Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pilot-scale mangrove wetland was constructed in Futian, Shenzhen for municipal sewage treatment. Three identical belts (length: 33m, width: 3m, depth: 0.5m) were filled with stone (bottom), gravel and mangrove sand (surface). Seedlings of two native mangrove species (Kandelia candel, Aegiceras corniculatum) and one exotic species (Sonneratia caseolaris) were transplanted to the belts with one species for each belt. The hydraulic loading was 5m(3)d(-1) and hydraulic retention time 3d. High levels of removal of COD, BOD(5), TN, TP and NH(3)-N were obtained. The treatment efficiency of S. caseolaris and A. corniculatum was higher than that of K. candel. Faster plant growth was obtained for S. caseolaris. The substrate in the S. caseolaris belt also showed higher enzyme activities including dehydrogenase, cellulase, phosphatase, urease and beta-glucosidase. The removal rates of organic matter and nutrients were positively correlated with plant growth. The results indicated that mangroves could be used in a constructed wetland for municipal sewage treatment, providing post-treatment to remove coliforms was also included.
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PMID:Potential use of mangroves as constructed wetland for municipal sewage treatment in Futian, Shenzhen, China. 1834 38

A greenhouse pot experiment was conducted to evaluate the effect of sewage sludge (SS), of sugar beet sludge (SBS), or of a combination of both, in the remediation of a highly acidic (pH 3.6) metal-contaminated soil, affected by mining activities. The SS was applied at 100 and 200 Mg ha(-1) (dry weight basis), and the SBS at 7 Mg ha(-1). All pots were sown with Italian ryegrass (Lolium multiflorum Lam.). After 60 d of growth, shoot biomass was quantified and analysed for Cu, Pb and Zn. The pseudo-total and bioavailable contents of Cu, Pb and Zn and the enzymatic activities of beta-glucosidase, acid phosphatase, cellulase, protease and urease were determined in the soil mixtures. Two indirect acute bioassays with leachates from the soil (luminescent inhibition of Vibrio fischeri and Daphnia magna immobilization) were also used. The SS, in particular when in combination with SBS, corrected soil acidity, while increasing the total organic matter content and the cation exchange capacity. The application of SS led to a decrease in the level of effective bioavailable metals (extracted by 0.01 M CaCl(2), pH 5.7, without buffer), but caused an increase in their potential bioavailability (extracted by a solution of 0.5M NH(4)CH(3)COO, 0.5 M CH(3)COOH and 0.01 M EDTA, pH 4.7). Plant biomass increased more than 10 times in the presence of 100 Mg SS ha(-1), and more than five times with the combined use of 100 Mg SS ha(-1) and SBS, but a considerable phytotoxic effect was observed for the application rate of 200 Mg SS ha(-1). Copper, Pb and Zn concentrations in the shoots of L. multiflorum decreased significantly when using 100 Mg SS ha(-1) or SBS. The activities of beta-glucosidase, urease and protease increased with increasing SS applications rates, but cellulase had a reduced activity when using 200 Mg ha(-1)SS. Both amendments were able to suppress soil toxicity to levels that did not affect D. magna, but increased the soil leachate toxicity towards V. fischeri, especially with the application of 200 Mg SS ha(-1). This study showed that for this type of mine soils, and when using SS of similar composition, the maximum SS application rate should be 100 Mg ha(-1), and that liming the SS amended soil with SBS did not contribute to a further improvement in soil quality.
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PMID:Assessment of chemical, biochemical and ecotoxicological aspects in a mine soil amended with sludge of either urban or industrial origin. 1854 5

A microcosm experiment was carried out to evaluate the effects of municipal solid waste compost (MSWC) or garden waste compost (GWC), and liming materials in the rehabilitation of a soil affected by mining activities, and to study the use of perennial ryegrass (Lolium perenne L.) for phystostabilization. The performance of the amendments was assessed by soil chemical parameters, total and bioavailable metals (Cu, Pb and Zn), soil enzymatic activities, and plant relative growth and mineral composition. In general, both composts corrected soil acidity and increased the total organic matter content of the soil, although with a better performance in the case of MSWC, especially when considering total N and available P and K levels in the amended soil. The application of both composts and liming materials led to a decrease in the mobile fractions of Cu, Pb and Zn, but mobilisable fractions of Cu and Zn increased with MSWC application. Plant biomass increased more than three times in the presence of 50 Mg MSWC ha(-1) and with the combined use of 25 or 50 Mg MSWC ha(-1) and CaO, but no significant differences were observed when GWC was applied. Plant tissue analysis showed that the treatments did not significantly reduce Cu, Pb and Zn uptake by the plant. Dehydrogenase, and the enzymes related to the N-cycle, urease and protease, had increased activities with increasing MSWC application rate. Conversely, the enzymatic activities of both enzymes related to the C-cycle, cellulase and beta-glucosidase, were only positively affected by GWC application, a compost obtained from raw materials rich in C. Principal component analyses evidenced this clear separation between the effect of MSWC on soil enzymes related to the N-cycle and of GWC on soil enzymes related to the C-cycle. This study indicates that MSWC (50 Mg ha(-1), limed or unlimed) can be used successfully in the remediation of a highly acidic metal-contaminated soil, allowing the establishment of perennial ryegrass.
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PMID:Evaluation of composts and liming materials in the phytostabilization of a mine soil using perennial ryegrass. 1879 97

Sewage sludge (SS), municipal solid waste compost, and garden waste compost (GWC) were used as immobilizing agents in aided phytostabilization of an acid metal-contaminated soil affected by mining activities. The organic residues were applied at 25, 50 and 100 Mg ha(-1) (dry weight basis) and perennial ryegrass (Lolium perenne L.) was used as a "green cover". We studied the effects of the treatments on soil phytotoxicity and enzymatic activities, and on the composition and toxicity of the soil leachate towards Vibrio fischeri and Daphnia magna. Application of SS led to the greatest values of dehydrogenase, acid phosphatase, beta-glucosidase, protease and urease activities, corresponding to the greatest overall microbial and biochemical activity in amended soils. Conversely, GWC did not increase these enzymatic activities, relative to the unamended soil, or enhance ryegrass growth. Cellulase activity increased with increasing application rates of the amendments tested, but decreased at the highest SS application rate. The organic amendments were able to suppress soil toxicity to levels that did not affect D. magna, when applied at 50 and 100 Mg ha(-1), but SS, at the same application rates, increased the soil leachate toxicity towards V. fischeri. Moreover, ryegrass showed some phytotoxic symptoms when 100 Mg ha(-1) of SS were applied. This study showed the importance of an integrated evaluation of soil quality on remediation processes. Although SS immobilized trace metals and corrected soil acidity, improving soil biochemical status, when used at high application rates it led to toxicity of soil leachate towards V. fischeri, decreased soil cellulase activity and impaired ryegrass growth.
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PMID:Organic residues as immobilizing agents in aided phytostabilization: (II) effects on soil biochemical and ecotoxicological characteristics. 1909 81

Enzymatic activity, i.e. respiratory activity, dehydrogenase activity, phosphatase activity, caseinian protease activity, BAA protease activity and urease activity, was determined to investigate the process of biochemical transformations and to select enzymatic indices of maturity of composts prepared from feathers and lignocellulose wastes (bark, straw). Composting was conducted for 7 months, with periodic determinations of activity of the enzymes. The study revealed significant differences in the enzymatic activity, related with the duration of composting and with the substrate composition of the composts. Generally, composts enriched with straw were characterised by higher enzymatic activity than composts without any addition of straw. It was found that the activity of such enzymes as cellulase and protease, towards the end of the period of composting decreased and stabilised. The enzymes enumerated can be taken into consideration in estimation of the maturity of composts prepared from feathers and lignocellulose wastes.
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PMID:Changes in enzymatic activity in composts containing chicken feathers. 1932 46

Sixteen small-scale wetlands planted with four plant species were constructed for domestic wastewater purification. The objective of this study was to determine the correlations between contaminant removal and soil enzyme activity, root activity, and growth in the constructed wetlands. The results indicated that correlations between contaminant removal efficiency and enzyme activity varied depending on the contaminants. The removal efficiency of NH4+ was significantly correlated with both urease and protease activity in all wetlands, and the removal of total phosphorus and soluble reactive phosphorus was significantly correlated with phosphatase activity in most wetlands, while the removal of total nitrogen, NO3(-) , and chemical oxygen demand (COD) was significantly correlated with enzyme activity only in a few instances. Correlations between soil enzyme activity and root activity varied among species. Activities of all enzymes were significantly correlated with root activity in Vetiveria zizanioides and Phragmites australis wetlands, but not in Hymenocallis littoralis wetlands. Significant correlations between enzyme activity and root biomass and between enzyme activity and root growth were found mainly in Cyperus flabelliformis wetlands. Root activity was significantly correlated with removal efficiencies of all contaminants except NO3(-) and COD in V. zizanioides wetlands. Enzyme activities and root activity showed single-peak seasonal patterns. Activities of phosphatase, urease, and cellulase were significantly higher in the top layer of the substrate than in the deeper layers, and there were generally no significant differences between the deeper layers (deeper than 15 cm).
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PMID:Enzyme and root activities in surface-flow constructed wetlands. 1949 8

Contamination of soils with cadmium (Cd) is a serious global issue due to its high mobility and toxicity. We investigated the application of insoluble polyacrylate polymers to improve soil and plant health. Sorghum was grown in a Cd-contaminated sandy soil. Polyacrylate polymers at 0.2% (w/w) were added to half of the soil. Control soil without plants was also included in the experiment. Growth of sorghum was stimulated in the polymer-amended soil. The concentration of Cd in the shoots, and the activities of catalase and ascorbate peroxidase decreased in plants from polymer-amended soil compared with unamended control. The amount of CaCl(2)-extractable Cd in the polymer-amended soil was 55% of that in the unamended soil. The Cd extracted in sorghum shoots was 0.19 mg per plant grown on soil without polymer and 0.41 mg per plant grown on polymer-amended soil. The total amount of Cd removed from each pot corresponded to 1.5 and more than 6% of soil CaCl(2)-extractable Cd in unamended and polymer-amended soil, respectively. The activities of soil acid phosphatase, beta-glucosidase, urease, protease and cellulase were greatest in polymer-amended soil with sorghum. In conclusion, the application of polyacrylate polymers to reduce the bioavailable Cd pool seems a promising method to enhance productivity and health of plants grown on Cd-contaminated soils.
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PMID:Improvement in soil and sorghum health following the application of polyacrylate polymers to a Cd-contaminated soil. 1977 13

To understand better the in situ microbial functional diversity under oil contamination stress, soils were sampled along a contamination gradient at an oil field in north-east China. Microbial community functional structure was examined with a functional gene array, termed GeoChip. Multivariate statistical analysis and meta-analysis were conducted to study the functional gene responses to oil concentrations. The total functional gene abundance and diversity decreased along the gradient of increasing contamination. The overall abundance of soil bacteria, archaea and fungi decreased to 10%, 40% and 80% of those in the pristine soil. Several functional genes in the families pgl, rbcL, nifH and nor and those encoding cellulase, laccase, chitinase, urease and key enzymes in metabolizing organic compounds were significantly decreased with oil contamination, especially under high contamination stress. However, a few genes encoding key enzymes for catechol, protocatechuate, and biphenyl degradation and in the gene families of nir, rbcL and pgl showed a significant increase at a medium level of oil contamination. Oil content and soil available nitrogen were found to be important factors influencing the microbial community structure. The results provide an insight into microbial functional diversity in oil-contaminated soils, providing potential information for on-site management and remediation measures.
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PMID:Microarray-based analysis of microbial functional diversity along an oil contamination gradient in oil field. 1978 Aug 23

To understand the effects of seasonal freeze-thaw on the ecological processes of subalpine forest ecosystem, the enzyme activities in Abies faxoniana and Betula platyphylla litters under freeze-thaw were measured from October 2006 to October 2007 by the method of litter bags. There was an obvious monthly change in the enzyme activities, but the peak time varied with enzymes. Compared to the control, freeze-thaw had significant effects on the activities of invertase, urease, cellulase, and dehydrogenase in the litters (P < 0.05). Over a growth season, the invertase, cellulase, and urease activities in fir litter increased by 66.1%, 14.8%, and 76.3%, respectively while dehydrogenase activity decreased by 18.4%, and the invertase activity in birch litter increased by 39.4% while the urease, cellulase and dehydrogenase activities decreased by 18.2%, 28.7% and 15.6%, respectively. As for the activities of peroxidase and polyphenol oxidase in fir and birch litters, they were less affected by freeze-thaw. All of these revealed that seasonal freeze-thaw had definite effects on the litter decomposition of subalpine forest, which closely related to the kind of litter and its decomposition stage.
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PMID:[Effects of seasonal freeze-thaw on the enzyme activities in Abies faxoniana and Betula platyphylla litters]. 1980 55

This study focused on the relationship between plant diversity (six species richness levels) and nutrient retention and enzyme activities associated with carbon, nitrogen and phosphorus cycling in a full-scale constructed wetland (CW) fed with post-treatment domestic wastewater. Effects of plant species richness on nutrient retention and enzyme activities were assessed using soil chemical and zymological methods, respectively. Retention of NH(4)-N and NO(3)-N in the wetland substrate increased with increasing species richness, while phosphorus retention significantly decreased under the richness level of 16 species per plot. Activities of enzymes such as dehydrogenase, beta-glucosidase, invertase, phenol oxidase, L-arsparaginase, protease and nitrate reductase, while they were affected by plant species richness, were strongly depended on the presence or absence of plants in CW substrate, while activities of enzymes such as CM-cellulase, urease and acid phosphatase were strongly depended on plant species richness. We conclude that plant species richness influenced nutrient retention and enzyme activities in the substrate in our subtropical CW; increase plant species richness in CW will likely improve the efficiency of wastewater treatment.
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PMID:Effects of plant diversity on nutrient retention and enzyme activities in a full-scale constructed wetland. 1986 27


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