Active Sulfate Research Articles

Immune-enhancing activities of chondroitin sulfate in murine macrophage RAW 264.7 cells

As a representative sulfated glycosaminoglycan (GAG), chondroitin sulfate (CS) has been reported playing vital roles in the immune response in vivo and in vitro. However, limited information is available about their immune-enhancing activity. This study was to achieve more precise understandings about the immuno-stimulating activity of CS. In in vitro experiments, CS was found to significantly promote the pinocytic, phagocytic activity and ROS production of RAW264.7 cells at the dose range of 100–1000 μg/mL compared with the untreated group (p < 0.05). Further experiments showed that CS could increase the secretion levels of NO, TNF-α, IL-6 and IL-10 via activating the corresponding mRNA expression in macrophages through the toll-like receptor 2 (TLR2). These results indicated that CS could function as an immunostimulator to enhance the immune responses and might be a potential candidate for application in immunological diseases or functional foods.

Effect of Ammonium Chloride on the Efficiency with Which Copper Sulfate Activates Marmatite: Change in Solution Composition and Regulation of Surface Composition

Zinc sulfide minerals are the primary choice for zinc extraction and marmatite is one of the two most common zinc sulphide minerals (sphalerite and marmatite), therefore it is of great significance to study and optimize the flotation of marmatite. To improve the activation of copper sulfate on marmatite, a method involving the addition of ammonium chloride is devised. The method has been proven to be an effective way of improving the activation efficiency of copper sulfate towards marmatite under alkaline conditions. The strengthening mechanism was studied using micro-flotation, adsorption test, X-ray photoelectron spectroscopy, and by analyzing changes in solution composition. Flotation test results show that the activation effect of the copper sulfate towards marmatite is enhanced with the addition of ammonium chloride. According to the results of the adsorption measurements and X-ray photoelectron spectroscopy analysis, when the marmatite surface is activated using copper sulfate with added ammonia chloride, it adsorbs more copper sulfide and less copper hydroxide and zinc hydroxide. These changes in surface composition are believed to occur via the following process: NH3(aq) promotes the dissolution of zinc hydroxide and then facilitates the conversion of surface copper hydroxide to copper sulfide. In addition, the occurrence of Cu(NH3)n2+ can promote the adsorption of copper ions (Cu2+ can be stored as Cu(NH3)n2+ via complexation, and then, when the concentration of copper ions decreases, Cu2+ can be released through the decompositionof Cu(NH3)n2+. Hence, the copper ion concentration can be maintained and this can facilitate the adsorption of Cu2+ on marmatite). Based on a comprehensive analysis of all our results, we propose that adding ammonium chloride to the copper sulfate changes the solution components (i.e., the presence of NH3(aq) and Cu(NH3)n2+) and then regulates the surface composition of marmatite. The change in surface composition improves the hydrophobicity of mineral surface and this leads to an improvement in activation of marmatite.

Utilization of commercial sulfate to modify early performance of high volume fly ash based binder

The current study aims at distinguishing the advantages of using commercial sulfate agents consisting of sodium sulfate (Na2SO4) and gypsum (CaSO4.2H2O) to improve the setting time and the engineering properties of a high volume Class F fly ash (HVFA) paste at early ages. Experimental results showed that both types of sulfate activators as added in the HVFA paste shortened the setting time and increased the compressive strengths of the hardened paste specimens at all days, especially at early ages of 1–7 days. The improved macro-behavior of the HVFA pastes modified with sulfate in comparison with the reference specimens without sulfate was associated with the microstructural refinement due to the increased ultrasonic pulse velocity (UPV) measurement induced by the extra hydration products contributed to the dissolution of fly ash particles as detected by using scanning electron microscope (SEM). In this study, using Na2SO4 to enhance the setting time and early compressive strength of the HVFA paste was more efficient than using CaSO4.2H2O. On the other hand, the CaSO4.2H2O distinguished its’ superior benefit on lowering the hydration heat released of sulfate modified HVFA pastes.

Sodium sulfate activation mechanism on co-sulfating roasting to nickel-copper sulfide concentrate in metal extractions, microtopography and kinetics

Due to the complexity of occurrence of valuable metals and high content of alkali gangue in nickel-copper sulfide concentrate, traditional pyrometallurgical processing is not suitable. In this work, a two-stage co-sulfating roasting process was used to selectively extract valuable metals from Chinese nickel-copper sulfide concentrate. A mixture of (NH4)2SO4 and Na2SO4 was selected as the co-sulfating agents. The effect of the dosage of (NH4)2SO4 and Na2SO4, first stage roasting temperature, roasting time and second roasting temperature on metal’s extractions were investigated. XRD, SEM, DTA-TG, and DSC-TG were used to reveal the mechanism of action of Na2SO4 and the mineral phase transformations in the two-stage sulfating roasting process. The results show that nearly all of Ni and Co, Cu, and 1.12% of Fe were extracted at the mass ratio of ammonium sulfate to ore of 3.5, first roasting at 500 °C for 2 h, dosage of sodium sulfate of 4 g (10 g ore), followed by second roasting at 680 °C for 2 h, then water leaching at 95 °C for 2 h. Na2S2O7 generated from Na2SO4 in the roasting process, shrinks the particle size of the ore, decrease the surface area of the roasted product, significantly promotes extent of the sulfating of metals, in particular for Ni. Thermal analysis kinetics indicates that Na2SO4 significantly reduces the apparent activation energy of the sulfating roasting process. The metal bearing mineral phases were transformed into sulfates or sodium double or ternary sulfates in the first roasting process, then the sodium double sulfates of Na3Fe(SO4)3 were decomposed.

Multi-ethnic SULT1A1 copy number profiling with multiplex ligation-dependent probe amplification.

To develop a SULT1A1 multiplex ligation-dependent probe amplification assay and to investigate multi-ethnic copy number variant frequencies. A novel multiplex ligation-dependent probe amplification assay was developed and tested on 472 African-American, Asian, Caucasian, Hispanic and Ashkenazi Jewish individuals. The frequencies of atypical total copy number (i.e., greater or less than two) were 38.7% for Hispanics, 38.9% for Ashkenazi Jewish, 43.2% for Caucasians, 53.6% for Asians and 64.1% for African-Americans. Heterozygous SULT1A1 deletion carriers (slow sulfators) were most common among Caucasians (8.4%), whereas African-Americans had the highest frequencies of three or more copies (rapid sulfators; 60.9%). Different ethnic and racial populations have varying degrees of SULT1A1-mediated sulfation activity, which warrants further research and that may have utility for drug response prediction among SULT1A1-metabolized medications.

Structural characterization and in vitro antioxidant activities of chondroitin sulfate purified from Andrias davidianus cartilage

Origin and manufacturing process are key factors affecting the biological activities of chondroitin sulfate (CS), which can be utilized as a nutraceutical in dietary supplements. Herein, we extracted and purified CS from the cartilage of artificially breeding Andrias davidianus (ADCS), i.e., Chinese giant salamander (CGS), one of the prospective functional food source materials in China. Low molecular weight CS (LMWADCS) was then prepared by free radical depolymerization of ADCS. High-performance gel permeation chromatography (HPGPC) analysis showed that the average molecular weight (Mw) of ADCS was 49.2 kDa, while the Mw of LMWADCS was 6.4 kDa. After the eliminative degradation of ADCS by chondroitinase ABC, strong anion-exchange high-performance liquid chromatography (SAX-HPLC) analysis showed that the disaccharide composition of ADCS was 14.6% ΔDi0S, 60.9% ΔDi6S and 24.5% ΔDi4S. Then, in vitro antioxidant assays were performed with ADCS, LMWADCS and CS from a commercial source. Our results showed that LMWADCS exerted the highest total antioxidant activity out of the total antioxidant capacity, including the capacity of scavenging DPPH radicals, hydroxyl radicals and superoxide anion radicals. From the results of this study, we can conclude that the Mw and composition of ADCS are different from those reported for bovine and shark CS, and LMWADCS can be utilized as a valuable and potential nutraceutical for the functional food industry.

Synergy of Sodium Nitroprusside and Nitrate in Inhibiting the Activity of Sulfate Reducing Bacteria in Oil-Containing Bioreactors.

Sodium nitroprusside (SNP) disrupts microbial biofilms through the release of nitric oxide (NO). The actions of SNP on bacteria have been mostly limited to the genera Pseudomonas, Clostridium, and Bacillus. There are no reports of its biocidal action on sulfate-reducing bacteria (SRB), which couple the reduction of sulfate to sulfide with the oxidation of organic electron donors. Here, we report the inhibition and kill of SRB by low SNP concentrations [0.05 mM (15 ppm)] depending on biomass concentration. Chemical reaction of SNP with sulfide did not compromise its efficacy. SNP was more effective than five biocides commonly used to control SRB. Souring, the SRB activity in oil reservoirs, is often controlled by injection of nitrate. Control of SRB-mediated souring in oil-containing bioreactors was inhibited by 4 mM (340 ppm) of sodium nitrate, but required only 0.05 mM (15 ppm) of SNP. Interestingly, nitrate and SNP were found to be highly synergistic with 0.003 mM (1 ppm) of SNP and 1 mM (85 ppm) of sodium nitrate being sufficient in inhibiting souring. Hence, using SNP as an additive may greatly increase the efficacy of nitrate injection in oil reservoirs.

A new interpretation of sulfate activation of rabbit muscle glycogen phosphorylase.

It is widely known that sulfate ion at high concentration serves like an allosteric activator of glycogen phosphorylase (GP). Based on the crystallographic studies on GP, it has been assumed that the sulfate ion is bound close to the phosphorylatable Ser14 site of nonactivated GP, causing a conformational change to catalytically-active GP. However, there are also reports that sulfate ion inhibits allosterically-activated GP by preventing the phosphate substrate from attaching to the catalytic site. In the present study, using a high concentration of sulfate ion, significant enhancement of GP activity was observed when macromolecular glycogen was used as substrate but not when smaller maltohexaose was used. In glycogen solution, nonreducing-end glucose residues are localized on the surface of glycogen and are not distributed homogenously in the solution. Using cyclodextrin-immobilized column chromatography, we found that sulfate at high concentration promoted GP-dextrin binding through the dextrin-binding site (DBS) located away from the catalytic site. This result is consistent with the properties of the DBSs found in glycogen-debranching enzyme and β-amylase. Therefore, we propose a new interpretation of the sulfate activation of GP, wherein sulfate ions at high concentration promote glycogen-binding to the DBS directly, and glycogen-binding to the catalytic site indirectly. Our findings were successfully applied to the affinity purification of porcine brain GP.

Understanding the coagulant activity of zirconium oxychloride to control THMs formation using response surface methodology

In the present study, impact of coagulant activity of zirconium oxychloride and aluminium sulphate on the kinetics of chlorine consumption and trihalomethanes (THMs) formation has been delineated. Zirconium Oxychloride showed rapid chlorine decay within the first 30 min, which further achieved steady rate after 60 min, but in case of aluminium sulphate chlorine consumption has been increased drastically throughout the chlorine decay. Zirconium oxychloride has effectively reduced significant amount of slow reducing agents (SRA) as well as fast reducing agents (FRA), which correspond to the rate of reduction in phenolic groups from water enriched with Natural Organic Matter (NOM) which eventually decreased trihalomethane mediated cancer risk by ~ 2.3 times among adults as compared to aluminium sulphate. Result depicts the outstanding coagulant activity of zirconium oxychloride as it tends to surpass aluminium sulphate in reducing NOM “measured as Absorbance Slope Index (ASI)” and phenol by 57.98% and 49.02% respectively from NOM enriched chlorinated water, which also resembles the THMs removal trend observed during cancer risk assessment.

Bioinformatics Analysis of Microbial Abundance and Diversity in Acid Mine Drainage from the Solomon Mine Near Creede, Colorado

This study focused on characterizing the phylotypic composition of acid mine drainage (AMD) communities associated with the Solomon Mine near Creede, Colorado, and its relative diversity compared to microbial communities found in the East Willow Creek (EWC) watershed. AMD from the Solomon Mine adit flows into an existing passive bioremediation wetland system located next to the Solomon Mine adit that currently is ineffective and is under consideration for renovation. We are interested in gaining an understanding of the baseline microbial communities present in AMD/EWC and to monitor them during future wetland renovation. Prokaryotic community profiling was approached using SSU 16S rRNA marker gene amplification coupled with next generation sequencing. Bioinformatics analysis included raw read preprocessing, data visualization, and statistical testing using a combination of USEARCH and QIIME-based scripts. A pH and conductivity gradient were observed for water moving through the currently inefficient wetland system at the Solomon Mine. The EWC microbiomes had statistically significant higher alpha diversity compared to the AMD microbiomes. Beta diversity analysis parsed the sample locations into statistically significant groups including core AMD microbiomes, the wetland Cell 3 microbiome, and EWC microbiomes using multidimensional scaling. Taxa driving beta diversity included the phylum Proteobacteria for the core AMD microbiomes, the phyla Firmicutes and Chloroflexi for the constructed wetland Cell 3, and the phyla Bacteroidetes and Verrucomicrobia for EWC. Our data suggests that the microbial community in constructed wetland Cell 3 is likely where limited sulfate reduction activity is operating at low capacity, which will be further investigated via shotgun metagenomic analysis.

Effects of human SULT1A3/SULT1A4 genetic polymorphisms on the sulfation of acetaminophen and opioid drugs by the cytosolic sulfotransferase SULT1A3

Sulfoconjugation has been shown to be critically involved in the metabolism of acetaminophen (APAP), morphine, tapentadol and O-desmethyl tramadol (O-DMT). The objective of this study was to investigate the effects of single nucleotide polymorphisms (SNPs) of human SULT1A3 and SULT1A4 genes on the sulfating activity of SULT1A3 allozymes toward these analgesic compounds. Twelve non-synonymous coding SNPs (cSNPs) of SULT1A3/SULT1A4 were investigated, and the corresponding cDNAs were generated by site-directed mutagenesis. SULT1A3 allozymes, bacterially expressed and purified, exhibited differential sulfating activity toward each of the four analgesic compounds tested as substrates. Kinetic analyses of SULT1A3 allozymes further revealed significant differences in binding affinity and catalytic activity toward the four analgesic compounds. Collectively, the results derived from the current study showed clearly the impact of cSNPs of the coding genes, SULT1A3 and SULT1A4, on the sulfating activity of the coded SULT1A3 allozymes toward the tested analgesic compounds. These findings may have implications in the pharmacokinetics as well as the toxicity profiles of these analgesics administered in individuals with distinct SULT1A3 and/or SULT1A4 genotypes.

Effects of genetic polymorphisms on the sulfation of dehydroepiandrosterone and pregnenolone by human cytosolic sulfotransferase SULT2A1.

The cytosolic sulfotransferase (SULT) SULT2A1 is known to mediate the sulfation of DHEA as well as some other hydroxysteroids such as pregnenolone. The present study was designed to investigate how genetic polymorphisms of the human SULT2A1 gene may affect the sulfation of DHEA and pregnenolone. Online databases were systematically searched to identify human SULT2A1 single nucleotide polymorphisms (SNPs). Of the 98 SULT2A1 non-synonymous coding SNPs identified, seven were selected for further investigation. Site-directed mutagenesis was used to generate cDNAs encoding these seven SULT2A1 allozymes, which were expressed in BL21 Escherichia coli cells and purified by glutathione-Sepharose affinity chromatography. Enzymatic assays revealed that purified SULT2A1 allozymes displayed differential sulfating activity toward both DHEA and pregnenolone. Kinetic analyses showed further differential catalytic efficiency and substrate affinity of the SULT2A1 allozymes, in comparison with wild-type SULT2A1. These findings provided useful information concerning the effects of genetic polymorphisms on the sulfating activity of SULT2A1 allozymes.

Sulfidogenic activity of sulfate and sulfur reducing bacteria under the influence of metal compounds

Due to their high content in natural environments, heavy metals exhibit toxic effects on living organisms, which leads to a decrease in the biological diversity and productivity of ecosystems. In niches with low oxidation reducing potential, sulfate and sulfur reducing bacteria carry out the reducing transformation of oxidized sulfur compounds with the formation of significant amounts of hydrogen sulfide. H2S produced by bacteria interacts with metal ions, precipitating them in the form of sulfides. The aim of this work was to investigate the influence of lead, cuprum (II), iron (II) and manganese (II) salts on the production of hydrogen sulfide by bacteria of the Desulfovibrio and Desulfuromonas genera, isolated from Yavorivske Lake, and to evaluate the efficiency of their use for purifying media, enriched with organic compounds, from hydrogen sulfide and heavy metals. The content of heavy metal ions in the water of Yavorivske Lake was determined by the spectrophotometric method. The bacteria were grown for 10 days at 30 °C in the Kravtsov-Sorokin medium under anaerobic conditions. To study the influence of metal ions on bacteria growth and their H2S production, cells were incubated with metal salts (0.5–4.0 mM), washed and grown in media with SO42– or S0. To determine the level of metal ions binding by H2S, produced by bacteria, cells were grown in media with metal compounds (0.5–4.0 mM), SO42– or S0. Biomass was determined by turbidimetric method. In the cultural liquid the content of H2S was determined quantitatively by spectrophotometric method, and qualitatively by the presence of metal cations. The content of metal sulfides in the growth medium was determined by weight method. Sulfate and sulfur-reducing bacteria were resistant to 2.0 mM Pb(NO3)2, 2.5 mM CuCl2, 2.5 mM FeCl2 × 4H2O and 2.0 mM MnCl2 × 4H2O, therefore they are promising for the development of biotechnologies for the purification of water resources contaminated by sulfur and metal compounds. When present in a medium with sulfates or sulfur of 1.0–1.5 mM lead, cuprum (II), iron (II) or manganese (II) ions, they almost completely bind with the H2S produced by bacteria in the form of insoluble sulfides, which confirms the negative results of qualitative reactions to their presence in the cultural liquid.

Investigation of the Effects of SULT2A1 Genetic Polymorphisms on the Sulfation of Dehydroepiandrosterone by Human Cytosolic Sulfotransferase SULT2A1

The cytosolic sulfotransferase (SULT) SULT2A1 is known to mediate the sulfation of dehydroepiandrosterone (DHEA) as well as many other sterols and steroids. The present study was designed to investigate how genetic polymorphisms of the human SULT2A1 gene may affect the sulfation of DHEA. Online databases were comprehensively searched to identify human SULT2A1 single nucleotide polymorphisms (SNPs). Of the 98 SULT2A1 non‐synonymous coding SNPs identified, seven were selected for further investigation. Site‐directed mutagenesis was used to generate cDNAs encoding these seven SULT2A1 allozymes, which were expressed in BL21 E. coli cells and purified by glutathione‐Sepharose affinity chromatography. Enzymatic assays revealed that purified SULT2A1 allozymes displayed differential sulfating activity toward DHEA. Kinetic analyses showed further differential catalytic efficiency and substrate affinity of the SULT2A1 allozymes, in comparison with wild‐type SULT2A1. These findings provided useful information concerning the effects of genetic polymorphisms on the sulfating activity of SULT2A1 allozymes.Support or Funding InformationThis work was supported in part by a grant from National Institutes of Health (Grant # R03HD071146).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of Genetic Polymorphisms on the Sulfation of 17α‐Ethinylestradiol (EE2) by Human Cytosolic Sulfotransferase SULT1E1

In human, previous pharmacokinetic studies have shown the metabolism of 17α‐ethinylestradiol (EE2) through sulfation, with estrogen sulfotransferase (SULT1E1). Since SULT1E1 is a major responsible enzyme that mediates the biotransformation of endogenous estrogens and estrogen‐like drugs, genetic polymorphisms of SULT1E1 may significantly impact the 17α‐ethinylestradiol‐sulfating activity by SULT1E1. Subsequently, this study was performed to investigate the implications of SULT1E1 genetic polymorphisms in the sulfation of 17α‐ethinylestradiol. By using the site directed mutagenesis technique, five selected recombinant SULT1E1 allozymes were generated, expressed and purified. Compared with the wild‐type SULT1E1, purified allozymes of SULT1E1 were shown to exhibit significantly distinct sulfating activity with 17α‐Ethinylestradiol as a substrate. In summary, the obtained results provide evidence related to differential metabolism of 17α‐ethinylestradiol in individuals with different SULT1E1 genotypes, which may be useful for further in‐vivo study contributed to the therapeutic‐ as well as adverse effects of 17α‐ethinylestradiol through sulfation.Support or Funding InformationThe College of Pharmacy, University of ToledoThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Sulfation of catecholamines and serotonin by SULT1A3 allozymes

Previous studies have demonstrated the involvement of sulfoconjugation in the metabolism of catecholamines and serotonin. The current study aimed to clarify the effects of single nucleotide polymorphisms (SNPs) of human SULT1A3 and SULT1A4 genes on the enzymatic characteristics of the sulfation of dopamine, epinephrine, norepinephrine and serotonin by SULT1A3 allozymes. Following a comprehensive search of different SULT1A3 and SULT1A4 genotypes, twelve non-synonymous (missense) coding SNPs (cSNPs) of SULT1A3/SULT1A4 were identified. cDNAs encoding the corresponding SULT1A3 allozymes, packaged in pGEX-2T vector were generated by site-directed mutagenesis. SULT1A3 allozymes were expressed, and purified. Purified SULT1A3 allozymes exhibited differential sulfating activity toward catecholamines and serotonin. Kinetic analyses demonstrated differences in both substrate affinity and catalytic efficiency of the SULT1A3 allozymes. Collectively, these findings provide useful information relevant to the differential metabolism of dopamine, epinephrine, norepinephrine and serotonin through sulfoconjugation in individuals having different SULT1A3/SULT1A4 genotypes.

Antimicrobial Activity of Copper Sulfate and Copper Oxide Embedded on Polyurethane Foam

CuSO4-deposited and CuO-deposited polyurethane foam (PUF) were fabricated in this study. Image analysis showed color transformation of the PUF from yellow to blue-green, which is indicative of the deposited CuSO4 particles on the substrate. Further color transformation of the material from blue-green to greenish-brown after soaking in NaOH suggest that the CuSO4 oxidized to form CuO, which was confirmed by the presence of CuO peaks during XRD analysis. SEM images also reveal the presence of CuO rods embedded in the PUF. The antibacterial activities of the CuSO4- and CuO-deposited samples against the gram-negative Escherichia coli bacteria were conducted.

Age of Enrolling to Kindergarten and First Grade in Canada: The Quebec Exception

Abstract PDF Full-Text e-Pub Heparin is a natural anticoagulant from animal organs with excellent anticoagulant activity, and it is of high price as the raw material for the preparation of heparin originates from the special organs of animals. There is also the problem of biological rejection. As Pentosan sulfate has a similar chemical structure to heparin and is prepared from renewable plant-derived pentosan, so the preparation and biological activity evaluation of pentosan sulfate has become a new research hotspot in the field. This paper mainly reviews the structure, physical and chemical properties, preparation methods and the analysis and evaluation of various biological activities of pentosan sulfate. The future development of pentosan sulfate is to find plant-based pentosans with similar structure to hep.....

Effects of Human Sulfotransferase 2A1 Genetic Polymorphisms 3 on the Sulfation of Tibolone.

Previous studies have demonstrated the metabolism of tibolone through sulfation, with the cytosolic sulfotransferase (SULT) SULT2A1 as the major responsible enzyme. The current study aimed to investigate how SULT2A1 genetic polymorphisms may affect the dehydroepiandrosterone (DHEA)- and tibolone-sulfating activity of SULT2A1. Site-directed mutagenesis was employed to generate cDNAs encoding ten different SULT2A1 allozymes. Recombinant SULT2A1 allozymes were expressed in BL21 E. coli cells, and purified using glutathione-sepharose affinity chromatography. An established sulfotransferase assay was used to analyze DHEA- and tibolone-sulfating activity of the purified SULT2A1 allozymes. The nine human SULT2A1 allozymes plus the wild-type SULT2A1 were found to display differential sulfating activity toward DHEA and tibolone. Kinetic analysis revealed that different SULT2A1 allozymes exhibited differential substrate affinity and catalytic efficiency toward the two substrates tested. The results obtained provided useful information concerning the differential metabolism of tibolone through sulfation in individuals with different SULT2A1 genotypes.

Characteristics of petroleum-contaminated groundwater during natural attenuation: a case study in northeast China.

The objective of this study was to investigate a petroleum-contaminated groundwater site in northeast China. We determined the physicochemical properties of groundwater that contained total petroleum hydrocarbons (TPH) with a view to developing a scientifically robust strategy for controlling and remediating pollution of groundwater already contaminated with petroleum. Samples were collected at regular intervals and were analyzed for dissolved oxygen (DO), iron (Fe3+), sulfate (SO42-), electrical conductivity (Eh), pH, hydrogen carbonate (HCO3-), and enzyme activities of catalase (CAT), peroxidase (HRP), catechol 1,2-dioxygenase (C12O), and catechol 2,3-dioxygenase (C23O). We used factor analysis in SPSS to determine the main environmental characteristics of the groundwater samples. The results confirmed that the study site was slightly contaminated and that TPH levels were decreasing slightly. Some of the physicochemical variables showed regular fluctuations; DO, Fe3+, and SO42- contents decreased gradually, while the concentrations of one of the microbial degradation products, HCO3-, increased. Microorganism enzyme activities decreased gradually. The microbiological community deteriorated noticeably during the natural attenuation process, so microbiological degradation of pollutants receded gradually. The HCO3- content increased and the pH and Eh decreased gradually. The groundwater environment tended to be reducing.