Abstract  From a screening on agar plates with bis(benzoyloxyethyl) terephthalate (3PET), a Bacillus subtilis p-nitrobenzylesterase (BsEstB) was isolated and demonstrated to hydrolyze polyethyleneterephthalate (PET). PET-hydrolase active strains produced clearing zones and led to the release of the 3PET hydrolysis products terephthalic acid (TA), benzoic acid (BA), 2-hydroxyethyl benzoate (HEB), and mono-(2-hydroxyethyl) terephthalate (MHET) in 3PET supplemented liquid cultures. The 3PET-hydrolase was isolated from non-denaturating polyacrylamide gels using fluorescein diacetate (FDA) and identified as BsEstB by LC-MS/MS analysis. BsEstB was expressed in Escherichia coli with C-terminally fused StrepTag II for purification. The tagged enzyme had a molecular mass of 55.2 kDa and a specific activity of 77 U/mg on p-nitrophenyl acetate and 108 U/mg on p-nitrophenyl butyrate. BsEstB was most active at 40°C and pH 7.0 and stable for several days at pH 7.0 and 37°C while the half-life times decreased to 3 days at 40°C and only 6 h at 45°C. From 3PET, BsEstB released TA, MHET, and BA, but neither bis(2-hydroxyethyl) terephthalate (BHET) nor hydroxyethylbenzoate (HEB). The k(cat) values decreased with increasing complexity of the substrate from 6 and 8 (s-1) for p-nitrophenyl-acetate (4NPA) and p-nitrophenyl-butyrate (4NPB), respectively, to 0.14 (s-1) for bis(2-hydroxyethyl) terephthalate (BHET). The enzyme hydrolyzed PET films releasing TA and MHET with a concomitant decrease of the water-contact angle (WCA) from 68.2° ± 1.7° to 62.6° ± 1.1° due to formation of novel hydroxyl and carboxyl groups. These data correlated with a fluorescence emission intensity increase seen for the enzyme treated sample after derivatization with 2-(bromomethyl)naphthalene. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011.

Abstract  The reaction methyl naphthalene-2-sulfonate + Br(-) was investigated in several alkanediyl-α-ω-bis(dodecyldimethylammonium) bromide, 12-s-12,2Br(-) (with s = 2, 3, 4, 5, 6, 8, 10, 12), micellar solutions in the absence and in the presence of various additives. The additives were 1,2-propylene glycol, which remains in the bulk phase, N-decyl N-methylglucamide, MEGA10, which forms mixed micelles with the dimeric surfactants, and 1-butanol, which distributes between the aqueous and micellar phases. Information about the micellar reaction media was obtained by using conductivity and fluorescence measurements. In all cases, with the exception of water-1,2-prop 12-5-12,2Br(-) micellar solutions, with 30% weight percentage of the organic solvent, a sphere-to-rod transition takes place upon increasing surfactant concentration. In order to quantitatively explain the experimental data within the whole surfactant concentration range, a kinetic equation based on the pseudophase kinetic model was considered, together with the decrease in the micellar ionization degree accompanying micellar growth. However, theoretical predictions did not agree with the experimental kinetic data for surfactant concentrations above the morphological transition. An empirical kinetic equation was proposed in order to explain the data. It contains a parameter b which is assumed to account for the medium micellar kinetic effects caused by the morphological transition. The use of this empirical equation permits the quantitative rationalization of the kinetic micellar effects in the whole surfactant concentration range.

Abstract  Micellization and micellar growth of cationic dimeric surfactants of the alkanedyil-alpha,omega-bis(dimethyldodecylammonium) bromide type, 12-s-12,2Br(-) (s=3, 4, 6), in the presence of various amounts of 1-butanol, 1-pentanol, and 1-hexanol have been investigated. The influence of the nature and concentration of alcohol on the cmc, on the micellar ionization degree, on the average micellar aggregation number, and on the polarity of the micellar interfacial region was investigated by using conductivity and fluorescence measurements. Subsequently, effects of alcohol addition on the surfactant concentration range where sphere to rod transitions occur were examined and information about changes in the micropolarity and in the microviscosity accompanying the morphological transition was obtained. The experimental results were explained by considering the variations in the different contributions to the Gibbs energy of micellization caused by the presence of alcohols. The study of the reaction methyl naphthalene-2-sulfonate+Br(-) in some water-alcohol 12-6-12,2Br(-) micellar solutions provided information about the characteristics of the dimeric micelles as microreactors and show the complexity of the microheterogeneous systems studied.

Abstract  EIS: Epidemiology Information System

Abstract  BIOSIS COPYRIGHT: BIOL ABS. The ability of supercritical fluid extraction (SFE) to extract nitropolycyclic aromatic hydrocarbons (nitro-PAHs) from tea matrices is described and discussed. An experimental approach was set up to determine the influences of various extraction parameters, i.e. pressure, temperature, extraction time and addition of modifier. The evaluation of the method was carried out by analysing samples of fortified tea and then comparing the results with those obtained from conventional extraction procedures, such as Soxhlet extraction and ultrasonication. SFE proved to be far better than the conventional methods at monitoring levels of nitro-PAHs in tea. However, due to the wide range of polarity of the analytes investigated, selective extraction with supercritical carbon dioxide was not possible; hence, subsequent purification steps were necessary, prior to the final GC analyses. The nitro-PAHs and PAHs concentrations in several tea samples were determined, any correlation betwee

Abstract  Final rept. Oct-Nov 2002.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. By use of a two-phase liquid-liquid equilibrium model, the distribution of nonpolar solutes between water (polar phase) and soil organic matter (nonpolar phase) was related to principles of equilibrium chemistry. Batch equilibrium experiments were conducted with field-contaminated soils. Aqueous concentrations were measured directly, predicted through the use of organic cosolvents, and calculated from Raoult's law, thereby providing a three-way comparison of solute behavior in water. Results showed that composition of the nonpolar phase strongly influences the solute concentrations in the polar phase, suggesting that Raoult's law is applicable to complex mixtures. Tar-water partitioning experiments demonstrated that the distribution of solutes in complex mixtures is analogous to partitioning among multiple solvents.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM P AMINOBENZOIC ACID PHENYTOIN URACIL PHARMACEUTICALS POLYNUCLEAR AROMATIC HYDROCARBONS BIOMEDICAL INSTRUMENTATION

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM THERAPY

Abstract  B1 is able to grow on a wide variety of aromatic compounds including biphenyl, naphthalene, phenanthrene, toluene, m-, and p-xylene. In addition, the initial enzymes for degradation of biphenyl have the ability to metabolize a wide variety of different polycyclic aromatic hydrocarbons. The catabolic pathways for the degradation of both the monocyclic and polycyclic aromatic hydrocarbons are intertwined, joining together at the level of (methyl)benzoate and catechol. Both upper branches of the catabolic pathways are induced when S. yanoikuyae B1 is grown on either class of compound. An analysis of the genes involved in the degradation of these aromatic compounds reveals that at least six operons are involved. The genes are not arranged in discrete pathway units but are combined in groups with genes for the degradation of both classes of compounds in the same operon. Genes for multiple dioxygenases are present perhaps explaining the ability of S. yanoikuyae B1 to grow on a wide variety of aromatic compounds.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM CRASSOSTREA-VIRGINICA SHELL GROWTH ESTUARINE ENVIRONMENT

Abstract  Pollutants in aged field sediments seem to differ from spiked sediments in their chemical and biological availability. Biphasic desorption is often used as an explanation. In the present study, desorption kinetics and partitioning of chlorobenzenes (CBs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in long term field contaminated sediment cores and top layer sediment were measured by gas-purging. Desorption from sediment was deduced to be triphasic:  fast, slowly, and very slowly desorbing fractions were distinguished. In both the sediment core and the top layer sediment no detectable fast fractions were present for all the compounds studied, so these were estimated as upper limits from the desorption curves. This observation coincided with very high in situ distribution coefficients for several PCBs and PAHs:  10−1000 times higher than literature values for short contact time experiments. Rate constants were (3−8) × 10-3 h-1 for slow desorption and (0.16−0.5) × 10-3 h-1 for very slow desorption. In some cases only a very slowly desorbing fraction was detectable. Desorption from field contaminated sediments with extended contact times may not be readily estimated from laboratory experiments in which contaminants have contact times with the sediment in the order of weeks.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM PHALACROCORAX-AURITUS POLYCHLORINATED STYRENES POLYCHLORINATED BIPHENYLS DDE HYDROCARBONS ORGANOCHLORINES DIELDRIN HEXACHLOROBENZENE INSECTICIDE SEASONALITY BODY FAT

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM SOIL MICROORGANISM ACETOPHENONE BENZENE AMYL ACETATE 2 DECANONE 4-TERT BUTYLBENZOIC ACID HEXADECANE PHENOL ISOPENTYL ALCOHOL NAPHTHALENE N METHYLANILINE

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Aqueous association of several organic compounds to Aldrich humic acid (AHA) was determined by equilibrium dialysis or solubility enhancement. The effect of varying concentrations of AHA on chemical degradation was also determined in batch experiments. Atrazine and glucose mineralization was greater in the presence of AHA and the enhancement was attributed to enhanced cellular uptake. No AHA inhibition on naphthalene or quinoline biodegradation was observed.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM ARCTICA-ISLANDICA BIOACCUMULATION MARINE POLLUTION BENTHIC ENVIRONMENT OIL DRILLING GRAIN SIZE POLLUTANT DEPOSITION SPATIAL VARIATION DRILLING FLUID EXTRACT DISCHARGE RESIDUE

Abstract  BIOSIS COPYRIGHT: BIOL ABS. This study deals with the estimation of mutagenicity of soil samples that have been decontaminated by a mixture of specific bacterial cultures degrading enzymatically foreign polycyclic organic substances which decompose with difficulty by natural processes. Mutagenicity was estimated by means of bacterial detection systems of Salmonella typhimurium His- and the SOS chromotest in variants with and without metabolic activation vitro using the liver fraction S9. The detection of mutagenicity was c nic activity: they testified to the chemical processes taking place in the soil. The obtained results show that bacterial detection systems can be used when the course and effectiveness of biodegradation processes of decontamination are considered.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. A numerical model was developed to describe the bioremediation of hydrocarbons in ground water aquifers considering aerobic degradation. The model solves the independent transport of three solutes (oxygen, hydrocarbons, and microorganisms) in ground water flow using the method of characteristics. Interactions between the three solutes, in which oxygen and hydrocarbons are consumed by microorganisms, are represented by Monod kinetics, solved using a Runge-Kutta method. Model simulations showed good correlation as compared with results of soil column experiments. The model was used to estimate the time needed to remediate the columns, which varied from one to two years.

Abstract  1. The accumulation of aromatic hydrocarbons (AHs) and polychlorinated biphenyls (PCBs) kv English sole (Parophrys vetulus) exposed for up to 108 days to an urban (test) sediment was compared to that for English sole exposed to sediment from a reference area. The concentrations of identified AHs and PCBs in the test sediment were 32 μg/g dry weight and 2·2 μg/g dry weight, respectively. English sole exposed to test and reference sediments for 108 days had biliary concentrations of aromatic compounds fluorescing at BaP wavelengths of 0·6 μg/g, wet weight and hepatic concentrations of PCBs of 1·4 ± 0·6 μg/g wet weight which were ten and eight times, respectively, as great as those in reference sole. These results show that accumulation of AHs and PCBs from sediment by English sole is a significant route of uptake in contaminated environments. 2. 3H-benzo(a)pyrene (BaP) and 14C-PCBs were added to the test sediment to compare the uptake and metabolism of BaP to that of PCBs by sole. Steady-state concentrations of 3H-BaP and 14C-PCBs in tissues and fluids were reached by 4 days and 14 days, respectively. At steady state, the level of covalent binding of 3H-BaP to hepatic proteins in test sole was six times greater than that of 14C-PCBs, and there was significantly greater relative formation of BaP-glutathione (GSH) conjugates than PCB-GSH conjugates. Thus, the amount of BaP metabolized to reactive metabolites was greater than that for PCBs, even though the concentration of 14C-PCBs in liver of test sole was five times as great as that of 3H-BaP. 3. Trace amounts of 3H-BaP were also added to the reference sediment to determine how simultaneous exposure of English sole to those contaminants already present in the test sediment affected the metabolism and disposition of BaP. The 3H-BaP concentration ratios for liver to sediment and bile to sediment, as well as proportions of biliary BaP-GSH conjugates in test sole, were significantly greater than in reference sole. Thus, the formation and accumulation of potentially toxic metabolites of a carcinogenic AH (BaP) in sole liver were increased by simultaneous exposure to contaminants present in an urban sediment.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM AROMATIC HYDROCARBONS AROMATIC AMINES PHENOLS THRESHOLD LIMIT VALUE AIR POLLUTION HAZARDOUS MATERIALS ENVIRONMENTAL SURVEILLANCE

Abstract  Baleen whale forestomach anaerobic microbes were studied for their ability to detoxify recalcitrant environmental pollutants; these include components of crude oil and some chlorinated aromatic compounds which are constituents of oil spills not biodegraded by aerobic microbes. In this study, forestomach rumen samples were collected on two occasions on the North Slope. When incubated with anthracene and naphthalene (PAH), these pollutants were degraded in the majority of sample sets. All simple aromatic hydrocarbons (benzine, toluene, xylenes, ethylbenzene) were degraded. PCBs were biodegraded by microbes from only two of the whales. Variable results were found with picric acid, trinitrotoluene (TNT), and atrazine, and were likely due to analytical difficulties. Whale forestomach bacteria have adapted to an ecological niche where flow rates, mixing, and catabolism occur at rapid rates. These rates and the ability to metabolize complex molecules far exceed those of aerobic sediment and soil bacteria in biodegradation of environmental pollutants.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Small exothermic or even endothermic heats of sorption for organic compounds in soft organic matter (SOM) have been traditionally considered evidence for a partitioning mechanism into the bulk of SOM. This derives from considerations of solute transfer enthalpy (DELTAHtr) from aqueous solution to organic solvent and partial molar enthalpies of solution in organic solvent (DELTAHsols) and aqueous (-DELTAHsolw) phases, where DELTAHtr = DELTAHsols - DELTAHsolw. The dissolution of many solutes in organic solvents is accompanied by positive solution enthalpies and conforms to the condition DELTAHtr -DELTAHsolw. It was suggested by analogy of SOM to organic solvents, that solute sorption enthalpies (DELTAHi) in SOM that conform to the analogous condition (i.e., DELTAHi -deltaHsolw) are consistent with partitioning into SOM. Systems that do not conform to this condition (i.e., DELTAHi -DELTAHsolw) were considered to be consistent with adsorption. The purpose of

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM MICROBIAL ECOLOGY DNA GENETIC ENGINEERING

Abstract  The purposes of this project were to evaluate whether indigenous microorganisms from polycyclic aromatic hydrocarbons (PAH)-contaminated soils produce surfactants (biosurfactants) as a means of enhancing the bioavailability of PAH; to improve the understanding of the general physiology of a diverse group of PAH-degrading bacteria; and to study in general how surfactants influence the biodegradation of hydrophobic chemicals.