Papers by Keyword: Enzyme Activity

Abstract: Black Carbon (BC) is a solid material obtainable from the remnants of incomplete burning of biological organisms or fossil fuels, which benefits pollution alleviation and soil amendment. In this study MBC was prepared using acidic potassium permanganate for inactivating heavy metal in soils. The specific surface area and pore volume of BC and MBC were measured by nitrogen adsorption and the space around the black carbon particles was observed by Scanning Electron Microscopy (SEM). The contents of carboxyl, ester and phenol hydroxyl group on their surface have been determined. The effect on availability of Cu in soils and soil enzyme activity of MBC was also investigated. Scanning electron microscopy analysis of MBC demonstrated large micropores with looser aggregate structure. MBC featured a higher surface area (956.88m²·g^-1), larger average pore size and pore volume than BC, which can improve its excellent adsorption ability. Using as a soil heavy metal passivator, MBC reduced the available content of copper in three soils significantly and MBC has the best passivation effect on copper in cinnamon soil. Comparison of the enzyme activities in three soils amended with MBC under constant moisture conditions revealed that MBC increased the activities of catalase, urease in different degrees and inhibited the activities of dehydrogenase in three soils. These findings suggest that MBC has a strong passivation ability to Cu and would be applied to the remediation of copper contaminated soil.

Abstract: The physical characteristics of fermented products from restaurant waste food with BIOMS probiotic at a dose of 8% which was incubated for 7 days were investigated in order to study effect of fermentation to the physical characteristic of biomaterial and its effect to enzyme activity of Clarias sp. Fermented products are added to the feed with doses of 0, 10%, 20%, 30% and 40% and physical tests include breaking time, sinking rate test, durability test, and stability test. Furthermore, the feed was given to catfish for 40 days and the enzyme activity (amylase and protease) was analyzed in its digestive tract at the end of the study. It is showed that the addition of fermented products decreased the physical quality of the feed. The best physical quality was found in the control feed with an average value of breaking time of 22.98 hours, an average value of sinking rate of 0.53 cm/s, a durability test of 97.23 %, and a stability test value of 93.53% (10 minutes), 88.8% (30 minutes), and 76.26% (60 minutes). For feed products with doses of fermented products of 10%, 20%, 30%, and 40%, the values ​​of breaking time and sinking rate, durability and stability were lower compared to that of control feed products. Meanwhile, the enzyme activity in the digestive tract of catfish shows that giving a dose of 20% fermented products in the feed resulted in the best composition of amylase and protease enzyme activity of 9.021 units/mL and 275 units/mL. These results indicated that improvements are needed in the fermentation process to produce better physical quality and suitable for catfish feed.

Abstract: To improve protein stability and membrane permeability the protein nanoparticles (NP) were fabricated from enzymes or virus-specific antibodies by nanoprecipitation. Lysozyme NP destroyed bacterial cellular walls. RNase-based NP hydrolyzed RNA. Lipase, catalase and horseradish peroxidase activities were also registered for corresponding protein NP. NP from polyclonal antibodies against the influenza A virus and monoclonal antibodies against hemagglutinin H1, H3; proteins NS and NP could interact with their specific antigens. NP from monoclonal antibodies against the hepatitis B surface antigen bound with the antigen as shown by ELISA. The protein NP were stable in water at 4°C for several months and in the presence of blood sera or saliva for more than 5 days. The protein NP were not toxic for human cells and mice. The protein NP could penetrate and accumulate in cells in 2 hours with maximum after 2 days and subsequent gradual decline until background values. Entry of foreign protein NP into the eukaryotic cells induced cytokine gene expression. RNA of interferon (IFN) a, b and l but not IFN g were detected by reverse transcription with real time PCR. Polarization index (Th2:Th1 cytokine RNA) was near 0. Accordingly, cellular uptake of non-toxic protein NP induced Th1 polarization of immune response.

Abstract: In this study, we illustrated enhanced biodegradation enzyme activity and the strains growth using the plants residues as carriers during the biodegradation of phenol in petrochemical wastewater. The three phenol-degrading strains named as A1, A2 and A3 were selected for an immobilized microorganism technique. A1, A2 and A3 were identified as Penicillium oxalicum, Aspergillus sp. and Sphingobacterium sp. using detailed morphological, biochemical and molecular characterization. The growth and degradation rate of phenol in wastewater by strains A1, A2 and A3 pre-grown in the agricultural residues (peanut shell) were higher than the free strains. Compared with the free strains,the enzyme activity of strains A1,A2 and A3, using the residues for pre-grown, increased 29.01 U/L, 30.30 U/L and 38.07 U/L, respectively. Hence, the immobilized microorganism technique is conducive to the phenol degradation.

Abstract: The effects of N and P addition on soil organic matter and nutrients, microbe and enzyme were investigated in a Eucalyptus urophylla stand to provide basis for soil management. Contents of organic matter, available P of N, P and N + P addition was significantly greater than the control, total N content of N and N+P addition was significant greater than the control, contents of total P, total K and available K of P and N + P addition was significantly greater than the control, available N content of N addition was significantly greater than the control, whereas that of P addition was significantly smaller than the control. N addition significantly increased the soil actinomyces number and urease activity, but had no significant effect on the number of soil bacteria and fungus, activities of phosphatase and catalase. Number of soil bacteria, fungus and actinomyces, activities of urease, phosphatase and catalase significantly increased after P addition, and biochemical indices except for bacteria number significantly increased after N + P addition.

Abstract: Soil enzyme activity is closely related to ecosystem course and function.Tendency and intensity of different biochemical course carried on in the soil was reflected by enzyme activity. This paper deals with the soil enzyme activity, content of organic matter, N,P 'and the relation of the enzyme activity with soil organic matter, N,P in soil of Liangzi Lake wetland by soil samples analyzed. The results shows that in the wetland soil,the urease activity is 0.397-0.652 mg/g ;the phosphatase activity is phenol6.52-11.53 mg/g; The activity of Cellulase in the soil is 0.397 - 0.652 mg/g. The change trend of Cellulase and phosphatase activity throughout the year is summer > autumn > winter > spring. The change trend of urinary enzyme throughout the year is summer > spring > autumn > winter. There is notably positive correlation between the urease activity and soil available nitrogen. There is notably positive corelation between the phosphatase activity and soil available P in the paddy field.There is notably positive correlation between the Cellulase activity and soil organic matter.

Abstract: This work regards the three main soil types in local area of eastern China as the research objects, that is, cinnamon, fluvo-aquic and brown soils are conducted corresponding investigations. In order to analyze the effects which Cu and Zn exert on urease’s and catalase’s activity as well as the microbial biomass carbon, the exogenous Cu and Zn were added to the gathered surface soil with the depth of 0-20cm.

Abstract: This study was designed to evaluate the antioxidant activity of samples extracted from Jinhua ham. The activities of SOD and contents of MDA and NO were measured after mice were kept on feeding the four peaks separated by using chromatographic column. Peak-3 obviously enhanced the activity of SOD and MDA. Peak-1 and peak-2 had little influence on the activity of SOD and MDA. Peak-4 decreased their activities. All peaks obviously decreased content of NO. Results showed that these four peaks had excellent antioxidant activity. Finally, influences of sample extracted from ham on SOD activity, MDA content and GSH-PX activity in vitro of mouse liver and heart were also studied. Certain dose of samples would lead the decrease of SOD activity, MDA content and GSH-PX activity. This results showed that the sample have certain oxidant capacity.

Abstract: Laccase Y20 (EC.1.10.3.2) was coated with poly (ethylene glycol)-block-polylactide (PEG-PLA, M_W = 27680) via water-in-oil emulsion, and the activity and stability of the resulting PEG-PLA-laccase complex have been compared to those for the native laccase and lyophilized native laccase in an ionic liquid (IL) [C₂mim][PF₆] (1-ethyl-3-methylimidazolium hexafluorophosphate. The formation of spherical PEG-PLA-laccase complex of 330-480 nm was demonstrated by scanning electron microscopy. This polymer-laccase complex retained most of its enzymatic catalytic activity and exhibited excellent storage stability in IL, with over 70% of its initial activity retained after 12 days of storage in IL at 40 °C, whereas it was about 20% for native laccase under the identical conditions. This strategy could be employed to fabricate polymer based composites materials with novel biological functions.

Abstract: To understand the effects of arsenic on enzyme activity of soil microorganisms in mining area, 18 soil samples were taken from Xinqiu open-pit mining area. The mechanism of soil microorganisms in response the change of arsenic concentration was studied by a pot experiment. The effects of arsenic on the activity of invertase, urease and catalase in soil microorganisms were characterized by enzyme activity experiment. The results showed that the microbial biomass in soil decreased with continuous elevated arsenic concentration. However, no significant effect was observed on the composition of microflora with the change of arsenic concentration. In soil microbial community, the predominant microorganism was bacteria (about 80%), then followed by actinomycetes and fungi. Most importantly, high concentration of arsenic obviously inhibited the activities of enzymes in soil especially for invertase and urease. The results obtained in this study provide additional insights into the microbial metabolic mechanisms under different concentration of arsenic in soil microbial community.