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| Titel |
Effect of afforestation on urate oxidase activity in two kinds of soils |
| VerfasserIn |
Teresa Meysner, Lech Wojciech Szajdak |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034895
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| Zusammenfassung |
| Researches were carried out in soils under a 125-m-long the afforestation located in the
Kościan Plain in Turew, which is a part of West Poland Lowland. Soil samples
were taken from four chosen sites marked as Nos. 1, 2, 3 and 4 near wells. One
part of this afforestation was allocated on mineral, whereas the second part was on
mineral-organic soil. Times of sampling were from March to November in 2009
from the layer at 0-20 cm depth after removing leaf litter. Urate oxidase activity
in soils was determined colorimetrically by measuring the absorbance at λ=293
nm.
Urate oxidase is a homotetrameric enzyme containing four identical active sites situated
at the interfaces between its four subunits. This enzyme catalyzes the oxidation of uric acid, a
final product of purine catabolism to 5-hydroxyisourate, which is non-enzymatically
transformed into allantoin, carbon dioxide and hydrogen peroxide. Uricase is also an essential
enzyme in the ureide pathway, where nitrogen fixation occurs in the root nodules of legumes.
Nitrogen heterocyclic compounds such as allantoin may serve as nitrogen sources or nitrogen
transport compounds in plants that are not able to fix nitrogen. It has been estimated that
heterocyclic nitrogen compounds represent about 30% of the reduced nitrogen in
soils.
These studies indicated that the flow of ground water was accompanied by an increase of
uricase activity from 16 to 71% (from point 1 to point 2) in all periods of sampling in mineral
soils. Similar trend was shown in mineral-organic soils. There was an increase of uricase
activity from the point 3 to 4 and ranged from 13 to 37% similar to the direction of the
flow of ground water. However, no significant differences of urate oxidase activity
between two kinds of soils were observed. This study showed that the uricase activity
ranged from 1.99 to 7.16 μmol-
h-1-
g-1 in the mineral soils and from 1.79 to 8.36
μmol-
h-1-
g-1.
The study indicated an impact of the afforestation located on mineral and mineral-organic
soils on the changes of uricase activity similar to the flow of ground water.
This work was supported by a grant No. N N305 3204 36 founded by Polish Ministry of
Education. |
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