BITÖK
Bayreuther Institut für Terrestrische Ökosystemforschung
  Home Printable form Search fulltext Seite in deutsch Uni-Bayreuth
|  | Organisation |  | Research Publications |

Publications


>> internal Site (SSL)

Search:



 

Karsten, GR; Drake, HL: Denitrifying bacteria in the earthworm gastrointestinal tract and the in vivo emission of nitrous oxide (N2O) by earthworms, Applied and Environmental Microbiology, 63, 1878-1882 (1997)
Abstract:
Earthworms (Lumbricus rubellus and Octolasium lacteum) and gut homogenates did not produce CH4, and methanogens were not readily culturable from gut material. In contrast, culturable denitrifiers averaged 7 x 107 and 9 x 106 per gram dry wt. gut material for L. rubellus and O. lacteum, respectively; these values were 256- and 35-fold larger than the number of culturable denitrifiers in the soil from which the earthworms were obtained. Anaerobically-incubated earthworm gut homogenates supplemented with nitrate produced N2O at rates exceeding that of soil homogenates. Furthermore, living earthworms emitted N2O under aerobic conditions, and N2O emission was stimulated by acetylene. For earthworms collected from a mildly acidic (pH 6) beech forest soil, the rates of N2O emission for earthworms and soil averaged 884 and 2 pmoles per hour per g (fresh wt.), respectively. In contrast, for earthworms collected from a more acidic (pH 4.6) oak-beech forest soil, N2O emission by earthworms and soil averaged 145 and 45 pmoles per hour per g (fresh wt.), respectively. Based on the extrapolation of this data, earthworms accounted for an estimated 16% and 0.25% of the total N2O produced at the stand level of these beech and oak-beech forest soils, respectively.
This site makes use of cookies More information