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1.
Pensri Plangklang Alissara Reungsang 《World journal of microbiology & biotechnology》2008,24(7):983-989
Rhizosphere soil contains important sources of nutrients for microorganisms resulting in high number of microorganisms capable
of degrading various types of chemicals in the soil. Thus, this study investigated a carbofuran dissipation in rhizosphere
soils of 6 weeds namely, umbrella sedge (Cyperus iria L.), fuzzy flatsedge (C. pilosus V.), small flower umbrella plant (C. difformis L.), tall-fringe-rush hoorah grass (Fimbristylis miliacea V.), cover fern (Marsilea crenata P.), and water primrose (Jussiaea linifolia V.). Rhizosphere soil of fuzzy flatsedge showed the shortest half-life (t1/2) of carbofuran (15 days) among other soils. So, it was selected to be used in the bioaugmentation experiment using carbofuran
degrader namely Burkholderia cepacia, PCL3, as inoculum in order to examine whether they would improve carbofuran degradation in soil. The results showed that
the addition of PCL3 into rhizosphere soil did not improve carbofuran degradation suggesting that microorganisms in rhizosphere
soil might be capable enough to remove carbofuran from soil. The number of carbofuran degraders in the rhizosphere soils was
greater than in bulk soil 10–100 times which might be responsible to a rapid degradation of carbofuran in rhizosphere soils
without the addition of PCL3. The ability of PCL3 to degrade carbofuran was evident in bulk soil (t1/2 of 12 days) and autoclaved soils (t1/2 13–14 days) when compared to soils without an inoculation (t1/2 of 58 days) indicated that the addition of a degrader was useful in improving carbofuran degradation in soil. 相似文献
2.
Pensri Plangklang Alissara Reungsang 《International biodeterioration & biodegradation》2009,63(4):515-522
Burkholderia cepacia PCL3 (GenBank accession number of EF990634) is a carbofuran degrader isolated from phytoremediated rhizosphere soil in our laboratory. Free and the immobilized PCL3 on corncob and sugarcane bagasse were investigated for their abilities to degrade carbofuran in Basal Salt Medium (BSM) and soil microcosm. The reusability and survival of immobilized PCL3 in comparison to free cells were also examined. Short half-lives (t1/2) of carbofuran of 3–4 d in BSM were obtained using the isolate PCL3 in both free and immobilized cell forms. Immobilized cells could survive (106–107 cfu ml?1) through 30 d of incubation, while the number of free cells decreased continuously after 10 d. Immobilized B. cepacia PCL3 could be reused twice without loss in their abilities to degrade carbofuran in BSM, which suggested an advantage of using immobilized cell over free cell. Free and immobilized cells were augmented into soil and showed an effective capability to remediate carbofuran residues, both of which indicated by 5-folds decrease in carbofuran half-lives in augmented soil. Immobilization of PCL3 on corncob and sugarcane bagasse provided the possibilities of reusing the cells as well as improving the cell survival without decreasing carbofuran degradation activity. 相似文献
3.
4.
《Process Biochemistry》2010,45(2):230-238
The effectiveness of bioremediation technology in the removal of carbofuran from contaminated soil using a bioslurry phase sequencing batch reactor (SBR) was investigated. A 2-L laboratory glass bottle was used as a bioreactor with a working volume of 1.5 L at room temperature (27 ± 2 °C). One total cycle period of the SBR was comprised of 1 h of fill phase, 82 h of react phase, and 1 h of decant phase. The carbofuran concentration in the soil was 20 mg/kg soil. A carbofuran degrader isolated from carbofuran phytoremediated soil, namely Burkholderia cepacia PCL3 (PCL3) immobilized on corncob, was used as the inoculum. The results revealed that bioaugmentation treatment (addition of PCL3) gave the highest percentage of carbofuran removal (96.97%), followed by bioaugmentation together with biostimulation (addition of molasses) treatment (88.23%), suggesting that bioremediation was an effective technology for removing carbofuran in contaminated soil. Abiotic experiments, i.e. autoclaved soil slurry with corncob and no PCL3 treatment and autoclaved soil slurry with no PCL3 treatment, could adsorb 31.86% and 7.70% of carbofuran, respectively, which implied that soil and corncob could act as sorbents for the removal of carbofuran. 相似文献
5.
Clusters [MoS4Ag3(PPh3)3{S2P(OPri)2}] (1), [WS4Ag3(PPh3)3{S2P(OPri)2}] (2) and [WOS3Ag3(PPh3)3{S2P(OPri)2}] (3) were synthesized by the reaction of (NH4)2MoS4/(NH4)2WS4, (NH4)2WOS3 with Ag[S2P(OPri)2]. Their structures have been characterized by X-ray diffraction. The clusters consist of a distorted tetrahedral MS4 (or MOS3) (M = Mo, W) with three Ag atoms and three sulfur atom bridges (Fig. 1), and resemble roughly that of cubane-like clusters. The nonlinear optical (NLO) properties were studied with an 8 ns pulsed laser at 532 nm. Its optical response to the incident light exhibits good optical absorptive and refractive effects, with α2 = 1.56 × 10−10 m W−1, n2 = 3.87 × 10−17 m2 W−1 for cluster 1; α2 = 1.33 × 10−10 m W−1, n2 = 6.52 × 10−17 m2 W−1for cluster 2; and α2 = 2.54 × 10−10 m W−1, n2 = 4.07 × 10−17 m2 W−1 for cluster 3 for a 1.56 × 10−4 mol dm−3 CH2Cl2 solution. 相似文献
6.
Shelley M. Elvington 《生物化学与生物物理学报:生物膜》2007,1768(3):502-508
It was recently shown that the structure of the fluorophore attached to the acyl chain of phosphatidylcholine analogs determines their mechanism of transport across the plasma membrane of yeast cells (Elvington et al., J. Biol Chem. 280:40957, 2005). In order to gain further insight into the physical properties of these fluorescent phosphatidylcholine (PC) analogs, the rate and mechanism of their intervesicular transport was determined. The rate of spontaneous exchange was measured for PC analogs containing either NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl), Bodipy FL (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene), Bodipy 530 (4,4-difluoro-5,7-diphenyl-4-bora-3a,4a-diaza-s-indacene), or Bodipy 581 (4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene) attached to a five or six carbon acyl chain in the sn-2 position. The rate of transfer between phospholipid vesicles was measured by monitoring the increase in fluorescence as the analogs transferred from donor vesicles containing self-quenching concentrations to unlabeled acceptor vesicles. Kinetic analysis indicated that the transfer of each analog occurred by diffusion through the water phase as opposed to transfer during vesicle collisions. The vesicle-to-monomer dissociation rate constants differed by over four orders of magnitude: NBD-PC (kdis = 0.115 s− 1; t1/2 = 6.03 s); Bodipy FL-PC (kdis = 5.2 × 10− 4; t1/2 = 22.2 min); Bodipy 530-PC (kdis = 1.52 × 10− 5; t1/2 = 12.6 h); and Bodipy 581-PC (kdis = 5.9 × 10− 6; t1/2 = 32.6 h). The large differences in spontaneous rates of transfer through the water measured for these four fluorescent PC analogs reflect their hydrophobicity and may account for their recognition by different mechanisms of transport across the plasma membrane of yeast. 相似文献
7.
A study was conducted to determine the diversity of 2-, 3-, and 4-chlorobenzoate (CB) degraders in two pristine soils with similar physical and chemical characteristics. Surface soils were collected from forested sites and amended with 500 g of 2-, 3-, or 4-CB g–1 soil. The CB levels and degrader numbers were monitored throughout the study. Degraders were isolated, grouped by DNA fingerprints, identified via 16S rDNA sequences, and screened for plasmids. The CB genes in selected degraders were isolated and/or sequenced. In the Madera soil, 2-CB and 4-CB degraded within 11 and 42 d, respectively, but 3-CB did not degrade. In contrast, 3-CB and 4-CB degraded in the Oversite soil within 14 and 28 d, respectively, while 2-CB did not degrade. Approximately 107 CFU g–1 of degraders were detected in the Madera soil with 2-CB, and the Oversite soil with 3- and 4-CB. No degraders were detected in the Madera soil with 4-CB even though the 4-CB degraded. Nearly all of the 2-CB degraders isolated from the Madera soil were identified as a Burkholderia sp. containing chromosomally encoded degradative genes. In contrast, several different 3- and 4-CB degraders were isolated from the Oversite soil, and their populations changed as CB degradation progressed. Most of these 3-CB degraders were identified as Burkholderia spp. while the majority of 4-CB degraders were identified as Bradyrhizobium spp. Several of the 3-CB degraders contained the degradative genes on large plasmids, and there was variation between the plasmids in different isolates. When a fresh sample of Madera soil was amended with 50, 100, or 200 g 3-CB g–1, 3-CB degradation occurred, suggesting that 500 g 3-CB g–1 was toxic to the degraders. Also, different 3-CB degraders were isolated from the Madera soil at each of the three lower levels of 3-CB. No 2-CB degradation was detected in the Oversite soil even at lower 2-CB levels. These results indicate that the development of 2-, 3-, and 4-CB degrader populations is site-specific and that 2-, 3-, and 4-CB are degraded by different bacterial populations in pristine soils. These results also imply that the microbial ecology of two soils that develop under similar biotic and abiotic environments can be quite different. 相似文献
8.
Disturbed soil columns, 5.8 cm in diameter and 25 cm in length, were used as a basic model to simulate the movement of carbofuran
in rice field soil under saturated conditions. Bioaugmentation using a specific carbofuran degrader, Burkholderia sp. PCL3, in free and immobilized cell forms and biostimulation using rice straw as organic amendment were applied with the
aim of enhancing the degradation of carbofuran in soil and to prevent the movement of carbofuran along with the flow through.
In the abiotic control and the treatment with only indigenous microorganisms, the mass recovery percentage of carbofuran in
the effluent was 52.1 and 22.5%, respectively. The application of bioaugmentation or biostimulation significantly enhanced
carbofuran degradation in soil and reduced the movement of carbofuran as indicated by a low mass recovery percentage of carbofuran
in the effluent of 14.6–15.5%. A low efficiency of carbofuran removal was obtained from the soil column with bioaugmentation
together with biostimulation treatments in which the mass recovery percentage of carbofuran in the effluent was in the range
of 22.1–22.6%. Sorption of carbofuran to soil, rice straw and corncob, formation of carbofuran metabolite and colony forming
unit (CFU) and pH variation with the time were also investigated during column operation. 相似文献
9.
Bente Aa. Lomstein Lise Bonne Guldberg Anne-Turi Amtoft Neubauer Jesper Hansen Andrew Donnelly Rodney A. Herbert Pierluigi Viaroli Gianmarco Giordani Roberta Azzoni Rutger de Wit Kai Finster 《Aquatic Botany》2006
The degradation of an Ulva lactuca mat (0.2 kg dw m−2) was studied in a controlled flow-through mesocosm for 31 d. Sediment chambers without U. lactuca served as controls. Fluxes of ∑CO2, O2, inorganic nitrogen, and urea were determined during the incubation period in addition to sulfate reduction rates, POC and PON content, enumeration of specific bacterial populations and evaluation of the physiological state of the added U. lactuca thalli. After U. lactuca addition to the chambers, there was an immediate increase in the efflux of ∑CO2 from 11 to 27 mmol-C m−2 d−1 and a concomitant increase in O2 uptake from 11 to 23 mmol m−2 d−1. These effluxes remained elevated throughout the incubation period. In contrast, the NH4+ efflux increased from 0.1 to 1.8 mmol NH4+ m−2 d−1 during the first 3 d of incubation, followed by 6 d with a constant efflux rate, after which time it decreased gradually to 0.3 mmol NH4+ m−2 d−1 by the end of the experiment. In total, NH4+accounted for 83% of the total nitrogen efflux after addition of U. lactuca. During the 31 d incubation period there was a continuous colonization of the thalli by bacteria. Sulfate reducers associated with the thalli accounted for 3% of the carbon oxidation on day 31. The molar C:N ratio in mineralization products (the ratio between the efflux of ∑CO2 and NH4+ + NO2− + NO3−) increased from 15 mol mol−1 at day 11 after U. lactuca addition to >80 mol mol−1 by the end of the incubation. Since the C:N ratio in the mineralization products was much higher than the original thallus material (8.9 mol mol−1) it is probable that a preferential incorporation of NH4+ into the increasing bacterial biomass occurred. The nitrogen for bacterial growth was most likely obtained from degradation of U. lactuca thalli as there was no stimulation of urea-N turnover in the sediment during incubation. The net increase in bacteria cell number in the 18-mm thick thallus layer was estimated to be 7.6 × 109 to 2.4 × 1010 bacterial cells cm−3. In contrast, the bacterial cell number remained constant in the −Ulva incubations. 相似文献
10.
Densely cross-linked poly(vinylamine) microbeads (∼2 μm) were prepared by precipitation copolymerization of N-vinyl formamide and ethylene glycoldimethacrylate in acetonitrile. The formamido groups of the microbeads were hydrolyzed into amino groups. Then, amino-functionalized microbeads were used for covalent immobilization of laccase via glutaraldehyde coupling. The average amount of immobilized enzyme was 18.7 mg/g microbeads. Kinetic parameters, Vmax and Km values were determined as 20.7 U/mg protein and 2.76 × 10−2 mmol/L for free enzyme and 15.8 U/mg protein and 4.65 mmol/L for the immobilized laccase, respectively. The immobilized laccase was operated in a batch reactor for the degradation of two different benzidine based dyes (i.e., Direct Blue 1 and Direct Red 128). The laccase immobilized on the microbeads was very effective for removal of these dyes which interfere with the hormonal system. 相似文献
11.
This study investigated the anaerobic degradation of tetrachlorobisphenol-A (TCBPA) in sediment samples collected at three sites along the Erren River in southern Taiwan. TCBPA anaerobic degradation half-lives (t1/2) in the sediment were 12.6, 16.9 and 21.7 d at concentrations of 50, 100, and 250 ??g g−1, respectively. TCBPA (50 ??g g−1) anaerobic degradation half-lives (t1/2) in the sediment were 10.1, 11.8, 11.0, 11.6, 10.8, 9.1, 8.5, 18.2, 19.3, and 16.1 d by the addition of yeast extract (5 mg l−1), cellulose (0.96 mg l−1), sodium chloride (1%), brij 30 (130 mg l−1), brij 35 (43 mg l−1), rhamnolipid (55 ??M), surfactin (91 ??M), phthalic esters (2 mg l−1), nonylphenol (2 mg l−1), and heavy metals (2 mg l−1), respectively. The degradation rate of TCBPA was enhanced by the addition of yeast extract, cellulose, sodium chloride, brij 30, brij 35, rhamnolipid, or surfactin. However, it was inhibited by the addition of phthalic esters, nonylphenol, or heavy metals. Also noted was the presence of dichlorobisphenol-A and bisphenol-A, two intermediate products resulting from the anaerobic degradation of TCBPA accumulated in the sediments. 相似文献
12.
Anthony K. Onifade Majekodunmi O. Fatope Michael L. Deadman Salma M.Z. Al-Kindy 《Biochemical Systematics and Ecology》2008
The potentials of Haplophyllum tuberculatum and Plectranthus cylindraceus oils to control Meloidogyne javanica were investigated in vitro and in a greenhouse. A mixture of Haplophyllum and Plectranthus oils (1:1) was highly toxic to M. javanica in vitro, as it killed all nematode juveniles and inhibited hatching of eggs at 12.5 μg/ml concentration after 24 h exposure time, as did carbofuran at the same concentration. In the green-house, tomatoes grown in soil treated with a combination (1:1) of the two oils developed fewer root galls than those grown in soil treated with higher doses of either oil. The oil mixture, at 2.5 and 5.0 μg/ml of soil, was not phytotoxic to tomato plants as evident from the appearance and height of plants after 12 weeks exposure time, compared to treatment over the same period at lower effective doses. The nematicidal activity of the combined essential oils was suggested by the presence of C10 dienes, C10 trienes and C10 phenol. 相似文献
13.
Statistics-based experimental designs were applied to optimize the culture conditions for tetrahydrofuran (THF) degradation by a newly isolated Rhodococcus sp. YYL that tolerates high THF concentrations. Single factor experiments were undertaken for determining the optimum range of each of four factors (initial pH and concentrations of K2HPO4 · 3H2O, NH4Cl and yeast extract) and these factors were subsequently optimized using the response surface methodology. The Plackett–Burman design was used to identify three trace elements (Mg2+, Zn2+and Fe2+) that significantly increased the THF degradation rate. The optimum conditions were found to be: 1.80 g/L NH4Cl, 0.81 g/L K2HPO4 · 3H2O, 0.06 g/L yeast extract, 0.40 g/L MgSO4 · 7H2O, 0.006 g/L ZnSO4 · 7H2O, 0.024 g/L FeSO4 · 7H2O, and an initial pH of 8.26. Under these optimized conditions, the maximum THF degradation rate increased to 137.60 mg THF h−1 g dry weight in Rhodococcus sp. YYL, which was nearly five times of that by the previously described THF degrading Rhodococcus strain. 相似文献
14.
Colantonio P Leboffe L Bolli A Marino M Ascenzi P Luisi G 《Biochemical and biophysical research communications》2008,377(3):757-762
Caspase-3 is responsible for the cleavage of several proteins including the nuclear enzyme poly(ADP-ribose) polymerase (PARP). Designed on the cleavage site of PARP, Ac-Asp-Glu-Val-Asp-H has been reported as a highly specific inhibitor. To overcome the susceptibility to proteolysis, the intrinsic instability, and the scarce membrane permeability of tetra-peptidyl aldehydes, di- and tri-peptidyl caspase-3 inhibitors have been synthesized. Here, the synthesis and the inhibition properties of peptidyl aldehydes Z-tLeu-Asp-H, Z-tLeu-Val-Asp-H, and Z-Val-tLeu-Asp-H are reported. Z-tLeu-Asp-H, Z-tLeu-Val-Asp-H, and Z-Val-tLeu-Asp-H inhibit competitively human caspase-3 activity in vitro with = 3.6 nM, 18.2 nM, and 109 nM, respectively (pH 7.4 and 25 °C). Moreover, Z-tLeu-Asp-H impairs apoptosis in human DLD-1 colon adenocarcinoma cells without affecting caspase-8. Therefore, Ac-Asp-Glu-Val-Asp-H can be truncated to Z-tLeu-Asp-H retaining nanomolar inhibitory activity in vitro and displaying action in whole cells, these properties reflect the unprecedented introduction of the bulky and lipophilic tLeu residue at the P2 position. 相似文献
15.
Xinfeng Zhao Yefei Nan Chaoni Xiao Jianbin Zheng Xiaohui Zheng Yinmao Wei Youyi Zhang 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(22):2029-2034
A receptor affinity chromatographic selection method was developed for screening the bioactive compounds binding to β2-adrenoceptor (β2-AR) in Coptidis rhizome. The bioactive compounds were analyzed by molecular recognition with a β2-AR affinity column. The retention compounds eluted from the β2-AR column were separated online with reverse-phase high-performance liquid chromatography by column switching technology, and identified by a coupled ion-trap mass spectrometer. Four compounds were screened as the bioactive compounds of Coptidis rhizome and identified as 2,9,10-trimethoxy-3-hydroxyl-protoberberine (jateorhizine), 2,3-methylenedioxy-9-methoxy-protoberberine, 2,3,9,10-tetramethoxy-protoberberine (palmatine) and 2,3-methylenedioxy-9,10-dimethoxy-protoberberine (berberine). The association constants of jatrorrhizine, palmatine and berberine to the β2-AR were determined by the zonal elution method with standards. Berberine and palmatine had only one type of binding site on the immobilized β2-AR. Their association constants were (2.28 ± 0.11) × 104/M and (3.00 ± 0.10) × 104/M, respectively. Jatrorrhizine had at least two type of binding sites on the immobilized β2-AR, and the corresponding association constants were (2.20 ± 0.09) × 10−4/M and (6.78 ± 0.001) × 105/M. 相似文献
16.
A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3−xPW12O40 (0 ≤ x ≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x = 2 and Cs2-PTA content of 5 wt%. The value is 6 × 10−3 S cm−1 and 1.75 × 10−2 S cm−1 at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6 × 10−7, 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1 × 104/S cm−3 s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells. 相似文献
17.
A bacterium, tentatively identified as an Arthrobacter sp., was isolated from flooded soil that was incubated at 35°C and repeatedly treated with carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl N-methylcarbamate). This bacterium exhibited an exceptional capacity to completely mineralize the ring-labeled 14C in carbofuran to 14CO2 within 72 to 120 h in a mineral salts medium as a sole source of carbon and nitrogen under aerobic conditions. Mineralization was more rapid at 35°C than at 20°C. No degradation of carbofuran occurred even after prolonged incubation under anaerobic conditions. The predicted metabolites of carbofuran, 7-phenol (2,3-dihydro-2,2-dimethyl-7-benzofuranol) and 3-hydroxycarbofuran, were also metabolized rapidly. 7-Phenol, although formed during carbofuran degradation, never accumulated in large amounts, evidently because of its further metabolism through ring cleavage. The bacterium readily hydrolyzed carbaryl (1-naphthyl N-methylcarbamate), but its hydrolysis product, 1-naphthol, resisted further degradation by this bacterium. 相似文献
18.
Candida rugosa lipase (CRL) was immobilized on glutaraldehyde-activated aminopropyl glass beads by using covalent binding method or sol-gel encapsulation procedure and improved considerably by fluoride-catalyzed hydrolysis of mixtures of RSi(OCH3)3 and Si(OCH3)4. The catalytic properties of the immobilized lipases were evaluated into model reactions, i.e. the hydrolysis of p-nitrophenylpalmitate (p-NPP). It has been observed that the percent activity yield of the encapsulated lipase was 166.9, which is 5.5 times higher than that of the covalently immobilized lipase. The enantioselective hydrolysis of racemic Naproxen methyl ester by immobilized lipase was studied in aqueous buffer solution/isooctane reaction system and it was noticed that particularly, the glass beads based encapsulated lipases had higher conversion and enantioselectivity compared to covalently immobilized lipase. In short, the study confirms an excellent enantioselectivity (E > 400) for the encapsulated lipase with an ee value of 98% for S-Naproxen. 相似文献
19.
Hydrogen production was studied using immobilized green alga Chlorella sp. through a two-stage cyclic process where immobilized cells were first incubated in oxygenic photosynthesis followed by anaerobic incubation for H2 production in the absence of sulfur. Chlorella sp. used in this study was capable of generating H2 under immobilized state in agar. The externally added glucose enhanced H2 production rates and total produced volume while shortened the lag time required for cell adaptation prior to H2 evolution. The rate of hydrogen evolution was increased as temperature increased, and the maximum evolution rate under 30 mM glucose was 183 mL/h/L and 238 mL/h/L at 37 °C and 40 °C, respectively. In order to continue repeated cycles of H2 production, at least two days of photosynthesis stage should be allowed for cells to recover H2 production potential and cell viability before returning to H2 production stage again. 相似文献
20.
Nilusha Ragunathan Benjamin Pluvinage Elodie Sanfins Fernando Rodrigues-Lima Julien Dairou 《FEBS letters》2010,584(15):3366-29
Human arylamine N-acetyltransferase 1 (NAT1) is a xenobiotic-metabolizing enzyme that biotransforms aromatic amine chemicals. We show here that biologically-relevant concentrations of inorganic (Hg2+) and organic (CH3Hg+) mercury inhibit the biotransformation functions of NAT1. Both compounds react irreversibly with the active-site cysteine of NAT1 (half-maximal inhibitory concentration (IC50) = 250 nM and kinact = 1.4 × 104 M−1 s−1 for Hg2+ and IC50 = 1.4 μM and kinact = 2 × 102 M−1 s−1 for CH3Hg+). Exposure of lung epithelial cells led to the inhibition of cellular NAT1 (IC50 = 3 and 20 μM for Hg2+ and CH3Hg+, respectively). Our data suggest that exposure to mercury may affect the biotransformation of aromatic amines by NAT1. 相似文献