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Extraction of high activity bacterial urease and its application to biomineralization of soil 认领 引用 被引量：1
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作者 Hanjiang Lai Yiwei Chen +2 位作者 Mingjuan Cui Junjie Zheng Zhibo Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2025年第3期1847-1861,共15页
Biomineralization based on bacterial enzyme induced carbonate precipitation(BEICP)process is a promising alternative to cement-based ground treatment technology.The bacterial urease used in BEICP process is usually ul... Biomineralization based on bacterial enzyme induced carbonate precipitation(BEICP)process is a promising alternative to cement-based ground treatment technology.The bacterial urease used in BEICP process is usually ultrasonic extracted from urease-producing bacteria.To efficiently extract urease with relatively higher activity from bacterial cells,the ultrasonic extraction parameters of urease were optimized in this study.Next,a series of bacterial urease extraction tests and sand column treatment tests were conducted to investigate the effects of vibration amplitude,upper temperature limit,and cooling method on the urease extraction process and biomineralization of sand.The results show that the upper temperature limit is an important factor affecting the extraction efficiency and the activity of the extracted urease solution,and the optimum upper temperature limit is 50℃.The results indicate that increasing vibration amplitude could improve the extraction efficiency,but it hardly affects the urease activity(UA)under the optimal temperature.Continuous cooling could effectively simplify the operation and further improve the efficiency of urease extraction.Under the same urease activity of biotreatment solution,there is no marked difference in calcium carbonate content(CCC)and unconfined compressive strength of biomineralized sand columns prepared by urease solution extracted with different vibration amplitudes and upper temperature limits.The results of this study could provide a reference for application of BEICP technology of urease extraction to large-scale soil treatment. 展开更多
关键词 Biomineralization Bacterial enzyme induced carbonate precipitation(BEICP) Urease extraction Ultrasound Soil improvement
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Effects of urease on strongly alkaline sodium-based dispersive soils from check dams under acidic conditions 认领 引用
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作者 Guanzhou Ren Minqiang Meng +4 位作者 Henghui Fan Yuan Gao Yuyang Ji Shuai Pang Xingyao Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2025年第11期7397-7409,共13页
This study explores the adaptation of microbial enzymatic techniques,which were originally developed to eliminate amino impurities in alcoholic beverages,for stabilizing strongly alkaline sodium-based dispersive soils... This study explores the adaptation of microbial enzymatic techniques,which were originally developed to eliminate amino impurities in alcoholic beverages,for stabilizing strongly alkaline sodium-based dispersive soils from check dams.Employing acid urease from Lactobacillus reuteri(L.reuteri)and a control group using soybean-derived urease,this research aimed to modify soil alkalinity through biomineralization.Ultraviolet(UV)mutagenesis optimized L.reuteri strains for biomass and activity.Solution experiments were conducted to assess the effects of pH,temperature,and storage duration on urease activity and to evaluate the calcium carbonate production and crystal morphology of the two ureases under varying calcium ion concentrations.Dispersivity identificationtests and tensile strength evaluations were conducted to analyze the disparities in the modifieddispersive soil treated with the two types of ureases.The results showed that soybean urease should be stored under low-temperature conditions and a neutral pH,whereas acid urease from L.reuteri can be stored at room temperature across a range of pH levels.Both urease treatments effectively reduced soil dispersivity and improved tensile strength significantly(up to 94%and 177%,respectively),with acid urease from L.reuteri resulting in superior soil strengthening and ammonia regulation.These findingssuggest that treating alkaline dispersive soils with acid urease is an efficientand eco-friendly method. 展开更多
关键词 Acidic conditions Urease Lactobacillus reuteri(L.reuteri) Dispersive soil Dispersivity Strength
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Miniaturized device to measure urease activity in the soil interstitial fluid using wenner method 认领 引用
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作者 Rafaela Cardoso Thomas Drouinot Susana Cardoso de Freitas 《Biogeotechnics》 2025年第1期27-33,共7页
This paper presents a microdevice developed to measure the electrical conductivity of a liquid or a saturated porous medium using Wenner method.It is developed in the context of biocementation as soil improvement tech... This paper presents a microdevice developed to measure the electrical conductivity of a liquid or a saturated porous medium using Wenner method.It is developed in the context of biocementation as soil improvement technique,which is used in Civil Engineering applications to produce calcium carbonate through bacterial or enzymatic activity,replacing the use of other binder materials such as cement or resins,and therefore reducing carbon footprint.The microdevice was used to measure urease activity in the soil interstitial fluid,to investigate if bacterial activity could be affected by the presence of the particles and tortuosity from pore geometry.Such analysis is important to understand biocementation mechanism inside the soil and helps to improve the design of such treatment solutions.The device is basically a squared reservoir printed in polypropylene using a 3D printing machine,incorporating stainless steel electrodes in its base.The electrical resistivity was computed adopting Wenner method,by connecting 4 PCB electrodes to a signal generator and an oscilloscope for measuring the voltage when a AC current of 1 mA was applied.Both square and sinusoidal waves with 5 kHz frequency were selected among other frequencies.The measurements were adjusted during the calibration of the microdevice,done using standard salt solutions with known electrical conductivity measured using an electrical conductivity probe.For the bacterial activity measurements,the bacterial and urea solutions were added to a uniform-graded size quarzitic sand(average diameter 0.3 mm)placed inside the microdevice and covering completely the electrodes.Bacterial activity was not affected by the presence of the sand,which confirms that this treatment is effective for this type of soils. 展开更多
关键词 Biocementation Urease activity Electrical conductivity Wenner method
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Urease-powered micro/nanomotors:Current progress and challenges 认领 引用 被引量：1
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作者 Wen-Wen Li Zi-Li Yu Jun Jia 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2025年第3期547-563,共17页
Enzyme-powered microanomotors(MNMs)(EMNMs)use natural enzymes to facilitate the decomposition of fuels,including hydrogen peroxide(H2O2),glucose,triglycerides,and urea to provide power.EMNMs can achieve self-propulsio... Enzyme-powered microanomotors(MNMs)(EMNMs)use natural enzymes to facilitate the decomposition of fuels,including hydrogen peroxide(H2O2),glucose,triglycerides,and urea to provide power.EMNMs can achieve self-propulsion through the in situ utilization of biofuels without additional fuels,exhibiting excellent biocompatibility and significant potential for application in the biomedical field.Compared with H2O2,which may cause oxidative damage to the body,urea exhibits superior biosafety characteristics.Presently,urease-powered MNMs(UMNMs)have made notable progress in their applications in the biomedical field and have garnered considerable attention from researchers.In this review,we present the latest advancements in the biomedical field of UMNMs,primarily focusing on:1)diverse materials used for constructing the fundamental framework of motors;2)control of motor movement through the regulation of enzymatic reaction rates;and 3)research directions for the clinical application of motors,including in vivo imaging,biomarker detection,cancer treatment,optical therapy,overcoming biological barriers,antibacterial interventions,antithrombotic strategies,and gastric disease management.Despite showing immense potential in biomedical applications,there are still several challenges impeding its practical implementation,such as maintaining activity in the in vivo environment while accurately targeting specific sites to achieve the desired clinical therapeutic effects. 展开更多
关键词 Microanomotor Imaging Drug delivery Urease Biomedicine
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Single and joint effects of pesticides and mercury on soil urease 认领 引用 被引量：16
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作者 YANG Chun-lu SUN Tie-hang +2 位作者 HE Wen-xiang ZHOU Qi-xing CHEN Su 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第2期210-216,共7页
The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentratio... The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations. 展开更多
关键词 chlorimuron-ethyl furadan mercury soil urease combined pollution
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Dual specimens increase the diagnostic accuracy and reduce the reaction duration of rapid urease test 认领 引用 被引量：14
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作者 Wen-Hung Hsu Sophie SW Wang +10 位作者 Chao-Hung Kuo Chiao-Yun Chen Ching-Wen Chang Huang-Ming Hu Jaw-Yuan Wang Yuan-Chieh Yang Yu-Chun Lin Wen-Ming Wang Deng-Chyang Wu Ming-Tsang Wu Fu-Chen Kuo 《World Journal of Gastroenterology》 SCIE CAS 2010年第23期2926-2930,共5页
AIM:To evaluate the influence of multiple samplings during esophagogastr oduodenoscopy(EGD)on the accuracy of the rapid urease test,and the validity of newly developed rapid urease tests,HelicotecUT plus test and Heli... AIM:To evaluate the influence of multiple samplings during esophagogastr oduodenoscopy(EGD)on the accuracy of the rapid urease test,and the validity of newly developed rapid urease tests,HelicotecUT plus test and HelicotecUT test,CLO test and ProntoDry test.METHODS:A total of 355 patients undergoing EGD for dyspepsia were included.Their Helicobacter pylori(H.pylori)treatment status was either nave or eradicated.Six biopsy specimens from antrum and gastric body,respectively,were obtained during EGD.Single antral specimens and dual(antrum+body)specimens were compared.Infection status of H.pylori was evaluated by three different tests:culture,histology,and four different commercially available rapid urease tests(RUTs)-including the newly developed HelicotecUT plus test and HelicotecUT test,and established CLO test and ProntoDry test.H.pylori status was defined as positive when the culture was positive or if there were concordant positive results among histology,CLO test and ProntoDry test.RESULTS:When dual specimens were applied,sensitivity was enhanced and RUT reaction time was signif icantly reduced,regardless of their treatment status.Thirty minutes were enough to achieve an agreeable positive rate in all the RUTs.Both newly developed RUTs showed comparable sensitivity,specif icity and accuracy to the established RUTs,regardless of patient treatment status,RUT reaction duration,and EGD biopsy sites.CONCLUSION:Combination of antrum and body biopsy specimens greatly enhances the sensitivity of rapid urease test and reduces the reaction duration to 30 min. 展开更多
关键词 Rapid urease test Helicobacter pylori eradication HelicotecUT plus test HelicotecUT test Esophagogastroduodenoscopy
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Biomineralization of soil with crude soybean urease using different calcium salts 认领 引用 被引量：11
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作者 Yajie Weng Junjie Zheng +2 位作者 Hanjiang Lai Mingjuan Cui Xingzhi Ding 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1788-1798,共11页
Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chl... Calcium salt is an important contributing factor for calcium-based biomineralization.To study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl2),calcium acetate ((CH3COO)2Ca) and calcium nitrate (Ca(NO3)2),were used to prepare the biotreatment solution to carry out the biomineralization tests in this paper.Two series of biomineralization tests in solution and sand column,respectively,were conducted.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO3) crystals.The experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH3COO)2Ca,and worst for Ca(NO3)2 under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO3.Besides Ca2+ ,the anions in solution can inhibit the activity of crude soybean urease,and NO3− has a stronger inhibitory effect on the urease activity compared with both CH3COO− and Cl− .The co-inhibition of Ca2+ and NO3− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO3)2 case in this study.The difference in biomineralization between the CaCl2 and (CH3COO)2 Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO3. 展开更多
关键词 Biomineralization Crude soybean urease Calcium salt Influence mechanism
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Oral Immunization of Mice With Vaccine of Attenuated Salmonella typhimurium Expressing Helicobacter pylori Urease B Subunit 认领 引用 被引量：6
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作者 XING-LONG YANG WEN-CHAO LID +5 位作者 Wu-WEI YANG DONG ZHONG Yu-Hu LIU JING-DONG ZHANG JIAN-HUI JIANG SHAN-SHAN LI 《Biomedical and Environmental Sciences》 SCIE CAS 2005年第6期411-418,共8页
Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine... Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain （SS1） as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups （including body weight, gastric inflammation, etc.） were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection. 展开更多
关键词 Helicobacterpylori Urease B subunit Recombination Attenuated Salmonella typhimurium Oral vaccine
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Characteristics of Soybean Urease Mineralized Calcium Carbonate and Repair of Concrete Surface Damage 认领 引用 被引量：5
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作者 FAN Yanan DU Hongxiu WEI Hong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2021年第1期70-76,共7页
The C60 concrete blocks with surface crack damage under high temperature environment were soaked by adding appropriate amount of soybean urease into the CO(NH2)2-CaCl2 solution,the soybean urease mineralized ... The C60 concrete blocks with surface crack damage under high temperature environment were soaked by adding appropriate amount of soybean urease into the CO(NH2)2-CaCl2 solution,the soybean urease mineralized calcium carbonate were characterized,and the effect of repairing concrete surface crack damage were evaluated by the surface sedimentation of C60 concrete blocks in the study.The experimental results showed that the activity of soybean powder was statistically significant,and its productivity of urease was comparable with that of urease-producing bacteria.After immersion in a soybean solution,a layer of complete and continuous white sediment covered the concrete surface.The cracks on the concrete surface were completely shielded,and the rising temperature on infrared thermal image of the concrete after repair was lower than before.Besides,through analysis by SEM,EDS,and XRD,the products formed after repair were found to be calcite-type CaCO3 with high purity,and the crystals exhibited different morphological features.The above results indicate that soybean urease can regulate and induce the formation of calcium carbonate,and the precipitate is innocuous and harmless,suitable for a new type of concrete crack repair material. 展开更多
关键词 soybean urease concrete calcium carbonate remediation damage
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Intraprocedural gastric juice analysis as compared to rapid urease test for real-time detection of Helicobacter pylori 认领 引用 被引量：3
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作者 Riccardo Vasapolli Florent Ailloud +7 位作者 Sebastian Suerbaum Jens Neumann Nadine Koch Lukas Macke Jörg Schirra Julia Mayerle Peter Malfertheiner Christian Schulz 《World Journal of Gastroenterology》 SCIE CAS 2023年第10期1638-1647,共10页
BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess... BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess the diagnostic performance of this technology and its impact on the management of H.pylori in the real-life clinical setting.METHODS Patients undergoing routine UGE were prospectively recruited.Biopsies were taken to assess gastric histology according to the updated Sydney system and for rapid urease test(RUT).Gastric juice sampling and analysis was performed using the Endofaster,and the diagnosis of H.pylori was based on real-time ammonium measurements.Histological detection of H.pylori served as the diagnostic gold standard for comparing Endofaster-based H.pylori diagnosis with RUT-based H.pylori detection.RESULTS A total of 198 patients were prospectively enrolled in an H.pylori diagnostic study by Endofasterbased gastric juice analysis(EGJA)during the UGE.Biopsies for RUT and histological assessment were performed on 161 patients(82 men and 79 women,mean age 54.8±19.2 years).H.pylori infection was detected by histology in 47(29.2%)patients.Overall,the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value(NPV)for H.pylori diagnosis by EGJA were 91.5%,93.0%,92.6%,84.3%,and 96.4%,respectively.In patients on treatment with proton pump inhibitors,diagnostic sensitivity was reduced by 27.3%,while specificity and NPV were unaffected.EGJA and RUT were comparable in diagnostic performance and highly concordant in H.pylori detection(κ-value=0.85).CONCLUSION Endofaster allows for rapid and highly accurate detection of H.pylori during gastroscopy.This may guide taking additional biopsies for antibiotic susceptibility testing during the same procedure and then selecting an individually tailored eradication regimen. 展开更多
关键词 Helicobacter pylori diagnostic Chronic gastritis Gastric juice Endofaster Rapid urease test Antimicrobial susceptibility testing
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Preparation of Glutaraldehyde Cross-Linked Chitosan Beads Under Microwave Irradiation and Properties of Urease Immobilized onto the Beads 认领 引用 被引量：4
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作者 梁足培 冯亚青 +1 位作者 孟舒献 张卫红 《Transactions of Tianjin University》 EI CAS 2005年第2期79-84,共6页
The glutaraldehyde cross-linked chitosan beads were prepared under microwave irradiation and urease was immobilized onto the beads. The activity and the yield of enzyme activity of the immobilized urease were 10.83 U/... The glutaraldehyde cross-linked chitosan beads were prepared under microwave irradiation and urease was immobilized onto the beads. The activity and the yield of enzyme activity of the immobilized urease were 10.83 U/g carrier and 47.700, respectively. The optimum conditions of immobilization were 100 of glutaraldehyde volume fraction, 10 mg/g of urease/beads weight ratio, 24 h of the processing time and pH 6.5 of the reaction medium for immobilization. The properties of the immobilized urease were investigated and compared with those of the free enzyme. The optimum pH values were 6.5 and 7.0 for the immobilized and free urease, respectively. The optimum temperature was 60 ℃ for the free urease, while it shifted to 65 ℃ for the immobilized enzyme. The Michaelis constant Km was 9.1 mmol/L for the immobilized and 12.5 mmol/L for the free urease. The immobilized urease retained 4000 of its initial enzyme activity even after 10 repeated uses. The immobilized urease stored at 4 ℃ retained 4600 of its initial activity even after 35 d. 展开更多
关键词 urease immobilization chitosan glutaraldehyde bead microwave
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Immobilization of urease in metal–organic frameworks via biomimetic mineralization and its application in urea degradation 认领 引用 被引量：2
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作者 Xiao Liang Qing Li +2 位作者 Zhiyuan Shi Shaowei Bai Quanshun Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第8期2173-2180,共8页
Enzyme immobilization has been accepted as an efficient technique for improving the stability and recyclability of enzymes.Herein,biomimetic mineralization strategy was employed to achieve the immobilization of urease... Enzyme immobilization has been accepted as an efficient technique for improving the stability and recyclability of enzymes.Herein,biomimetic mineralization strategy was employed to achieve the immobilization of urease in a type of metal–organic frameworks(zeolite imidazolate framework-8,ZIF-8),and the immobilized enzyme urease@ZIF-8 was systematically evaluated for its structure,activity,stability and recyclability,using the hydrolysis of urea as a model.The entrapment of urease was found to be realized in a synchronous manner with the formation of ZIF-8 crystal.The loading of urease in ZIF-8 was measured to be ca.10.6%through the bicinchoninic acid(BCA)protein assay.The encapsulated urease could efficiently maintain its native conformation,which endowed the immobilized urease with excellent activity and stability,even in harsh conditions(e.g.,in the presence of trypsin,acidic or alkali conditions,or at high temperature).Further,urease@ZIF-8 exhibited good recyclability during the degradation of urea,in which it could keep 58.86%of initial activity after being used for 5 cycles.Thus,biomimetic mineralization could be potentially utilized as a promising method to prepare immobilized ureases with superior activity,stability and recyclability,thereby facilitating the construction of efficient catalysts for industrial biocatalysis and biosensing. 展开更多
关键词 Urease Metal–organic frameworks Immobilization Biomimetic mineralization Stability Recyclability
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Effect of Combined Heavy Metal Pollution on Nitrogen Mineralization Potential,Urease and Phosphatase Activities in a Typic Udic Ferrisol 认领 引用 被引量：13
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作者 ZHENG CHUNRONG TU CONG and CHEN HUAIMAN)(Received April 20, 1999 revised June 2, 1999) 《Pedosphere》 SCIE CAS 1999年第3期251-258,共8页
Individual and combined effects of Cu, Pb, Zn and Cd on N mineralization, urease and phosphatase were examined in a Typic Udic Ferrisol in laboratory by employing an uniform design and a single factor design.Soil poll... Individual and combined effects of Cu, Pb, Zn and Cd on N mineralization, urease and phosphatase were examined in a Typic Udic Ferrisol in laboratory by employing an uniform design and a single factor design.Soil pollution caused by heavy metals inhibited N mineralization (No value) and urease and phosphatase activities. The combined pollution of metals alleviated their toxicity to N mineralization to some extent,whereas aggravated the toxicity to urease and phosphatase. Phosphorous application could mitigate the toxic effect of heavy metals on phosphatase activities, while alleviating effect of N application on the toxicity of heavy metals to urease was inconsistent. However, the mitigating effect of the fertilizers was limited in heavily polluted soils. 展开更多
关键词 heavy metal pollution N mineralization phosphatase urease
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Response of Nematodes in a Hapli-Udic Argosol to Urea Amended with Urease and Nitrification Inhibitors 认领 引用 被引量：4
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作者 HUA Jian-Feng JIANG Yong LIANG Wen-Ju 《Pedosphere》 SCIE CAS 2006年第4期428-434,共7页
Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design... Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design with four treatments, i.e., conventional urea （CU）, slow-release urea amended with a liquid urease inhibitor （SRU1）, SRU1 ＋nitrification inhibitor dicyandiamide （SRU2）, and SRU1 ＋ nitrification inhibitor 3,5-dimethylpyrazole （SRU3） and four replicates were applied. Thirty-nine genera of nematodes were identified, with Cephalobus and Aphelenchus being dominant; and in all treatments, the dominant trophic group was bacterivores. In addition, during the growth period of spring wheat （Triticum aestivum L.）, soil urease activity was lower in SRUs than in CU. The numbers of total nematodes and bacterivores at wheat heading and ripening stages, and omnivores-predators at ripening stage were higher in SUR3 than in CU, SRU1 and SRU2 （P 〈 0.05）. 展开更多
关键词 Hapli-Udic Argosol nitrification inhibitor slow-release urea soil nematodes urease inhibitor
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Soil Urease Activity of Sundarban Mangrove Ecosystem, India 认领 引用 被引量：9
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作者 Subhajit Das Dipnarayan Ganguly +2 位作者 Abhishek Mukherjee Sabyasachi Chakraborty Tarun Kumar De 《Advances in Microbiology》 CAS 2017年第8期617-632,共16页
Vertical occurrence of soil urease activity along with ammonia content from three distinct regions viz. Deep forest region (No tidal action and wave attack occurs as it is furthest from river shore and it contains max... Vertical occurrence of soil urease activity along with ammonia content from three distinct regions viz. Deep forest region (No tidal action and wave attack occurs as it is furthest from river shore and it contains maximum content of organic carbon and minimum soil salinity and silicate concentration. In this zone plenty of pneumatophores, below ground root and dense vegetation are found), Rooted region (It is situated in between Deep forest region and Un-rooted region. This region contains only pneumatophores but it is devoid of long roots and vegetations. It faces wave attack and tidal action less than that of Un-rooted region) and Un-rooted region (It is closest to river shore and faces maximum wave attack and tidal action;it contains minimum organic carbon but maximum soil salinity and silicate concentration. This zone is totally devoid of any roots, pneumatophores and vegetations) of Sundarban mangrove forest ecosystem, India revealed an interesting explanation. Soil urease activity showed a decreasing pattern with increase in depth from the deep forest region of the Sundarban forest ecosystem. Soil urease activity was found to be more sensitive to soil temperature and pH rather than soil salinity. This ensured that soil urease along with the microbes present in the Sundarban forest ecosystem are more tolerant to fluctuation in salinity than that of temperature. Soil ammonia concentration was found to be directly governed by the soil urease activity [The regression equation is Ammonia in soil = -1.64 + 0.0402 Urease Activity (R-Sq = 62.9%, P < 0.001, n = 41)]. 展开更多
关键词 Soil Urease Activity Soil Ammonia Deep Forest Region Rooted Region Un-Rooted Region and Sundarban Forest Ecosystem
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Detection of Helicobacter pylori:A faster urease test can save resources 认领 引用 被引量：1
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作者 Andriani Koumi Theodoros Filippidis +2 位作者 Vassilia Leontara Loukia Makri Marios Zenon Panos 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第3期349-353,共5页
AIM: To investigate whether differences in the rapidity of a positive result for Helicobacter pylori can save res ources, by comparing two commercially available urease kits. METHODS: One hundred and eighty-five adult... AIM: To investigate whether differences in the rapidity of a positive result for Helicobacter pylori can save res ources, by comparing two commercially available urease kits. METHODS: One hundred and eighty-five adults (130 outpatients, 55 inpatients) undergoing gastroscopy were entered prospectively. Patients were divided into two groups: Group 1 (if they were not on PPIs, antibiotics, H2A, bismuth or sucralfate for up to 14 d prior to the endoscopy) and Group 2 (if they were on, or had been on, any of the above medication in the previous 14 d). At endoscopy two sets of biopsies, taken in random order, were placed in the wells of the Campylobacter-like organism (CLO) test (Kimberly-Clark, Utah, USA) and the Quick test (Biohit Plc, Helsinki, Finland). Five additional gastric biopsies were taken for histology/Giemsa and immunohistochemical study. The two urease test slides were read at 2 min, 30 min, 2 h and 24 h. Sensitivity and specif icity at 24 h were determined. RESULTS: At 24 h, for all patients, there was no difference in sensitivity (100% vs 97.5%), specificity (99.3%), positive (97.5%) and negative predictive values (100% vs 99.3%) between the CLO and Quick tests, respectively. There was a positive result at 30 min in 17/41 (41.5%) CLO tests, and in 28/40 (70%) Quick tests, P = 0.05. Quick test enabled the prescription of eradication therapy before discharge in all 28/40 patients. Only 12 (30%) follow-up appointments were needed. If the CLO test had been used alone, only 17 (41.5%) prescriptions would have been possible prior to discharge and 24 (58%) follow-up appointments would be needed (P = 0.001). Of 2000 gastroscopies performed annually at our unit, a saving of 123 follow-up appointments (total: 8856 Euros or 11 808 USD) would be achieved if we switched to the Quick test. CONCLUSION: Direct comparison of locally available urease test kits is worthwhile, since the appropriate choice results in a significant saving of resources. Local costs and follow-up protocols will determine the magnitude of these savings. 展开更多
关键词 Campylobacter-like organism test Diagnosis Helicobacterpylori Quick test Urease test kits
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Nickel trafficking system responsible for urease maturation inHelicobacter pylori 认领 引用 被引量：1
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作者 Rui-Guang Ge Dong-Xian Wang +1 位作者 Ming-Cong Hao Xue-Song Sun 《World Journal of Gastroenterology》 SCIE CAS 2013年第45期8211-8218,共8页
Helicobacter pylori(H.pylori)is a common human pathogen responsible for various gastric diseases.This bacterium relies on the production of urease and hydrogenase to inhabit the acidic environment of the stomach.Nicke... Helicobacter pylori(H.pylori)is a common human pathogen responsible for various gastric diseases.This bacterium relies on the production of urease and hydrogenase to inhabit the acidic environment of the stomach.Nickel is an essential cofactor for urease and hydrogenase.H.pylori has to uptake sufficient nickel ions for the maturation of urease,and on the other way,to prevent the toxic effects of excessive nickel ions.Therefore,H.pylori has to strike a delicate balance between the import of nickel ions,its efficient intracellular storage,and delivery to nickel-dependent metalloenzymes when required.The assembly and maturation of the urease enzyme is a complex and timely ordered process,requiring various regulatory,uptake,chaperone and accessory proteins.In this review,we focus on several nickel trafficking proteins involved in urease maturation:NikR,NixA,HypAB,UreEFGH,HspA,Hpn and Hpnl.The work will deepen our understanding of how this pathogenic bacterium adapts to severe habitant environments in the host. 展开更多
关键词 Urease Histidine-rich protein NikR NixA Helicobacter pylori
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Experimental Study on Urease Activity and Cementation Characteristics of Soybean 认领 引用 被引量：1
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作者 FAN Yanan DU Hongxiu +1 位作者 WEI Hong ZHAO Teng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第4期636-644,共9页
A new and more ecologically sound cementing material known as“bio-cement”has been found to have the capacity to consolidate loose gravel into sand columns offering a certain degree of strength,and to fill and repair... A new and more ecologically sound cementing material known as“bio-cement”has been found to have the capacity to consolidate loose gravel into sand columns offering a certain degree of strength,and to fill and repair cracks in concrete to restore resilience.The typical representative is the microbial induced calcium carbonate deposition technology(MICP)and enzyme induced calcite precipitation(EICP).As part of this research,EICP with soybean urease as the core was studied.The test results show that soybean urease activity is significantly affected by pH and urea concentration values,while the external nickel source is not found to impair a stimulating effect on activity.When the concrete specimens were immersed in the composite solution of soybean urease,urea,and calcium chloride after having been subjected to a high temperature,a continuous layer of white precipitations quickly appeared on the surface of the specimens.Measured using a metalloscope,the thickness of the precipitations was found to reach up to 2.0 mm,while the surface water absorption rate was reduced by 70%.The effects of this combined outcome are believed to significantly protect and improve the durability of the concrete specimens previously subjected to a high temperature.At the same time,the composite solution is shown to be capable of cementing fly ash,with the cubic strength of the finished samples reaching 4.0 MPa after 3 days.Results from the use of a scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD),reveal that both the white precipitations on the surface of the concrete specimens and the cement binding the fly ash particles are calcite crystals.It is concluded from these preliminary study results that the use of soybean urease as a bio-cement had proved successful. 展开更多
关键词 soybean urease bio-cement concrete fly ash nickel ions calcite crystals high-temperature damage
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Experimental Study for the Cementation Effect of Dust Soil by Using Soybean Urease 认领 引用 被引量：1
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作者 Jianwei Zhang Yue Yin +3 位作者 Lei Shi Yi Han Mi Zhou Xihong Zhang 《Journal of Renewable Materials》 SCIE EI CAS 2023年第6期2893-2911,共19页
Dust is an environmental and health hazard.In this study,a new technology for dust suppressant is introduced using soybean urease with an optimal cementing solution.Calcium carbonate is produced by soybean urease and ... Dust is an environmental and health hazard.In this study,a new technology for dust suppressant is introduced using soybean urease with an optimal cementing solution.Calcium carbonate is produced by soybean urease and cementing solution,which bonds the soil particles towards a dust suppressant.A laboratory wind tunnel test is carried out to examine its effectiveness and discover possible optimization solutions.Several factors,including soybean meal concentration,cementing solution concentration,and volume of solution per unit area,are examined to quantify their influences on soil transport mass,evaporation ratio,evaporation rate,surface strength,water retention ratio,and infiltration rate of soil treated by different dust suppressants.Field tests are conducted to explore the performance of this method in the natural environment.The results show that compared with other dust suppressants,the optimized soybean urease has the smallest evaporation rate,a moderate infiltration rate,the largest water retention ratio and surface strength.The indexes of soybean urease for dust suppressant are found to be better than traditional materials.In the natural environment,soybean urease has a stronger anti-disturbance ability.This study concludes that soybean urease dust suppressant has great application potential as a cheap and green method. 展开更多
关键词 Soybean urease dust suppressant wind erosion evaporation rate surface strength
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Effect of acid type on biomineralization of soil using crude soybean urease solution 认领 引用 被引量：1
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作者 Yajie Weng Hanjiang Lai +6 位作者 Junjie Zheng Mingjuan Cui Yihang Chen Zhitao Xu Wensong Jiang Jianwei Zhang Yu Song 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第12期5135-5146,共12页
The one-phase-low-pH method is a simple,efficient,and user-friendly biogrouting technique that can effectively improve the biomineralization of enzyme-induced carbonate precipitation(EICP)using free urease enzyme.One ... The one-phase-low-pH method is a simple,efficient,and user-friendly biogrouting technique that can effectively improve the biomineralization of enzyme-induced carbonate precipitation(EICP)using free urease enzyme.One of the most significant advantages of this method is its capacity to effectively delay calcium carbonate(CaCO3)precipitation by reducing the pH of the solution through the addition of acid.This prevents bioclogging during the biogrouting process and improves the biomineralization effect.However,the biomineralization of the one-phase-low-pH based EICP method may be influenced by the specific acid used.To investigate the impact of acid type on the one-phase-low-pH EICP method using crude soybean urease solution(CSUS),four types of acids,including hydrochloric acid(HCl),nitric acid(HNO3),acetic acid(CH3COOH),and lactic acid(C3H6O3),were used to adjust the pH of CSUS.A series of macroscopic and microscopic experiments were conducted to evaluate the effect of acid type on the onephase-low-pH EICP method.The results indicate that the acid has an inhibition on the urease activity(UA)of CSUS.Among the acids tested,HNO3exhibits the most pronounced inhibitory effect on the UA of CSUS,followed by HCl,and the least pronounced inhibitory effect for CH3COOH and C3H6O3under the same pH conditions.Meanwhile,CH3COOH and C3H6O3could provide a longer delay duration of CaCO3precipitation than HNO3and HCl.Therefore,the one-phase-low-pH EICP method based on CH3COOH and C3H6O3can significantly improve the effective biocementation depth compared to that based on HNO3and HCl.Nevertheless,the different types of acids appear to have no obvious effect on the polymorph and crystalline of the precipitated CaCO3crystals. 展开更多
关键词 Enzyme-induced carbonate precipitation(EICP) One-phase-low-pH method Acid type Crude soybean urease solution(CSUS) Biomineralization
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