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*

*Corresponding author for this work

Research output: Contribution to journalArticle

14 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
Early online date29 Jul 2012
DOIs
Publication statusPublished - Jan 2013

Keywords

  • bacteria
  • assay
  • Arctic tundra
  • amidase
  • parameters
  • urease
  • nitrogen mineralization
  • respiration
  • moisture
  • urease activity
  • mineralization
  • model
  • protease
  • temperature response
  • communities

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