Effects of dissolved oxygen on extracellular enzymes activities and transformation of carbon sources from plant biomass: implications for denitrification in constructed wetlands.

Dissolved oxygen (DO) concentrations have often been shown to be important to decomposition rates of plant litter and thus may be a key factor in determining the supply of dissolved organic carbon (DOC) and carbon-dependent denitrification in wetlands. During the 2 months operation, DOC accumulation in anaerobic condition was superior to aerobic condition due to higher activities of hydrolase enzymes and lower hydrolysates converted to gaseous C. Also, much higher denitrification rates were observed in wetland when using anaerobic litter leachate as the carbon source, and the available carbon source (ACS) could be used as a good predictor of denitrification rate in wetland. According to the results of this study, extracellular enzymes activities (EEAs) in wetland would change as a short-term consequence of DO. This may alter balance of litter carbon flux and the characteristics of DOC, which may, in turn, have multiple effects on denitrification in wetlands.

[1]  A. Horne,et al.  Plant carbohydrate limitation on nitrate reduction in wetland microcosms. , 2002, Water research.

[2]  K. Poutanen,et al.  Production of xylanolytic enzymes by strains of Aspergillus , 2004, Applied Microbiology and Biotechnology.

[3]  E. Rejmánková,et al.  Wetland macrophyte decomposition under different nutrient conditions : Relationships between decomposition rate, enzyme activities and microbial biomass , 2007 .

[4]  G. Godshalk,et al.  Decomposition of aquatic angiosperms. I. Dissolved components , 1978 .

[5]  M. Gessner,et al.  Methods to Study Litter Decomposition: A Practical Guide , 2020 .

[6]  C. Freeman,et al.  Carbon supply and the regulation of enzyme activity in constructed wetlands , 2000 .

[7]  Qi Zhou,et al.  Effects of plant biomass on nitrate removal and transformation of carbon sources in subsurface-flow constructed wetlands. , 2010, Bioresource technology.

[8]  L. Baker,et al.  Nitrate removal in wetland microcosms , 1998 .

[9]  L. Kong,et al.  Enzyme and root activities in surface-flow constructed wetlands. , 2009, Chemosphere.

[10]  P. Mccarty,et al.  Environmental Biotechnology: Principles and Applications , 2000 .

[11]  Raimund Haberl,et al.  Constructed Wetlands for Pollution Control , 2001 .

[12]  B. Logan,et al.  Molecular weight distribution of hydrolysis products during the biodegradation of model macromolecules in suspended and biofilm cultures. II. Dextran and dextrin , 1997 .

[13]  P. Gerhardt,et al.  Methods for general and molecular bacteriology , 1994 .

[14]  C. Freeman,et al.  Exogenous enzyme supplements to promote treatment efficiency in constructed wetlands. , 2006, The Science of the total environment.

[15]  R. Sinsabaugh,et al.  Allocation of extracellular enzymatic activity in relation to litter composition, N deposition, and mass loss , 2002 .

[16]  Dong Liu,et al.  Effects of plant diversity on nutrient retention and enzyme activities in a full-scale constructed wetland. , 2010, Bioresource technology.

[17]  Jan Vymazal,et al.  Wastewater Treatment in Constructed Wetlands with Horizontal Sub-Surface Flow , 2008 .

[18]  P. Elefsiniotis,et al.  The effect of temperature and carbon source on denitrification using volatile fatty acids , 2006 .

[19]  Maia S Fleming-Singer,et al.  Enhanced nitrate removal efficiency in wetland microcosms using an episediment layer for denitrification. , 2002, Environmental science & technology.

[20]  P. Nielsen,et al.  Enzymatic activity in the activated-sludge floc matrix , 1995, Applied Microbiology and Biotechnology.

[21]  Seyoum Y. Gebremariam,et al.  Nitrate removal and DO levels in batch wetland mesocosms: Cattail (Typha spp.) versus bulrush (Scirpus spp.) , 2008 .

[22]  Chris Freeman,et al.  A regulatory role for phenol oxidase during decomposition in peatlands. , 2004 .

[23]  B. Cade,et al.  Macrophyte decomposition in a surface-flow ammonia-dominated constructed wetland: Rates associated with environmental and biotic variables , 2008 .

[24]  F. Schinner,et al.  Xylanase-, CM-cellulase- and invertase activity in soil: An improved method , 1990 .

[25]  Qi Zhou,et al.  Influence of vegetation and substrate on the removal and transformation of dissolved organic matter in horizontal subsurface-flow constructed wetlands. , 2008, Bioresource technology.

[26]  Ying‐Feng Lin,et al.  Effects of macrophytes and external carbon sources on nitrate removal from groundwater in constructed wetlands. , 2002, Environmental pollution.

[27]  M. Schlautman,et al.  Microbial transformation of dissolved leaf litter organic matter and its effects on selected organic matter operational descriptors. , 2009, Environmental science & technology.

[28]  Raimund Haberl,et al.  Constructed wetlands for pollution control: Processes, performance, design and operation , 2000 .

[29]  R. Song,et al.  Coupling of the hydrogen and polyhydroxyalkanoates (PHA) production through anaerobic digestion from Taihu blue algae. , 2010, Bioresource technology.

[30]  R. Qualls.  Biodegradability of fractions of dissolved organic carbon leached from decomposing leaf litter. , 2005, Environmental science & technology.

[31]  B. Hendel,et al.  Spectrophotometric determination of lignin-degrading enzyme activities (phenoloxidase and peroxidase) , 2005 .

[32]  F. Eivazi,et al.  Phosphatases in soils , 1977 .

[33]  I. Röske,et al.  Evaluation of the metabolic diversity of microbial communities in four different filter layers of a constructed wetland with vertical flow by Biolog analysis. , 2009, Water research.