How do enzymes catalysing soil nitrogen transformations respond to changing temperatures?

Fiona C. Fraser, Paul D. Hallett, Philip A. Wookey, Iain P. Hartley, David W. Hopkins

    Research output: Contribution to journalArticle

    15 Citations (Scopus)

    Abstract

    Biological processes in soils are regulated in part by soil temperature, and there is currently considerable interest in obtaining robust information on the temperature sensitivity of carbon cycling process. However, very little comparable information exists on the temperature regulation of specific nitrogen cycling processes. This paper addresses this problem by measuring the temperature sensitivity of nitrogen cycling enzymes in soil. A grassland soil was incubated over a range of temperatures (-2 to 21 A degrees C) reflecting 99 % of the soil temperature range during the previous 50 years at the site. After 7 and 14 days of incubation, potential activities of protease, amidase and urease were determined. Activities of protease and urease were positively related to temperature (activation energy; E (a) = 49.7 and 73.4 kJ mol(-1), respectively, and Q (10) = 2.97 and 2.78, respectively). By contrast, amidase activity was relatively insensitive to temperature, but the activity was significantly increased after the addition of glucose. This indicated that there was a stoichiometric imbalance with amidase activity only being triggered when there was a supply of exogenous carbon. Thus, carbon supply was a greater constraint to amidase activity than temperature was in this particular soil.

    Original languageEnglish
    Pages (from-to)99-103
    Number of pages5
    JournalBiology and Fertility of Soils
    Volume49
    Issue number1
    DOIs
    Publication statusPublished - Jan 2013

    Keywords

    • Nitrogen mineralization
    • Temperature response
    • Protease
    • Urease
    • Amidase
    • UREASE ACTIVITY
    • ARCTIC TUNDRA
    • MINERALIZATION
    • BACTERIA
    • RESPIRATION
    • COMMUNITIES
    • PARAMETERS
    • MOISTURE
    • MODEL
    • ASSAY

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