Enzymatic activities in coniferous leaf litter
Assays for measuring the activities of cellulase, xylanase, mannase, amylase, ..beta..-glucosidase, invertase, and protease employing buffered suspensions of ground coniferous and deciduous leaf litter exhibited zero-order kinetics. Only a small percentage of the whole-litter activities of invertase, ..beta..-glucosidase, and protease were extractable into 0.05M potassium acetate, pH 5.0; however, extractable activities of cellulase and xylanase represented from 39 to 174% of the whole-litter activities indicating their soluble exocellar nature. Extractable protease and amylase activities were best correlated with the average daily rates of CO/sub 2/ evolution in a group of 90 leaf litter samples equally representing 18 coniferous species. Enzymatic activities were readily detectable in extracts of all samples but classification of the samples by species provided little differentiation in the distribution of either enzymatic activities or rates of CO/sub 2/ evolution. Mannase, cellulase, and xylanase activities were well-correlated with each other in all samples. Assays attempting to measure a pool of readily-metabolizable substances in litter by extractable reducing substances, ninhydrin-positive substances, glucose, and phenolics failed to show correlation coefficients >0.41 with rates of CO/sub 2/ evolution. Addition of D-(+)-catechin to litter extracts, up to levels equivalent to those observed in the group of samples, did not inhibit any carbohydrase thus suggesting the lack of inhibition of litter-decomposing enzymes by the concentrations of phenolics present in these coniferous leaf litters.
- Research Organization:
- Environmental Protection Agency, Corvallis, OR
- OSTI ID:
- 5717600
- Journal Information:
- Soil Sci. Soc. Am. J.; (United States), Vol. 44:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BIODEGRADATION
BIOCHEMICAL REACTION KINETICS
DETRITUS
CARBON DIOXIDE
CONIFERS
ENZYME ACTIVITY
ENZYMES
FORESTS
INHIBITION
LEAVES
METABOLISM
METABOLITES
QUANTITATIVE CHEMICAL ANALYSIS
SAMPLING
SOILS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
DECOMPOSITION
KINETICS
OXIDES
OXYGEN COMPOUNDS
PLANTS
REACTION KINETICS
510100* - Environment
Terrestrial- Basic Studies- (-1989)