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PubMedDate not supplied

[Degradation of aniline by Delftia tsuruhatensis 14S in batch and continuous processes].

A Delftia tsuruhatensis strain capable of consuming aniline as the sole source of carbon, nitrogen, and energy at concentrations of up to 3200 mg/l was isolated from activated sludge of purification works of OAO Volzhskii Orgsintez. The strain grew on pyrocatechol and p-hydroxybenzoic acid, but did not consume phenol, 2-aminophenol, 3-chloroaniline, 4-chloroaniline, 2,3-dichloroaniline, 2,4-dichloroaniline, 3,4-dichloroaniline, 2-nitroaniline, 2-chlorophenol, or aminobenzoate. Aniline is degraded by cleavage of the pyrocatechol aromatic ring at the ortho position. Cells were immobilized on polycaproamide fiber. It was shown that the strain degraded aniline at 1000 mg/l in a continuous process over a long period of time.

Aniline Compounds↗

PubMedDate not supplied

[Inhibitory effects of phenolic ecotoxicants on photobacteria at various pH values].

Kinetic characteristics of light emission by intact cells of the photobacteria Photobacterium phosphoreum and Vibrio harveyi at pH 5.5, 7.0, and 8.0 were studied as well as specific features of inhibitory effects of 2,4-di- and 2,4,5-triphenoxyacetic acids (2,4-D and 2,4,5-T), pentachlorophenol (PCP), and 2,6-dimethylphenol (2,6-DMP) at the same pH values. Nonstationarity of emission kinetics was observed at all the pH values studied. Exponential luminescence decay in a 60-sec range was observed at pH 5.5; a 5-min luminescence activation, at pH 7.0 and 8.0. The cell respiratory activity drops by over one order of magnitude at pH 5.5 compared with the activities at pH 7.0 and 8.0. The inhibitory effects of 2,4-D, 2,4,5-T, and PCP differ by one-two orders of magnitude depending on pH. The maximal cell sensitivity to these compounds appears at pH 5.5; the minimal, at pH 8.0. The effect of 2,6-DMP is independent of pH. As is demonstrated, it is hydrophobicity of the molecule and pK values of the toxicants that determine the inhibitory effect. Characteristic of the substrate-starved photobacterial cells are higher sensitivity to chlorophenolic compounds compared with the cells provided with high energy supply at all the pH values.

2,4,5-Trichlorophenoxyacetic Acid↗

PubMed2004

Preparation and photocatalytic behavior of MoS2 and WS2 nanocluster sensitized TiO2.

A new approach has been developed for the fabrication of visible light photocatalysts. Nanoclusters of MoS2 and WS2 are coupled to TiO2 by an in situ photoreduction deposition method taking advantage of the reducing power of the photogenerated electrons from TiO2 particles. The photocatalytic degradation of methylene blue and 4-chlorophenol in aqueous suspension has been employed to evaluate the visible light photocatalytic activity of the powders. The blue shift in the absorption onset confirms the size quantization of MS2 nanoclusters, which act as effective and stable sensitizers, making it possible to utilize visible light in photocatalysis. Quantum size effects alter the energy levels of the conduction and valence band edges in the coupled semiconductor systems, which favors the interparticle electron transfer. In addition, the coupled systems are believed to act in a cooperative manner by increasing the degree of charge carrier separation, which effectively reduces recombination.

Journal Article↗

PubMed2006

[Isolation and identification of Bacillus cereus strain Jp-A and its capability in phenol degradation].

In this study, a bacterial strain named as Jp-A was isolated from the activated sludge of a steel factory. Through morphological observation,physiological and biochemical test, and 16srRNA sequence analysis, the strain was identified as Bacillus cereus. Under laboratory condition, the phenol at its initial concentration of 5,10 and 15 mmol x L(-1) could be completely degraded by the strain within 16,24 and 32 h, respectively, but the growth of the strain was inhibited when the phenol concentration was 30 mmol x L(-1). The strain could also utilize and degrade other aromatic hydrocarbons, e. g. , benzene, toluene, chlorophenol and nitrophenol, as its sole source of carbon and energy. Dioxygenase test indicated that the strain degraded phenol via meta-pathways. The key enzyme catechol 2,3-dioxygenase was an induced enzyme, which was mainly located on the cell membrane, and adding glucose could inhibit its generation.

Bacillus cereus↗

PubMed2006

[Origin, structure and distribution of dioxins].

Polychlorinated dibenzo-para-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are generated as unintentional by-products in a number of thermal and chemical-industrial processes. Biogenic formation through dimerization of chlorinated precursors, such as chlorophenols, is know but does not play a major role in national dioxin release inventories and in most cases is not quantified. PCDD/PCDF are semi-volatile substances and undergo long-range transport; they are persistent and accumulate in the environment and organismus; and they are toxic. They have become a global environmetnal problem. At the international level this issue is addressed by the Stockholm Convention on Persistent Organic Pollutants, a legally binding instrument to eliminate PCDD/PCDF through step-wise implementation of reduction measures. Within the Stockholm Convention, Parties have to develop national or regional dioxin inventories. First results show that in most industrialized countries, incineration of municipal solid waste does no longer represent the largest dioxin source; instead, certain processes in the metallurgical industry have become largest emitters. In developing countries, the situation is very different: open burning processes such as forest and grassland fires, burning of agricultural residues either before or after harvest as well as fires in waste dumps or the private fires to dispose of municipal waste represent the largest dioxin sources. First steps for a global environmental monitoring program under the Stockholm Convention have been initiated.

Dioxins↗

PubMed1991

[Diastereospecific synthesis of antifungal threo-BAY 19139].

BAY 19139, 1-(4-chlorophenoxy)-1-(1-imidazolyl)-3,3-dimethyl-2-butanol is a new imidazolyl derivative of antifungal agent. Its threo-isomer(Ia) shows marked antifungal activity, and the antiprotozoal activity is higher than the well-known metronidazole or clotrimazole, but the activity of the erythro-isomer is weak. This paper reports the sequential reactions of chloro or bromo-oxirane with p-chlorophenolate, and then with sodium imidazolate in two stereocontrolled steps to the threo-BAY 19139 (Ia). Halo-oxirane is accomplished by the stereochemistry of ring closure of alpha, alpha-dihalopinacolone. The molecular structure of Ia was confirmed unambiguously by X-ray crystal analysis. Furthermore, the nucleophilic substitution of chloro-oxirane was investigated. We found that under the solid-liquid PTC condition at room temperature, the reaction time was shortened and a higher yield was obtained.

Antifungal Agents↗

PubMed1991

[Determination of beta-N-acetylglucosaminidase and albumin in urine: comparison of methods and effect of gel filtration in human and rat urine].

A new kinetic method for determination of beta-N-acetylglucosaminidase (beta-NAG, EC 3.2.1.30) in human and rat urine with chlorophenol red-NAG as substrate is compared to two other methods with 4-nitrophenyl-NAG and 3-cresol-sulfonphthaleinyl-NAG respectively as substrates. The impact of gel filtration of urinary specimens on the determination of beta-NAG-activity and of low albumin concentrations in urine is described.

Acetylglucosaminidase↗

PubMed1991

[Results of multicenter determination of preliminary reference values for beta-N-acetylglucosaminidase in urine of adults].

Reference intervals for beta-N-acetylglucosaminidase (beta-NAG) using the method with chlorophenol red-N-acetylglucosaminide (CPR-NAG) as substrate were evaluated in second morning urine samples of 358 adults, combined from 4 laboratories of 3 countries. As upper reference limits for 37 degrees C measuring temperature are proposed: 5 U/l or 4 U/g creatinine respectively.

Acetylglucosaminidase↗

PubMed1990

An in vitro study of the diffusibility of intracanal medicaments.

In this study, the diffusion properties of the vapors of four canal antiseptics were examined. Tricresol, camphore-chlorophenol, Cresophene, and povidone-iodine in clinical doses were tested against Staphylococcus aureus and Streptococcus faecalis. Forty-five extracted human maxillary central incisor teeth were used, and their root canals were prepared. A small amount of antiseptic was placed on a cotton pellet in the pulp chamber of each tooth, and the chamber was sealed with Cavit. Vapors from each of the test medicaments produced zones of inhibition on Staphylococcus aureus and Streptococcus faecalis. The study showed that vapors of the test medicaments do pass through the apex of a tooth and thus have a potential effect at the periapical area. The largest zone of inhibition resulted from the vapor of tricresol.

Diffusion↗

PubMed1990

Absorption spectra of the hydroxycyclohexadienyl radicals of substrates for phenol hydroxylase.

The absorption spectra of the hydroxycyclohexadienyl radicals formed upon the addition of OH radicals to six substrates for phenol hydroxylase have been determined using pulse radiolysis. Combining the radical spectra of thiophenol (lambda max, 390 nm; epsilon, 10,500 M-1 cm-1) and resorcinol (lambda max, 340 nm; epsilon, 4,100 M-1 cm-1) with their respective published spectra of enzyme-bound reduced flavin that is substituted in the C(4a) position of the dihydroflavin ring gave composite spectra that closely match the spectra formed concomitantly with the introduction of an oxygen atom into the substrates, the so-called Intermediate II species. A similar procedure for the substrates hydroquinone, 3-aminophenol, 3-chlorophenol, and 3-methylphenol yielded spectra that are also consistent with the known characteristics of their Intermediate II species. These spectral results give further support to the proposed biradical mechanism (Anderson, R.F., Patel, K. B., and Stratford, M. R. L. (1987) J. Biol. Chem. 262, 17475-17479) for the functioning of this class of flavoprotein hydroxylases.

Free Radicals↗

PubMed1990

Sensitive and rapid colorimetric immunoenzymometric assay of ferritin in biological samples.

We describe a rapid and sensitive enzyme-linked immunosorbent assay (ELISA) for quantifying ferritin in human and rat biological fluids. We used chlorophenol red beta-D-galactopyranoside as the colorimetric substrate of beta-galactosidase (EC 3.2.1.23), which is coupled to specific antibodies to either human or rat liver ferritin. The assay is sensitive (detection limit for human assay = 0.58 micrograms/L and for rat assay = 0.37 micrograms/L), accurate (average recovery for human assay = 93% and for rat assay = 92%), and precise (total CVs for human assay = 2.3-12.2% and for rat assay = 5.6-11.3%). The results correlated well with those of an established immunoradiometric technique (r = 0.99691). This assay has a prolonged shelf-life, is inexpensive, and utilizes a stable colorimetric substrate that requires relatively short incubation.

Animals↗

PubMed1990

Falsely low estimation of triglycerides in lipemic plasma by the enzymatic triglyceride method with modified Trinder's chromogen.

The enzymatic assay of triglyceride, based on the use of L-glycerol-3-phosphate oxidase (EC 1.1.3.21) and a modified Trinder's chromogen involving 4-chlorophenol, is subject to strong negative interference at concentrations of triglyceride greater than 20 mmol/L, such as occur in grossly lipemic plasma. This interference is caused by the rapid utilization of oxygen, resulting in the reaction becoming transiently anaerobic. The dye product already formed may then be reduced ("bleached") by acting as an alternative electron acceptor for glycerol-3-phosphate oxidase. Reduction of the dye leads to a marked decrease in final absorbance at 505 nm. Grossly underestimated values for triglyceride concentrations, apparently within the linear range of the assay, may therefore be inadvertently obtained with equilibrium methods. We suggest that samples giving unexpectedly low results for lipemic plasma should be re-assayed after dilution or with use of a smaller volume of sample.

Autoanalysis↗

PubMed1989

Biochemical and genetic studies on degradation of chlorobenzoates by Pseudomonas.

The chlorobenzoates constitute an important class of recalcitrant compounds polluting this biosphere. Two bacterial strains B16 (Pseudomonas aeruginosa) and DT4 (Pseudomonas sp.) isolated by enrichment technique were found to utilize 2-chlorobenzoic acid (2-Cba) and 4-chlorobenzoic acid (4-Cba) respectively as sole source of carbon and energy. 2-Cba and 4-Cba were supplemented in synthetic medium at 1500 micrograms/ml and 1000 micrograms/ml (w/v) respectively. Addition of 100 micrograms/ml (w/v) yeast extract stimulated growth of cultures. Degradation studies revealed that substrates were degraded without release of chloride ion with possible accumulation of respective chlorophenols. Respiration studies revealed inducible nature of enzymes for break down of 2-Cba, 4-Cba benzoic acid, 4-hydroxybenzoic acid and catechol. Extraction of plasmid DNA from parent strains showed presence of plasmid of same size in both strains. Cured strains showed absence of corresponding plasmid DNA bands thus indicating plasmid-borne genes for degradation of chlorobenzoates.

Biodegradation, Environmental↗

PubMed1989

Temperature-sensitive steps in the secretory pathway for von Willebrand factor in endothelial cells.

The effect of reduced temperature on the post-translational processing and stimulated release of von Willebrand factor (vWf) from human umbilical vein endothelial cells was studied. Following pulse-labeling, cells were incubated for 4 h at 18 degrees C or 20 degrees C. Post-translational processing was reversibly arrested at the dimer stage, dimers were composed of Endo H-sensitive precursor subunits, and no vWf was detected in the culture medium. This block was reversible, since warming cells to 37 degrees C relieved it and resulted in the appearance of fully processed vWf in the cells and the culture medium. The same results were obtained when cells were incubated with carbonyl cyanide m-chlorophenol hydrazone or dinitrophenol which inhibit mitochondrial oxidative phosphorylation, known to block exit of secretory proteins from the endoplasmic reticulum (ER). This indicated that ER exit is not required for the complete dimerization of vWf. Reduced temperature (18 degrees C and 20 degrees C) also reversibly and nearly completely inhibited the secretagogue-induced release of vWf from Weibel-Palade bodies without affecting the microtubular cytoskeleton. We add reduced temperature to the list of useful tools for the study of the vWf secretory pathway in endothelial cells.

Calcimycin↗

PubMed1988

Multistep reactions with immobilized microorganisms.

This review presents some examples of new semicontinuous and continuous processes for product formation and for degradation of xenobiotics with immobilized microorganisms. A semicontinuous process for glycerol formation with Saccharomyces cerevisiae cells, adsorbed on sintered glass, and a continuous production of citric acid with Aspergillus niger, entrapped in calcium alginate, are given as examples of the production of primary metabolites. The production of ergot alkaloids with entrapped Claviceps purpurea demonstrates the possibilities of production of secondary metabolites. The continuous degradation of phenolic substances and that of 4-chlorophenol by entrapped and adsorbed microorganisms are given as examples of the possibility of a continuous degradation of xenobiotics by immobilized microorganisms. The continuous degradation of these substances was successful not only in artificial solutions but also in sterile and nonsterile wastewater.

Aspergillus niger↗

PubMedDate not supplied

Halogenated phenols in water at forty Canadian potable water treatment facilities.

Samples of raw and treated water were collected once in each of 3 seasons at 40 potable water treatment plants across Canada and were analyzed for phenol and 33 halogenated phenolic compounds including chlorophenols, bromophenols, bromochlorophenols, and chloroguaiacols. Eighteen of the compounds were not found at any treatment plant; phenol and each of the remaining halogenated phenols were found in at least 1 sample. Pentachlorophenol was the only halogenated phenolic compound found in more than 20% of the raw water samples in the fall and winter samples at levels up to 53 ng/L with mean values of 1.9 and 2.8 ng/L, respectively. No halogenated phenols were detected in raw water summer samples. The halogenated phenols found most frequently in treated water samples were 4-chloro-, 2,4-dichloro-, 2,4,6-trichloro-, and bromodichlorophenols. Mean values were less than 15 ng/L and maximum values seldom exceeded 100 ng/L. Most of the positive values for the treated water samples were found at 8 of the 40 treatment plants but no correlations could be found between halogenated phenol levels and raw water type, treatment process, or chemical dosages.

Canada↗

PubMedDate not supplied

[Hodgkin's disease and occupation].

In order to discuss the hypothesized existence of occupational risk factors in the etiology of Hodgkin's disease (HD), the available literature data are reviewed. The occupations most often considered to be at increased risk of the disease are woodworking, school teaching, hospital occupations and occupations entailing exposure to chemicals. The association between HD and employment in wood industry suggest that exposure to unknown occupational factors may play a role as etiologic agent in this disease. A number of chemical substances that are regularly used may be suspected as causative factors. There are many discrepancies among the results of the studies on the association between school teaching and HD. To date no certain conclusion may be drawn from the presented data. However it has been suggested that the reported excess risk for HD among teachers may be explicable by social class gradient for the disease. The existence of risk factors other than viral may explain the excess risk among physicians and nurses. Because of the characteristics of some highly reactive chemicals their etiologic role may not be underestimated. An association between HD and occupations entailing exposure to various chemicals (organic solvents, benzene, phenoxy acids, chlorophenols) was shown; however no definitive conclusion may be drawn. There are increasing findings that point out the importance of the association between some occupations and development of HD. In spite of the evidence of a link between exposure to various chemicals and HD, there is a clear need to evaluate dose-response relationship between specific type and amount of chemicals and the disease, in order to provide some of the answer we need about the etiology of HD.

Benzene↗

PubMed1981

Polychlorinated biphenyls and other organic chemical residues in fish from major United States watersheds near the Great Lakes, 1978.

Twenty-six composite samples of fish were collected during 1978 from United States watersheds near the Great Lakes and analyzed for polychlorinated biphenyls (PCBs) and related organic chemicals. PCB mixtures resembling Aroclor 1254 were found in all samples, and mixtures resembling Aroclor 1242 (or 1016) were found in 77 percent of the samples. Total PCB concentrations in the whole-fish composite samples ranged from 0.13 to 14.6 ppm; 65 percent of the samples contained more than 2 ppm PCBs. DDT and its metabolites were found in all samples. sigma DDT concentration was 1.66 ppm, and 81 percent of the samples contained less than 1.0 ppm sigma DDT. Chlordane ranged from less than 0.001 to 2.57 ppm in 38 percent of the samples. Hexachlorobenzene was found in 65 percent of the samples, ranging from less than 0.005 to 0.447 ppm. Other chemicals identified by gas chromatography/mass spectrometry included petroleum hydrocarbons and chlorobenzenes, chlorostyrenes, chlorophenols, and chlorinated aliphatic compounds. Fish from the Ashtabula River (Ohio), Rock River (Ohio), and Wabash River (Indiana) contained extremely complex residues of chlorinated and other organic chemicals.

Animals↗