Stoichiometry of soil enzyme activity at global scale

Abstract

Extracellular enzymes are the proximate agents of organic matter decomposition and measures of these activities can be used as indicators of microbial nutrient demand. We conducted a global-scale meta-analysis of the seven-most widely measured soil enzyme activities, using data from 40 ecosystems. The activities of b-1,4-glucosidase, cellobiohydrolase, b-1,4-N-acetylglucosaminidase and phosphatase g)1 soil increased with organic matter concentration; leucine aminopeptidase, phenol oxidase and peroxidase activities showed no relationship. All activities were significantly related to soil pH. Specific activities, i.e. activity g )1 soil organic matter, also varied in relation to soil pH for all enzymes. Relationships with mean annual temperature (MAT) and precipitation (MAP) were generally weak. For hydrolases, ratios of specific C, N and P acquisition activities converged on 1 : 1 : 1 but across ecosystems, the ratio of C : P acquisition was inversely related to MAP and MAT while the ratio of C : N acquisition increased with MAP. Oxidative activities were more variable than hydrolytic activities and increased with soil pH. Our analyses indicate that the enzymatic potential for hydrolyzing the labile components of soil organic matter is tied to substrate availability, soil pH and the stoichiometry of microbial nutrient demand. The enzymatic potential for oxidizing the recalcitrant fractions of soil organic material, which is a proximate control on soil organic matter accumulation, is most strongly related to soil pH. These trends provide insight into the biogeochemical processes that create global patterns in ecological stoichiometry and organic matter storage.

Priming and microbial nutrient limitation in lowland tropical forest soils of contrasting fertility

“…enzymes involved in the hydrolysis of amino acids; Acosta-Martinez and Tabatabai 2000). Our interpretation of up-regulated phosphomonoesterase activity is supported by several studies that have measured higher phosphomonoesterase activity in response to greater P deficiency in soils (Olander and Vitousek 2000;Allison et al 2007;Sinsabaugh et al 2008). …”

“…Phosphomonoesterase is released by microorganisms in response to phosphorus (P) deficiency to hydrolyze ester bonds between C and P in organic matter and liberate orthophosphate (Quiquampoix and Mousain 2005). Activity of these enzymes can indicate microbial mineralization of nutrients from organic matter due to N or P demand (Olander and Vitousek 2000;Allison et al 2007;Sinsabaugh et al 2008) and consequently may provide a useful indication of nutrient limitation during priming. Priming due to increased abundance of recalcitrant-C degrading microorganisms can be identified by a shift in microbial community composition (e.g.…”

Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer

“…Their activities can indicate microbial activity, decay rates, and availability of substrates for microbial or plant uptake (Garcia-Gil et al, 2000;Lagomarsino et al, 2009). Activities of β-1,4-glucosidase (βG), β-1,4-N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid (alkaline) phosphatase (AP) control the release of biologically available nutrients from organic compounds of carbon (C), N, and P (Sinsabaugh et al, 2008(Sinsabaugh et al, , 2010Zhou et al, 2012).…”

Responses of peat carbon at different depths to simulated warming and oxidizing

“…Warming leads to an earlier spring thawing in peatlands (Briones et al, 2014) with an advanced increase in microbial activity, as well as Rs. O 2 can activate most oxygen enzyme activities which could be a proximate control of soil organic matter (SOM) dynamics, especially in plateau peatlands (Laiho, 2006;Sinsabaugh et al, 2008;Tian and Shi, 2014). O 2 also relieves the inhibition effect of polyphenolic on soil hydrolase and microbial activity (Freeman et al, 1997;Freeman et al, 2001a).…”