Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dynamic changes of soil enzymatic activities during remediation of phenanthrene contaminated soil with clover or clover and wheat were investigated with pot experiments. Clover and wheat increased the activities of soil sucrase, polyphenol oxidase, urease and phosphatase with an increase rate in the range of 14.72%-46.52%, but inhibited the catalase activity with an inhibition rate in the range of 36.13%-94.79%. Sucrase and polyphenol oxidase reached the maximum activity values at the 14th day, and urease and phosphatase at the 21th day. Catalase got to the minimum activity value at the 7th day. In the light of these, catalase was relatively more sensitive to phenanthrene than the other enzymes, and could be employed as a key indicator to evaluate the risk of polycyclic aromatic hydrocarbon contaminated soil during remedying. Sucrase and polyphenol oxidase activities in wheat and clover intercropping system were significantly higher than in wheat or clover single-cropping system. Furthermore, there was a good negative correlation between catalase and sucrase (r = - 0.482), and polyphenol oxidase (r = -0.599), and urease (r = -0.329), and phosphatase (r = -0.297). Nonetheless, a good positive correlation existed among sucrase, polyphenol oxidase, urease and phosphatase. It is concluded that in the process of phytoremediation, soil enzymes can be employed as indicators for soil quality, it is not necessary to monitor each enzymatic activity, but to the activity of a key enzyme.
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PMID:[Enzymatic activities of phenanthrene contaminated soil in wheat and clover intercropping system]. 2018 7

From November 2007 to May 2009, a simulation test was conducted in a Pleioblastus amarus plantation in Rainy Area of West China to study the effects of nitrogen deposition on the activities of soil enzymes. Four treatments were installed, i.e., control (0 g N x m(-2) x a(-1)), low nitrogen (5 g N x m(-2) x a(-1)), medium nitrogen (15 g N x m(-2) x a(-1)), and high nitrogen (30 g N x m(-2) x a(-1)). Half year after N deposition, 0-20 cm soil samples were collected monthly, and the activities of peroxidase, polyphenol oxidase, cellulase, sucrase, urease, and acid phosphatase were determined. All test enzyme activities had apparent, seasonal variation, with the peak of cellulase, suerase, and acid phosphatase activities in spring, of urease activity in autumn, and of peroxidase and polyphenol oxidase activities in winter. Nitrogen deposition stimulated the activities of polyphenol oxidase, sucrase, urease, and acid phosphatase, inhibited cellulase activity, but had no significant effects on peroxidase activity. The test P. amurus plantation ecosystem was N-limited, and nitrogen deposition stimulated the decomposition of soil organic matter by microbe-enzyme system.
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PMID:[Soil enzyme activities in a Pleioblastus amurus plantation in Rainy Area of West China under simulated nitrogen deposition]. 2035 60

A pot experiment was conducted to study the effects of rotation and fallowing on the microbial communities and enzyme activities in a greenhouse soil continuously cropped with cucumber and on the growth and yield of followed cucumber. Comparing with continuous cropping, rotation improved the components of soil microbial communities, which was manifested in the increase of bacteria and actinomycetes and the decrease of fungi. Rotation and fallowing enhanced the activities of soil invertase, urease, catalase, and polyphenol oxidase significantly. The quantities of soil bacteria and actinomycetes and the activity of soil invertase increased at the fruiting stage of cucumber plants, being the maximum at harvest stage, but decreased thereafter. In contrast, the quantity of soil fungi had a linear increase, and the activities of soil urease, catalase, and polyphenol oxidase decreased gradually during fruit development. Welsh onion and waxy maize promoted the growth and fruiting of the followed cucumber plants significantly, being the optimal rotation crops for cucumber.
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PMID:[Effects of rotation and fallowing on the microbial communities and enzyme activities in a solar greenhouse soil under continuous cucumber cropping]. 2035 66

Surface soil samples were collected from a wastewater-irrigated agricultural area near a smelter in the Xinluo District of Longyan City, Pujian Province, and their basic physical and chemical properties, activities of urease, cellulase, alkaline phosphomonoesterase, polyphenol oxidase and catalase, and contents of Cu, Cd, Pb and Zn were determined, aimed to approach the effects of heavy metals pollution and soil properties on the activities of soil enzymes. Correlation analysis showed that the total and available contents of soil Cu, Cd, Pb and Zn had significant positive correlations with the activities of soil urease, cellulase, alkaline phosphomonoesterase and polyphenol oxidase, but significant negative correlation with the activity of soil catalase. Soil pH had significant positive correlation with the activity of soil alkaline phosphomonoesterase, and soil silt content had significant negative correlation with the activity of soil catalase. Path analysis showed that Cu, Cd, Pb and Zn pollution promoted the activities of soil urease, cellulase and polyphenol oxidase, but had less effects on the activity of soil alkaline phosphomonoesterase. Soil available Cu, Cd, Pb and Zn didn't directly affect the activity of soil catalase, but indirectly inhibited it significantly. Soil physical and chemical properties had greater effects on soil enzyme activities, e.g., alkaline-hydrolyzable N directly inhibited the activity of soil urease, total P directly stimulated the activities of soil alkaline phosphomonoesterase and catalase and indirectly stimulated the activity of soil cellulase via available P, available P directly promoted the activity of soil cellulase but inhibited the activities of soil alkaline phosphomonoesterase and catalase, total K directly inhibited the activities of soil alkaline phosphomonoesterase and polyphenol oxidase, available K stimulated the activity of soil catalase via available P, and particle composition had significant effects on the activities of soil polyphenol oxidase and catalase. The above results demonstrated that because of the complicated and uncertain relationships between the contents of soil Cd, Pb, Zn and Cu and the activities of the five soil enzymes, it should be cautious to use the test enzyme activities to indicate soil heavy metals pollution.
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PMID:[Changes of soil enzyme activities in heavy metals polluted region: a case study in a wastewater-irrigated agricultural area near a smelter in Xinluo District of Longyan City, Fujian Province]. 2035 74

With the continuing increase in human activities, ecologists are increasingly interested in understanding the effects of acid rain on litter decomposition. Two dominant litters were chosen from Zijin Mountain in China: Quercus acutissima from a broad-leaved forest and Pinus massoniana from a coniferous forest. The litters were incubated in microcosms and treated with simulated acid rain (gradient pH levels). During a six-month incubation, changes in chemical composition (i.e., lignin, total carbohydrate, and nitrogen), litter mass losses, soil pH values, and activities of degradative enzymes were determined. Results showed that litter mass losses were depressed after exposure to acid rain and the effects of acid rain on the litter decomposition rates of needles were higher than on those of leaves. Results also revealed that simulated acid rain restrained the activities of cellulase, invertase, nitrate reductase, acid phosphatase, alkaline phosphatase, polyphenol oxidase, and urease, while it enhanced the activities of catalase in most cases during the six-month decomposition process. Catalase and polyphenol oxidase were primarily responsible for litter decomposition in the broad-leaved forest, while invertase, nitrate reductase, and urease were primarily responsible for litter decomposition in the coniferous forest. The results suggest acid rain-restrained litter decomposition may be due to the depressed enzymatic activities. According to the results of this study, soil carbon in subtropical forests would accumulate as a long-term consequence of continued acid rain. This may presumably alter the balance of ecosystem carbon flux, nutrient cycling, and humus formation, which may, in turn, have multiple effects on forest ecosystems.
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PMID:Effect of simulated acid rain on the litter decomposition of Quercus acutissima and Pinus massoniana in forest soil microcosms and the relationship with soil enzyme activities. 2038 10

The ability of the thermo-tolerant lipolytic actinomycete, Thermoactinomyces vulgaris A31, to efficiently decompose food waste into mature compost was studied. Using a range of chemical parameters (pH, total organic carbon content (TOC), total nitrogen content, C/N ratio), CO(2) evolution, enzymatic activities (dehydrogenase, polyphenol oxidase, urease) and germination assays, the composition, stability and maturity of the compost produced were assessed. Inoculation reduced crude fat and decreased the maturation time of the compost when compared with the control. TOC, C/N ratio, CO(2) evolution, and enzymatic activities (dehydrogenase, polyphenol oxidase, urease) decreased, pH, total nitrogen content, germination rate, and germination index increased. The dehydrogenase, polyphenol oxidase, and urease activities were shown to be useful indicators for the stability of food waste composts. Based on germination assays, the food waste composts were phytotoxicity free and matured after composting for 2 months. Therefore, inoculation of food waste with the thermo-tolerant lipolytic actinomycete, T. vulgaris A31, presents as a feasible strategy to convert food wastes into mature compost efficiently.
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PMID:Inoculation of food waste with the thermo-tolerant lipolytic actinomycete Thermoactinomyces vulgaris A31 and maturity evaluation of the compost. 2046 53

The investigation of dissolved organic matter (DOM) on urease, catalase and polyphenol oxidase activity in a phenanthrene (Phe)-contaminated soil was conducted under laboratory incubation conditions. Values of soil enzymatic activity depended mainly on incubation time. In the initial 16 days, urease activity increased, and was followed by a decrease. In the initial 8 days, catalase activity decreased and then increased. Variation of polyphenol oxidase activity was just the reverse of catalase activity. After 30 days of incubation, no pronounced difference among treatments with Phe, Phe and DOM, and control were detected in urease, catalase and polyphenol oxidase activity. Phe might inhibit urease and catalase, and stimulate polyphenol oxidase. DOM could improve inhibition of Phe in soil urease and catalase activity during the initial period of applying DOM. Nevertheless, DOM had no significant effect on polyphenol oxidase activity in the Phe contaminated soil. There was a negative correlation between catalase and polyphenol oxidase (r = -0.761***), and catalase and urease (r = -0.554**). Additionally, a positive correlation between polyphenol oxidase and urease was also detected (r = 0.701***). It is implied that the formed DOM after application of organic wastes into soils may counteract the inhibition of polycyclic aromatic hydrocarbons in soil enzyme activities.
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PMID:Interactive effect of dissolved organic matter and phenanthrene on soil enzymatic activities. 2061 39

A pot experiment was conducted to study the effects of inoculation with root-knot nematodes on the cucumber leaf N and P contents, and the rhizospheric and non-rhizospheric soil pH and enzyme activities. The rhizospheric soil pH didn't have a significant decrease until the inoculation rate reached 6000 eggs per plant. With the increase of inoculation rate, the leaf N and P contents, rhizospheric soil peroxidase activity, and rhizospheric and non-rhizospheric soil polyphenol oxidase activity all decreased gradually, rhizospheric soil catalase activity was in adverse, non-rhizospheric soil pH decreased after an initial increase, and non-rhizospheric soil catalase activity had no regular change. After inoculation, rhizospheric soil urease activity decreased significantly, but rhizospheric and non-rhizospheric soil phosphatase activity and non-rhizospheric soil peroxidase activity only had a significant decrease under high inoculation rate. In most cases, there existed significant correlations between rhizospheric soil pH, enzyme activities, and leaf N and P contents; and in some cases, there existed significant correlations between non-rhizospheric soil pH, enzyme activities, and leaf N and P contents.
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PMID:[Effects of root-knot nematodes on cucumber leaf N and P contents, soil pH, and soil enzyme activities]. 2104 13

With open top chamber (OTC), this paper studied the effects of simulated warming on the activities of soil invertase, urease, catalase, polyphenol oxidase in two contrasting subalpine coniferous forests (a dragon spruce plantation and a natural conifer forest) in west Sichuan. The dynamic changes of soil temperature and soil moisture were monitored synchronously. In the whole growth season, simulated warming enhanced the daily mean temperature at soil depth 5 cm by 0.61 degrees C in the plantation, and by 0.55 degrees C in the natural forest. Conversely, the volumetric moisture at soil depth 10 cm was declined by 4.10% and 2.55%, respectively. Simulated warming also increased soil invertase, urease, catalase, and polyphenol oxidase activities. The interactive effect of warming and forest type was significant on soil urease and catalase, but not significant on soil invertase and polyphenol oxidase. The warming effect on soil catalase depended, to some extent, on season change. In all treatments, the soil enzyme activities in the natural forest were significantly higher than those in the plantation. The seasonal changes of test soil enzyme activities were highly correlated with soil temperature, but less correlated with soil moisture. This study indicated that warming could enhance soil enzyme activities, and the effect had definite correlations with forest type, enzyme category, and season change. The soil enzyme activities in the subalpine coniferous forests were mainly controlled by soil temperature rather than soil moisture.
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PMID:[Effects of simulated warming on soil enzyme activities in two subalpine coniferous forests in west Sichuan]. 2136 Sep 92

The aim of this study was to assess the effect of a 2% (v/v) addition of biochar on the quality of a composting mixture prepared with poultry manure and different local organic wastes (rice husk and apple pomace). Compost quality was evaluated in terms of typical stabilisation indices, the microbial biomass and selected enzymatic activities related to the C, N and P cycles. The main effects of biochar were a 10% increase in C captured by humic substance extraction and a 30% decrease of water-soluble C, due to an enhanced degradation rate and/or the sorption of these labile compounds into the biochar. The urease, phosphatase and polyphenol oxidase activities of the biochar-blended compost were enhanced by 30-40% despite the lower amount of microbial biomass. Denaturing gradient gel electrophoresis revealed a higher diversity of fungi in biochar-amended compost, suggesting a change in microbial composition compared to the unamended compost.
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PMID:Chemical and biochemical characterisation of biochar-blended composts prepared from poultry manure. 2237 78


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