpson E C 1975 Denitrification and associated nitrogen transformations in soils. Soil Sci. 120, 147–152.Google Scholar