Microbes in soils and other environments produce extracellular enzymes to depolymerize and hydrolyze organic macromolecules so that they can be assimilated for energy and nutrients. Measuring soil microbial enzyme activity is crucial in understanding soil ecosystem functional dynamics. The general concept of the fluorescence enzyme assay is that synthetic C-, N-, or P-rich substrates bound with...

abstract earthworms are an important component of soil fauna, and play a crucial role in the improvement of soil properties. however, very little is known of the interactive influence of earthworms and organic materials on soil enzyme activities, particularly in arid and semi-arid soils. the low organic matter content and the significant role of earthworms in stimulating microbiological and bio...

Both microbially produced enzymes and mineral surfaces can be considered catalysts of chemical transformation in soils and other geological environments such as sediments and subsurface aquifers. While both are important direct agents of organic matter (OM) remineralization and transformation, mineral surfaces can also act as “heterogeneous co-catalysts,” influencing the kinetic properties of b...

Currently, measuring enzyme activities in soils or other lignocellulose-based materials is technically feasible; this measurement is particularly suitable for evaluating soil processes of biopolymer (cellulose, hemicelluloses, lignin, chitin and others) degradation by microbes and for assessing cycling and mobilization of principal nutrients including nitrogen, phosphorus and sulfur. With some ...

Riparian zones are recognized as landscape features that buffer streams from pollutants, particularly nitrogen. The objectives of this experiment were to (i) assess denitrification activity within a riparian zone and (ii) determine the influence of physical, chemical, and landscape features on denitrification. This experiment was conducted from 1994 to 1997 in North Carolina on a riparian zone ...

soil enzyme activities can be used as indicators of soil quality for assessing the sustainability of agricultural ecosystems. the objective of this study was to determine the effects of barley residue input rate, burning, urea fertilizer and tillage management on activities of alkaline phosphatase and urease under field conditions, after a period of 90 days. the experiment was carried out based...

Salinity is a major driver of bacterial community composition across the globe. Despite growing recognition that different bacterial species are present or active at different salinities, the mechanisms by which salinity structures community composition remain unclear. We tested the hypothesis that these patterns reflect ecological coherence in the salinity preferences of phylogenetic groups us...

The effects of air drying soil on denitrifying enzyme activity, denitrifier numbers, and rates of N gas loss from soil cores were measured. Only 29 and 16% of the initial denitrifying enzyme activity in fresh, near field capacity samples of Maury and Donerail soils, respectively, were lost after 7 days of air drying. The denitrifying activity of bacteria added to soil and activity recently form...