Inhibitory Effects of Luteolin 7-Methyl Ether Isolated from Wikstroemia ganpi on Tnf-A/Ifn-Γ Mixture-Induced Inflammation in Human Keratinocyte.

Plants of the genus Wikstroemia are traditionally used in China to treat various inflammatory diseases. The purpose of this study was to isolate the components of Wikstroemia ganpi (Siebold & Zucc.) Maxim., to evaluate their anti-atopic activities and to identify candidates with anti-atopic therapeutics. A total of 24 compounds were isolated by bioassay-guided separation, including one novel compound, which was tilianin 5-methyl ether. The anti-atopic activities of the isolated compounds were determined using TNF-α-treated RBL-2H3 cells and HaCaT cells. The mRNA expressions of IL-4, IL-6, GM-CSF, G-CSF and TRPV1 were reduced by luteolin 7-methyl ether. The study shows that the luteolin 7-methyl ether isolated from W. ganpi is a potential therapeutic agent for the treatment of atopic dermatitis.

Bioremediation of gaseous methyl tert-butyl ether by combination of sulfuric acid modified bagasse activated carbon-bone biochar beads and Acinetobacter indicus screened from petroleum contaminated soil.

Combination of sulfuric acid modified bagasse activated carbon-bone biochar beads and Acinetobacter indicus screened from petroleum contaminated soil was the best condition for gaseous methyl tert-butyl ether (MTBE) removal. It was found that H2SO4 modified bagasse AC in powder form had higher adsorption capacity (989.33 mg g-1) than that in bead form (1.94 mg g-1). In addition, bone biochar in powder form (3.51 mg g-1) also had higher adsorption capacity than that in bead form (1.63 mg g-1). This was the fact that material beads contained high moisture content that inhibited the penetration of gaseous MTBE into the material. And a mixed material of H2SO4 modified bagasse AC-bone biochar beads had the highest adsorption capacity (2.22 mg g-1) compared to individual H2SO4 modified bagasse AC beads (1.94 mg g-1) and bone biochar beads (1.63 mg g-1) due to a mixed material had more rough surface and high surface area on its material. So, gaseous MTBE can penetrate through this material more easily. Although the maximum adsorption capacity of H2SO4 modified bagasse AC in powder form was the highest but microorganism cannot sustain and survive in this form for a long time. Therefore, the material beads were more suitable for microorganism to grow and degrade gaseous MTBE. Microorganism can degrade MTBE and caused no secondary wastes. Moreover, A. indicus was a novel strain for MTBE removal that has not been previously reported. Therefore, a combination of A. indicus-mixed material beads was a good choice for MTBE removal in a biofilter system.

Purification, crystallization and anticancer activity evaluation of the compound alternariol methyl ether from endophytic fungi Alternaria alternata.

AIMS: Medicinal plant-associated endophytic fungi are important sources of precious bioactive compounds, contributing more than 80% of the natural drugs for various ailments. The present study was aimed at evaluating the anticancer activity of the crystallized compound alternariol methyl ether (AME) against hepatocellular carcinoma (HCC) both in vitro and in vivo from an endophytic fungus residing in the medicinal plant Vitex negundo. METHODS AND RESULTS: The secondary metabolites from the endophytic fungus Alternaria alternata MGTMMP031 were isolated. Purification and characterization of the compound was performed and the potential compound was identified as AME. The crystal structure of AME was unambiguously confirmed by X-ray analysis. AME has been checked for its antibacterial and anticancer properties which showed its effectiveness against various bacteria and demonstrated marked anti-proliferative activity against the human HCC cells (HUH-7) both in vitro and in vivo. Mode of actions included cell cycle arrest, reducing the level of markers enzymes of liver cancer and preventing tumour growth. CONCLUSIONS: Alternariol methyl ether acts as a potential therapeutic target against HCC. The compound was isolated and the crystal structure was obtained for the first time from the endophytic fungus A. alternata MGTMMP031. In the present study, the crystallized structure of AME was obtained by slow evaporation technique. It can be concluded that AME acts as a potential therapeutic target against HCC. SIGNIFICANCE AND IMPACT OF THE STUDY: Endophytic fungi residing in the medicinal plants have strong biological significance and bioactive compounds from these fungi provide better therapeutic targets against diseases.

Selective Inhibition of Human Monoamine Oxidase B by Acacetin 7-Methyl Ether Isolated from Turnera diffusa (Damiana).

The investigation of the constituents that were isolated from Turnera diffusa (damiana) for their inhibitory activities against recombinant human monoamine oxidases (MAO-A and MAO-B) in vitro identified acacetin 7-methyl ether as a potent selective inhibitor of MAO-B (IC50 = 198 nM). Acacetin 7-methyl ether (also known as 5-hydroxy-4', 7-dimethoxyflavone) is a naturally occurring flavone that is present in many plants and vegetables. Acacetin 7-methyl ether was four-fold less potent as an inhibitor of MAO-B when compared to acacetin (IC50 = 50 nM). However, acacetin 7-methyl ether was >500-fold selective against MAO-B over MAO-A as compared to only two-fold selectivity shown by acacetin. Even though the IC50 for inhibition of MAO-B by acacetin 7-methyl ether was ~four-fold higher than that of the standard drug deprenyl (i.e., SelegilineTM or ZelaparTM, a selective MAO-B inhibitor), acacetin 7-methyl ether's selectivity for MAO-B over MAO-A inhibition was greater than that of deprenyl (>500- vs. 450-fold). The binding of acacetin 7-methyl ether to MAO-B was reversible and time-independent, as revealed by enzyme-inhibitor complex equilibrium dialysis assays. The investigation on the enzyme inhibition-kinetics analysis with varying concentrations of acacetin 7-methyl ether and the substrate (kynuramine) suggested a competitive mechanism of inhibition of MAO-B by acacetin 7-methyl ether with Ki value of 45 nM. The docking scores and binding-free energies of acacetin 7-methyl ether to the X-ray crystal structures of MAO-A and MAO-B confirmed the selectivity of binding of this molecule to MAO-B over MAO-A. In addition, molecular dynamics results also revealed that acacetin 7-methyl ether formed a stable and strong complex with MAO-B. The selective inhibition of MAO-B suggests further investigations on acacetin 7-methyl as a potential new drug lead for the treatment of neurodegenerative disorders, including Parkinson's disease.

Adsorption of methyl tert-butyl ether (MTBE) onto ZSM-5 zeolite: Fixed-bed column tests, breakthrough curve modelling and regeneration.

ZSM-5, as a hydrophobic zeolite, has a good adsorption capacity for methyl tert-butyl ether (MTBE) in batch adsorption studies. This study explores the applicability of ZSM-5 as a reactive material in permeable reactive barriers (PRBs) to decontaminate the MTBE-containing groundwater. A series of laboratory scale fixed-bed column tests were carried out to determine the breakthrough curves and evaluate the adsorption performance of ZSM-5 towards MTBE under different operational conditions, including bed length, flow rate, initial MTBE concentration and ZSM-5 dosage, and regeneration tests were carried out at 80, 150 and 300 °C for 24 h. Dose-Response model was found to best describe the breakthrough curves. MTBE was effectively removed by the fixed-bed column packed with a ZSM-5/sand mixture with an adsorption capacity of 31.85 mg g-1 at 6 cm bed length, 1 mL min-1 flow rate, 300 mg L-1 initial MTBE concentration and 5% ZSM-5 dosage. The maximum adsorption capacity increased with the increase of bed length and the decrease of flow rate and MTBE concentration. The estimated kinetic parameters can be used to predict the dynamic behaviour of column systems. In addition, regeneration study shows that the adsorption capacity of ZSM-5 remains satisfactory (>85%) after up to four regeneration cycles.

(R)-(-)-Aloesaponol III 8-Methyl Ether from Eremurus persicus: A Novel Compound against Leishmaniosis.

Leishmaniosis is a neglected tropical disease which affects several millions of people worldwide. The current drug therapies are expensive and often lack efficacy, mainly due to the development of parasite resistance. Hence, there is an urgent need for new drugs effective against Leishmania infections. As a part of our ongoing study on the phytochemical characterization and biological investigation of plants used in the traditional medicine of western and central Asia, in the present study, we focused on Eremurus persicus root extract in order to evaluate its potential in the treatment of leishmaniosis. As a result of our study, aloesaponol III 8-methyl ether (ASME) was isolated for the first time from Eremurus persicus root extract, its chemical structure elucidated by means of IR and NMR experiments and the (R) configuration assigned by optical activity measurements: chiroptical aspects were investigated with vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectroscopies and DFT (density functional theory) quantum mechanical calculations. Concerning biological investigations, our results clearly proved that (R)-ASME inhibits Leishmania infantum promastigotes viability (IC50 73 µg/mL), inducing morphological alterations and mitochondrial potential deregulation. Moreover, it is not toxic on macrophages at the concentration tested, thus representing a promising molecule against Leishmania infections.

8-Hydroxyirilone 5-methyl ether and 8-hydroxyirilone, new antioxidant and α-amylase inhibitors isoflavonoids from Iris germanica rhizomes.

Iris species are well recognized as wealthy sources of isoflavonoids. In the present study, phytochemical investigation of the rhizomes of Iris germanica (Iridaceae) procure the isolation of two new isoflavonoids namely, 8-hydroxyirilone 5-methyl ether (2) and 8-hydroxyirilone (3), along with eight known isoflavonoids: irilone 4'-methyl ether (1), irilone (4), irisolidone (5), irigenin S (6), irigenin (7), irilone 4'-O-ß-d-glucopyranoside (8), iridin S (9), and iridin (10). The isolated flavonoids were structurally characterized with the assist of comprehensive spectroscopic analyses (UV, IR, 1D and 2D NMR, and HRMS) and comparing with the published data. They were estimated for their antioxidant and antidaibetic capacities using DPPH and α-amylase inhibition assays, respectively. Compounds 2, 3, and 4 exhibited prominent antioxidant activities with IC50 values of 12.92, 9.23, and 10.46µM, respectively compared to propyl gallate (IC50 7.11µM). Moreover, 2-5 possessed highest α-amylase inhibitory activity with % inhibition 66.1, 78.3, 67.3, and 70.1, respectively in comparison to acarbose (reference α-amylase inhibitor). Additionally, their structure-activity relationship has been discussed.

The Isolation of Lutein and Lutein 3'-methyl ether from Peristrophe lanceolaria.

Two carotenoids, lutein (1) and lutein 3'-methyl ether (2), have been isolated from the EtOAc fraction othe MeOH extract of Peristrophe lanceolaria, growing in Thailand. The structures of these compounds were elucidated from their ID and 2D NMR spectroscopic data and from comparisons made with the literature data. This is the first report of the isolation of lutein-3'-methyl ether as a natural product.

Ionic-liquid-mediated poly(dimethylsiloxane)- grafted carbon nanotube fiber prepared by the sol-gel technique for the head space solid-phase microextraction of methyl tert-butyl ether using GC.

A headspace solid-phase microextraction method was developed for the preconcentration and extraction of methyl tert-butyl ether. An ionic-liquid-mediated multiwalled carbon nanotube-poly(dimethylsiloxane) hybrid coating, which was prepared by covalent functionalization of multiwalled carbon nanotubes with hydroxyl-terminated poly(dimethylsiloxane) using the sol-gel technique, was used as solid-phase microextraction adsorbent. This innovative fiber exhibited a highly porous surface structure, high thermal stability (at least 320°C) and long lifespan (over 210 uses). Potential factors affecting the extraction efficiency were optimized. Under the optimum conditions, the method LOD (S/N = 3) was 0.007 ng/mL and the LOQ (S/N = 10) was 0.03 ng/mL. The calibration curve was linear in the range of 0.03-200 ng/mL. The RSDs for one fiber (repeatability, n = 5) at three different concentrations (0.05, 1, and 150 ng/mL) were 5.1, 4.2, and 4.6% and for the fibers obtained from different batches (reproducibility, n = 3) were 6.5, 5.9, and 6.3%, respectively. The developed method was successfully applied to the determination of methyl tert-butyl ether in different real water samples on three consecutive days. The relative recoveries for the spiked samples with 0.05, 1, and 150 ng/mL were between 94-104%.

Isolation and identification of 4, 4'-diapolycopene-4,4'-dioic acid produced by Bacillus firmus GB1 and its singlet oxygen quenching activity.

We succeeded in purifying the carotenoid produced by Bacillus firmus GB1 using chromatography on polystyrenic synthetic adsorbents, and identified it as 4,4'-diapolycopene-4,4'-dioic acid by HRESI-MS and NMR analyses of it and its dimethylester. In addition, we clarified the singlet oxygen (¹O2) quenching activities of 4,4'-diapolycopene-4,4'-dioic acid and its methyl esters (mono and dimethyl ester). Their IC50 values were 5.8 µM, 6.0 µM, and 6.2 µM, respectively. To our knowledge, this is the first report concerning the isolation and antioxidative activity of 4,4'-diapolycopene-4,4'-dioic acid, a product of the C30 carotenoid biosynthesis pathway.

Three acylated glycosidic acid methyl esters and two acylated methyl glycosides generated from the convolvulin fraction of seeds of Quamoclit pennata by treatment with indium(III) chloride in methanol.

Treatment of the ether-insoluble resin glycoside (convolvulin) fraction from seeds of Quamoclit pennata (Convolvulaceae) with indium(III) chloride in methanol provided three oligoglycosides of hydroxy fatty acid (glycosidic acid) methyl esters and two methyl glycosides, which were partially acylated by a glycosidic acid, 7S-hydroxydecanoic acid 7-O-ß-D-quinovopyranoside (quamoclinic acid B) and/or two organic acids, (E)-2-methylbut-2-enoic (tiglic) acid and/or 3R-hydroxy-2R-methylbutyric (nilic) acid. Their structures were elucidated on the basis of spectroscopic data and chemical conversions.

Determination of fuel ethers in water by membrane extraction ion mobility spectrometry.

Fuel oxygenates are environmentally detrimental compounds due to their rapid migration to groundwater. Fuel oxygenates have been reported to cause taste and odour problems in drinking water, and they also have long-term health effects. Feasible analytical methods are required to observe the presence of fuel oxygenates in drinking and natural water. The authors studied ion mobility spectrometry (IMS) to determinate isomeric fuel ether oxygenates; ethyl tert-butyl ether (ETBE), diisopropyl ether (DIPE), and tert-amyl methyl ether (TAME), separated from aqueous matrices with a pervaporation membrane module. Methyl tert-butyl ether (MTBE) was also membrane extracted and detected with IMS. The authors demonstrated that fuel ethers (MTBE, ETBE, DIPE, and TAME) can be quantified at µg/L level with membrane extraction IMS. A membrane extraction module coupled to IMS is a time and cost effective analysis method because sampling can be performed in a single procedure and from different natural water matrices within a few minutes. Consequently, IMS combined with membrane extraction is suitable not only for waterworks and other online applications but also in the field monitoring the quality of drinking and natural water.

Genetic analyses of Xanthomonas axonopodis pv. dieffenbachiae strains reveal distinct phylogenetic groups.

A comprehensive analysis of 175 Xanthomonas axonopodis pv. dieffenbachiae strains isolated from 10 Araceae hosts was done to identify pathogen variation. The strains were subjected to repetitive extragenic palindromic sequence polymerase chain reaction and four major phylogenetic clusters were generated. A subset of 40 strains isolated from Anthurium, Dieffenbachia, and Syngonium was further defined by amplified fragment length polymorphism and fatty acid methyl ester analysis and the same four phylogenetic clusters were observed. Comparison of representative strains in the first three clusters using DNA-DNA hybridization and multilocus sequence analysis supports the previous reclassification of strains in cluster I, including the X. axonopodis pv. dieffenbachiae pathovar reference strain (LMG695), to X. citri. Our research findings indicate that strains in cluster I, isolated primarily from anthurium, probably represent an undescribed pathovar. Other phylogenetic subclusters consisting primarily of strains isolated from xanthosoma and philodendron in clusters III and IV, respectively, may yet represent other undescribed species or pathovars of Xanthomonas.

Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply.

A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, Escherichia coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters.

Comparative evaluation of pilot scale horizontal subsurface-flow constructed wetlands and plant root mats for treating groundwater contaminated with benzene and MTBE.

In order to evaluate technology options for the treatment of groundwater contaminated with benzene and MTBE in constructed wetlands (CWs), a scarcely applied plant root mat system and two horizontal subsurface-flow (HSSF) CWs were investigated. The inflow load of benzene and MTBE were 188-522 and 31-90 mg d(-1)m(-2), respectively. Higher removal efficiencies were obtained during summer in all systems. The benzene removal efficiencies were 0-33%, 24-100% and 22-100% in the unplanted HSSF-CW, planted HSSF-CW and the plant root mat, respectively; the MTBE removal efficiencies amounted to 0-33%, 16-93% and 8-93% in the unplanted HSSF-CW, planted HSSF-CW and the plant root mat, respectively. The volatilisation rates in the plant root mat amounted to 7.24 and 2.32 mg d(-1)m(-2) for benzene and MTBE, which is equivalent to 3.0% and 15.2% of the total removal. The volatilisation rates in the HSSF-CW reached 2.59 and 1.07 mg d(-1)m(-2), corresponding to 1.1% and 6.1% of the total removal of benzene and MTBE, respectively. The results indicate that plant root mats are an interesting option for the treatment of waters polluted with benzene and MTBE under moderate temperatures conditions.

Removal of BTEX, MTBE and TAME from aqueous solutions by adsorption onto raw and thermally treated lignite.

The removal of BTEX (benzene, toluene, ethyl-benzene and m-,p-,o-xylenes), MTBE (methyl tertiary butyl ether) and TAME (tertiary amyl methyl ether) from aqueous solutions by raw (L(raw)) and thermally treated lignite at 250 C, 550 °C and 750 °C (L250, L550 and L750, respectively) was studied, through batch experiments. Selected physical characteristics of both raw and treated lignite such as surface area and pore volume distribution were determined. Competitive adsorption effects were also explored. It was proved that the examined lignite samples were quite effective in removing BTEX, MTBE and TAME from aqueous solutions, with sample treated at 750 °C being the most effective. Among the contaminants, BTEX appeared to have the strongest affinity, based on mass uptake by lignite samples. BTEX presence was found to significantly prevent MTBE and TAME adsorption on lignite (up to ∼55%). In all cases, equilibrium was achieved within 3h. The kinetics data proved a closer fit to the pseudo second order model, while the isotherm experimental data were a better fit to the Freundlich model, producing in some cases values of the isotherm constant 1/n less than one, indicating favorable adsorption. Respective batch experiments using commercial activated carbon (AC) were also conducted for comparison.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis / Atividade antifúngica in vitro dos ésteres metílicos de ácidos graxos das sementes de Annona cornifolia A.St.-Hil. (Annonaceae) sobre o fungo patogênico Paracoccidioides brasiliensis

INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

INTRODUÇÃO: Os ácidos graxos são abundantes em óleos vegetais. Eles são conhecidos por suas propriedades antibacterianas e antifúngicas. MÉTODOS: A suscetibilidade a antifúngicos foi avaliada pelo ensaio de microdiluição em caldo de acordo com CLSI (anteriormente NCCLS) sobre 16 isolados de interesse clínico. RESULTADOS: Nesse trabalho, os ésteres metílicos de ácidos graxos (FAME) inibiram doze isolados clínicos do fungo patogênico Paracoccidioides brasiliensis, e também foi muito ativo no ensaio de bioautografia sobre o fungo Cladosporium sphaerospermum. CONCLUSÕES: FAME foi um antifúngico mais potente do que sulfametoxazol-trimetoprim contra P. brasiliensis, nas condições utilizadas no presente trabalho.

[Biodegradation of methyl tert-butyl ether by stabilized immobilized Methylibium petroleiphilum PM1 cells and its biodegradation kinetics analysis].

Methylibium petroleiphilum PM1, which is capable of degrading methyl tert-butyl ether (MTBE) , was immobilized in calcium alginate gel beads. Several methods were explored to increase the strength of these gel beads. The central composite design analysis indicated that the introduction of 0.2 mol x L(-1) Ca2+ into the crosslinking solution, 1.38 mmol x L(-1) Ca2+ into the growth medium and 0.1% polyethyleneimine (PEI) as the chemical crosslinking agent could increase the stability of the Ca-alginate gel beads with no loss of biodegradation activity. The stabilized immobilized cells could be used 400 h continuously with no breakage and no bioactivity loss. Examination of scanning electron microscope demonstrated that a membrane surrounding the gel beads was formed and the cells could grow and breed well in the stabilized calcium alginate gel beads. Kinetic analysis of the gel bead-degradation indicated that the rate-limiting step was biochemical process instead of intraparticle diffusion process. The diameter of 3 mm affected the biodegradability less while high concentration of PEI induced much more serious mass transfer restraint.

Remediation of groundwater contaminated with MTBE and benzene: the potential of vertical-flow soil filter systems.

Field investigations on the treatment of MTBE and benzene from contaminated groundwater in pilot or full-scale constructed wetlands are lacking hugely. The aim of this study was to develop a biological treatment technology that can be operated in an economic, reliable and robust mode over a long period of time. Two pilot-scale vertical-flow soil filter eco-technologies, a roughing filter (RF) and a polishing filter (PF) with plants (willows), were operated independently in a single-stage configuration and coupled together in a multi-stage (RF+PF) configuration to investigate the MTBE and benzene removal performances. Both filters were loaded with groundwater from a refinery site contaminated with MTBE and benzene as the main contaminants, with a mean concentration of 2970±816 and 13,966±1998 µg L(-1), respectively. Four different hydraulic loading rates (HLRs) with a stepwise increment of 60, 120, 240 and 480 L m(-2) d(-1) were applied over a period of 388 days in the single-stage operation. At the highest HLR of 480 L m(-2) d(-1), the mean concentrations of MTBE and benzene were found to be 550±133 and 65±123 µg L(-1) in the effluent of the RF. In the effluent of the PF system, respective mean MTBE and benzene concentrations of 49±77 and 0.5±0.2 µg L(-1) were obtained, which were well below the relevant MTBE and benzene limit values of 200 and 1 µg L(-1) for drinking water quality. But a dynamic fluctuation in the effluent MTBE concentration showed a lack of stability in regards to the increase in the measured values by nearly 10%, which were higher than the limit value. Therefore, both (RF+PF) filters were combined in a multi-stage configuration and the combined system proved to be more stable and effective with a highly efficient reduction of the MTBE and benzene concentrations in the effluent. Nearly 70% of MTBE and 98% of benzene were eliminated from the influent groundwater by the first vertical filter (RF) and the remaining amount was almost completely diminished (∼100% reduction) after passing through the second filter (PF), with a mean MTBE and benzene concentration of 5±10 and 0.6±0.2 µg L(-1) in the final effluent. The emission rate of volatile organic compounds mass into the air from the systems was less than 1% of the inflow mass loading rate. The results obtained in this study not only demonstrate the feasibility of vertical-flow soil filter systems for treating groundwater contaminated with MTBE and benzene, but can also be considered a major step forward towards their application under full-scale conditions for commercial purposes in the oil and gas industries.

[Determination the parameters of bacteria transport in soil].

The tested bacterial in this study is the efficient degrading bacteria Chryseobacterium sp. A-3 to methyl tert-butyl ether (MTBE). The bacterial transport parameters during the process of soil bioremediation were described and determined, which included the properties of soils, adsorption isothermal parameters, adsorption dynamics, effective diffusion coefficient and growth coefficients of bacterial. The results showed, compared with other adsorption isotherms, experimental data are correlated reasonably well by Freundlich isotherm models with correlation coefficient of 99.5%. The exponential coefficient is 1.1, which is close to 1. So linear isotherm model can be used to describe the adsorption isothermal process of bacterial in soil. The adsorption constant of Chryseobacterium sp. A-3 value is 0.98 mL/g. The bacteria adsorption dynamics can be well forecasted by the stagnant film theory, which showed the adsorption process is reversible. The microbial reversible attachment rate coefficient is 0. 004 s(-1), and the microbial reversible detachment rate coefficient is 0. 002 s(-1). Based on the membrane cell and fractal dimension model, the diffusion coefficient 3.66 x 10(-6) cm2/s and effective diffusion coefficient 5.18 x 10(-7) cm2/s can be obtained. Simulation of biodegradation process was carried out. The results showed the maximum bacterial growth rate is 0.01 h(-1), the half saturated constant of MTBE is 134 mg/L as well as the biology rate is 0.33. The proposed of determine methods of bacterial transport parameters can be widely used in laboratory and field studies of microbial migration during soil. These parameters are great significance for the model establishment and study of bacteria transport in soil.