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Sample records for biodegradation du 2-ethylhexyl

  1. Biodegradation and bioavailability of bis(2-ethylhexyl)phthalate in soil

    SciTech Connect

    Fogel, S.; Findlay, M.; Scholl, C.; Warminsky, M.

    1995-12-31

    The feasibility of biologically treating process chemicals in soil at a plasticizer manufacturing site containing bis(2-ethylhexyl)phthalate, bis(2-ethylhexyl)adipate, di-n-octylphthalate, and naphthalene was investigated. It was found that direct biological treatment of site soil was not feasible because part of the contamination existed as insoluble crystalline still-bottom material ranging in size from < 1 mm to several cm. Bench-scale soil biodegradation studies indicated that spiked phthalates and naphthalene could be biodegraded in site soil, but that only portions of the soil contaminant phthalates and naphthalene were bioavailable.

  2. Biodegradation of di(2-ethylhexyl)phthalate in a typical tropical soil.

    PubMed

    Carrara, Silvia Marta Castelo de Moura; Morita, Dione Mari; Boscov, Maria Eugenia Gimenez

    2011-12-15

    The aim of this research was to evaluate the possibility of biodegradation of di(2-ethylhexyl)phthalate (DEHP), widely used as an industrial plasticizer and considered an endocrine-disrupting chemical included in the U.S. Environmental Protection Agency priority list, in a Brazilian tropical soil, which has not been previously reported in the literature, despite the geographic importance of tropical soils. Preliminary laboratory testing comprised respirometric, air and water permeability, and pilot scale infiltration tests. Standard respirometric tests were found inadequate for studying biodegradation in tropical contaminated soils, due to the effect of the addition of significant amounts of calcium carbonate, necessary to adjust soil pH. Pilot scale infiltration tests performed for 5 months indicated that DEHP was retained in the superficial layer of the soil, barely migrating downwards, whereas air and water permeability tests discarded in situ bioremediation. However, ex situ bioremediation was possible, using a slurry-phase reactor with acclimated microorganisms, in pilot scale tests conducted to remediate a total mass of 150 kg of contaminated soil with 100 mg DEHP/kg. The removal of DEHP in the slurry-phase reactor achieved the percentage of 99% in 49 days, with biodegradation following a first-order kinetic model with a biodegradation coefficient of 0.127 day(-1).

  3. Di(2-ethylhexyl) phthalate biodegradation and denitrification by a Pseudoxanthomonas sp. strain.

    PubMed

    Meng, Xuezheng; Niu, Guilong; Yang, Weiming; Cao, Xiangsheng

    2015-03-01

    A bacterial strain (designated as N4) of Pseudoxanthomonas was isolated from a denitrification biofilter reactor. This study examined its degradation capability of di(2-ethylhexyl) phthalate (DEHP) and its denitrification ability. All results showed that, strain N4 could use DEHP as a carbon and energy source. Strain N4 demonstrated good DEHP degradation ability over a broad pH and temperature range. The optimal temperature and pH for DEHP degradation were 32°C and 6.0, respectively. The kinetics of DEHP degradation by strain N4 were exponential in nature. Strain N4 showed denitrification ability and could reduce nitrate and nitrite but not with DEHP as its carbon source.

  4. Biodegradation of 2-Ethylhexyl Nitrate by Mycobacterium austroafricanum IFP 2173▿

    PubMed Central

    Nicolau, Elodie; Kerhoas, Lucien; Lettere, Martine; Jouanneau, Yves; Marchal, Rémy

    2008-01-01

    2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel that is used to increase the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected from among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous-phase liquid, suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation, as well as organic-carbon measurement, indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by gas chromatography/mass spectrometry and was provisionally identified as 4-ethyldihydrofuran-2(3H)-one by liquid chromatography-tandem mass spectrometry analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolized further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability. PMID:18723659

  5. Di(2-ethylhexyl)adipate

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) adipate ; CASRN 103 - 23 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  6. Di (2-ethylhexyl)phthalate (DEHP)

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) phthalate ( DEHP ) ; CASRN 117 - 81 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  7. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  8. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  9. Bioremediation of di(2-ethylhexyl)phthalate in contaminated soil

    SciTech Connect

    Yu, J.J.; Ward, O.P.

    1995-12-31

    An efficient process has been developed for bioremediation of di(2-ethylhexyl) phthalate (DEHP) using soil tilling. The process involves application of a proprietary nutrient formulation and bioaugmentation with a site-specific DEHP-degrading inoculum. Laboratory feasibility studies were conducted to evaluate different factors that affect the process. The effects of moisture content, inoculum, nutrient rate, and initial DEHP concentration on biodegradation were investigated. A novel supplementary system--treatment system 2--was shown to accelerate DEHP degradation and facilitate remediation of residual persistent contaminant DEHP, which may be tightly bound to soil. In pilot studies, DEHP-contaminated soils were remediated to below 100 mg/kg in 70 to 80 days. Use of treatment system 2 resulted in reduction of contaminants to less than 15 mg/kg.

  10. Effects of 2-Ethylhexyl Nitrate on Diesel-Spray Processes

    SciTech Connect

    Higgins, B.; Mueller, C.; Siebers, D.

    1998-08-01

    Diesel fuel ignition-enhancing additives, such as 2-ethylhexyl nitrate, are known to reduce emissions from diesel engines; however, the mechanisms by which the emissions reduction occur are not understood. This report covers the first phase of a research project supported by Ethyl Corporation that is aimed at developing a detailed understanding of how 2-ethylhexyl nitrate alters in-cylinder injection, ignition, and combustion processes to reduce diesel engine emissions.

  11. Physical proprieties of low viscosity estolide 2-ethylhexyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acetic- and butyric-capped oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one-pot process from industrial 90% oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process ...

  12. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from...

  13. Estimation of human percutaneous uptake for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (TBB) and bis(2-ethylhexyl) tetrabromophthalate (TBPH) using the parallelogram method

    EPA Science Inventory

    2-ethylhexyl- tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromobenzoate (TBPH) are novel brominated flame retardants (FRs). TBPH is used as a plasticizer or with TBB in polyurethane foam FRs. TBB & TBPH have been detected in both indoor and outdoor environmental sampl...

  14. Biotransformation of di(2-ethylhexyl)phthalate by rainbow trout

    SciTech Connect

    Barron, M.G.; Hayton, W.L.

    1995-05-01

    The biotransformation of di(2-ethylhexyl)phthalate (DEHP) was studied in rainbow trout (Oncorhynchus mykiss) following intravascular administration. Methyl-esterified metabolites were identified using rodent-derived standards and non-linear gradient elution HPLC; metabolites were confirmed by gas chromatography. Similarities between the biotransformation of DEHP by rainbow trout and mammalian species included (a) mono-ethylhexyl phthalate (MEHP) appeared to be the obligatory first step in DEHP metabolism; (b) the phthalate ring was not oxidized; (c) phthalic acid was a minor metabolite; and (d) several metabolites contained multiple oxidations of the 2-ethylhexyl moiety of MEHP. No metabolites unique to rainbow trout were identified. However, fewer oxidized metabolites were identified in rainbow trout than in mammalian species, possibly due to limited mitochondrial metabolism of MEHP in rainbow trout. The amount of biliary MEHP glucuronide after intravascular administration of DEHP was substantially less than reported in rainbow trout exposed to DEHP via the water. Results confirmed that DEHP metabolism in rainbow trout proceeds by initial rapid formation of MEHP, followed by excretion or extensive oxidation by microsomal P450.

  15. Bis-(2-ethylhexyl) phthalate, an ubiquitous environmental contaminant

    SciTech Connect

    Griffiths, W.C.; Camara, P.; Lerner, K.S.

    1985-03-01

    Bis-(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizing agent for the widely used plastic polyvinylchloride (PVC). Consequently, this compound is found everywhere in the environment of civilization, where it is in frequent contact with every person. Blood storage bags and tubing, food wrappers, and many children's toys contain appreciable amounts of DEHP. Given this frequency of exposure, the toxic potential of the compound has become a major concern. Many workers have demonstrated its exceedingly low acute toxicity, while results from chronic exposure studies have been mixed. However, in 1982 the National Toxicology Program reported a significantly increased incidence of hepatocellular carcinoma in rats and mice exposed to high doses of DEHP over a period of two years. The significance of these studies remains in question. Bis-(2-ethylhexyl) phthalate is metabolized extensively by mammals, but reports of the direct study of the toxic effects of its metabolites are few. Efficient methods for analysis of biological samples for DEHP are available, but they are complicated by the constant presence of this compound as a contaminant.

  16. Effect of sterilization process on the formation of mono(2-ethylhexyl)phthalate from di(2-ethylhexyl)phthalate.

    PubMed

    Ito, Rie; Seshimo, Fumie; Miura, Naoko; Kawaguchi, Migaku; Saito, Koichi; Nakazawa, Hiroyuki

    2006-05-01

    The risk assessment of di(2-ethylhexyl)phthalate (DEHP) migrating from polyvinyl chloride (PVC) medical devices is an important issue. Many studies have been conducted to determine the level of DEHP migration. A recent report has indicated that DEHP in blood bags is hydrolyzed by esterase into mono(2-ethylhexyl)phthalate (MEHP). However, MEHP is thought to be even more toxic than the parent compound. Therefore, a method for the simultaneous determination of DEHP and MEHP was developed. The limits of quantification (LOQs) of DEHP and MEHP were 2.5 and 0.75 ng/ml, respectively. In this study, the effect of sterilization process on the levels of DEHP and MEHP migration was investigated. The level of migration of DEHP from gamma(gamma)-ray sterilized PVC sheet was low compared with that of the unsterilized control. By contrast, the level of MEHP migration from the gamma-ray sterilized PVC sheet was high compared with that of the unsterilized control. In addition, a high content of MEHP was found in the gamma-ray sterilized PVC sheet.

  17. Antiandrogenic effects in male rats perinatally exposed to a mixture of di(2-ethylhexyl) phthalate and di(2-ethylhexyl) adipate.

    PubMed

    Jarfelt, Kirsten; Dalgaard, Majken; Hass, Ulla; Borch, Julie; Jacobsen, Helene; Ladefoged, Ole

    2005-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a well-known testicular toxicant inducing adverse effects in androgen responsive tissues. Therefore, di(2-ethylhexyl) adipate (DEHA) is currently being evaluated as a potential substitute for DEHP. Similarities in structure and metabolism of DEHP and DEHA have led to the hypothesis that DEHA can modulate the effects of DEHP. Wistar rats were gavaged with either vehicle, DEHP (300 or 750mg/kg bw/day) or DEHP (750mg/kg bw/day) in combination with DEHA (400mg/kg bw/day) from gestation day (GD) 7 to postnatal day (PND) 17. Decreased anogenital distance (AGD) and retention of nipples in male offspring were found in all three exposed groups. Dosed males exhibited decreased weights of ventral prostate and m. levator ani/bulbocavernosus. Histopathological investigations revealed alterations in testis morphology in both juvenile and adult animals. The litter size was decreased and postnatal mortality was increased in the combination group only, which is likely a combined effect of DEHP and DEHA. However, no combination effect was seen with respect to antiandrogenic effects, as males receiving DEHP in combination with DEHA did not exhibit more pronounced effects in the reproductive system than males receiving DEHP alone. PMID:15749265

  18. Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro

    SciTech Connect

    Gupta, Rupesh K.; Singh, Jeffery M.; Leslie, Tracie C.; Meachum, Sharon; Flaws, Jodi A.; Yao, Humphrey H-C

    2010-01-15

    Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 mug/ml) and MEHP (0.1-10 mug/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin-dependant-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators.

  19. Critical cleaning agents for Di-2-ethylhexyl sebacate.

    SciTech Connect

    Hartley, Mya; Archuleta, Kim M.

    2013-08-01

    It is required that Di-2-ethylhexyl Sebacate oil, also commonly known as Dioctyl Sebacate oil, be thoroughly removed from certain metals, in this case stainless steel parts with narrow, enclosed spaces. Dioctyl Sebacate oil is a synthetic oil with a low compressibility. As such, it is ideally used for high pressure calibrations. The current method to remove the Dioctyl Sebacate from stainless steel parts with narrow, enclosed spaces is a labor-intensive, multi-step process, including a detergent clean, a deionized (DI) water rinse, and several solvent rinses, to achieve a nonvolatile residue of 0.04 mg per 50 mL rinse effluent. This study was undertaken to determine a superior detergent/solvent cleaning method for the oil to reduce cleaning time and/or the amount of detergent/solvent used. It was determined that while some detergent clean the oil off the metal better than the current procedure, using only solvents obtained the best result. In addition, it can be inferred, based on elevated temperature test results, that raising the temperature of the oil-contaminated stainless steel parts to approximately 50ÀC will provide for improved cleaning efficacy.

  20. Contemporary carbon content of bis (2-ethylhexyl) phthalate in butter.

    PubMed

    Tong, T; Ondov, J M; Buchholz, B A; VanDerveer, M C

    2016-01-01

    The fraction of naturally produced bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid-liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈ 250 μg extracts of DEHP with carbon purity ranging from 92.5 ± 1.2% (n = 3, 1σ) to 97.1 ± 0.8% (n = 3, 1σ) as measured with gas chromatography mass spectrometry (GC-MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16 ± 0.12 (n = 5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S.

  1. Di-(2-ethylhexyl) phthalate and autism spectrum disorders

    PubMed Central

    Testa, Chiara; Nuti, Francesca; Hayek, Joussef; De Felice, Claudio; Chelli, Mario; Rovero, Paolo; Latini, Giuseppe; Papini, Anna Maria

    2012-01-01

    ASDs (autism spectrum disorders) are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors) suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl) phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11±5 years) and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12±5 years) were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS), was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl) 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl) 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl) 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl) 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98%) taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18) and 5-oxo-MEHP (46.0%, median 0.096) urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (rs = 0.668, P<0.0001). The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for these

  2. Risk assessment of di(2-ethylhexyl) phthalate in the workplace

    PubMed Central

    2016-01-01

    Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor (“Survey on the work environment”) and by the Ministry of Environment (“Survey on the circulation amount of chemicals”). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be 0.990 mg/m3, as compared to the threshold exposure level of 5 mg/m3. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the

  3. Simultaneous determination of polyvinylchloride plasticizers di(2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate and its degradation products in blood by liquid chromatography-tandem mass spectrometry.

    PubMed

    Eckert, Elisabeth; Müller, Johannes; Göen, Thomas

    2015-09-01

    Di(2-ethylhexyl) phthalate (DEHP) and tri(2-ethylhexyl) trimellitate (TEHTM or TOTM) are common plasticizers that are also largely used for PVC medical devices, e.g. bags and tubing for blood transfusions and infusions. The leachability of medical devices is a well-known situation of increasing toxicological concern. To assess the migration of plasticizers from PVC medical devices into human blood we developed and validated an analytical method for the determination of DEHP and TOTM in combination with the determination of their primary degradation products mono(2-ethylhexyl) phthalate (MEHP), 1,2-di(2-ethylhexyl) trimellitate (1,2-DEHTM) and 2-mono(2-ethylhexyl) trimellitate (2-MEHTM). The presented method involves liquid-liquid extraction of the analytes from the blood followed by the subsequent analytical separation and detection using LC-MS/MS analysis. The validation of the procedure showed a good precision in the range of 1.8 to 5.3%. Mean accuracy ranged from 86% for 1,2-DEHTM to 109% for MEHP. LOQ was found to be 2 to 5μg/L for each of the analytes. Additionally, the method is characterised by its wide linear range up to 2mg/L each for the degradation products of TOTM to 100mg/L for the parent plasticizer DEHP. The presented method promises to be of major advantage for further studies as it allows for the first time the simultaneous determination of DEHP and TOTM in human blood in combination with the analysis of their degradation products that render possible to investigate the leachability of a broad range of PVC medical devices in human blood using only one analytical method.

  4. Toxicogenomic Screening of Replacements for Di(2-Ethylhexyl) Phthalate (DEHP) Using the Immortalized TM4 Sertoli Cell Line

    PubMed Central

    Nardelli, Thomas C.; Erythropel, Hanno C.; Robaire, Bernard

    2015-01-01

    Phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) are being phased out of many consumer products because of their endocrine disrupting properties and their ubiquitous presence in the environment. The concerns raised from the use of phthalates have prompted consumers, government, and industry to find alternative plasticizers that are safe, biodegradable, and have the versatility for multiple commercial applications. We examined the toxicogenomic profile of mono(2-ethylhexyl) phthalate (MEHP, the active metabolite of DEHP), the commercial plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and three recently proposed plasticizers: 1,4-butanediol dibenzoate (BDB), dioctyl succinate (DOS), and dioctyl maleate (DOM), using the immortalized TM4 Sertoli cell line. Results of gene expression studies revealed that DOS and BDB clustered with control samples while MEHP, DINCH and DOM were distributed far away from the control-DOS-BDB cluster, as determined by principle component analysis. While no significant changes in gene expression were found after treatment with BDB and DOS, treatment with MEHP, DINCH and DOM resulted in many differentially expressed genes. MEHP upregulated genes downstream of PPAR and targeted pathways of cholesterol biosynthesis without modulating the expression of PPAR’s themselves. DOM upregulated genes involved in glutathione stress response, DNA repair, and cholesterol biosynthesis. Treatment with DINCH resulted in altered expression of a large number of genes involved in major signal transduction pathways including ERK/MAPK and Rho signalling. These data suggest DOS and BDB may be safer alternatives to DEHP/MEHP than DOM or the commercial alternative DINCH. PMID:26445464

  5. Extraction kinetics of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester using a hollow fiber membrane extractor

    SciTech Connect

    Kubota, Fukiko; Goto, Masahiro; Nakashio, Fumiyuki; Hano, Tadashi

    1995-03-01

    A kinetic study concerning chemical complexation-based solvent extraction of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester dissolved as an extractant in n-heptane was carried out using a microporous hydrophobic hollow fiber membrane extractor. The effects of concentration of chemical species in aqueous and organic feed solutions on the apparent permeabilities of metal species for extraction and stripping, respectively, were investigated to clarify the permeation mechanism. From the experimental results it was predicted that the permeation rate is controlled by diffusion of the chemical species in aqueous and organic phases and by interfacial chemical reaction. The experimental data were analyzed by the diffusion model accompanied with an interfacial reaction, taking into account the velocity distributions of the aqueous and organic phases through the inner and outer sides of the hollow fiber.

  6. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and enviro...

  7. Dose Reconstruction of Di-2-Ethylhexyl Phthalate Using a Simple Pharmacokinetic Model [Manuscript

    EPA Science Inventory

    Background In 2005, eight adults provided full volumes and times of urine voids during one normal work week. These samples were analyzed for four di-2-ethylhexyl phthalate (DEHP) metabolites. Participants also provided diary information on their diet, driving, and out¬door a...

  8. VITELLOGENIN GENE EXPRESSION IN MALE FATHEAD MINNOWS EXPOSED TO DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used extensively in the plastics industry. DEHP has been shown to be ubiquitous in the environment and has been detected in ground and surface waters, sediment sludge and at several Superfund sites. Previous studies using rats ...

  9. Endoplasmic reticulum stress as a novel cellular response to di (2-ethylhexyl) phthalate exposure.

    PubMed

    Peropadre, Ana; Fernández Freire, Paloma; Pérez Martín, José Manuel; Herrero, Óscar; Hazen, María José

    2015-12-25

    Di (2-ethylhexyl) phthalate is a high-production chemical widely used as a plasticizer for polyvinyl chloride products. Due to its ubiquitous presence in environmental compartments and the constant exposure of the general population through ingestion, inhalation, and dermal absorption, this compound has been subjected to extensive in vivo and in vitro toxicological studies. Despite the available information, research on the cytotoxicity of di (2-ethylhexyl) phthalate in mammalian cells is relatively limited.In this paper, an in vitro multi-parametric approach was used to provide further mechanistic data on the toxic activity of this chemical in Vero and HaCaT cells. Our results reveal that a 24 h exposure to di (2-ethylhexyl) phthalate causes, in both cell lines, an inhibition of cell proliferation that was linked to cell cycle delay at the G1 phase. Concomitantly, the tested compound induces mild endoplasmic reticulum stress which leads to an adaptive rather than a pro-apoptotic response in mammalian cells. These findings demonstrate that there are multiple potential cellular targets of di (2-ethylhexyl) phthalate-induced toxicity and the need to develop further experimental studies for the risk assessment of this ubiquitous plasticizer.

  10. MODULATION OF RAT LEYDIG CELL STEROIDOGENIC FUNCTION BY DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate.

    Akingbemi BT, Youker RT, Sottas CM, Ge R, Katz E, Klinefelter GR, Zirkin BR, Hardy MP.

    Center for Biomedical Research, Population Council, New York, New York 10021, USA. benson@popcbr...

  11. Distribution of di(2-ethylhexyl) phthalate and products in blood and blood components.

    PubMed Central

    Rock, G; Labow, R S; Tocchi, M

    1986-01-01

    In order to impart flexibility, plastic medical devices incorporate liquid plasticizers into their structure. Data from several laboratories, including ours, have shown that these compounds leach from blood bags and tubing during collection of blood, storage of various blood components and during kidney dialysis and cell and plasma apheresis procedures. After the plasticizer di(2-ethylhexyl) phthalate leaches from poly(vinyl chloride) blood packs, it is converted by a plasma enzyme to a more toxic metabolite, mono(2-ethylhexyl) phthalate. Blood fractionation products from outdated plasma contain mono(2-ethylhexyl) phthalate, the highest level being found in normal serum albumin. Recently, we have reported that di(2-ethylhexyl) phthalate actually binds to the red blood cell membrane and reduces its osmotic fragility. Current methods of red cells storage, which permit utilization up to 35 days after collection, are not possible without this membrane stabilization. Platelets are now stored for 5 days in the Fenwal PL 732 polyolefin bag. Although stated to be essentially free of liquid plasticizers, a significant level of leaching from this bag into the extracts of stored platelet concentrates was observed. PMID:3709456

  12. Endoplasmic reticulum stress as a novel cellular response to di (2-ethylhexyl) phthalate exposure.

    PubMed

    Peropadre, Ana; Fernández Freire, Paloma; Pérez Martín, José Manuel; Herrero, Óscar; Hazen, María José

    2015-12-25

    Di (2-ethylhexyl) phthalate is a high-production chemical widely used as a plasticizer for polyvinyl chloride products. Due to its ubiquitous presence in environmental compartments and the constant exposure of the general population through ingestion, inhalation, and dermal absorption, this compound has been subjected to extensive in vivo and in vitro toxicological studies. Despite the available information, research on the cytotoxicity of di (2-ethylhexyl) phthalate in mammalian cells is relatively limited.In this paper, an in vitro multi-parametric approach was used to provide further mechanistic data on the toxic activity of this chemical in Vero and HaCaT cells. Our results reveal that a 24 h exposure to di (2-ethylhexyl) phthalate causes, in both cell lines, an inhibition of cell proliferation that was linked to cell cycle delay at the G1 phase. Concomitantly, the tested compound induces mild endoplasmic reticulum stress which leads to an adaptive rather than a pro-apoptotic response in mammalian cells. These findings demonstrate that there are multiple potential cellular targets of di (2-ethylhexyl) phthalate-induced toxicity and the need to develop further experimental studies for the risk assessment of this ubiquitous plasticizer. PMID:26514933

  13. PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    Nigel Noriega, Jonathan Furr, Christy Lambright, Vickie Wilson, L. Earl Gray Jr.

    The plasticizer Di (2-ethylhexyl) phtha...

  14. Plant uptake and enhanced dissipation of di(2-ethylhexyl) phthalate (DEHP) in spiked soils by different plant species.

    PubMed

    Li, Yan-Wen; Cai, Quan-Ying; Mo, Ce-Hui; Zeng, Qiao-Yun; Lü, Huixiong; Li, Qu-Sheng; Xu, Guo-Sheng

    2014-01-01

    This study was conducted to investigate the uptake, accumulation and the enhanced dissipation of di(2-ethylhexyl) phthalate (DEHP) spiked in soil (with a concentration of 117.4 +/- 5.2 mg kg(-1)) by eleven plants including eight maize (Zea mays) cultivars and three forage species (alfalfa, ryegrass and teosinte). The results showed that, after 40 days of treatment, the removal rates of DEHP ranged from 66.8% (for the control) to 87.5% (for the maize cultivar of Huanong-1). Higher removal rate was observed during the first 10 days than the following days. Plants enhanced significantly the dissipation of DEHP in soil. Enhanced dissipation amount in planted soil was 13.3-122 mg pot(-1) for DEHP, and a net removal of 2.2%-20.7% of the initial DEHP was obtained compared with non-plant soil. The contribution of plant uptake to the total enhanced dissipation was < 0.3%, and the enhanced dissipation of soil DEHP might be derived from plant-promoted biodegradation and sorption stronger to the soil. Nevertheless, the capability in accumulation and enhanced dissipation of DEHP from spiked soils varied within different species and cultivars.

  15. Comparison of hepatic peroxisome proliferative effect and its implication for hepatocarcinogenicity of phthalate esters, di(2-ethylhexyl) phthalate, and di(2-ethylhexyl) adipate with a hypolipidemic drug.

    PubMed Central

    Reddy, J K; Reddy, M K; Usman, M I; Lalwani, N D; Rao, M S

    1986-01-01

    Peroxisome proliferation is inducible in hepatocytes of rodent and nonrodent species by structurally dissimilar hypolipidemic drugs and certain phthalate ester plasticizers. The induction of peroxisome proliferation appears to be a tissue specific response limited largely to the hepatocyte. Peroxisome proliferation is associated with increases in the activity of the H2O2-generating peroxisomal fatty acid beta-oxidation system and in the amount of peroxisome proliferation-associated 80,000 MW polypeptide (PPA-80). Chronic administration of these non-DNA damaging and nonmutagenic peroxisome proliferators to rats and mice results in the development of hepatocellular carcinomas. Comparative morphometric and biochemical data from rats treated with varying dose levels of ciprofibrate, a hypolipidemic drug, and di(2-ethylhexyl) phthalate, and di(2-ethylhexyl) adipate, the widely used plasticizers, indicate that the hepatocarcinogenic potency of these agents is correlatable with their ability to induce peroxisome proliferation, peroxisomal beta-oxidation and PPA-80. Available evidence strongly favors the role of peroxisome proliferation-associated oxidative stress in the induction of liver tumors by peroxisome proliferators. Images FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 7. FIGURE 10. A FIGURE 10. B PMID:3709457

  16. Mechanism of tetrabutyl titanate catalysis of the esterification of mono-2-ethylhexyl phthalate

    SciTech Connect

    Siling, M.I.; Kharrasova, A.N.; Kuznetsov, V.V.; Nosovskii, Y.E.; Osintseva, S.A.

    1986-07-01

    On the basis of the literature and experimental data on the influence of the composition of the medium on the rate of esterification of mono-2-ethylhexyl phthalate by 2-ethylhexanol in the presence of a tetraalkyltitanium catalyst, a mechanism of catalysis was proposed, considering the effects of coordination and the formation of hydrogen bonds. The kinetic equation derived, corresponding to the proposed mechanism, describes the literature and experimental data on the kinetics of esterification within a wide range of variation of the reagent concentrations.

  17. Uptake of di-(2-ethylhexyl) phthalate of vegetables from plastic film greenhouses.

    PubMed

    Fu, Xiaowei; Du, Qizhen

    2011-11-01

    Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination.

  18. Uptake of di-(2-ethylhexyl) phthalate of vegetables from plastic film greenhouses.

    PubMed

    Fu, Xiaowei; Du, Qizhen

    2011-11-01

    Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination. PMID:21958198

  19. Inhibition of human platelet phospholipase A/sub 2/ by mono(2-ethylhexyl)phthalate

    SciTech Connect

    Labow, R.S.; Meek, E.; Adams, G.A.; Rock, G.

    1988-06-01

    There is evidence that the carcinogenic and teratogenic effects attributed to the plasticizer di(2-ethylhexyl)phthalate (DEHP) are due to its major metabolite mono(2-ethylhexyl)phthalate (MEHP). MEHP is also formed ex vivo by a plasma enzyme in blood products stored in polyvinyl chloride (PVC) DEHP plastic containers. People who receive large amounts of blood products, such as hemophiliacs or patients undergoing hemodialysis, cardiopulmonary bypass, or massive transfusion, are exposed to significant levels of plasticizer. In this study, the platelet was used to show that MEHP inhibits phospholipase A/sub 2/ (PLA/sub 2/), one of the enzymes important in the release of arachidonic acid from membrane phospholipids. PLA/sub 2/ was measured by the liberation of /sup 14/C-arachidonic acid from 1-stearoyl-2-(1-/sup 14/C)arachidonyl-L-3-phosphatidylcholine. MEHP inhibits PLA/sub 2/ activity noncompetitively in intact human platelets and lysates with a K/sub i/ of 3.7 x 10/sup -4/ M. DEHP does not inhibit PLA/sub 2/ in whole platelets. Inhibition of PLA/sub 2/ by MEHP occurs at only three times the circulating level of MEHP measured in neonates undergoing exchange transfusion and 20-fold the levels experienced by patients during cardiopulmonary bypass. Therefore, infants and adult patients with multisystem failure who accumulate MEHP in their blood may be at risk for decreased platelet function.

  20. Effects of maternal exposure to di(2-ethylhexyl)phthalate (DEHP) during pregnancy on susceptibility to neonatal asthma

    SciTech Connect

    Shin, In-Sik; Lee, Mee-Young; Cho, Eun-Sang; Choi, Eun-young; Son, Hwa-Young; Lee, Kyoung-Youl

    2014-02-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and is widely dispersed in the environment. In this study, we investigated the effects of maternal exposure to DEHP during pregnancy on neonatal asthma susceptibility using a murine model of asthma induced by ovalbumin (OVA). Pregnant BALB/c mice received DEHP from gestation day 13 to lactation day 21. Their offspring were sensitized on postnatal days (PNDs) 9 and 15 by intraperitoneal injection of 0.5 μg OVA with 200 μg aluminum hydroxide. On PNDs 22, 23 and 24, live pups received an airway challenge of OVA for 30 min. Offspring from pregnant mice that received DEHP showed reductions in inflammatory cell count, interleukin (IL)-4, IL-13, and eotaxin in their bronchoalveolar lavage fluid and in total immunoglobulin E and OVA-specific IgE in their plasma compared with offspring from pregnant mice that did not receive DEHP treatment. These results were consistent with histological analysis and immunoblotting. Maternal exposure to DEHP reduces airway inflammation and mucus production in offspring, with a decrease in inducible nitric oxide synthase (iNOS) in the lung tissue. This study suggests that maternal exposure to DEHP during pregnancy reduces asthmatic responses induced by OVA challenge in offspring. These effects were considered to be closely related to the suppression of Th2 immune responses and iNOS expression. - Highlights: • Maternal exposure to di(2-ethylhexyl)phthalate reduces asthmatic response in pups. • Di(2-ethylhexyl)phthalate reduces eosinophilia induced by ovalbumin exposure. • Di(2-ethylhexyl)phthalate reduces T-helper type 2 cytokine production. • Di(2-ethylhexyl)phthalate attenuates airway inflammation and mucus production. • Di(2-ethylhexyl)phthalate suppresses inducible nitric oxide synthase in lung tissue.

  1. Comparison of the release behaviors of di (2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate from the polyvinyl-chloride infusion set into pharmaceutical solutions.

    PubMed

    Zhang, Hong; Yang, Fengmin; Shen, Gang; Yang, Yueyang; Tang, Yalin

    2015-05-01

    Polyvinyl-chloride (PVC) with plasticizers of di(2-ethylhexyl) phthalate (DEHP) and tris(2-ethyl- hexyl) trimellitate (TOTM) is widely used in medical and paramedical appliances. However, such plasticizers can leach from PVC products into contact solutions. The aim of this study is to investigate the release behaviors of DEHP and TOTM from the PVC intravenous infusion set into various pharmaceutical solutions under the simulated clinical conditions, such as the lipophilic substances (paclitaxel) , parenteral nutrition (fat emulsion injection) , acid and alkali pharmaceutical solution (levofloxacin hydrochloride injection, pH 3.0-5.0 and furosemide, pH 8.0-9.0). A simple and rapid high-performance liquid chromatographic method with UV detection (HPLC-UV) for the determination of DEHP or TOTM released from PVC medical devices into the above intravenous preparations was developed. The cumulative amounts of DEHP or TOTM released in 24 h were in the same following order: paclitaxel > fat emulsion injection levofloxacin hydrochloride > furosemide solution. From a comparison of the cumulative amounts of released DEHP and TOTM from the above solutions, we found that the cumulative amount of TOTM is far less than that of DEHP, under the same conditions. The cumulative amount of the DEHP released in 24 h in the paclitaxel solution was 21. 14 mg, while under the same conditions, the cumulative amount of TOTM was only 0. 078 mg. The cumulative amount of DEHP is assumed to be about 270 times that of the released TOTM. Thus TOTM could be a superior alternative to DEHP for use in medical devices because of its potential lower leachability.

  2. N-(2-Ethylhexyl)carbazole: A New Fluorophore Highly Suitable as a Monomolecular Liquid Scintillator.

    PubMed

    Montbarbon, Eva; Sguerra, Fabien; Bertrand, Guillaume H V; Magnier, Élodie; Coulon, Romain; Pansu, Robert B; Hamel, Matthieu

    2016-08-16

    The synthesis, photophysical properties, and applications in scintillation counting of N-(2-ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC-501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1-methylnaphthalene (1-MeNapht), and 4-isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC-501 A. PMID:27406840

  3. Antitumour evaluation of di-(2-ethylhexyl) phthalate (DEHP) isolated from Calotropis gigantea L. flower.

    PubMed

    Habib, Muhammad Rowshanul; Karim, Muhammad Rezaul

    2012-12-01

    The objective of the study is to explore the anticancer activity of di-(2-ethylhexyl) phthalate (DEHP) isolated from Calotropis gigantea flower against Ehrlich ascites carcinoma cells (EAC) in Swiss albino mice. The activity of DEHP was evaluated at doses of 10, 20 and 40 mg kg-1 body mass applied intraperitoneally. DEHP showed a significant decrease in viable cell count (p < 0.05), mass gain (due to tumour burden) and elevated the life span of EAC cell bearing mice. Altered hematological profiles such as RBC, hemoglobin, WBC and differential count were reverted to normal levels in DEHP-treated mice. DEHP also brought back altered biochemical parameters (glucose, cholesterol, triglycerides, blood urea, SALP and SGOT) to normal level. Results of this study indicate that DEHP show potent dose dependent antitumour activity against EAC in vivo.

  4. An Advanced TALSPEAK Concept Using 2-Ethylhexylphosphonic Acid Mono-2-Ethylhexyl Ester as the Extractant

    SciTech Connect

    Lumetta, Gregg J.; Casella, Amanda J.; Rapko, Brian M.; Levitskaia, Tatiana G.; Pence, Natasha K.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-12-21

    A method for separating the trivalent actinides and lanthanides is being developed using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) as the extractant. The method is based on the preferential binding of the actinides in the aqueous phase by N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), which serves to keep the actinides in the aqueous phase while the lanthanides are extracted into an organic phase containing HEH[EHP]. The process is very robust, showing little dependence upon the pH or the HEH[EHP], HEDTA, and citrate concentrations over the ranges that might be expected in a nuclear fuel recycling plant. Single-stage runs with a 2-cm centrifugal contactor indicate that modifications to the process chemistry may be needed to increase the extraction rate for Sm, Eu, and Gd. The hydraulic properties of the system are favorable to application in centrifugal contactors.

  5. Biochar reduces the bioavailability of di-(2-ethylhexyl) phthalate in soil.

    PubMed

    He, Lizhi; Fan, Shiliang; Müller, Karin; Hu, Guotao; Huang, Huagang; Zhang, Xiaokai; Lin, Xiaoming; Che, Lei; Wang, Hailong

    2016-01-01

    A pot experiment was conducted to evaluate the effect of biochars on the bioavailability of di-(2-ethylhexyl) phthalate (DEHP) in two soils using Brassica chinensis L. as an indicator plant. The residual concentrations of DEHP tended to be higher in the biochar-amended soils than in the control soils. They were lower (p<0.05) in the high organic carbon content soil (HOC; 2.2%C) than in the low organic carbon content soil (LOC; 0.35%C). The DEHP concentrations in plant shoots grown in the HOC soils were lower than those in the LOC soils (p<0.05). Compared to the control, the biochar addition decreased the DEHP concentrations in shoots grown in the LOC soils; whereas there was no significant difference in the HOC soils. Our results showed that soil OC content as well as biochar properties are the key factors influencing the bioavailability of DEHP in soils.

  6. Effect of nanoparticle encapsulation on the photostability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

    PubMed

    Perugini, P; Simeoni, S; Scalia, S; Genta, I; Modena, T; Conti, B; Pavanetto, F

    2002-10-10

    The aim of this study was to investigate the influence of nanoparticle-based systems on the light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC). Ethylcellulose (EC) and poly-D,L-lactide-co-glycolide (PLGA) were used as biocompatible polymers for the preparation of the particulate systems. The "salting out" method was used for nanoparticle preparation and several variables were evaluated in order to optimize product characteristics. The photodegradation of the sunscreen agent in emulsion vehicles was reduced by encapsulation into the PLGA nanoparticles (the extent of degradation was 35.3% for the sunscreen-loaded nanoparticles compared to 52.3% for free trans-EHMC) whereas the EC nanoparticle system had no significant effect. Therefore, PLGA nanoparticles loaded with trans-EHMC improve the photostability of the sunscreen agent. PMID:12270607

  7. Prenatal exposure to di(2-ethylhexyl) phthalate impairs development of the mouse neocortex.

    PubMed

    Komada, Munekazu; Gendai, Yuuya; Kagawa, Nao; Nagao, Tetsuji

    2016-09-30

    Di(2-ethylhexyl) phthalate (DEHP) is currently the most commonly used phthalate for the production of flexible polyvinyl chloride. Phthalates including DEHP have been labeled as potential endocrine disruptors. The effect on the development of the neocortex, however, is unknown. To evaluate the neurodevelopmental effects of prenatal DEHP exposure at 1 and 100mg/kg/day or 100 and 500mg/kg/day in fetal and newborn mice, we performed a detailed histologic analysis of the developing dorsal telencephalon and neocortex. The observation of fetuses exposed to DEHP revealed reductions of proliferation and neurogenesis (1 and 100mg/kg) and an increase in cell death (500mg/kg). In addition, the newborns prenatally exposed to DEHP showed an abnormal neuronal distribution and a decrease in neurons. These findings suggest that prenatal DEHP exposure induces neurodevelopmental toxicity associated with the neural stem cell niche and corticogenesis. PMID:27472966

  8. The Adverse Cardiac Effects of Di(2-ethylhexyl) phthalate and Bisphenol A

    PubMed Central

    Posnack, Nikki Gillum

    2014-01-01

    The ubiquitous nature of plastics has raised concerns pertaining to continuous exposure to plastic polymers and human health risks. Of particular concern is the use of endocrine-disrupting chemicals (EDCs) in plastic production, including Di(2-ethylhexyl) phthalate (DEHP) and Bisphenol A (BPA). Widespread and continuous exposure to DEHP and BPA occurs through dietary intake, inhalation, dermal and intravenous exposure via consumer products and medical devices. This article reviews the literature examining the relationship between DEHP and BPA exposure and cardiac toxicity. In vitro and in vivo experimental reports are outlined, as well as epidemiological studies which examine the association between these chemicals and cardiovascular outcomes. Gaps in our current knowledge are also discussed, along with future investigative endeavors that may help resolve whether DEHP and/or BPA exposure has a negative impact on cardiovascular physiology. PMID:24811950

  9. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    SciTech Connect

    Tetz, Lauren M.; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D.; Loch-Caruso, Rita

    2013-04-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene

  10. Effect of mono-(2-ethylhexyl) phthalate on steroid production of human granulosa cells

    SciTech Connect

    Reinsberg, Jochen Wegener-Toper, Petra; Ven, Katrin van der; Ven, Hans van der; Klingmueller, Dietrich

    2009-08-15

    The phthalate ester mono-(2-ethylhexyl) phthalate (MEHP) is the active metabolite of di-(2-ethylhexyl) phthalate, a high-production-volume chemical used as a plasticizer and solvent in numerous consumer products. MEHP has been demonstrated to be a reproductive toxicant in rodents decreasing estradiol and progesterone production in preovulatory granulosa cells. In the present study, we examined the effect of MEHP on steroid production of human granulosa-lutein (GL) cells. Human GL cells collected from women undergoing in vitro fertilization were cultured in medium containing FSH, hCG and 8-Br-cAMP, respectively, together with various concentrations of MEHP (0-500 {mu}mol L{sup -1}). After incubation for 48 h estradiol and progesterone were assayed in the spent culture medium. Furthermore, aromatase activity and mRNA levels of GL cells were determined. Basal as well as FSH-, hCG- and 8-Br-cAMP-stimulated estradiol production of GL cells was suppressed by MEHP in a dose-dependent manner (IC{sub 50} = 105 {mu}mol L{sup -1}, 138 {mu}mol L{sup -1}, 49 {mu}mol L{sup -1} and 78 {mu}mol L{sup -1}). Furthermore aromatase activity and mRNA levels were reduced in GL cells cultured with MEHP. In contrast, MEHP did not alter the production of progesterone up to a concentration of 167 {mu}mol L{sup -1}. The present data indicate that MEHP is a specific inhibitor of estradiol production in human GL cells with a post-cAMP site of action. The inhibition of estradiol production obviously results from a reduction of aromatase activity on the transcript level. As the in vitro effective doses of MEHP are within the range of real environmental exposure levels an inhibitory effect on estrogen production in vivo seems to be possi0009b.

  11. Thyroid endocrine disruption in zebrafish larvae after exposure to mono-(2-ethylhexyl) phthalate (MEHP).

    PubMed

    Zhai, Wenhui; Huang, Zhigang; Chen, Li; Feng, Cong; Li, Bei; Li, Tanshi

    2014-01-01

    Phthalates are extensively used as plasticizers in a variety of daily-life products, resulting in widespread distribution in aquatic environments. However, limited information is available on the endocrine disrupting effects of phthalates in aquatic organisms. The aim of the present study was to examine whether exposure to mono-(2-ethylhexyl) phthalate (MEHP), the hydrolytic metabolite of di-(2-ethylhexyl) phthalate (DEHP) disrupts thyroid endocrine system in fish. In this study, zebrafish (Danio rerio) embryos were exposed to different concentrations of MEHP (1.6, 8, 40, and 200 μg/L) from 2 h post-fertilization (hpf) to 168 hpf. The whole-body content of thyroid hormone and transcription of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis were examined. Treatment with MEHP significantly decreased whole-body T4 contents and increased whole-body T3 contents, indicating thyroid endocrine disruption. The upregulation of genes related to thyroid hormone metabolism (Dio2 and UGT1ab) might be responsible for decreased T4 contents. Elevated gene transcription of Dio1 was also observed in this study, which might assist to degrade increased T3 contents. Exposure to MEHP also significantly induced transcription of genes involved in thyroid development (Nkx2.1 and Pax8) and thyroid hormone synthesis (TSHβ, NIS and TG). However, the genes encoding proteins involved in TH transport (transthyretin, TTR) was transcriptionally significantly down-regulated after exposure to MEHP. Overall, these results demonstrate that acute exposure to MEHP alters whole-body contents of thyroid hormones in zebrafish embryos/larvae and changes the transcription of genes involved in the HPT axis, thus exerting thyroid endocrine toxicity. PMID:24658602

  12. In utero exposure to di-(2-ethylhexyl)phthalate and duration of human pregnancy.

    PubMed Central

    Latini, Giuseppe; De Felice, Claudio; Presta, Giuseppe; Del Vecchio, Antonio; Paris, Irma; Ruggieri, Fabrizio; Mazzeo, Pietro

    2003-01-01

    Di-(2-ethylhexyl)phthalate (DEHP), the most commonly used plasticizer in flexible polyvinylchloride formulations, is a ubiquitous environmental contaminant. To date, no information exists on the potential health hazards from exposure to DEHP and/or its main metabolite, mono-(2-ethylhexyl)phthalate (MEHP), in high-risk conditions, such as pregnancy and during the neonatal period. The aim of this study was to evaluate prenatal exposure to DEHP and/or MEHP and its possible biologic effects. We measured serum DEHP and MEHP concentrations in the cord blood of 84 consecutive newborns by high-performance liquid chromatography. Relationships between DEHP/MEHP and infant characteristics were tested using Fisher's exact test, unpaired t-tests, and univariate linear regression analyses, and significant differences on univariate analysis were evaluated using multiple logistic regression analysis. We found detectable cord blood DEHP and/or MEHP concentrations in 88.1% of the samples. Either DEHP or MEHP was present in 65 of 84 (77.4%) of the examined samples. Mean concentrations of DEHP and MEHP were 1.19 +/- 1.15 microg/mL [95% confidence interval (CI), 0.93-1.44, range = 0-4.71] and 0.52 +/- 0.61 microg/mL (95% CI, 0.39-0.66, range = 0-2.94), respectively. MEHP-positive newborns showed a significantly lower gestational age compared with MEHP-negative infants (p = 0.033). Logistic regression analysis results indicated a positive correlation between absence of MEHP in cord blood and gestational age at delivery (odds ratio = 1.50, 95% CI, 1.013-2.21; p = 0.043). These findings confirm that human exposure to DEHP can begin in utero and suggest that phthalate exposure is significantly associated with a shorter pregnancy duration. PMID:14594632

  13. Mono-2-Ethylhexyl Phthalate Induces Oxidative Stress Responses in Human Placental Cells In Vitro

    PubMed Central

    Tetz, Lauren M; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D; Loch-Caruso, Rita

    2013-01-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. PMID:23360888

  14. In Vitro Metabolites of Di-2-ethylhexyl Adipate (DEHA) as Biomarkers of Exposure in Human Biomonitoring Applications

    PubMed Central

    Silva, Manori J.; Samandar, Ella; Ye, Xiaoyun; Calafat, Antonia M.

    2015-01-01

    Di-2-ethylhexyl adipate (DEHA) is a common plasticizer used in food packaging. At high doses, DEHA can cause adverse health effects in rats. Although the potential for human exposure to DEHA is high, no DEHA specific biomarkers are identified for human biomonitoring. Using human liver microsomes, we investigated the in vitro phase I metabolism of DEHA and its hydrolytic metabolite mono-2-ethylhexyl adipate (MEHA) and, for comparison purposes, of the analogous di-2-ethylhexyl phthalate (DEHP) and its hydrolytic metabolite mono-2-ethylhexyl phthalate. We unequivocally identified MEHA, a DEHA specific biomarker, and adipic acid, a nonspecific biomarker, using authentic standards. On the basis of their mass spectrometric fragmentation patterns, we tentatively identified two other DEHA specific metabolites: mono-2-ethylhydroxyhexyl adipate (MEHHA) and mono-2-ethyloxohexyl adipate (MEOHA), analogous to the oxidative metabolites of DEHP. Interestingly, although adipic acid was the major in vitro metabolite of DEHA, the analogous phthalic acid was not the major in vitro metabolite of DEHP. Our preliminary data for 144 adults with no known exposure to DEHA suggests that adipic acid is also the main in vivo urinary metabolite, while MEHA, MEHHA, and MEOHA are only minor metabolites. Therefore, the use of these specific metabolites for assessing the exposure of DEHA may be limited to highly exposed populations. PMID:24016063

  15. Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

  16. URINARY AND AMNIOTIC FLUID LEVELS OF PHTHALATE MONOESTERS IN RATS AFTER THE ORAL ADMINISTRATION OF DI(2-ETHYLHEXYL) PHTHALATE AND DI-N-BUTYL PHTHALATE

    EPA Science Inventory

    Two studies were designed to examine amniotic fluid and maternal urine concentrations of the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethylhexyl) phthalate (MEHP) and the di-n-butyl phthalate (DBP) metabolite monobutyl phthalate (MBP) after administration of DEHP and D...

  17. Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

    PubMed

    Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

    2015-10-01

    This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics. PMID:25966329

  18. Evaluation of the effect of the concentration of plasticizer di(2-ethylhexyl) phthalate on the quantity of residual monomer vinyl chloride in PVC chest drainage tubes.

    PubMed

    Kicheva, Y I; Richter, H; Popova, E

    2004-08-01

    The effect of amount of plasticizer di(2-ethylhexyl) phthalate (DEHP) amount on the amount of residual monomer vinyl chloride (VC) was determined in samples of plasticised polyvinyl chloride (PVC) with different concentration of plasticiser (22.32-33.05%), before and after sterilisation by a titrimetric method. The titrimetric method was used to determine the VC concentration in a KMnO4 solution where the samples were kept immersed under the same conditions for 2 h. The influence of PVC film extracts with different amounts of DEHP on mouse fibroblast cells L-929 in a culture medium was evaluated by using quantitative tests: the amount of cells (protein determination), viability (MTT test) and proliferation (incorporation of bromodeoxyuridine (BrDU). The amount of vinyl chloride before and after heat sterilisation at 120 degrees C for 30 min was found to be almost the same for all samples and without any dependence on the concentration of DEHP. The extracts of the PVC films which were tested have no toxic effect on cells in a culture medium.

  19. Effect of the plasticizer di(2-ethylhexyl)phthalate on red cell deformability

    SciTech Connect

    Labow, R.S.; Card, R.T.; Rock, G.

    1987-07-01

    Red cell concentrates (RCC) are stored for 35 to 42 days in plastic containers manufactured with the liquid plasticizer di(2-ethylhexyl)phthalate (DEHP). DEHP leaches from the polyvinylchloride (PVC) plastic bag, then binds to and stabilizes the RC membrane. This study was undertaken to determine the deformability of the RC membrane using an osmotic gradient ektacytometer and to relate these measurements to the concentration of DEHP in the stored RCC. Pooled RCC was aliquoted into PL146 (PVC), PL732 (polyolefin), and PL732 (with added DEHP) bags with samples removed weekly for analysis of osmotic fragility, deformability, and DEHP concentration. The adenosine triphosphate (ATP) content was also measured. The increase in osmotic fragility during storage was greater when RCC was stored without DEHP. In addition, there was a decrease in the maximum elongation index (El max) when there was decreased DEHP in the storage bag. The osmolarity (Omax) at which El max occurred, as well as the Omin, the osmolarity at which minimum elongation (El min) occurred was higher in the PL732 container than in the PL146 or in the PL732 to which DEHP had been added. These changes could be reversed by addition of DEHP at the beginning of the storage period, showing a direct correlation between DEHP concentration during storage and RC membrane flexibility. By a better understanding of the mechanism of DEHP protection, it might be possible to substitute a less toxic stabilizing compound.

  20. Clinically relevant concentrations of di (2-ethylhexyl) phthalate (DEHP) uncouple cardiac syncytium

    SciTech Connect

    Gillum, Nikki; Karabekian, Zaruhi; Swift, Luther M.; Brown, Ronald P.; Kay, Matthew W.; Sarvazyan, Narine

    2009-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer found in a variety of polyvinyl chloride (PVC) medical products. The results of studies in experimental animals suggest that DEHP leached from flexible PVC tubing may cause health problems in some patient populations. While the cancerogenic and reproductive effects of DEHP are well recognized, little is known about the potential adverse impact of phthalates on the heart. This study examined the effects of clinically relevant concentrations of DEHP on neonatal rat cardiomyocytes. It was found that application of DEHP to a confluent, synchronously beating cardiac cell network, leads to a marked, concentration-dependent decrease in conduction velocity and asynchronous cell beating. The mechanism behind these changes was a loss of gap junctional connexin-43, documented using Western blot analysis, dye-transfer assay and immunofluorescence. In addition to its effect on electrical coupling, DEHP treatment also affected the mechanical movement of myocyte layers. The latter was linked to the decreased stiffness of the underlying fibroblasts, as the amount of triton-insoluble vimentin was significantly decreased in DEHP-treated samples. The data indicate that DEHP, in clinically relevant concentrations, can impair the electrical and mechanical behavior of a cardiac cell network. Applicability of these findings to human patients remains to be established.

  1. Streptomyces bangladeshensis sp. nov., isolated from soil, which produces bis-(2-ethylhexyl)phthalate.

    PubMed

    Al-Bari, M Abdul Alim; Bhuiyan, M Shah Alam; Flores, María Elena; Petrosyan, Pavel; García-Varela, Martín; Islam, M Anwar Ul

    2005-09-01

    The taxonomic position of an actinomycete strain isolated from soil from Natore, Bangladesh, was examined by using a polyphasic approach. The strain, designated AAB-4(T), was assigned to the genus Streptomyces on the basis of chemical and morphological criteria. It formed Rectiflexibiles aerial hyphae that carried long chains of rounded spores. The 16S rRNA gene of strain AAB-4(T) was sequenced directly and then compared with those of previously studied streptomycetes following the generation of two phylogenetic trees by using maximum-likelihood and neighbour-joining algorithms. This confirmed the assignment of the novel strain to the genus Streptomyces. This strain showed a high level of 16S rRNA gene sequence similarity to Streptomyces thermoviolaceus, Streptomyces thermodiastaticus and Streptomyces longisporus, among others, but could be distinguished from them by phenotypic and physiological traits. This micro-organism produces bis-(2-ethylhexyl)phthalate, an antibacterial and antifungal agent. It is proposed that strain AAB-4(T) be classified as a novel species within the genus Streptomyces, as Streptomyces bangladeshensis sp. nov. (type strain, AAB-4(T)=LMG 22738(T)=NRRL B-24326(T)).

  2. Mono-(2-Ethylhexyl) Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta.

    PubMed

    Wang, Ximi K; Agarwal, Monica; Parobchak, Nataliya; Rosen, Alex; Vetrano, Anna M; Srinivasan, Aarthi; Wang, Bingbing; Rosen, Todd

    2016-01-01

    Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2) are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52) signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl)-phthalate (MEHP), increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth.

  3. A cost-effective method for estimating di(2-ethylhexyl)phthalate in coastal sediments.

    PubMed

    Muñoz-Ortuño, M; Argente-García, A; Moliner-Martínez, Y; Verdú-Andrés, J; Herráez-Hernández, R; Picher, M T; Campíns-Falcó, P

    2014-01-10

    This study describes the development of a new method for the analysis of di(2-ethylhexyl)phthalate (DEHP) using 0.1-0.3 g of sediment sample, based on matrix solid phase dispersion (MSPD) using C18 as dispersant phase (0.4 g) and acetonitrile-water as eluting solvent (3.4 mL 1:3.25, v/v). No evaporation step is required. 3 mL of extracts were processed on-line by in-tube solid phase microextraction (IT-SPME) coupled to capillary liquid chromatography (CapLC) and diode array detector (DAD). A short analytical column Zorbax SB C18 (35×0.5 mm, 5 μm) provided suitable results. FTIR-ATR was employed for characterizing sediment samples and MSPD procedure. The total analysis time was less than 20 min (MSPD takes about 10 min). The utility of the described approach has been tested by analyzing several real samples. No matrix effect was found. Achieved precision was less than 10% for DEHP estimation. Detection limits in samples were 270 and 90 μg/kg for 0.1 and 0.3 g of taken sediment, respectively. PMID:24290764

  4. Di-(2-ethylhexyl) phthalate accelerates atherosclerosis in apolipoprotein E-deficient mice.

    PubMed

    Zhao, Jin-Feng; Hsiao, Sheng-Huang; Hsu, Ming-Hua; Pao, Kuan-Chuan; Kou, Yu Ru; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is associated with atherosclerosis-related cardiovascular disease complications, but we lack direct evidence of its unfavorable effect on atherogenesis. In this study, we aimed to clarify in vivo and in vitro the contribution of DEHP to the development of atherosclerosis and its underlying mechanisms. Apolipoprotein E-deficient (apoE(-/-)) mice chronically treated with DEHP for 4 weeks showed exacerbated hyperlipidemia, systemic inflammation, and atherosclerosis. In addition, DEHP promoted low-density lipoprotein (LDL) oxidation, which led to inflammation in endothelial cells as evidenced by increased protein expression of pro-inflammatory mediators. Furthermore, chronic DEHP treatment increased hepatic cholesterol accumulation by downregulating the protein expression of key regulators in cholesterol clearance including LDL receptor, cholesterol 7α-hydrolase, ATP-binding cassette transporter G5 and G8, and liver X receptor α. Moreover, the adiposity and inflammation of white adipose tissues were promoted in DEHP-treated apoE(-/-) mice. In conclusion, DEHP may disturb cholesterol homeostasis and deregulate the inflammatory response, thus leading to accelerated atherosclerosis.

  5. Experimental density measurements of bis(2-ethylhexyl) phthalate at elevated temperatures and pressures

    SciTech Connect

    Bamgbade, Babatunde A; Wu, Yue; Baled, Hseen O; Enick, Robert M; Burgess, Ward A

    2013-08-01

    Experimental high-temperature, high-pressure (HTHP) density data for bis(2-ethylhexyl) phthalate (DEHP) are reported in this study. DEHP is a popular choice as a reference fluid for viscosity calibrations in the HTHP region. However, reliable HTHP density values are needed for accurate viscosity calculations for certain viscometers (e.g. rolling ball). HTHP densities are determined at T = (373, 424, 476, 492, and 524) K and P to 270 MPa using a variable-volume, high-pressure view cell. The experimental density data are satisfactorily correlated by the modified Tait equation with a mean absolute percent deviation (δ) of 0.15. The experimental data are modeled with the Peng–Robinson (PREoS), volume-translated PREoS (VT-PREoS), and perturbed chain statistical associating fluid theory (PC-SAFT EoS) models. The required parameters for the two PREoS and the PC-SAFT EoS models are determined using group contribution methods. The PC-SAFT EoS performs the best of the three models with a δ of 2.12. The PC-SAFT EoS is also fit to the experimental data to obtain a new set of pure component parameters that yield a δ of 0.20 for these HTHP conditions.

  6. Primary neuronal-astrocytic co-culture platform for neurotoxicity assessment of di-(2-ethylhexyl) phthalate.

    PubMed

    Wu, Yang; Li, Ke; Zuo, Haoxiao; Yuan, Ye; Sun, Yi; Yang, Xu

    2014-05-01

    Plastics such as polyvinyl chlorides (PVC) are widely used in many indoor constructed environments; however, their unbound chemicals, such as di-(2-ethylhexyl) phthalates (DEHP), can leach into the surrounding environment. This study focused on DEHP's effect on the central nervous system by determining the precise DEHP content in mice brain tissue after exposure to the chemical, to evaluate the specific exposure range. Primary neuronal-astrocyte co-culture systems were used as in vitro models for chemical hazard identification of DEHP. Oxidative stress was hypothesized as a probable mechanism involved, and therefore the total reactive oxygen species (ROS) concentration was determined as a biomarker of oxidative stress. In addition, NeuriteTracer, a neurite tracing plugin with ImageJ, was used to develop an assay for neurotoxicity to provide quantitative measurements of neurological parameters, such as neuronal number, neuron count and neurite length, all of which could indicate neurotoxic effects. The results showed that with 1 nmol/L DEHP exposure, there was a significant increase in ROS concentrations, indicating that the neuronal-astrocyte cultures were injured due to exposure to DEHP. In response, astrocyte proliferation (gliosis) was initiated, serving as a mechanism to maintain a homeostatic environment for neurons and protect neurons from toxic chemicals. There is a need to assess the cumulative effects of DEHP in animals to evaluate the possible uptake and effects on the human neuronal system from exposure to DEHP in the indoor environment.

  7. Effects of airway exposure to di-(2-ethylhexyl) phthalate on allergic rhinitis.

    PubMed

    He, Miao; Inoue, Ken-Ichiro; Yoshida, Seiichi; Tanaka, Michitaka; Takano, Hirohisa; Sun, Guifan; Ichinose, Takamichi

    2013-06-01

    Recent epidemiological studies have suggested a positive link between atopy morbidity and exposure to phthalate esters, which are environmental chemicals mainly involved in house dust. Nevertheless, experimental studies applying several allergic in vivo models (in addition to epidemiological studies) are needed to prove the precise correlation between phthalates and facilitation of the allergic response/pathophysiology. Among the phthalate esters, di-(2-ethylhexyl) phthalate (DEHP) has been widely used in flexible polyvinyl chloride products, including vinyl flooring and wall covering, and has been widely suggested to have immunomodulating potential. In the present study, we examined the effects of airway exposure to DEHP on allergen (ovalbumin: OVA)-induced rhinitis in mice. The repeated administration of OVA via an intranasal route induced nasal inflammation characterized by the infiltration of granulocytes (neutrophils and eosinophils) into the nasal cavity. In this experimental setting, DEHP did not exaggerate OVA-related inflammatory pathology. However, local (nasal) IL-13 levels were significantly higher in mice treated with allergen plus DEHP than with allergen alone. Taken together, phthalate esters including DEHP have the potential to exacerbate the allergic milieu in the nasal system, as well as dermal and respiratory systems. PMID:23672524

  8. In vivo immunoamplifying effects of di-(2-ethylhexyl) phthalate on cytokine response.

    PubMed

    Tanaka, Michitaka; Inoue, Ken-ichiro; Momoi, Takashi; Takano, Hirohisa

    2013-02-01

    A recent epidemiological study has revealed the positive association between atopy morbidity in children and phthalate esters, environmental chemicals in house dust. Nonetheless, experimental and molecular evidences regarding the correlation between phthalates and allergic response/pathophysiology are not fully investigated. Among phthalate esters, di-(2-ethylhexyl) phthalate (DEHP) has been widely used for flexible polyvinyl chloride products including vinyl flooring and wall covering. In the present study, we examined the effects of exposure to DEHP on allergen (ovalbumin: OVA) -induced peritonitis in ICR mice. Repeated administration of OVA via intraperitoneal route induced peritoneal inflammation characterized by infiltration of granulocytes (neutrophils and eosinophils) into the cavity. DEHP synergistically exaggerated the OVA-related neutrophilic inflammation. Furthermore, DEHP + OVA profoundly amplified OVA-elicited inflammation- and allergy-related molecules such as interleukin-5, eotaxin, and keratinocyte-derived chemoattractant production/release in the peritoneal cavity. Taken together, DEHP aggravated OVA-related peritoneal inflammation, which is concomitant with local enhanced production/release of inflammation- and allergy-related molecules. PMID:23098214

  9. Effect of Di(2-ethylhexyl)phthalate on Helicobacter pylori-Induced Apoptosis in AGS Cells

    PubMed Central

    Wu, Chien-Yi; Kou, Hwang-Shang; Chen, Chiao-Yun; Huang, Meng-Chuan; Hu, Huang-Ming; Wu, Meng-Chieh; Lu, Chien-Yu; Wu, Deng-Chyang; Wu, Ming-Tsang; Kuo, Fu-Chen

    2013-01-01

    Plastic products are wildly used in human life. Di(2-ethylhexyl)phthalate (DEHP) is an essential additive in plastic manufacturing and is used as plasticizer for many products including plastic food packaging. DEHP is a teratogenic compound and can cause potent reproductive toxicity. DEHP can also cause liver damage, peroxisome proliferation, and carcinogenesis. DEHP is also strongly associated with peptic ulcers and gastric cancer; however, the underlying effect and mechanism of DEHP on the gastrointestinal tract are not entirely clear. The oral infection route of H. pylori parallels the major ingestion route of DEHP into the human body. Therefore, we wanted to study the effect of DEHP and H. pylori exposure on the human gastric epithelial cell line, AGS (gastric adenocarcinoma). The viability of the AGS cell line was significantly lower in 80 μM-DEHP and H. pylori (MOI = 100 : 1) coexposure than DEHP or H. pylori alone. DEHP and H. pylori coexposure also induced caspase-3 activation, and increased Bax/Bcl-2 ratio and DNA fragmentation in AGS cells. These results indicate that DEHP can enhance H. pylori cytotoxicity and induce gastric epithelial cell apoptosis. Therefore, it is possible that DEHP and H. pylori coexposure might enhance the disruption of the gastric mucosa integrity and potentially promote the pathogenesis of gastric carcinogenesis. PMID:24454344

  10. Prepubertal Exposure to Genistein Alleviates Di-(2-ethylhexyl) Phthalate Induced Testicular Oxidative Stress in Adult Rats

    PubMed Central

    Zhang, Lian-Dong; Li, He-Cheng; Chong, Tie; Gao, Ming; Yin, Jian; Fu, De-Lai; Deng, Qian; Wang, Zi-Ming

    2014-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN) is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22) to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw)/day (G), DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450) and their mixture (G + D50, G + D150, G + D450). On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient), testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors. PMID:25530965

  11. The therapeutic applications of celery oil seed extract on the plasticizer di(2-ethylhexyl) phthalate toxicity.

    PubMed

    El-Shinnawy, Nashwa A

    2015-04-01

    The present study investigated the impact of two doses, 500 mg/kg and 1000 mg/kg, of di(2-ethylhexyl) phthalate (DEHP) and studied the possible therapeutic dose of celery oil seed extract for 6 weeks on some atheroscelerogenic, obesogenic, antioxidant and liver functions in rats. Both doses of DEHP caused over-expression of peroxisome proliferator-activated receptor alpha (PPARα) messenger RNA with significant increase in liver weights, relative liver weights, serum cholesterol (Chol), triglycerides, low-density lipoprotein Chol, liver total lipids, along with an increase in the activities of serum aspartate aminotransferase, alanine aminotransferase, serum endothelin 1 and liver tissue thiobarbituric acid reactive substances (TBARS). Additionally, DEHP administration to rats resulted in significant decrease in final body weights, serum total protein, albumin, liver total protein and serum total nitric oxide. Our study confirmed the role of oral combination of Apium graveolens (celery) oil seed extract at small cumulative doses (50 µl/kg for 6 weeks) with DEHP in ameliorating the toxicological effects of DEHP, which was revealed in reducing the expression of PPARα, lipid profile, with restoring liver functions, vascular oxidative stress and inhibition of TBARS activity.

  12. Peroxisome proliferation due to di(2-ethylhexyl) phthalate (DEHP): species differences and possible mechanisms.

    PubMed Central

    Elcombe, C R; Mitchell, A M

    1986-01-01

    The exposure of cultured rat hepatocytes to mono(2-ethylhexyl)phthalate (MEHP) for 72 hr resulted in marked induction of peroxisomal enzyme activity (beta-oxidation; cyanide-insensitive palmitoyl CoA oxidase) and concomitant increases in the number of peroxisomes. Similar treatment of cultured guinea pig, marmoset, or human hepatocytes revealed little or no effect of MEHP. In order to eliminate possible confounding influences of biotransformation, the proximate peroxisome proliferator(s) derived from MEHP have been identified. Using cultured hepatocytes these agents were found to be metabolite VI [mono(2-ethyl-5-oxohexyl) phthalate] and metabolite IX [mono(2-ethyl-5-hydroxyhexyl) phthalate]. The addition of these "active" metabolites to cultured guinea pig, marmoset, or human hepatocytes again revealed little effect upon peroxisomes or related enzyme activities (peroxisomal beta-oxidation or microsomal lauric acid hydroxylation). These studies demonstrate a marked species difference in the response of hepatocytes to MEHP-elicited peroxisome proliferation. Preliminary studies have also suggested that peroxisome proliferation due to MEHP may be due to an initial biochemical lesion of fatty acid metabolism. Images FIGURE 4. a FIGURE 4. b PMID:3104023

  13. Effect of gamma-ray irradiation on degradation of di(2-ethylhexyl)phthalate in polyvinyl chloride sheet.

    PubMed

    Ito, Rie; Miura, Naoko; Ushiro, Masaru; Kawaguchi, Migaku; Nakamura, Hiroko; Iguchi, Hirofumi; Ogino, Jun-Ichi; Oishi, Manabu; Wakui, Nobuyuki; Iwasaki, Yusuke; Saito, Koichi; Nakazawa, Hiroyuki

    2009-07-01

    The risk assessment of di(2-ethylhexyl)phthalate (DEHP) migration from polyvinyl chloride (PVC) medical devices is an important issue for patients. The aim of this study was to determine DEHP degradation and migration from PVC sheets. To this end, the method for the simultaneous determination of DEHP and its breakdown products (mono(2-ethylhexyl)phthalate (MEHP) and phthalic acid (PA)) was improved. Their migration levels from 0 to 50 kGy gamma-ray irradiated PVC sheets were determined. DEHP migration level decreased in proportion to the dose of gamma-ray irradiation, while MEHP and PA migration levels increased. The hardness and the elastic modulus of PVC sheets were examined, but no clear relationship between DEHP migration and these parameters was observed.

  14. Developmental changes in the conversion rates of di(2-ethylhexyl)phthalate to monoethylhexyl phthalate in rats

    SciTech Connect

    Gollamudi, R.; Hanumantha, R.; Lawrence, W.H.; Autian, J.

    1985-01-01

    The activities of liver, lung, and kidney of rats of various age groups and that of placenta in hydrolyzing di(2-ethylhexyl) phthalate to mono(2-ethylhexyl) phthalate have been measured. Male and female rats of 45 d of age, neonatal rats within 12 h of parturition, and fetuses and placenta on d 19 of gestation were used. The liver was most active in all age groups; however, the lung and the kidney also had considerable activity. The tissues of the fetuses and the neonate had significant activity. The k/sub m/ values of the enzyme were 4mM in the neonatal liver and 5.9 mM in the adult liver.

  15. Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

    PubMed

    Espinoza, Josué Daniel García; Drogui, Patrick; Zolfaghari, Mehdi; Dirany, Ahmad; Ledesma, Maria Teresa Orta; Gortáres-Moroyoqui, Pablo; Buelna, Gerardo

    2016-06-01

    Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4.

  16. Ion pairs of crystal violet in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles.

    PubMed

    Oliveira, Carla S; Bastos, Erick L; Duarte, Evandro L; Itri, Rosangela; Baptista, Mauricio S

    2006-10-10

    The interfacial localization and the ion pair formation of the positively charged dye crystal violet (CV) in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles (AOT RMs) were studied by several structural and spectroscopic techniques and by quantum chemical calculations. The size and shape of the AOT RMs in the presence of CV were investigated by small-angle X-ray scattering, showing that CV does not significantly change the RM structure. CV localization as a function of the water to surfactant molar ratio (w(0)) was characterized by H(1) and (13)C NMR, indicating the close proximity of CV to the sulfosuccinate group of AOT at small and large w(0) values. These results were confirmed by calculation of magnetic shielding constants using the gauge-independent atomic orbital method with the HF/6-31G(d) basis set. Two different types of ion pairs between AOT and CV, i.e., contact ion pair (CIPs) and solvent-separated ion pair (SSIPs), were characterized by UV-vis spectroscopy and quantum chemical calculations using the semiempirical ZINDO-CI method. In nonpolar isotropic solvents CIPs are formed with an association constant (K(ASSOC)) of 2 x 10(4) mol(-1) L in isooctane and 750 mol(-1) L in chloroform. In AOT RMs at low w(0), CV-AOT CIPs are also formed. By increasing w(0), there is a sharp decrease in the CIP association free energy, and SSIPs are formed. (CV(+))(H(2)O)(AOT(-)) SSIPs are stable in the AOT RM up to the largest w(0) tested (w(0) = 33). PMID:17014109

  17. Preparation of Nanowire Silica Inside Self-Assembled Sodium Bis(2-ethylhexyl) Sulfosuccinate (AOT) Gels.

    PubMed

    Lai, Wei-Chi; Hong, Li-Tzuen

    2016-09-22

    In conventional sol-gel methods, gel formation occurs due to aggregation of particles into irregular shapes of larger size. In this study, we conducted hydrolysis-condensation reactions of tetraethyl orthosilicate (TEOS) within water-laden channels inside the space created by self-assembled AOT molecules to prepare regular and nanosized silica in self-assembled sodium bis(2-ethylhexyl) sulfosuccinate (AOT) gels. The AOT gels were obtained by adding small amounts of water to organic solvents containing high concentrations of AOT. Adding silica significantly influenced the rheological properties and microstructures of these AOT/silica gels. Rheological studies showed that the storage modulus G' and loss modulus G″ of the AOT gel systems became very close and even crossed, indicating that the gel is "weak"; however, for the AOT/silica gel systems, the rheological data demonstrated that G' is greater than G″ at all frequencies, indicative of a real gel with a G' of approximately 10(5) pa. Small-angle X-ray scattering (SAXS) results showed that the gels initially had a hexagonal close-packed cylindrical structure with long-range order and transitioned to nonclose-packed cylindrical structures without long-range order as the silica formed. The cylinder is expected to comprise stacks of silica molecules surrounded by AOT molecules, and the radius of the cylinder is close to the sum of the length of one AOT molecule and half the size of one silica molecule. The rheological and SAXS data show that silica in the AOT/silica systems grew in the axial direction due to the confinement of these cylindrical structures, leading to nanowire silica structures. After removal of the AOT components, the nanowire silica was approximately 5-10 nm in diameter, as observed using transmission electron microscopy (TEM). PMID:27602986

  18. Resveratrol and curcumin ameliorate di-(2-ethylhexyl) phthalate induced testicular injury in rats.

    PubMed

    Abd El-Fattah, Amal Ahmed; Fahim, Atef Tadros; Sadik, Nermin Abdel Hamid; Ali, Bassam Mohamed

    2016-01-01

    The present study aimed to evaluate the protective role of resveratrol and curcumin on oxidative testicular damage induced by di-(2-ethylhexyl) phthalate (DEHP). Male Wistar rats were divided into six groups; three groups received oral daily doses of DEHP (2g/kgBW) for 45days to induce testicular injury. Two of these groups received either resveratrol (80mg/kgBW) or curcumin (200mg/kgBW) orally for 30days before and 45days after DEHP administration. A vehicle-treated control group was also included. Another two groups of rats received either resveratrol or curcumin alone. Oxidative damage was observed by decreased levels of total antioxidant capacity (TAC) and glutathione (GSH) and increased malondialdehyde (MDA) level in the testes of DEHP-administered rats. Serum testosterone level as well as testicular marker enzymes activities; acid and alkaline phosphatases (ACP and ALP) and lactate dehydrogenase (LDH) showed severe declines. DEHP administration caused significant increases in the testicular gene expression levels of Nrf2, HO-1, HSP60, HSP70 and HSP90 as well as a significant decrease in c-Kit protein when compared with the control group. Histopathological observations provided evidence for the biochemical and molecular analysis. These DEHP-induced pathological alterations were attenuated by pretreatment with resveratrol and curcumin. We conclude that DEHP-induced injuries in biochemical, molecular and histological structure of testis were recovered by pretreatment with resveratrol and curcumin. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties along with boosting Nrf2, HSP 60, HSP 70 and HSP 90 gene expression levels and as such may be useful potential tools in combating DEHP-induced testicular dysfunction.

  19. Endocrine disruption by di-(2-ethylhexyl)-phthalate in Chinese rare minnow (Gobiocypris rarus).

    PubMed

    Wang, Xiaofang; Yang, Yuanjin; Zhang, Liping; Ma, Yanbo; Han, Jian; Yang, Lihua; Zhou, Bingsheng

    2013-08-01

    Great concern has been raised over the potential impact of environmental contaminants on fish populations that inhabit the Three Gorge Reservoir. The present study investigated the endocrine-disrupting effects of di-(2-ethylhexyl)-phthalate (DEHP) on the Chinese rare minnow (Gobiocypris rarus), an endemic fish distributed in upstream waters in the Yangtze River. Adult rare minnow were exposed to environmentally relevant concentrations of DEHP (0 µg/L, 3.6 µg/L, 12.8 µg/L, 39.4 µg/L, and 117.6 µg/L) for a 21-d period. Then, concentrations of sex hormones in the plasma and relative transcription of various associated genes were measured in the hypothalamic-pituitary-gonadal (HPG) axis and liver of the fish. Exposure to DEHP resulted in greater circulating concentrations of testosterone (T) and lower concentrations of estradiol (E2), which were accompanied by upregulation of Cyp17 mRNA and downregulation of Cyp19a mRNA in the gonads of females. In males, increases of T and E2 levels were consistent with upregulation of Cyp17 and Cyp19a in the gonads. Furthermore, the T/E2 ratio was increased in females but reduced in males. A significant increase in the levels of hepatic vitellogenin (VTG) gene transcription was observed in both females and males. The present study showed that waterborne exposure to DEHP altered plasma sex hormone levels and modulated gene transcription profiles of associated genes in the HPG axis and liver, occurring mostly at higher concentrations (>39.4 µg/L), which suggests that environmental concentration of DEHP (5.4 µg/L) alone might not disturb the endocrine system of the rare minnow in the TGR.

  20. Di-(2-ethylhexyl) adipate in selected total diet food composite samples.

    PubMed

    Cao, Xu-Liang; Zhao, Wendy; Churchill, Robin; Dabeka, Robert

    2013-11-01

    Polyvinyl chloride (PVC) food-wrapping films plasticized with di-(2-ethylhexyl) adipate (DEHA) are commonly used by grocery stores in Canada to rewrap meat, poultry, fish, cheese, and other foods. DEHA was assessed as part of the Government of Canada's Chemicals Management Plan. The main source of exposure for most age groups was expected to be food. Although the margin of exposure from food and beverages is considered to be adequately protective, the Government of Canada committed to performing targeted surveys of DEHA in foods and food packaging materials to better define Canadian exposure to DEHA through dietary intake. In order to determine whether more-comprehensive targeted surveys on DEHA in foods should be conducted, 26 food composite samples from the 2011 Canadian total diet study were selected and analyzed for DEHA using a method based on solvent and dispersive solid-phase extraction and gas chromatography-mass spectrometry. These 26 food composites include cheese, meat, poultry, fish, and fast foods, and PVC films were likely used in packaging the individual foods used to make the composites. DEHA was detected in most of the meat, poultry, and fish composite samples, with the highest concentration found in ground beef (11 μg/g), followed by beef steak (9.9 μg/g), freshwater fish (7.8 μg/g), poultry liver pâté (7.4 μg/g), fresh pork (6.9 μg/g), cold cuts and luncheon meats (2.8 μg/g), veal cutlets (2.1 μg/g), roast beef (1.3 μg/g), lamb (1.2 μg/g), and organ meats (0.20 μg/g). Targeted surveys should be conducted to investigate the presence of DEHA in various foods packaged with PVC films in more detail and provide updated occurrence data for accurate human exposure assessment.

  1. Resveratrol and curcumin ameliorate di-(2-ethylhexyl) phthalate induced testicular injury in rats.

    PubMed

    Abd El-Fattah, Amal Ahmed; Fahim, Atef Tadros; Sadik, Nermin Abdel Hamid; Ali, Bassam Mohamed

    2016-01-01

    The present study aimed to evaluate the protective role of resveratrol and curcumin on oxidative testicular damage induced by di-(2-ethylhexyl) phthalate (DEHP). Male Wistar rats were divided into six groups; three groups received oral daily doses of DEHP (2g/kgBW) for 45days to induce testicular injury. Two of these groups received either resveratrol (80mg/kgBW) or curcumin (200mg/kgBW) orally for 30days before and 45days after DEHP administration. A vehicle-treated control group was also included. Another two groups of rats received either resveratrol or curcumin alone. Oxidative damage was observed by decreased levels of total antioxidant capacity (TAC) and glutathione (GSH) and increased malondialdehyde (MDA) level in the testes of DEHP-administered rats. Serum testosterone level as well as testicular marker enzymes activities; acid and alkaline phosphatases (ACP and ALP) and lactate dehydrogenase (LDH) showed severe declines. DEHP administration caused significant increases in the testicular gene expression levels of Nrf2, HO-1, HSP60, HSP70 and HSP90 as well as a significant decrease in c-Kit protein when compared with the control group. Histopathological observations provided evidence for the biochemical and molecular analysis. These DEHP-induced pathological alterations were attenuated by pretreatment with resveratrol and curcumin. We conclude that DEHP-induced injuries in biochemical, molecular and histological structure of testis were recovered by pretreatment with resveratrol and curcumin. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties along with boosting Nrf2, HSP 60, HSP 70 and HSP 90 gene expression levels and as such may be useful potential tools in combating DEHP-induced testicular dysfunction. PMID:26361869

  2. Kinetics of di-(2-ethylhexyl)phthalate mineralization in sludge-amended soil

    SciTech Connect

    Madsen, P.L.; Thyme, J.B.; Henriksen, K.; Moeldrup, P.; Roslev, P. . Environmental Engineering Lab.)

    1999-08-01

    Sewage sludge is frequently used as a soil fertilizer although it may contain elevated concentrations of priority pollutants including di-(2-ethylhexyl)phthalate (DEHP). In the present study, the kinetics of microbial [[sup 14]C]DEHP mineralization was studied in laboratory microcosms with sewage sludge and agricultural soil. A biphasic model with two independent kinetic expressions was used to fit the mineralization data. The initial mineralization activity was described well by first-order kinetics, whereas mineralization in long-term incubations was described better by fractional power kinetics. The mineralization activity was much lower in the late phase presumably due to a decline in the bioavailability of DEHP caused by diffusion-limited desorption. The initial DEHP mineralization rate in sludge-amended soil varied between 3.7 and 20.3 ng of DEHP (g dw)[sup [minus]1]d[sup [minus]1] depending on incubation conditions. Aerobic DEHP mineralization was 4--5 times faster than anaerobic mineralization, DEHP mineralization in sludge-amended soil was much more temperature sensitive than was DEHP mineralization in soil without sludge. Indigenous microorganisms in the sewage sludge appeared to dominate DEHP degradation in sludge-amended soil. It was estimated that > 41% of the DEHP in sludge-amended soil will have escaped mineralization after 1 year. In the absence of oxygen, > 68% of the DEHP will not be mineralized within 1 year. Collectively, the data suggest that a significant fraction of the DEHP in sludge-amended soils may escape mineralization under in situ conditions.

  3. Di (2-ethylhexyl) Phthalate Exposure Impairs Growth of Antral Follicle in Mice

    PubMed Central

    Li, Lan; Liu, Jing-Cai; Lai, Fang-Nong; Liu, Huan-Qi; Zhang, Xi-Feng; Dyce, Paul W.; Shen, Wei; Chen, Hong

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp) to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative) related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice. PMID:26845775

  4. Concentration of di(2-ethylhexyl) phthalate (DEHP) in foods and its dietary exposure in China.

    PubMed

    Sui, Hai-Xia; Zhang, Lei; Wu, Ping-Gu; Song, Yan; Yong, Ling; Yang, Da-Jin; Jiang, Ding-Guo; Liu, Zhao-Ping

    2014-07-01

    Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in food contact materials that has been reported as an endocrine disruptor. In the present study, DEHP concentrations were analyzed in foods in order to determine dietary exposure among the Chinese population, including the general population (aged 2-100) and four age group, that is children aged 2-6, adolescent aged 7-12, young people aged 13-17 and adults aged 18 years old and above. 1704 food samples were collected during 2011-2012 and categorized into 12 food groups which covered major foods in China. Food consumption data were taken from China National Nutrient and Health Survey which was performed in 2002 and includes data from 68,959 subjects. Mean concentrations of DEHP were combined with individual food consumption data to estimate dietary exposure. It was found that DEHP levels in foods ranged from not detected to 3.41 mg/kg, with highest mean values in meat (0.23 mg/kg) and vegetable oils (0.21 mg/kg). Mean dietary intakes of DEHP in the general population, children, and adults were 2.34, 4.51, 2.03 μg/kg bw per day, respectively. The 97.5% intakes in these populations were 5.22, 8.43, 3.64 μg/kg bw per day, respectively. The main food sources of DEHP dietary intake were cereals (39.44%), drinking water (16.94%) and meat (15.81%) in children, and cereals (44.57%), meat (15.70%) and drinking water (12.28%) for adults. These findings suggested that dietary exposure to DEHP among Chinese population was lower than tolerable daily intake of DEHP and there are no health concerns based on generally accepted exposure limits.

  5. Transgenerational Effects of Di-(2-Ethylhexyl) Phthalate (DEHP) on Stress Hormones and Behavior

    PubMed Central

    Quinnies, Kayla M.; Doyle, Timothy J.; Kim, Kwan Hee

    2015-01-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been linked to male reproductive abnormalities. Here, we assessed transgenerational actions of DEHP on several behaviors and stress responses. We used 2 doses of DEHP (150- and 200-mg/kg body weight) and a treatment regimen previously shown to produce transgenerational effects on male reproduction. Mice, 3 generations removed from DEHP exposure (F3), were tested for social behavior and anxiety on the elevated plus maze. We collected blood and pituitaries from undisturbed and restrained mice. Body weights, anogenital distances, and reproductive organ weights were collected at killing. In social interaction tests juvenile males from the DEHP lineage (200 mg/kg) displayed more digging and less self-grooming than did controls. Interestingly, 150-mg/kg lineage males, killed in early puberty, had smaller seminal vesicle weights than their controls. However, the 200-mg/kg males (killed on average 10 d later) did not show this effect. Females from a DEHP lineage had lower corticosterone concentrations than controls after restraint stress. We also found sex- and DEHP-specific mRNA expression changes in the pituitary in 2 of the 6 stress-related genes we measured. In particular, Gnas mRNA was elevated by the combination of DEHP lineage and stress. Thus, transgenerational effects of DEHP are noted in male behavior, and in females, DEHP had transgenerational effects on levels of corticosterone. Both of these results may be related to transgenerational modifications in the expression of several pituitary hormones involved in the hypothalamic-pituitary-adrenal axis. PMID:26168342

  6. Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

    PubMed

    Espinoza, Josué Daniel García; Drogui, Patrick; Zolfaghari, Mehdi; Dirany, Ahmad; Ledesma, Maria Teresa Orta; Gortáres-Moroyoqui, Pablo; Buelna, Gerardo

    2016-06-01

    Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4. PMID:26971515

  7. Beneficial role of celery oil in lowering the di(2-ethylhexyl) phthalate-induced testicular damage.

    PubMed

    Madkour, Naglaa K

    2014-10-01

    Di(2-ethylhexyl) phthalate (DEHP), the most abundant phthalate in the environment, is known to be a reproductive toxicant. Considering the therapeutic significance of medicinal plants, this study was conducted to evaluate the effects of administration of celery oil on DEHP-induced testicular toxicity. The experiment was carried out for 8 weeks on 36 male rats that were divided equally into six groups. Group 1 was kept as normal control (given vehicle), while rats of group 2 were administered orally 200 mg/kg/day of celery oil. Groups 3 and 5 were orally given 500 and 1000 mg DEHP/kg/day, respectively. Groups 4 and 6 were treated with similar doses of DEHP as in groups 3 and 5 plus celery oil (200 mg/kg/day). Body and testicular weights, sperm parameters, serum hormones (testosterone, follicle-stimulating hormone, luteinizing hormone and estradiol), antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) and expression of cytochrome P450 aromatase (CYP19) messenger RNA (mRNA) were investigated at the end of 8th week. Treatment with DEHP alone resulted in a significant decrease in body and testicular weights, sperm parameters and serum hormone levels when compared with control. On the other hand, testicular antioxidant enzymes showed a significant dose-dependent increase. The expression of CYP19 mRNA was significantly reduced by increasing the doses of DEHP. Administration of celery oil along with DEHP partially prevented the decrease in body and testicular weights and enhanced epididymal sperm count, serum hormone levels and the expression of CYP19 mRNA along with diminution in the activities of SOD, GPx and CAT enzymes. The obtained results showed that the celery improved the testicular alterations induced by DEHP in albino rats.

  8. Di (2-ethylhexyl) Phthalate Exposure Impairs Growth of Antral Follicle in Mice.

    PubMed

    Li, Lan; Liu, Jing-Cai; Lai, Fang-Nong; Liu, Huan-Qi; Zhang, Xi-Feng; Dyce, Paul W; Shen, Wei; Chen, Hong

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp) to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative) related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice. PMID:26845775

  9. Preparation of Nanowire Silica Inside Self-Assembled Sodium Bis(2-ethylhexyl) Sulfosuccinate (AOT) Gels.

    PubMed

    Lai, Wei-Chi; Hong, Li-Tzuen

    2016-09-22

    In conventional sol-gel methods, gel formation occurs due to aggregation of particles into irregular shapes of larger size. In this study, we conducted hydrolysis-condensation reactions of tetraethyl orthosilicate (TEOS) within water-laden channels inside the space created by self-assembled AOT molecules to prepare regular and nanosized silica in self-assembled sodium bis(2-ethylhexyl) sulfosuccinate (AOT) gels. The AOT gels were obtained by adding small amounts of water to organic solvents containing high concentrations of AOT. Adding silica significantly influenced the rheological properties and microstructures of these AOT/silica gels. Rheological studies showed that the storage modulus G' and loss modulus G″ of the AOT gel systems became very close and even crossed, indicating that the gel is "weak"; however, for the AOT/silica gel systems, the rheological data demonstrated that G' is greater than G″ at all frequencies, indicative of a real gel with a G' of approximately 10(5) pa. Small-angle X-ray scattering (SAXS) results showed that the gels initially had a hexagonal close-packed cylindrical structure with long-range order and transitioned to nonclose-packed cylindrical structures without long-range order as the silica formed. The cylinder is expected to comprise stacks of silica molecules surrounded by AOT molecules, and the radius of the cylinder is close to the sum of the length of one AOT molecule and half the size of one silica molecule. The rheological and SAXS data show that silica in the AOT/silica systems grew in the axial direction due to the confinement of these cylindrical structures, leading to nanowire silica structures. After removal of the AOT components, the nanowire silica was approximately 5-10 nm in diameter, as observed using transmission electron microscopy (TEM).

  10. Di-(2-Ethylhexyl)-Phthalate (DEHP) Causes Impaired Adipocyte Function and Alters Serum Metabolites

    PubMed Central

    Klöting, Nora; Hesselbarth, Nico; Gericke, Martin; Kunath, Anne; Biemann, Ronald; Chakaroun, Rima; Kosacka, Joanna; Kovacs, Peter; Kern, Matthias; Stumvoll, Michael; Fischer, Bernd; Rolle-Kampczyk, Ulrike; Feltens, Ralph; Otto, Wolfgang; Wissenbach, Dirk K.; von Bergen, Martin; Blüher, Matthias

    2015-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP), an ubiquitous environmental contaminant, has been shown to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies, but the underlying mechanisms are still unknown. We therefore tested the hypothesis that chronic DEHP exposure causes impaired insulin sensitivity, affects body weight, adipose tissue (AT) function and circulating metabolic parameters of obesity resistant 129S6 mice in vivo. An obesity-resistant mouse model was chosen to reduce a potential obesity bias of DEHP effects on metabolic parameters and AT function. The metabolic effects of 10-weeks exposure to DEHP were tested by insulin tolerance tests and quantitative assessment of 183 metabolites in mice. Furthermore, 3T3-L1 cells were cultured with DEHP for two days, differentiated into mature adipocytes in which the effects on insulin stimulated glucose and palmitate uptake, lipid content as well as on mRNA/protein expression of key adipocyte genes were investigated. We observed in female mice that DEHP treatment causes enhanced weight gain, fat mass, impaired insulin tolerance, changes in circulating adiponectin and adipose tissue Pparg, adiponectin and estrogen expression. Serum metabolomics indicated a general increase in phospholipid and carnitine concentrations. In vitro, DEHP treatment increases the proliferation rate and alters glucose uptake in adipocytes. Taken together, DEHP has significant effects on adipose tissue (AT) function and alters specific serum metabolites. Although, DEHP treatment led to significantly impaired insulin tolerance, it did not affect glucose tolerance, HOMA-IR, fasting glucose, insulin or triglyceride serum concentrations. This may suggest that DEHP treatment does not cause impaired glucose metabolism at the whole body level. PMID:26630026

  11. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    SciTech Connect

    Wang, Wei Craig, Zelieann R. Basavarajappa, Mallikarjuna S. Gupta, Rupesh K. Flaws, Jodi A.

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  12. In Vitro Metabolism of the Brominated Flame Retardants 2-Ethylhexyl-2,3,4,5-Tetrabromobenzoate (TBB) and Bis(2-Ethylhexyl) 2,3,4,5-Tetrabromophthalate (TBPH) in Human and Rat Tissues

    PubMed Central

    Roberts, Simon C.; Macaulay, Laura J.; Stapleton, Heather M.

    2012-01-01

    Due to the phaseout of polybrominated diphenyl ether (PBDE) flame retardants, new chemicals, such as 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH), have been used as replacements in some commercial flame retardant mixtures. Both chemicals have been detected in indoor dust at concentrations approaching the concentrations of PBDEs; however, little is known about their fate, metabolism, or toxicity. The goal of this study was to investigate the potential metabolism of these two brominated flame retardants in human and rat tissues by conducting in vitro experiments with liver and intestinal subcellular fractions. In all the experiments, TBB was consistently metabolized to 2,3,4,5-tetrabromobenzoic acid (TBBA) via cleavage of the 2-ethylhexyl chain without requiring any added cofactors. TBBA was also formed in purified porcine carboxylesterase, but at a much faster rate of 6.29 ± 0.58 nmol min-1 mg protein-1. The estimated Km and Vmax values for TBB metabolism in human microsomes were 11.1 ± 3.9 μM and 0.644 ± 0.144 nmol min-1 mg protein-1, respectively. A similar Km of 9.3 ± 2.2 μM was calculated for porcine carboxylesterase, indicating similar enzyme specificity. While the rapid formation of TBBA may reduce the bioaccumulation potential of TBB in mammals and may be useful as a biomarker of TBB exposure, the toxicity of this brominated benzoic acid is unknown and may be a concern based on its structural similarity to other toxic pollutants. In contrast to TBB, no metabolites of TBPH were detected in human or rat subcellular fractions. However, a metabolic product of TBPH, mono(2-ethylhexyl) tetrabromophthalate (TBMEHP), was formed in purified porcine carboxylesterase at an approximate rate of 1.08 pmol min-1 mg protein-1. No Phase II metabolites of TBBA or TBMEHP were observed. More research is needed to understand the in vivo toxicokinetics and health effects of these compounds given their current

  13. Modeling of facilitated transport of phenylalanine by emulsion liquid membranes with di(2-ethylhexyl)phosphoric acid as a carrier

    SciTech Connect

    Liu, X.; Liu, D.

    1998-12-01

    A mathematical model is developed in this paper to simulate the facilitated transport of phenylalanine (Phe) in emulsion liquid membrane (ELM) systems with di(2-ethylhexyl)phosphoric acid as a carrier. The model takes into account the mass transfer in both the external aqueous phase and the organic membrane phase interfacial reaction as well as membrane breakage during agitation. The model is tested by comparing theoretical predications with experimental results using Phe extraction by ELM processes. It is found that the model is valid for simulating the facilitated transport of Phe with ELM under various experimental conditions.

  14. Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine.

    PubMed

    Eckert, Elisabeth; Münch, Frank; Göen, Thomas; Purbojo, Ariawan; Müller, Johannes; Cesnjevar, Robert

    2016-02-01

    Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures.

  15. Decoupling of dynamic processes in surfactant-based liquid mixtures: the case of lithium-containing bis(2-ethylhexyl)phosphoric acid/bis(2-ethylhexyl)amine systems.

    PubMed

    Nicotera, Isabella; Oliviero Rossi, Cesare; Turco Liveri, Vincenzo; Calandra, Pietro

    2014-07-22

    Pure surfactant liquids and their binary mixtures, because of the amphiphilic nature of the molecules involved, can exhibit nanosegregation and peculiar transport properties. The idea that inspired this work is that the possibility of including in such media salts currently used for technological applications should lead to a synergy between the properties of the salt and those of the medium. Therefore, the dynamic features of bis(2-ethylhexyl)amine (BEEA) and bis(2-ethylhexyl)phosphoric acid (HDEHP) liquid mixtures were investigated as a function of composition and temperature by (1)H nuclear magnetic resonance (NMR) spectroscopy and rheometry. Inclusion of litium trifluoromethanesulfonate (LiT) has been investigated by infrared spectroscopy, pulsed field gradient NMR, and conductimetry methods to highlight the solubilizing and confining properties of these mixtures as well as the lithium conductivity. It was found that BEEA/HDEHP binary liquid mixtures show zero-threshold percolating self-assembly with a maximum in viscosity and a minimum in molecular diffusion at a 1:1 composition. Dissolution of LiT in such system can occur via confinement in the locally self-assembled polar domains. Despite this confinement, Li(+) conduction is scarcely dependent on the medium composition because of the possibility of a field-induced hopping decoupled by the structural and dynamical features of the medium.

  16. Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine.

    PubMed

    Eckert, Elisabeth; Münch, Frank; Göen, Thomas; Purbojo, Ariawan; Müller, Johannes; Cesnjevar, Robert

    2016-02-01

    Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures. PMID:26650574

  17. Human biofluid concentrations of mono(2-ethylhexyl)phthalate extrapolated from pharmacokinetics in chimeric mice with humanized liver administered with di(2-ethylhexyl)phthalate and physiologically based pharmacokinetic modeling.

    PubMed

    Adachi, Koichiro; Suemizu, Hiroshi; Murayama, Norie; Shimizu, Makiko; Yamazaki, Hiroshi

    2015-05-01

    Di(2-ethylhexyl)phthalate (DEHP) is a reproductive toxicant in male rodents. The aim of the current study was to extrapolate the pharmacokinetics and toxicokinetics of mono(2-ethylhexyl)phthalate (MEHP, a primary metabolite of DEHP) in humans by using data from oral administration of DEHP to chimeric mice transplanted with human hepatocytes. MEHP and its glucuronide were detected in plasma from control mice and chimeric mice after single oral doses of 250mg DEHP/kg body weight. Biphasic plasma concentration-time curves of MEHP and its glucuronide were seen only in control mice. MEHP and its glucuronide were extensively excreted in urine within 24h in mice with humanized liver. In contrast, fecal excretion levels of MEHP glucuronide were high in control mice compared with those with humanized liver. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated urine MEHP concentrations in humans were consistent with reported concentrations. This research illustrates how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of pharmacokinetics or toxicokinetics of the primary or secondary metabolites of DEHP.

  18. Experimental study on infusion devices containing polyvinyl chloride: to what extent are they di(2-ethylhexyl)phthalate-free?

    PubMed

    Genay, Stéphanie; Luciani, Chiara; Décaudin, Bertrand; Kambia, Nicolas; Dine, Thierry; Azaroual, Nathalie; Di Martino, Piera; Barthélémy, Christine; Odou, Pascal

    2011-06-30

    The use of medical devices containing highly criticized phthalates including di(2-ethylhexyl) phthalate (DEHP) has been challenged by European directive 2007/47/CE, put into effect in March 2010. New plasticizers are now being used to soften PVC in medical devices: trioctyltrimellitate (TOTM), di-isononyl-cyclohexan-1,2-dicarboxilate (DINCH) and di(2-ethylhexyl) terephthalate (DEHT). To quantify DEHP in nine DEHP-free medical devices made of PVC softened by alternative plasticizers, high performance liquid chromatography analysis with ultraviolet detection at 220 nm wavelength was achieved. An NMR spectroscopy was performed to confirm DEHP presence. Only two medical devices out of the nine tested were truly without DEHP. One of them showed traces of DEHP exceeding the threshold contamination of 0.1% in plastic mass set by REACH regulations. TOTM plasticizer is still incriminated when polyvinyl-chloride (PVC) is contaminated with DEHP. Manufacturers must verify the purity of their raw material, not only on PVC, but also on other soft plastics entering into the composition of medical infusion devices. The clinical consequences of exposure to certain levels of DEHP have not been evaluated. A solution could be to use alternative PVC-free materials.

  19. Determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate in commercial sunscreens and cosmetic products.

    PubMed

    Chou, H J; Yates, R L; Havery, D C; Wenninger, J A

    1995-01-01

    An analytical method has been developed for determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate (NMPABAO), a nitrosamine contaminant in sunscreen products containing 2-ethylhexyl 4-(N,N-dimethylamino) benzoate (Padimate O). The method involves extraction of NMPABAO by column chromatography followed by liquid chromatographic separation and analysis wit a nitric oxide detector. To confirm the presence of NMPABAO in sunscreen products, the N-nitrosamine was synthesized and its structure was determined by infrared spectrophotometry, nuclear magnetic resonance spectrometry, and mass spectrometry (MS). For method validation, recovery studies were performed on a commercial suntan lotion, cream, and gel. Recoveries of NMPABAO added to representative test samples averaged 83%. The method has an estimated detection limit of 30 ppb. The method was used to analyze 25 commercial cosmetic and sunscreen products containing Padimate O. Eleven products contained NMPABAO at levels ranging from 160 to 21000 ppb. NMPABAO presence in 4 products was confirmed by MS at levels > or = 4000 ppb. The highest levels of NMPABAO were associated with products that contained the nitrite-releasing preservative 2-bromo-2-nitro-1,3-propanediol.

  20. Do diethyl phthalate (DEP) and di-2-ethylhexyl phthalate (DEHP) influence the metabolic syndrome parameters? Pilot study.

    PubMed

    Medic Stojanoska, Milica; Milankov, Andrijana; Vukovic, Bojan; Vukcevic, Dejan; Sudji, Jan; Bajkin, Ivana; Curic, Nikola; Icin, Tijana; Kovacev Zavisic, Branka; Milic, Natasa

    2015-08-01

    The study objective was to determine if the healthy participants were exposed to diethyl phthalate (DEP) and di (2-ethylhexyl) phthalate (DEHP) and if this exposure could be linked to the development of metabolic syndrome. The study included 103 healthy volunteers of similar age with normal BMI values, waist circumference, total cholesterol, HDL, LDL, and triglycerides. DEP and DEHP were measured in the morning urine samples to detect monoethyl phthalate (MEP) and mono-2-ethylhexyl phthalate (MEHP). Two phthalate groups and a control group were formed. Both MEP group and control group had similar results. The correlations between MEP and the measured parameters were insignificant. The correlation between the MEHP group and the age was significantly negative, but between the MHEP group and the waist circumference the correlation was significantly positive. Lipids and lipoproteins were within the reference values and equal in both groups. The significant negative correlation was observed only between MEHP and HDL. Our population is exposed to DEP and DEHP. There was only a significant correlation between DEHP and the observed metabolic syndrome components. Its negative impact was higher as the participants were younger.

  1. The thermodynamic properties of 2-ethylhexyl acrylate over the temperature range from T → 0 to 350 K

    NASA Astrophysics Data System (ADS)

    Kulagina, T. G.; Samosudova, Ya. S.; Letyanina, I. A.; Sevast'yanov, E. V.; Smirnova, N. N.; Smirnova, L. A.; Mochalova, A. E.

    2012-05-01

    The temperature dependence of the heat capacity C {/p o}= f( T) 2 of 2-ethylhexyl acrylate was studied in an adiabatic vacuum calorimeter over the temperature range 6-350 K. Measurement errors were mainly of 0.2%. Glass formation and vitreous state parameters were determined. An isothermic shell calorimeter with a static bomb was used to measure the energy of combustion of 2-ethylhexyl acrylate. The experimental data were used to calculate the standard thermodynamic functions C {/p o}( T), H o( T)- H o(0), S o( T)- S o(0), and G o( T)- H o(0) of the compound in the vitreous and liquid states over the temperature range from T → 0 to 350 K, the standard enthalpies of combustion Δc H o, and the thermodynamic characteristics of formation Δf H o, Δf S o, and Δf G o at 298.15 K and p = 0.1 MPa.

  2. Di-(2-ethylhexyl) adipate and 20 phthalates in composite food samples from the 2013 Canadian Total Diet Study.

    PubMed

    Cao, Xu-Liang; Zhao, Wendy; Dabeka, Robert

    2015-01-01

    A sensitive and selective GC-MS method was developed and used for simultaneous analysis of di-(2-ethylhexyl) adipate (DEHA) and 20 selected phthalates in the food samples from the 2013 Canadian Total Diet Study. At least one of the 21 target chemicals was detected in 141 of the 159 different food composite samples analysed. However, only seven of the 21 target chemicals were detected, with di-(2-ethylhexyl) phthalate (DEHP) and DEHA being detected most frequently, in 111 and 91 different food composite samples, respectively, followed by di-n-butyl phthalate (DBP) (n = 44), n-butyl benzyl phthalate (BBzP) (32), di-iso-butyl phthalate (DiBP) (27), di-ethyl phthalate (DEP) (3), and di-cyclohexyl phthalate (DCHP) (1). Levels of DEP (di-ethyl phthalate), DiBP, DBP, BBzP and DCHP were low, in general, with average concentrations of 9.63, 8.26, 23.2, 12.4 and 64.9 ng g(-1), respectively. Levels of DEHA and DEHP varied widely, ranging from 1.4 to 6010 ng g(-1) and from 14.4 to 714 ng g(-1), respectively. High levels of DEHA were found mainly in the composite samples where the individual food items used to prepare the composite were likely packaged in polyvinyl chloride (PVC) wrapping film, while the highest DEHP levels were found in the vegetable and fruit samples.

  3. ATSDR evaluation of health effects of chemicals. VI. Di(2-ethylhexyl)phthalate. Agency for Toxic Substances and Disease Registry.

    PubMed

    Fay, M; Donohue, J M; De Rosa, C

    1999-12-01

    Di(2-ethylhexyl)phthalate (also known as DEHP, bis(2-ethylhexyl)phthalate, or BEHP; CAS Registry Number 117-81-7) is a widely-used plasticizer. It is found in numerous plastic articles, such as paints, inks, floor tiles, upholstery, shower curtains, footwear, plastic bags, food-packaging materials, toys, and medical tubing. Not surprisingly, DEHP appears at many waste sites. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals that are of greatest public health concern at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priority List (NPL) sites. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of the bulk of ATSDR's profile for DEHP (ATSDR, 1993) into the mainstream scientific literature. An extensive listing of human and animal health effects, organized by route, duration, and endpoint, is presented. Toxicological information on toxicokinetics, biomarkers, interactions, sensitive subpopulations, reducing toxicity after exposure, and relevance to public health is also included. Environmental information encompasses physical properties, production and use, environmental fate, levels seen in the environment, analytical methods, and a listing of regulations. ATSDR, at the behest of Congress and therefore the citizenry, prepares these profiles to inform the public about site contaminants. PMID:10786378

  4. Occurrence of Di-(2-ethylhexyl) adipate and phthalate plasticizers in samples of meat, fish, and cheese and their packaging films.

    PubMed

    Cao, Xu-Liang; Zhao, Wendy; Churchill, Robin; Hilts, Carla

    2014-04-01

    Di-(2-ethylhexyl) adipate (DEHA) and phthalates are commonly used as plasticizers to soften polyvinyl chloride products. Because both DEHA and certain phthalates have been identified as priority chemicals for assessment of human health risk under the Government of Canada's Chemicals Management Plan, a comprehensive targeted survey was conducted to investigate the occurrence of DEHA and eight phthalates (di-methyl phthalate, di-ethyl phthalate, di-n-butyl phthalate, di-iso-butyl phthalate, butyl benzyl phthalate, di-n-hexyl phthalate, d-(2-ethylhexyl) phthalate, and di-n-octyl phthalate) in a total of 118 samples of meat (beef, pork, and chicken), fish, and cheese packaged mostly in cling films. The eight phthalates were not detected in any of the food packaging, but DEHA was detected in most of the cling films, indicating that although DEHA-plasticized films (e.g., polyvinyl chloride film) are currently being used by most grocery stores, nonplasticized cling films such as polyethylene film, are also being used by some stores. DEHA was not detected in any of the 10 cheese samples packaged in nonplasticized rigid plastics but was detected in all 30 cheese samples packaged in DEHA-plasticized cling films at levels from 0.71 to 879 μg/g, with an average of 203 μg/g. Only DEHA was detected in the beef, pork, chicken, and fish samples packaged in DEHA-plasticized cling films but at considerably lower levels than those found in cheese, with averages of 6.3, 9.1, 2.5, and 5.9 μg/g, respectively. Among the eight phthalates, only di-(2-ethylhexyl) phthalate (DEHP) was detected in a few cheese samples at levels from 0.29 to 15 μg/g, with an average of 2.8 μg/g; these levels were very likely due to environmental contamination. Levels of DEHA found in most of the cheese samples from this study are above the European specific migration limit of 18 mg/kg for DEHA in food or food simulants, and levels of phthalates (i.e., DEHP) were low.

  5. Evaluation of cytotoxicity and oxidative DNA damaging effects of di(2-ethylhexyl)-phthalate (DEHP) and mono(2-ethylhexyl)-phthalate (MEHP) on MA-10 Leydig cells and protection by selenium

    SciTech Connect

    Erkekoglu, Pinar; Rachidi, Walid; Giray, Belma; Favier, Alain; Hincal, Filiz

    2010-10-01

    Di(2-ethylhexyl)-phthalate (DEHP) is the most abundantly used phthalate derivative, inevitable environmental exposure of which is suspected to contribute to the increasing incidence of testicular dysgenesis syndrome in humans. Oxidative stress and mitochondrial dysfunction in germ cells are suggested to contribute to phthalate-induced disruption of spermatogenesis in rodents, and Leydig cells are one of the main targets of phthalates' testicular toxicity. Selenium is known to be involved in the modulation of intracellular redox equilibrium, and plays a critical role in testis, sperm, and reproduction. This study was aimed to investigate the oxidative stress potential of DEHP and its consequences in testicular cells, and examine the possible protective effects of selenium using the MA-10 mouse Leydig tumor cell line as a model. In the presence and absence of selenium compounds [30 nM sodium selenite (SS), and 10 {mu}M selenomethionine (SM)], the effects of exposure to DEHP and its main metabolite mono(2-ethylhexyl)-phthalate (MEHP) on the cell viability, enzymatic and non-enzymatic antioxidant status, ROS production, p53 expression, and DNA damage by alkaline Comet assay were investigated. The overall results of this study demonstrated the cytotoxicity and genotoxicity potential of DEHP, where MEHP was found to be more potent than the parent compound. SS and SM produced almost the same level of protection against antioxidant status modifying effects, ROS and p53 inducing potentials, and DNA damaging effects of the two phthalate derivatives. It was thus shown that DEHP produced oxidative stress in MA-10 cells, and selenium supplementation appeared to be an effective redox regulator in the experimental conditions used in this study, emphasizing the critical importance of the appropriate selenium status.

  6. Antimicrobial and Cytotoxic Activity of Di-(2-ethylhexyl) Phthalate and Anhydrosophoradiol-3-acetate Isolated from Calotropis gigantea (Linn.) Flower.

    PubMed

    Habib, M Rowshanul; Karim, M Rezaul

    2009-03-01

    A phytochemical study on the flowe r of Calotropis gigantea (Linn.) using silica gel column chromatography and preparative thin layer chromatography, led to the first time isolation of Di-(2-ethylhexyl) phthalate (compound 1) and anhydrosophoradiol-3-acetate (compound 2). The structures of these compounds were confirmed by spectroscopic analyses (IR, HRTOFMS and NMR). The antibacterial and antifungal activities of ethyl acetate extract, compound 1 and compound 2 were measured using the disc diffusion method. Ethyl acetate extract and compound 1 presented better results than compound 2. The minimum inhibitory concentrations (MICs) of the extract and compounds were found to be in the range of 16~128 µg/ml. The cytotoxicity (LC50) against brine shrimp nauplii (Artemia salina) were also evaluated and found to be 14.61 µg/ml for ethyl acetate, 9.19 µg/ml for compound 1 and 15.55 µg/ml for compound 2.

  7. Antimicrobial and Cytotoxic Activity of Di-(2-ethylhexyl) Phthalate and Anhydrosophoradiol-3-acetate Isolated from Calotropis gigantea (Linn.) Flower

    PubMed Central

    Habib, M. Rowshanul

    2009-01-01

    A phytochemical study on the flowe r of Calotropis gigantea (Linn.) using silica gel column chromatography and preparative thin layer chromatography, led to the first time isolation of Di-(2-ethylhexyl) phthalate (compound 1) and anhydrosophoradiol-3-acetate (compound 2). The structures of these compounds were confirmed by spectroscopic analyses (IR, HRTOFMS and NMR). The antibacterial and antifungal activities of ethyl acetate extract, compound 1 and compound 2 were measured using the disc diffusion method. Ethyl acetate extract and compound 1 presented better results than compound 2. The minimum inhibitory concentrations (MICs) of the extract and compounds were found to be in the range of 16~128 µg/ml. The cytotoxicity (LC50) against brine shrimp nauplii (Artemia salina) were also evaluated and found to be 14.61 µg/ml for ethyl acetate, 9.19 µg/ml for compound 1 and 15.55 µg/ml for compound 2. PMID:23983504

  8. Health hazards associated with the use of di-(2-ethylhexyl) phthalate (commonly referred to as DOP) in HEPA filter test

    SciTech Connect

    1995-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), commonly referred to as di-octyl phthalate, is an important production chemical in the US. In addition to its major use as an additive in plastics, DEHP is widely used to evaluate the effectiveness of high efficiency particulate air (HEPA) filters. Historically, DEHP was also used in quantitative fit testing for respirators. Evaluations of this compound a decade ago showed that it can induce hepatocellular carcinomas in laboratory animals. Although most Department of Energy (DOE) facilities have since discontinued using DEHP in respirator fit testing, DEHP continues to be used for evaluating HEPA filters. This report summarizes available information on the toxicity, mutagenicity, carcinogenicity, and other hazards and problems posed by DEHP, specifically with reference to HEPA filter testing. Information on work practice improvements as well as the availability and suitability of DEHP substitutes are also presented. This material should assist the DOE in the safe use of this material.

  9. Hierarchical Structure of Supramolecular Polymers Formed by N,N'-Di(2-ethylhexyl)urea in Solutions.

    PubMed

    Świergiel, Jolanta; Bouteiller, Laurent; Jadżyn, Jan

    2015-10-01

    Supramolecular chain polymers formed by N,N'-di(2-ethylhexyl)urea (EHU) dissolved at low concentrations (up to 0.1 mole fraction) in heptane were investigated with the use of the dielectric spectroscopy. The experimental data show an exceptional ability of the chains for the antiparallel self-aggregation due to dipole-dipole interactions, leading to an anomalous dependence of the static permittivity of EHU + heptane solutions on temperature and concentration of the urea. The primary molecular assembly into polymeric chains is therefore followed by a secondary bundling of the chains which facilitates a longitudinal translation of the chains. That peculiarity and an asymmetry of the alkyl substituent in the EHU molecule making the system a mixture of diastereoisomers of unfavorable packing of the side group, are the most probable molecular mechanisms which prevent the crystallization of EHU-the only known liquid urea derivative. PMID:26371560

  10. Characterizing interfacial friction in bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles from photoisomerization studies of carbocyanine derivatives

    SciTech Connect

    Gangamallaiah, V.; Dutt, G. B.

    2011-01-14

    Photoisomerization of two carbocyanine derivatives has been examined in bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles to understand the factors that govern this process in the interfacial region of organized assemblies. To this effect, fluorescence lifetimes and quantum yields of 3,3{sup '}-diethyloxadicarbocyanine iodide and merocyanine 540 have been measured in AOT/isooctane/water and AOT/cyclohexane/water reverse micellar systems as a function of the mole ratio of water to the surfactant, W. The nonradiative rate constants, which have been identified as the rates of photoisomerization for these solutes, were obtained from the experimentally measured parameters. The steady rise and subsequent saturation observed in the nonradiative rate constants upon increasing W has been rationalized in terms of micellar packing. An inverse correlation has been obtained between the nonradiative rate constants and the critical packing parameter, indicating that the interfacial friction experienced by the solute molecule is essentially described by this parameter.

  11. Determination of Activity Coefficients of di-(2-ethylhexyl) Phosphoric Acid Dimer in Select Organic Solvents Using Vapor Phase Osmometry

    SciTech Connect

    Michael F. Gray; Peter Zalupski; Mikael Nilsson

    2013-08-01

    Effective models for solvent extraction require accurate characterization of the nonideality effects for each component, including the extractants. In this study, the nonideal behavior of the industrial extractant di(2-ethylhexyl) phosphoric acid has been investigated using vapor pressure osmometry (VPO). From the osmometry data, activity coefficients for the HDEHP dimer were obtained based on a formulation of the regular solution theory of Scatchard and Hildebrand, and the Margules two- and three-suffix equations. The results show similarity with a slope-analysis based relation from previous literature, although important differences are highlighted. The work points towards VPO as a useful technique for this type of study, but care must be taken with the choice of standard and method of analysis.

  12. Extraction equilibrium of indium(III) from nitric acid solutions by di(2-ethylhexyl)phosphoric acid dissolved in kerosene.

    PubMed

    Tsai, Hung-Sheng; Tsai, Teh-Hua

    2012-01-04

    The extraction equilibrium of indium(III) from a nitric acid solution using di(2-ethylhexyl) phosphoric acid (D2EHPA) as an acidic extractant of organophosphorus compounds dissolved in kerosene was studied. By graphical and numerical analysis, the compositions of indium-D2EHPA complexes in organic phase and stoichiometry of the extraction reaction were examined. Nitric acid solutions with various indium concentrations at 25 °C were used to obtain the equilibrium constant of InR₃ in the organic phase. The experimental results showed that the extraction distribution ratios of indium(III) between the organic phase and the aqueous solution increased when either the pH value of the aqueous solution and/or the concentration of the organic phase extractant increased. Finally, the recovery efficiency of indium(III) in nitric acid was measured.

  13. Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios.

    NASA Astrophysics Data System (ADS)

    Koiry, Bishnu; Singha, Nikhil

    2014-10-01

    Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N’,N”,N”- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights versus conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using 1H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2) were determined using the Finemann-Ross (FR), inverted Finemann-Ross (FR) and Kelen-Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

  14. Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios.

    PubMed

    Koiry, Bishnu P; Singha, Nikhil K

    2014-01-01

    Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N',N″,N″- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights vs. conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using (1)H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2) were determined using the Finemann-Ross (FR), inverted Finemann-Ross (IFR), and Kelen-Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis. PMID:25368866

  15. Mono(2-Ethylhexyl) Phthalate Accelerates Early Folliculogenesis and Inhibits Steroidogenesis in Cultured Mouse Whole Ovaries and Antral Follicles1

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Flaws, Jodi A.

    2015-01-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant present in common consumer products. DEHP potentially targets the ovary through its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, the direct effects of MEHP on ovarian folliculogenesis and steroidogenesis, two processes essential for reproductive and nonreproductive health, are unknown. The present study tested the hypotheses that MEHP directly accelerates early folliculogenesis via overactivation of phosphatidylinositol 3-kinase (PI3K) signaling, a pathway that regulates primordial follicle quiescence and activation, and inhibits the synthesis of steroid hormones by decreasing steroidogenic enzyme levels. Neonatal ovaries from CD-1 mice were cultured for 6 days with vehicle control, DEHP, or MEHP (0.2–20 μg/ml) to assess the direct effects on folliculogenesis and PI3K signaling. Further, antral follicles from adult CD-1 mice were cultured with vehicle control or MEHP (0.1–10 μg/ml) for 24–96 h to establish the temporal effects of MEHP on steroid hormones and steroidogenic enzymes. In the neonatal ovaries, MEHP, but not DEHP, decreased phosphatase and tensin homolog levels and increased phosphorylated protein kinase B levels, leading to a decrease in the percentage of germ cells and an increase in the percentage of primary follicles. In the antral follicles, MEHP decreased the mRNA levels of 17alpha-hydroxylase-17,20-desmolase, 17beta-hydroxysteroid dehydrogenase, and aromatase leading to a decrease in testosterone, estrone, and estradiol levels. Collectively, MEHP mediates the effect of DEHP on accelerated folliculogenesis via overactivating PI3K signaling and inhibits steroidogenesis by decreasing steroidogenic enzyme levels. PMID:25810477

  16. Mono-(2-ethylhexyl) phthalate (MEHP) regulates glucocorticoid metabolism through 11{beta}-hydroxysteroid dehydrogenase 2 in murine gonadotrope cells

    SciTech Connect

    Hong, Dun; Li, Xing-Wang; Lian, Qing-Quan; Lamba, Pankaj; Bernard, Daniel J.; Hardy, Dianne O.; Chen, Hai-Xiao; Ge, Ren-Shan

    2009-11-13

    Di-(2-ethylhexyl) phthalate (DEHP) and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) have been classified as toxicants to the reproductive system at the testis level and DEHP may also impair reproductive axis function at the pituitary levels. However, MEHP is 10-fold more potent than DEHP in toxicity and little is known about the toxicological effect of MEHP on pituitary. In this study, we demonstrated that 11{beta}-hydroxysteroid dehydrogenase type 2 (11{beta}-HSD2), not 11{beta}-HSD1, is strongly expressed in murine gonadotrope L{beta}T2 cells. Interestingly, MEHP inhibited Hsd11b2 mRNA level and 11{beta}-HSD2 enzyme activity in L{beta}T2 cells at as low as 10{sup -7} M. Corticosterone (CORT) at a concentration of 10{sup -6} M significantly inhibited L{beta}T2 cell proliferation after 2-day culture, and 10{sup -6} M RU486, an antagonist of glucocorticoid receptor (GR), reversed this inhibition. However, in the presence of 10{sup -5} or 10{sup -4} M MEHP, the minimal concentration of CORT to inhibit the proliferation of L{beta}T2 cells was lowered to 10{sup -7} M, and 10{sup -6} M RU486 was not able to completely reverse the CORT effect. In conclusion, along with the regulation of GR, 11{beta}-HSD2 may have a key role in glucocorticoid metabolism in L{beta}T2 cells. MEHP may participate in the glucocorticoid metabolism in L{beta}T2 cells through inhibition of 11{beta}-HSD2 enzyme activity. Such perturbation may be of pathological significance as MEHP may interfere with the reproductive system at pituitary level through regulation of glucocorticoid metabolism, especially in neonates with higher risk of phthalates exposure.

  17. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite.

    PubMed

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2016-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.

  18. Use of Mass Spectrometry for Identification of Biomarkers of Exposure to the Flame Retardant DI(2-Ethylhexyl)-2,3,4,5-Tetrabromophthlate

    EPA Science Inventory

    Di-(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one component in the technical formulation of Firemaster 550, a fire retardant used after phasing out certain polybrominated diphenyl ethers. Firemaster 550 is used widely and its use may result in human exposure to TBPH. To...

  19. Data from one test "Semi-Volatile Organic Compound Small Chamber for bis (2-Ethylhexyl) phthalate in Vinyl Flooring Test 2"

    EPA Science Inventory

    This data was generated from a small chamber bis(2-ethylhexyl) phthalate (DEHP) emission test. It was to participate an interaboratory study of DEHP emissions from vinyl flooring in a SVOC emission chamber organized by Virginia Polytechnic Institute and State University (VT).

  20. HEPATOCYTE EXPRESION OF TUMOR ASSOCIATED ALDEHYDE DEHYDROGENASE (ALDH-3) AND P21 RAS FOLLOWING DIETHYLNITROSAMINE (DEN) INITIATION AND CHRONIC EXPOSURE TO DI(2-ETHYLHEXYL) PHTHALATE (DHEP)

    EPA Science Inventory

    Phthalate esters such as di(2-ethylhexyl)phthalate (DEHP)either promote or inhibit rat liver tumorigenesis depending on the carcinogenesis protocol. In this study, we examined the expression of two histochemical markers, the tumor associated isozyme of aldehyde dehydrogenase (ALD...

  1. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    SciTech Connect

    Kessler, Winfried; Numtip, Wanwiwa; Völkel, Wolfgang; Seckin, Elcim; Csanády, György A.; Pütz, Christian; and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  2. Fourier transform infrared study on microemulsion system of potassium salt of bis(2-ethylhexyl) phosphinic acid (HA)

    NASA Astrophysics Data System (ADS)

    Zhou, Weijin; Shi, Nai; Wang, Yi; Chang, Zhiyuan; Wu, JinGuang

    1994-01-01

    To study microemulsion formation in a solvent extraction system is to probe into some basic principles of extraction chemistry in the light of combining extraction chemistry with surface chemistry. In our previous investigations, the microemulsions of the salts of HDEHP and PC88A have been studied systematically by FT-IR. In the experiment, we observed the change of peak positions and intensities of P equals O, P-O-C and P-O-H groups during saponification and hydration, and discovered that the peak of P-O-C splits apart into 1045 and 1075 cm-1. The vibration frequency of the P-O-C group in HDEHP and PC88A is quite close to the symmetric stretching frequency of the POO- group, and thus causes difficulties in the study of their peak position and absorbance variation. For this reason we synthesized bis(2-ethylhexyl) phosphinic acid without the P-O-C group. Infrared spectra in the range of 800 - 4000 cm-1 of this microemulsion system was studied.

  3. Maternal exposure to di-(2-ethylhexyl) phthalate exposure deregulates blood pressure, adiposity, cholesterol metabolism and social interaction in mouse offspring.

    PubMed

    Lee, Kuan-I; Chiang, Chin-Wei; Lin, Hui-Ching; Zhao, Jin-Feng; Li, Cheng-Ta; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2016-05-01

    Long-term exposure to di-(2-ethylhexyl) phthalate (DEHP) is highly associated with carcinogenicity, fetotoxicity, psychological disorders and metabolic diseases, but the detrimental effects and mechanisms are not fully understood. We investigated the effect of exposing mouse mothers to DEHP, and the underlying mechanism, on blood pressure, obesity and cholesterol metabolism as well as psychological and learning behaviors in offspring. Tail-cuff plethysmography was used for blood pressure measurement; Western blot used was for phosphorylation and expression of protein; hematoxylin and eosin staining, Nissl staining and Golgi staining were used for histological examination. The serum levels of cholesterol, triglycerides and glucose were measured by blood biochemical analysis. Hepatic cholesterol and triglyceride levels were assessed by colorimetric assay kits. Offspring behaviors were evaluated by open-field activity, elevated plus maze, social preference test and Morris water maze. Maternal DEHP exposure deregulated the phosphorylation of endothelial nitric oxide synthase and upregulated angiotensin type 1 receptor in offspring, which led to increased blood pressure. It led to obesity in offspring by increasing the size of adipocytes in white adipose tissue and number of adipocytes in brown adipose tissue. It increased the serum level of cholesterol in offspring by decreasing the hepatic capacity for cholesterol clearance. The impaired social interaction ability induced by maternal DEHP exposure might be due to abnormal neuronal development. Collectively, our findings provide new evidence that maternal exposure to DEHP has a lasting effect on the physiological functions of the vascular system, adipose tissue and nerve system in offspring.

  4. Degradation of phthalate and di-(2-ethylhexyl)phthalate by indigenous and inoculated microorganisms in sludge-amended soil

    SciTech Connect

    Roslev, P.; Madsen, P.L.; Thyme, J.B.; Henriksen, K.

    1998-12-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl) (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [{sup 14}C]PA and [{sup 14}C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [{sup 14}C]DEHP to {sup 14}CO{sub 2} increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of {sup 14}C-labelled phospholipid ester-linked fatty acids ({sup 14}C-PLFAs).

  5. Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane.

    PubMed

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-08-31

    Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine, and trimethoprim were selected as model analytes, and were extracted from 300 μL of human plasma, through 10 μL of DEHPi as SLM, and into 100 μL of 10 mM formic acid as acceptor solution. The extraction potential across the SLM was 100 V, and extractions were performed for 20 min. After EME, the acceptor solutions were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus, electrolysis in the sample and acceptor solution was kept at an acceptable level with no detrimental consequences. For the polar model analytes, representing a log P range from -0.40 to 1.32, recoveries in the range 25-91% were obtained from human plasma. Strong hydrogen bonding and dipole interactions were probably responsible for efficient transfer of the model analytes into the SLM, and this is the first report on efficient EME of highly polar analytes without using any ionic carrier in the SLM.

  6. The influence of di-(2-ethylhexyl) phthalate on steroidogenesis by the ovarian granulosa cells of immature female rats.

    PubMed

    Svechnikova, I; Svechnikov, K; Söder, O

    2007-09-01

    Phthalate esters are known to exert harmful effects on mammalian reproduction and fertility, but their potential adverse effects on the hormonal functions of the ovary have not yet been elucidated in detail. Here, we investigated the effects of di-(2-ethylhexyl) phthalate (DEHP) on the hypothalamic-pituitary-gonadal axis of young developing female rats, as well as on ex vivo steroidogenesis by granulosa cells (GCs) and secretion of LH by gonadotropes. Exposure of 20-day-old female rats to 500 mg DEHP by oral gavage once daily for 10 days reduced their serum levels of progesterone and estradiol, while tending to enhance levels of LH. Furthermore, primary cultures of GCs isolated from these rats exhibited an attenuated capacity to produce progesterone in response to stimulation by LH and FSH, as well as a lower degree of transport of endogenous cholesterol into mitochondria. Moreover, the ability of primary cultures of pituitary cells isolated from DEHP-treated rats to produce and secrete LH in response to GnRH was significantly enhanced. In addition, 2-ethylhexanoic acid, a metabolite of DEHP, significantly potentiated GnRH-stimulated production of LH by cultures of pituitary cells isolated from untreated 20-day-old female rats. Together, these data indicate that DEHP exerts dual effects on the pituitary-gonadal axis, stimulating the hormonal function of the pituitary and, at the same time, by inhibiting steroidogenesis by GCs.

  7. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials

    PubMed Central

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains. PMID:22934997

  8. CO2 foam properties and the stabilizing mechanism of sodium bis(2-ethylhexyl)sulfosuccinate and hydrophobic nanoparticle mixtures.

    PubMed

    Zhang, Chao; Li, Zhaomin; Sun, Qian; Wang, Peng; Wang, Shuhua; Liu, Wei

    2016-01-21

    In this work, we have prepared CO2-in-water foam by mixing partially hydrophobic SiO2 nanoparticles and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and studied its properties. The observation of the appearance of the foam revealed that, with the continuous addition of AOT, the phase behavior of the SiO2 nanoparticle and the AOT mixed system transformed from that of a two-phase system of aggregated nanoparticles into that of a uniform dispersed phase. Both foaming ability and foam stability were optimized when the nanoparticles and the AOT were mixed in a proportion of 1 : 5. On the basis of our findings from measurements of the dispersion properties, including measurements of the adsorption isotherm of the surfactant on the nanoparticles, zeta potentials, interfacial tension and the three-phase contact angle, we concluded that the synergistic interactions between the SiO2 nanoparticles and the AOT led to the adsorption of nanoparticles around the bubble surface and the formation of a spatial network structure of nanoparticles in the film, thereby enhancing the mechanical strength of the bubble and improving the resistance to outside disturbances, deformation and drainage. Laser scanning confocal microscopy (LCSM) analysis of the same foams further confirmed the existence of a "viscoelastic shell" wrapped around and protecting the bubble. PMID:26563818

  9. Effects of in vitro exposure to butylparaben and di-(2 ethylhexyl) phthalate, alone or in combination, on ovarian function.

    PubMed

    Guerra, Marina T; Furlong, Hayley C; Kempinas, Wilma G; Foster, Warren G

    2016-09-01

    Parabens and phthalates are commercial chemicals widely used in the manufacture of industrial and consumer products frequently found as contaminants in biological fluids. We evaluated the effects of di-(2-ethylhexyl) phthalate (DEHP) (ranging from 10(-9) to 10(-7) m [1-100 nm; 0.39-39 ng ml(-1) ]) and butylparaben (BP) (ranging from 10(-8) to 10(-5) m [10 nm-10 μm; 1.9 ng ml(-1) to 1.9 μg ml(-1) ]), alone and in combination, on isolated mouse preantral follicle and human granulosa cell (hGC) cultures to study direct effects on follicle growth and ovarian steroidogenesis. Our results revealed that, in follicle culture, DEHP and BP attenuate estradiol output but only when present together. DEHP decreases progesterone concentrations in the spent media of hGC cultures, an effect that was attenuated when BP was added together with DEHP. Although changes in steroidogenesis were observed, no effects on follicular development or survival were noted in the culture systems. We suggest that BP and DEHP act with additive effect to decrease estradiol production whereas at later stages of follicle development BP blocks the effect of DEHP in hGCs resulting in decreased progesterone output. Taken together our results suggest that DEHP and BP adversely affect steroidogenesis from the preantral stage onward and the effects of these chemicals are both stage-dependent and modified by co-exposure. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27135907

  10. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials.

    PubMed

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains. PMID:22934997

  11. Estimating Emissions and Environmental Fate of Di-(2-ethylhexyl) Phthalate in Yangtze River Delta, China: Application of Inverse Modeling.

    PubMed

    Zhan, Yu; Sun, Jianteng; Luo, Yuzhou; Pan, Lili; Deng, Xunfei; Wei, Zi; Zhu, Lizhong

    2016-03-01

    A georeferenced multimedia model was developed for evaluating the emissions and environmental fate of di-2-ethylhexyl phthalate (DEHP) in the Yangtze River Delta (YRD), China. Due to the lack of emission inventories, the emission rates were estimated using the observed concentrations in soil as inputs for the multimedia model solved analytically in an inverse manner. The estimated emission rates were then used to evaluate the environmental fate of DEHP with the regular multimedia modeling approach. The predicted concentrations in air, surface water, and sediment were all consistent with the ranges and spatial variations of observed data. The total emission rate of DEHP in YRD was 13.9 thousand t/year (95% confidence interval: 9.4-23.6), of which urban and rural sources accounted for 47% and 53%, respectively. Soil in rural areas and sediment stored 79% and 13% of the total mass, respectively. The air received 61% of the total emissions of DEHP but was only associated with 0.2% of the total mass due to fast degradation and intensive deposition. We suggest the use of an inverse modeling approach under a tiered risk assessment framework to assist future development and refinement of DEHP emission inventories. PMID:26861906

  12. Characterisation of immune-related gene expression in clam (Venerupis philippinarum) under exposure to di(2-ethylhexyl) phthalate.

    PubMed

    Lu, Yali; Zhang, Peng; Li, Chenghua; Su, Xiurong; Jin, Chunhua; Li, Ye; Xu, Yongjian; Li, Taiwu

    2013-01-01

    Di(2-ethylhexyl) phthalate (DEHP) mediates the immune system mainly by triggering the production of reactive oxygen species (ROS) and nitric oxide (NO) in higher animals. In the present study, spatial variation in the expression of immune-related genes in clam (Venerupis philippinarum) under acute short-term DEHP treatment was assessed by qPCR. The expression of six genes including glutamine synthetase (GS), IkB (IK), transcription factor activator protein-1 (AP-1), cyclophilin A-1 (CypA-1), heat shock protein 90 (HSP90) and superoxide dismutase (SOD) was dose-dependent. A negative correlation between expression and DEHP treatment was observed for big defensin (BD), glutathione S-transferase (GST), and thioredoxin peroxidase (TP). Surprisingly, lysozyme (LYZ) exhibited two distinct expression patterns at two DEHP doses. Significant differences between the experimental and control groups were observed for all tested genes at the various time points. Overall, our results revealed that DEHP mediates immune responses in clams by various means, and certain genes are promising candidate for biomarkers in DEHP monitoring.

  13. Low-dose exposure to di-(2-ethylhexyl) phthalate (DEHP) increases susceptibility to testicular autoimmunity in mice.

    PubMed

    Hirai, Shuichi; Naito, Munekazu; Kuramasu, Miyuki; Ogawa, Yuki; Terayama, Hayato; Qu, Ning; Hatayama, Naoyuki; Hayashi, Shogo; Itoh, Masahiro

    2015-09-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) induces spermatogenic disturbance (SD) through oxidative stress, and affects the immune system by acting as an adjuvant. Recently, we reported that in mice, a low dose of DEHP, which did not affect spermatogenesis, was able to alter the testicular immune microenvironment. Experimental autoimmune orchitis (EAO) can be induced by repeated immunization with testicular antigens, and its pathology is characterized by production of autoantibodies and SD. In the present study, we investigated the effect of a low-dose DEHP on the susceptibility of mice to EAO. The exposure to DEHP-containing feed (0.01%) caused a modest functional damage to the blood-testis barrier (BTB) with an increase in testicular number of interferon gamma (IFN-γ)-positive cells and resulted in the production of autoantibodies targeting haploid cells, but did not affect spermatogenesis. While only single immunization with testicular antigens caused very mild EAO, the concurrent DEHP exposure induced severe EAO with significant increases in number of interferon gamma-positive cells and macrophages, as well as lymphocytic infiltration and serum autoantibody titer accompanied by severe SD. To summarize, the exposure of mice to the low-dose DEHP does not induce significant SD, but it may cause an increase in IFN-γ positive cells and modest functional damage to the BTB in the testis. These changes lead to an autoimmune response against haploid cell autoantigens, resulting in increased susceptibility to EAO.

  14. An assessment of the dietary uptake of di-2-(ethylhexyl) adipate (DEHA) in a limited population study.

    PubMed

    Loftus, N J; Woollen, B H; Steel, G T; Wilks, M F; Castle, L

    1994-01-01

    The plasticizer di-2-(ethylhexyl) adipate (DEHA), which may be present in food-contact films, can migrate into certain foodstuffs. Results from plasticizer migration studies into food have enabled an indirect estimate of the maximum daily dietary intake of DEHA. A previous study of the metabolism and pharmacokinetics of DEHA in humans identified the urinary metabolite 2-ethylhexanoic acid (EHA) as a useful marker metabolite for assessing DEHA intake. The present study was designed to investigate urinary EHA concentrations following a controlled dose of DEHA presented with food, and to assess the average daily intake of DEHA in a limited population survey. The urinary elimination profile of EHA, following a dose of DEHA in food, showed that in order to extrapolate DEHA intake from EHA measurements, a 24-hr urine sample was required. In the survey the elimination of EHA was determined in 24-hr urine samples in 112 individuals from five different geographical locations in the UK. No restrictions were placed on age or gender. Estimates of daily intake of DEHA show a skewed distribution with a median value of 2.7 mg. This is similar to an estimated maximum daily intake of 8.2 mg/day, derived using an indirect method by the UK Ministry of Agriculture, Fisheries and Food.

  15. A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit

    PubMed Central

    Van Vliet, EDS; Reitano, EM; Chhabra, JS; Bergen, GP; Whyatt, RM

    2012-01-01

    Objective To conduct an extensive literature and toxicological database review on substitute compounds and available alternative medical products to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate (DEHP), and conduct a DEHP-medical inventory analysis at a large metropolitan neonatal intensive care unit (NICU). Study Design A systematic search for DEHP-free alternative products was performed using online databases. An informal audit of a large metropolitan NICU was undertaken in 2005 and 2006; 21 products were identified that could potentially contain DEHP. Availability of DEHP-free alternatives was determined through company websites and phone interviews. Result Two alternative approaches are available for replacing DEHP in NICU medical products: (1) replacement by DEHP-free plasticizers; and (2) replacement of PVC entirely through the use of other polymers. Both approaches seem to provide less harmful substitutes to DEHP, but support PVC-free polymers as the preferred alternative. However, significant data gaps exist, particularly for the alternative polymers. In all, 10 out of 21 (48%) products in the NICU audit were DEHP-free; six consisted of alternative polymers and four of alternative plasticizers. Of the remaining 11 products, only three were available without DEHP at the time of the audit. Conclusion Because of significant data gaps, systematic toxicological testing of DEHP-free alternatives is imperative. Continued development of alternative products is also needed. PMID:21311501

  16. Achromobacter denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate.

    PubMed

    Pradeep, S; Sarath Josh, M K; Balachandran, S; Sudha Devi, R; Sadasivam, R; Thirugnanam, P E; Doble, Mukesh; Anderson, Robin C; Benjamin, Sailas

    2014-11-01

    This first report describes the purification and identification of an orange-red pigment produced by Achromobacter denitrificans strain SP1 (isolated from sewage sludge heavily contaminated with plastics) during its growth in a simple basal salt medium supplemented with the hazardous di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood bag (in situ) or free DEHP (ex situ) as carbon source. The cell-bound pigment was elucidated, characterized at molecular level, and described as an unusual 25C prodigiosin analog for the first time. At laboratory conditions (in flasks), the dry cell mass was 75.2mg/g blood bag, which upon extraction yielded 7.1mg prodigiosin; at this stage the pH of the medium was dropped from 7.2 to 3.5. Considering its pharmaceutical importance, taking 10 known prodigiosins as controls, this 25C prodigiosin was subjected to molecular docking studies, showed comparable and promising binding efficiencies with the crucial molecular human targets like cycloxygenase-2, ZAP-70 kinase and Jak-3 kinase.

  17. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1-100μg/ml) for 24-96 hr to establish the temporal effects of DEHP on the follicle. Following 24-96 hr of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydorxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. PMID:25701202

  18. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    SciTech Connect

    Hannon, Patrick R. Brannick, Katherine E. Wang, Wei Gupta, Rupesh K. Flaws, Jodi A.

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  19. Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

    PubMed

    Erythropel, Hanno C; Maric, Milan; Nicell, Jim A; Leask, Richard L; Yargeau, Viviane

    2014-12-01

    Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are

  20. Environmental exposure to di-2-ethylhexyl phthalate is associated with low interest in sexual activity in premenopausal women

    PubMed Central

    Barrett, Emily S.; Parlett, Lauren E.; Wang, Christina; Drobnis, Erma Z.; Redmon, J. Bruce; Swan, Shanna H.

    2016-01-01

    Phthalates, a ubiquitous class of environmental chemicals, may interfere with typical reproductive hormone production both in utero and in adulthood. Although they are best known as anti-androgens, increasingly, evidence suggests that phthalates, particularly di-2-ethylhexyl phthalate (DEHP), may also suppress estrogen production. Given that both androgens and estrogens are essential for sexual function, particularly sexual interest, it is plausible that adult exposure to phthalates alters sexual function. To this end, we used data from 360 women participating in a pregnancy cohort study (the Study for Future Families) to examine whether urinary phthalate metabolite concentrations were associated with two dimensions of self-reported sexual dysfunction in the months prior to conception: lack of sexual interest and vaginal dryness. Women in the highest quartile of urinary concentrations of mono-2-ethyl-5-hydroxyhexyl phthalate, a DEHP metabolite, had 2.58 (95% CI 1.33, 5.00) times the adjusted odds of reporting that they almost always or often lacked interest in sexual activity, and results were similar for mono-2-ethyl-5-oxohexyl phthalate (aOR: 2.56, 95% CI 1.32, 4.95), another DEHP metabolite. Self-reported vaginal dryness was not associated with any phthalate metabolite concentration. This study is novel in its focus on sexual function in relation to environmentally relevant (rather than occupational) exposure to phthalates in adult women and these preliminary findings merit replication in a large, prospective study. Better understanding how adult exposure to phthalates may affect reproductive health, including sexual function, is of public health interest given that virtually all Westerners are exposed to phthalates. PMID:25448532

  1. Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane.

    PubMed

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-08-31

    Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine, and trimethoprim were selected as model analytes, and were extracted from 300 μL of human plasma, through 10 μL of DEHPi as SLM, and into 100 μL of 10 mM formic acid as acceptor solution. The extraction potential across the SLM was 100 V, and extractions were performed for 20 min. After EME, the acceptor solutions were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus, electrolysis in the sample and acceptor solution was kept at an acceptable level with no detrimental consequences. For the polar model analytes, representing a log P range from -0.40 to 1.32, recoveries in the range 25-91% were obtained from human plasma. Strong hydrogen bonding and dipole interactions were probably responsible for efficient transfer of the model analytes into the SLM, and this is the first report on efficient EME of highly polar analytes without using any ionic carrier in the SLM. PMID:27506347

  2. Induction of apoptosis and cell cycle arrest by Bis (2-ethylhexyl) phthalate produced by marine Bacillus pumilus MB 40.

    PubMed

    Moushumi Priya, A; Jayachandran, S

    2012-01-25

    Marine microorganisms represent a potential source for the production of biomedically useful compounds active against inflammation, cancer, diabetes, etc. Marine Bacillus pumilus MB 40 (GenBank accession no. HQ705771) isolated from deep sea water column (1000m depth) near Andaman and Nicobar islands produced a bioactive lead, Bis (2-ethylhexyl) phthalate (BEHP) with a molecular formula of C(6)H(4)(CO(2)C(8)H(17))(2) and a molecular ion at m/z 391 (M(+)). Anti proliferative effect of the isolated compound was examined by MTT assay in human erythroleukemic K562 cells and the IC(50) of BEHP was found to be 21μM. BEHP was able to induce apoptosis involving caspases pathway, besides regulating mitochondrial enzymes. Further, western blot analysis revealed the activation of caspases family proteins viz., caspase 8, caspase-9 and caspase-3. An increase in the expression of Bax mRNA concomitant with a decrease in mRNA of Bcl-2 in BEHP treated K562 cells was also observed. AO/EB staining of BEHP treated K562 cells further confirmed the progression of apoptosis as evidenced by morphological changes including nuclear condensation, cell shrinkage, and formation of apoptotic bodies. Treatment of K562 cells with BEHP induced the progressive accumulation of fragmented DNA in a time dependent manner. This pattern appeared as a typical laddering distribution of DNA fragmentation due to intranucleosomal cleavage associated with apoptosis. Based on flow cytometric analysis it has become evident that the compound was also effective in arresting the cell cycle at a sub G0/G1 phase.

  3. Accumulation of di(2-ethylhexyl) phthalate causes endocrine-disruptive effects in marine medaka (Oryzias melastigma) embryos.

    PubMed

    Ye, Ting; Kang, Mei; Huang, Qiansheng; Fang, Chao; Chen, Yajie; Liu, Liangpo; Dong, Sijun

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is extensively distributed in marine environments. However, limited research on the toxicological and molecular effects of DEHP on marine organisms has been conducted. Our study investigated the accumulation, elimination, and endocrine-disruptive effects of DEHP on embryonic marine medaka (Oryzias melastigma). The medaka embryos were continuously exposed to DEHP (0.01, 0.1, and 1 mg/L) or 17β-estradiol (E2, 0.01 mg/L) until hatching, and the newly hatched larvae were then transferred to clean sea water for 12 days of depuration. DEHP and E2 appeared to have no significant effects on the mortality and hatching rates of medaka embryos, but E2 exposure significantly delayed the hatching. Significantly higher DEHP embryonic burdens were detected in the group treated with higher DEHP (0.1 and 1 mg/L) at 10 dpf (days post fertilization). The recovered larvae showed an elimination tendency of DEHP during the recovery period. DEHP had no significant effects on the transcriptional responses of endocrine-disrupting biomarker genes in the 3-dpf embryos. Treatment with 0.1 and 1 mg/L DEHP elicited a significant induction of transcriptional responses of ER, PPAR, and the CYP19 genes in a concentration-dependent manner at 10 dpf, indicating endocrine disruption may be due to bioaccumulation of DEHP. With the elimination of DEHP during the depuration period, all of the effects on these genes showed no significant effects. However, 0.1 mg/L E2 significantly affected the expression of ER, PPAR, and the CYP19 genes in the exposed embryos at both 3 and 10 dpf and recovered larvae. Therefore, these results demonstrate that accumulation of DEHP caused endocrine disruption in medaka embryos and that recovery in clean sea water may weaken the endocrine-disrupting effects. PMID:25066029

  4. Effect of mono-(2-ethylhexyl) phthalate on human and mouse fetal testis: In vitro and in vivo approaches

    SciTech Connect

    Muczynski, V.; Cravedi, J.P.; Lehraiki, A.; Levacher, C.; Moison, D.; Lecureuil, C.; Messiaen, S.; Perdu, E.; Frydman, R.; Habert, R.; and others

    2012-05-15

    The present study was conducted to determine whether exposure to the mono-(2-ethylhexyl) phthalate (MEHP) represents a genuine threat to male human reproductive function. To this aim, we investigated the effects on human male fetal germ cells of a 10{sup −5} M exposure. This dose is slightly above the mean concentrations found in human fetal cord blood samples by biomonitoring studies. The in vitro experimental approach was further validated for phthalate toxicity assessment by comparing the effects of in vitro and in vivo exposure in mouse testes. Human fetal testes were recovered during the first trimester (7–12 weeks) of gestation and cultured in the presence or not of 10{sup −5} M MEHP for three days. Apoptosis was quantified by measuring the percentage of Caspase-3 positive germ cells. The concentration of phthalate reaching the fetal gonads was determined by radioactivity measurements, after incubations with {sup 14}C-MEHP. A 10{sup −5} M exposure significantly increased the rate of apoptosis in human male fetal germ cells. The intratesticular MEHP concentration measured corresponded to the concentration added in vitro to the culture medium. Furthermore, a comparable effect on germ cell apoptosis in mouse fetal testes was induced both in vitro and in vivo. This study suggests that this 10{sup −5} M exposure is sufficient to induce changes to the in vivo development of the human fetal male germ cells. -- Highlights: ► 10{sup −5} M of MEHP impairs germ cell development in the human fetal testis. ► Organotypic culture is a suitable approach to investigate phthalate effects in human. ► MEHP is not metabolized in the human fetal testis. ► In mice, MEHP triggers similar effects both in vivo and in vitro.

  5. Exposure to di-2-ethylhexyl phthalate, di-n-butyl phthalate and bisphenol A through infant formulas.

    PubMed

    Cirillo, Teresa; Latini, Giuseppe; Castaldi, Maria Antonietta; Dipaola, Lucia; Fasano, Evelina; Esposito, Francesco; Scognamiglio, Gelsomina; Francesco, Fabio Di; Cobellis, Luigi

    2015-04-01

    Phthalates and bisphenol A (BPA) are ubiquitous contaminants identified as endocrine disruptors. Phthalates are worldwide used as plasticizers, in particular to improve the mechanical properties of polymers such as polyvinyl chloride. Because they are not chemically bound to the polymer, they tend to leach out with time and use. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the two most common phthalates. BPA is an estrogenic compound used to manufacture polycarbonate containers for food and drink, including baby bottles. It can migrate from container into foods, especially at elevated temperatures. Diet is a predominant source of exposure for phthalates and BPA, especially for infants. The aim of this study was to test the presence of DEHP, DnBP, and BPA in infant formulas. DEHP, DnBP, and BPA concentrations were measured in 22 liquid and 28 powder milks by gas chromatography with flame ionization detection and high performance liquid chromatography with fluorimetric detection, respectively. DEHP concentrations in our samples were between 0.005 and 5.088 μg/g (median 0.906 μg/g), DnBP concentrations were between 0.008 and 1.297 μg/g (median 0.053 μg/g), and BPA concentrations were between 0.003 and 0.375 μg/g (median 0.015 μg/g). Concentrations of the investigated contaminants in liquid and powder milks were not significantly different, even though samples were packed in different types of containers. These data point out potential hazards for infants fed with baby formulas. Contamination seems more related to the production of formulas than to a release from containers. PMID:25730646

  6. Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

    PubMed

    Erythropel, Hanno C; Maric, Milan; Nicell, Jim A; Leask, Richard L; Yargeau, Viviane

    2014-12-01

    Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are

  7. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content.

  8. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content. PMID:20496185

  9. Maternal in utero exposure to the endocrine disruptor di-(2-ethylhexyl) phthalate affects the blood pressure of adult male offspring

    SciTech Connect

    Martinez–Arguelles, D.B.; McIntosh, M.; Rohlicek, C.V.; Culty, M.; Zirkin, B.R.; Papadopoulos, V.

    2013-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used industrially to add flexibility to polyvinyl chloride (PVC) polymers and is ubiquitously found in the environment, with evidence of prenatal, perinatal and early infant exposure in humans. In utero exposure to DEHP decreases circulating testosterone levels in the adult rat. In addition, DEHP reduces the expression of the angiotensin II receptors in the adrenal gland, resulting in decreased circulating aldosterone levels. The latter may have important effects on water and electrolyte balance as well as systemic arterial blood pressure. Therefore, we determined the effects of in utero exposure to DEHP on systemic arterial blood pressure in the young (2 month-old) and older (6.5 month-old) adult rats. Sprague-Dawley pregnant dams were exposed from gestational day 14 until birth to 300 mg DEHP/kg/day. Blood pressure, heart rate, and activity data were collected using an intra-aortal transmitter in the male offspring at postnatal day (PND) 60 and PND200. A low (0.01%) and high-salt (8%) diet was used to challenge the animals at PND200. In utero exposure to DEHP resulted in reduced activity at PND60. At PND200, systolic and diastolic systemic arterial pressures as well as activity were reduced in response to DEHP exposure. This is the first evidence showing that in utero exposure to DEHP has cardiovascular and behavioral effects in the adult male offspring. Highlights: ► In utero exposure to 300 mg DEHP/kg/day decreases activity at postnatal day 60. ► In utero exposure to DEHP decreases aldosterone levels at postnatal day 200. ► In utero exposure to DEHP decreases systolic blood pressure at postnatal day 200. ► An 8% salt diet recovers the decreased blood pressure at postnatal day 200.

  10. Levels of di-(2-ethylhexyl)phthalate and total phthalate esters in milk, cream, butter and cheese.

    PubMed

    Sharman, M; Read, W A; Castle, L; Gilbert, J

    1994-01-01

    Di-(2-ethylhexyl)phthalate (DEHP) and total phthalate ester plasticizer levels were determined in milk, cream, butter and cheese samples from a variety of sources from three European countries (UK, Norway and Spain). Samples of milk (from Norway) obtained at various stages during collection, transportation and packaging operations showed no apparent trends in phthalate contamination with total phthalate levels (expressed as DEHP equivalents) in the raw milk of between 0.12 and 0.28 mg/kg. On processing the DEHP was concentrated in the cream at levels up to 1.93 mg/kg, whereas low fat milk contained from < 0.01 to 0.07 mg/kg. Retail dairy products (from Spain) were contaminated with < 0.01-0.55 mg/kg DEHP with a maximum total phthalate level of 3.0 mg/kg in cream samples. UK pooled milk samples from doorstep delivery (obtained from different regions of the country) contained low levels of DEHP (< 0.01-0.09 mg/kg) and total phthalate (0.06-0.32 mg/kg). Retail UK samples of cheese, butter and other fatty products varied considerably in their levels of contamination, the highest being cheese samples containing 17 mg/kg of DEHP and 114 mg/kg total phthalate. However, the majority of samples contained 0.6-3.0 mg/kg DEHP and 4-20 mg/kg total phthalate. UK cream samples contained levels of 0.2-2.7 mg/kg DEHP and 1.8-19.0 mg/kg total phthalate. The level found in these products was too high to have resulted solely from milk by concentration in the fat phase and must therefore have arisen in other ways.

  11. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    SciTech Connect

    Tonk, Elisa C.M.; Verhoef, Aart; Gremmer, Eric R.; Loveren, Henk van; Piersma, Aldert H.

    2012-04-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

  12. Study of confined 5-aza[5]helicene in ytterbium(III) bis(2-ethylhexyl) sulfosuccinate reversed micelles.

    PubMed

    Abbate, Sergio; Caronna, Tullio; Longo, Alessandro; Ruggirello, Angela; Liveri, Vincenzo Turco

    2007-04-26

    Some relevant physicochemical properties of 5-aza[5]helicene (H5) in solutions of ytterbium bis(2-ethylhexyl) sulfosuccinate (Yb(DEHSS)3) reversed micelles have been investigated by UV-vis-NIR, photoluminescence, and FT-IR techniques with the aim of emphasizing the role played by specific Yb(III)/H5 interactions and confinement effects as driving forces of its binding to reversed micelles, preferential solubilization site, and local photophysical properties. It has been found that the binding strength of 5-aza[5]helicene to reversed micelles, triggered by steric and orientational constrains as well as the water content, is mainly regulated by its interaction with the Yb(III) counterion. Moreover, when H5 is entrapped in Yb(DEHSS)3 reversed micelles, the combined action of this interaction and of confinement effects leads to marked changes of its photophysical properties with respect to those of H5 molecularly dispersed in apolar medium. The influence of the entrapment of finite amounts of H5 on the reversed micelle structure was investigated by SAXS. The analysis of experimental results brings to the hypothesis that H5 is preferentially solubilized and opportunely oriented in the micellar palisade layer and that its insertion causes an unidimensional growth of reversed micelles. From an analysis of WAXS spectra of H5/Yb(DEHSS)3 composites, obtained by complete evaporation of the volatile components of the H5/water/Yb(DEHSS)3/n-heptane solutions, it was ascertained that also on these systems H5 is dispersed molecularly or in a quite amorphous state in the surfactant liquid crystals without forming a separate crystalline nanophase.

  13. Evaluation of a predictive mathematical model of di-(2-ethylhexyl) adipate plasticizer migration from PVC film into foods.

    PubMed

    Mercer, A; Castle, L; Comyn, J; Gilbert, J

    1990-01-01

    The diffusion coefficient of the plasticizer di-(2-ethylhexyl)adipate (DEHA) in Cheddar cheese (Df) was determined by measuring the extent to which DEHA penetrated cheese that was placed in intimate contact with artificially DEHA-contaminated cheese. Slices (20 microns) of cheese from the boundary layer, into which DEHA had migrated, were microtomed at -40 degrees C, and analyzed for DEHA by gas chromatography (GC). Mean values of Df determined by graph fitting experimental and calculated data were 1.5 x 10(-9) cm2 s-1 at 5 degrees C and 3.0 x 10(-8) cm2 s-1 at 25 degrees C. The partition coefficient (K) of DEHA between cheese and PVC film was derived from the partition coefficients of DEHA between acetonitrile (ACN) and cheese lipid, ACN and cheese solid, and ACN and PVC film. The mean values of K between cheese and PVC film were estimated to be 0.70 at 5 degrees C and 0.58 at 25 degrees C. The estimated values of Df and K were then used in a mathematical model (Till et al. 1982) to predict migration levels of DEHA into cheese. Good agreement with previously published experimental data was obtained. Extrapolation of the prediction of DEHA migration into fatty foods, such as salami and avocado, was also successful (ratio of experimental to predicted results within a factor of two). The values of Df and K for cheese are, however, inappropriate for modelling non-fatty foods such as meat, cakes, fruit and vegetables. Predicted values for these foods were typically 3-10-fold too high. More accurate predictions would probably be obtained if values of Df more relevant to these foods are used. The predictions were relatively insensitive to the value of K.

  14. Di-(2-ethylhexyl)-phthalate disrupts pituitary and testicular hormonal functions to reduce sperm quality in mature goldfish.

    PubMed

    Golshan, Mahdi; Hatef, Azadeh; Socha, Magdalena; Milla, Sylvain; Butts, Ian A E; Carnevali, Oliana; Rodina, Marek; Sokołowska-Mikołajczyk, Mirosława; Fontaine, Pascal; Linhart, Otomar; Alavi, Sayyed Mohammad Hadi

    2015-06-01

    Di-(2-ethylhexyl) phthalate (DEHP) interferes with male reproductive endocrine system in mammals, however its effects on fish reproduction are largely unknown. We evaluated sperm quality and investigated reproductive endocrine system in mature goldfish (Carassius auratus) exposed to nominal 1, 10, and 100μg/L DEHP. To examine DEHP estrogenic activity, one group of goldfish was exposed to 17β-estradiol (5μg/L E2) for comparison. Following 30d of exposure, sperm production was decreased and suppressed in DEHP and E2 treated goldfish, respectively. Sperm motility and velocity were decreased in goldfish exposed to 100 and 10μg/L DEHP at 15s post-sperm activation, respectively. Compared to control, 11-ketotestosterone (11-KT) levels were decreased at 10 and 1μg/L DEHP at day 15 and 30, respectively. In E2 treated goldfish, 11-KT levels were decreased compared to control during the period of exposure. E2 levels were increased in goldfish exposed to E2, but remained unchanged in DEHP treated goldfish during the period of exposure. StAR mRNA levels encoding regulator of cholesterol transfer to steroidogenesis were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. Luteinizing hormone (LH) levels were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. In DEHP treated goldfish, gnrh3, kiss1 and its receptor (gpr54) mRNA levels did not change during the experimental period. In E2 treated goldfish, gnrh3 mRNA levels were decreased at day 7, but kiss1 and gpr54 mRNA levels were increased at day 30 of exposure. The mRNA levels of genes encoding testicular LH and androgen receptors remained unchanged in DEHP and E2 treated goldfish. In contrast to E2 treated goldfish, vitellogenin production was not induced in DEHP treated goldfish and mRNA levels of genes with products mediating estrogenic effects remained unchanged or decreased. In conclusion, DEHP interferes with testis and pituitary hormonal

  15. Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign.

    PubMed

    Petersen, J H; Breindahl, T

    1998-07-01

    A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was

  16. Ultimate biodegradation of dialkyl phthalate ester plasticizers

    SciTech Connect

    Lee, C.L.; Sinko, C.J.; Winkelmann, D.A.; Peterson, D.R.; Parkerton, T.F.

    1995-12-31

    Phthalate Esters (PEs) are primarily used as plasticizers in the polymer industry to impart the desired degree of flexibility to plastic products. The single isomer, di-2-ethylhexyl phthalate (DEHP) is the most common plasticizer. However, other commercially important PE plasticizers possess branched alkyl chains of a mixed isomeric nature. The purpose of this study was to compare the ultimate biodegradability of mixed isomer PEs dihexyl (DHP), diisoheptyl (DIHP), diisononyl (DINP), diisodecyl (DIDP), and diisoundecyl (DIUP) phthalate to DEHP using the standardized OECD test (301 F) which is based on mannometric respirometry. Ultimate biodegradation results after 28 days under unacclimated conditions at 25 C were as follows: DHP (80 {+-} 10%), DIHP (82 {+-} 13%), DEHP (63 {+-} 18%), DINP (70 {+-} 11%), DIDP (67 {+-} 13%), DUP (57 {+-} 14%). These data confirm the readily biodegradable nature of DEHP and mixed isomer PEs reported in previous studies and provide additional data to contradict the misperception that PEs are environmentally persistent. The influence of alkyl chain structure on the rate and extent of biodegradation observed in this and other biodegradation studies are discussed.

  17. Is peroxisome proliferation an obligatory precursor step in the carcinogenicity of di(2-ethylhexyl)phthalate (DEHP)?

    PubMed

    Melnick, R L

    2001-05-01

    Di(2-ethylhexyl)phthalate (DEHP), a peroxisome proliferator, has been listed by the International Agency for Research on Cancer (IARC) and by the National Toxicology Program as a possible or reasonably anticipated human carcinogen because it induces dose-related increases in liver tumors in both sexes of rats and mice. Recently, the suggestion has been advanced that DEHP should be considered unlikely to be a human carcinogen because it is claimed that the carcinogenic effects of this agent in rodents are due to peroxisome proliferation and that humans are nonresponsive to this process. An IARC working group recently downgraded DEHP to "not classifiable as to its carcinogenicity to humans" because they concluded that DEHP produces liver tumors in rats and mice by a mechanism involving peroxisome proliferation, which they considered to be not relevant to humans. The literature review presented in this commentary reveals that, although our knowledge of the mechanism of peroxisome proliferation has advanced greatly over the past 10 years, our understanding of the mechanism(s) of carcinogenicty of peroxisome proliferators remains incomplete. Most important is that published studies have not established peroxisome proliferation per se as an obligatory pathway in the carcinogenicity of DEHP. No epidemiologic studies have been reported on the potential carcinogenicity of DEHP, and cancer epidemiologic studies of hypolipidemic fibrate drugs (peroxisome proliferators) are inconclusive. Most of the pleiotropic effects of peroxisome proliferators are mediated by the peroxisome proliferator activated receptor (PPAR), a ligand-activated transcription factor that is expressed at lower levels in humans than in rats and mice. In spite of this species difference in PPAR expression, hypolipidemic fibrates have been shown to induce hypolipidemia in humans and to modulate gene expression (e.g., genes regulating lipid homeostasis) in human hepatocytes by PPAR activation. Thus, humans

  18. Mono-(2-ethylhexyl) phthalate stimulates basal steroidogenesis by a cAMP-independent mechanism in mouse gonadal cells of both sexes.

    PubMed

    Gunnarsson, David; Leffler, Per; Ekwurtzel, Emelie; Martinsson, Gunilla; Liu, Kui; Selstam, Gunnar

    2008-05-01

    Phthalates are widely used as plasticizers in a number of daily-life products. In this study, we investigated the influence of mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of the frequently used plasticizer di-(2-ethylhexyl) phthalate (DEHP), on gonadal steroidogenesis in vitro. MEHP (25-100 microM) stimulated basal steroid synthesis in a concentration-dependent manner in immortalized mouse Leydig tumor cells (MLTC-1). The stimulatory effect was also detected in KK-1 granulosa tumor cells. MEHP exposure did not influence cAMP or StAR protein levels and induced a gene expression profile of key steroidogenic proteins different from the one induced by human chorionic gonadotropin (hCG). Simultaneous treatment with MEHP and a p450scc inhibitor (aminoglutethimide) indicated that MEHP exerts its main stimulatory effect prior to pregnenolone formation. MEHP (10-100 microM) up-regulated hormone-sensitive lipase and 3-hydroxy-3-methylglutaryl coenzyme A reductase, suggesting that MEHP increases the amount of cholesterol available for steroidogenesis. Our data suggest that MEHP, besides its known inhibitory effect on hCG action, can directly stimulate gonadal steroidogenesis in both sexes through a cAMP- and StAR-independent mechanism. The anti-steroidogenic effect of DEHP has been proposed to cause developmental disorders such as hypospadias and cryptorchidism, whereas a stimulation of steroid synthesis may prematurely initiate the onset of puberty and theoretically affect the hypothalamic-pituitary-gonadal axis.

  19. Genotoxicity evaluation of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate using a combined rat comet/micronucleus assays.

    PubMed

    Kitamoto, Sachiko; Matsuyama, Ryoko; Uematsu, Yasuaki; Ogata, Keiko; Ota, Mika; Yamada, Toru; Miyata, Kaori; Kimura, Juki; Funabashi, Hitoshi; Saito, Koichi

    2015-07-01

    As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo alkaline comet assay (comet assay), we examined DNA damage in the liver, stomach, and bone marrow of rats dosed orally three times with up to 2000 mg/kg of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate. All three compounds gave negative results in the liver and stomach. In addition, a bone marrow comet and micronucleus analysis revealed that benzene, but not di(2-ethylhexyl) phthalate or trisodium ethylenediamine tetraacetic acid monohydrate induced a significant increase in the median % tail DNA and micronucleated polychromatic erythrocytes, compared with the respective concurrent vehicle control. These results were in good agreement with the previously reported genotoxicity findings for each compound. The present study has shown that combining the micronucleus test with the comet assay and carrying out these analyses simultaneously is effective in clarifying the mechanism of action of genotoxic compounds such as benzene.

  20. The occurrence of phthalate ester and di-2-ethylhexyl adipate plasticizers in Canadian packaging and food sampled in 1985-1989: a survey.

    PubMed

    Page, B D; Lacroix, G M

    1995-01-01

    Selected foods (260 samples) packaged in materials with the potential to contribute plasticizers to the food, and available food composites (98 samples) obtained from the Canadian Health Protection Branch Total Diet Program, were analysed for phthalate plasticizers and di-2-ethylhexyl adipate (DEHA). The available contacting packaging was also analysed for plasticizers. The results show DEHA in food-contacting film and as a migrant in store-wrapped meat, poultry, fish, cheese and ready-to-eat foods at levels as high as 310 micrograms/g (cheese). DEHA levels in unheated film-wrapped ready-to-eat foods were increased by heating. The di-2-ethylhexyl, dibutyl, butylbenzyl and diethyl phthalate esters (DEHP, DBP, BBP and DEP, respectively) were also found in both the packaging and the contacted foods. Low levels of DEHP (0.065 micrograms/g, average in beverages and 0.29 micrograms/g, average in foods) associated with the use of DEHP-plasticized cap or lid seals, were found in a variety of glass-packaged foods; DBP, BBP and DEHP were found, as previously described, in butter and margarine as migrants from the aluminium foil-paper laminates; and DEP in pies at 1.8 micrograms/g (average) as a migrant from the pie carton windows. In most cases, plasticizers detected in the food were also found in the associated packaging. When possible, 'core' or non-contacting food portions were analysed to verify the migration phenomena.

  1. Acute pulmonary pathology and sudden death in rats following the intravenous administration of the plasticizer, DI (2-ethylhexyl) phthalate, solubilized with Tween surfactants. [pathology of vinyl plastics poisoning

    NASA Technical Reports Server (NTRS)

    Schulz, C. O.; Rubin, R. J.; Hutchins, G. M.

    1975-01-01

    Intravenous administration of 200-300 mg/kg of di(2-ethylhexyl)phthalate (DEHP) solubilized in aqueous solutions of several Tween surfactants caused respiratory distress in rats. There was a dose-dependent lethality with death generally occurring within 90 minutes after injection. The lungs from DEHP:Tween treated animals were enlarged, generally darkened, and in some cases showed hemorrhagic congestion. Neither the overt symptoms nor the morphologic alterations resulting from DEHP:Tween administration could be reproduced by intravenous administration of aqueous Tween solutions alone. The absence of pulmonary abnormalities following the intravenous administration of DEHP as an aqueous emulsion given either alone or even as soon as 2 minutes after pretreatment with Tween 80, suggests that the specific in vivo interaction between DEHP and Tween surfactants depends on the prior formation of water-soluble micelles of DEHP.

  2. Optical Studies of Poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) and its Nanocomposites

    NASA Astrophysics Data System (ADS)

    Layek, S.; Ghosh, M.; Reddy, K. Siddarth; Senapati, S.; Maiti, P.; Sinha, S.

    2015-11-01

    Steady state and time-resolved spectroscopic measurements are carried out to understand the fluorescent optical properties of the conjugated polymer poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) (PFV) in liquid phase and solid phase. Quite significant color tuning is observed in the fluorescence emission of PFV in the blue side of the spectra in the solid phase, especially in powder form, when the polymer is doped with 30B nanoclay (organically modified Montmorillonite) and graphene nanoparticles. Interestingly, the average fluorescence lifetime of PFVgraphene nanocomposite in thin film is found to be much higher (8.1 ns) compared to that for PFV only in thin film (3 ns). These novel nanocomposites may have potential applications in polymer optoelectronics industry.

  3. Role of Ca/CaN/NFAT signaling in IL-4 expression by splenic lymphocytes exposed to phthalate (2-ethylhexyl) ester in spleen lymphocytes.

    PubMed

    Pei, Xiucong; Duan, Zhiwen; Ma, Mingyue; Zhang, Yuming; Guo, Li

    2014-01-01

    The aims of present study were to investigate the effect of phthalate (2-ethylhexyl) ester (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) on Th1/Th2 balance signaling for interleukin 4 (IL-4) expression in splenic lymphocytes, and contribution of MEHP to any hypothesized changes in vitro. Primary splenic lymphocytes were exposed to DEHP/MEHP. ELISA and Western blotting were used to detect proteins. Confocal-microscopy was used to examine nuclear translocation. Nuclear factor of activated T cells (NFAT) DNA binding activity was examined by electrophoretic mobility-shift assay. DEHP significantly increased IL-4 and interferon gamma (IFN-γ) level, and reduced Th1/Th2 ratio (reflected by IFN-γ/IL-4) with 5 μg/L Concanavalin A (ConA) treatment. While MEHP reduced Th1/Th2 ratio (represented by IFN-γ/IL-6). IL-4 mRNA was significantly increased by DEHP but not by MEHP after PMA and Ion treatment. DEHP significantly inhibited NFATp protein in cytosol and nucleus. DEHP augmented nuclear translocation of NFATc in transfected EL4 cells and NFAT DNA-binding activity. DEHP-mediated enhancement of calcium-dependent phosphatase calcineurin (CaN) protein, and NFAT and IL-4 expression were abrogated by calcium antagonist verapamil and CaN inhibitor tarcolimus. Ca(2+)/calmodulin antagonist chlorpromazine significantly suppressed IL-4 and CaN production with no NFAT mRNA change. Our study suggests that DEHP and MEHP impact Th1/Th2 balance by modulating different cytokines. DEHP-affected IL-4 expression through Ca/CaN/NFAT signaling pathway, but no effect was discovered for MEHP.

  4. Estimating the contribution of inhalation exposure to di-2-ethylhexyl phthalate (DEHP) for PVC production workers, using personal air sampling and urinary metabolite monitoring.

    PubMed

    Fong, Jer-Pei; Lee, Fang-Jin; Lu, I-Syuan; Uang, Shi-Nian; Lee, Ching-Chang

    2014-01-01

    Because of troubling reports of high urinary metabolite levels and adverse reproductive health effects in workers exposed to di(2-ethylhexyl)phthalate (DEHP) in occupational settings, concern about exposure to DEHP in occupational settings is increasing. However, the contributions of different routes of exposure to DEHP are unclear. We used personal air sampling and biomonitoring to determine the contribution of inhalation exposure to the body burden of DEHP in the workplace. Eighty-nine workers (high-exposure group: 66 raw-materials workers; low-exposure group: 23 administrative workers) were recruited from three polyvinyl chloride (PVC) factories. Urinary levels of mono(2-ethylhexyl) phthalate (MEHP), (mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were measured in pre-shift and post-shift samples. The geometric means of airborne concentrations of DEHP were 5.3 μg/m3 (low-exposure group) and 32.7 μg/m3 (high-exposure group) (P<0.01). Correlation analysis showed a consistently significant association between airborne DEHP concentration and urinary DEHP metabolite levels in the high-exposure group. Calculating daily DEHP intake based on total urinary metabolite levels showed that the geometric means of total daily urinary metabolite levels of DEHP were 9.2 μg/kg/day (low-exposure group) and 15.5 μg/kg/day (high-exposure group) (P<0.01). A quartile analysis of all workers showed a significant trend toward an association between the individual contribution of inhalation exposure to DEHP and urinary DEHP metabolite levels, for which the mean inhalation contribution was 46.7% in the highest quartile. We conclude that inhalation-absorbed airborne DEHP significantly increased the total body burden of DEHP in these occupationally exposed workers.

  5. Preventive effect of D-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury in rat.

    PubMed

    Suna, Shigeru; Yamaguchi, Fuminori; Kimura, Shoji; Tokuda, Masaaki; Jitsunari, Fumihiko

    2007-09-10

    To investigate the preventive effects of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury, prepubertal male Sprague-Dawley rats were exposed to DEHP via their diet or orally, while under treatment with d-psicose. The rats given a diet-containing 1% DEHP alone for 7-14 days showed severe testicular atrophy accompanied by aspermatogenesis. On the other hand, those given the diet plus 2% but not 1% d-psicose-supplemented water for 14 days did not develop testicular atrophy, and exhibited an almost complete spermatogenesis. There was no significant difference in plasma mono-(2-ethylhexyl) phthalate (MEHP) levels between the d-psicose-free and d-psicose-treated groups. The testicular malondialdehyde (MDA) level after a single oral administration of 2g/kg of DEHP showed a similar pattern of increase to the plasma MEHP level and peaked in 24h suggesting a close and dose-dependent relation between plasma MEHP and testicular reactive oxygen species (ROS) levels. Pretreatment with d-psicose at a concentration of 2% and 4% resulted in an almost complete but not absolute suppression of testicular MDA production among rats administered 2g/kg of DEHP. The microarray analysis showed the induction of oxidative stress related genes including the thioredoxin, glutathione peroxidase 1 and 2, glutaredoixn 1 after 24h of the DEHP treatment in the testis. These results show that d-psicose prevents DEHP-induced testicular injury by suppressing the generation of ROS in the rat testis. This effect may be due to the direct scavenging by d-psicose of ROS generated in the testis.

  6. Di-(2-Ethylhexyl) Phthalate Metabolites in Urine Show Age-Related Changes and Associations with Adiposity and Parameters of Insulin Sensitivity in Childhood

    PubMed Central

    Smerieri, Arianna; Testa, Chiara; Lazzeroni, Pietro; Nuti, Francesca; Grossi, Enzo; Cesari, Silvia; Montanini, Luisa; Latini, Giuseppe; Bernasconi, Sergio; Papini, Anna Maria; Street, Maria E.

    2015-01-01

    Objectives Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl) phthalate (DEHP) in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity. Design and Methods DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP), were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables. Results The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity. Conclusion It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects. PMID:25706863

  7. Epigallocatechin-3-O-Gallate Protects Against Hepatic Damage and Testicular Toxicity in Male Mice Exposed to Di-(2-Ethylhexyl) Phthalate.

    PubMed

    Ge, Jian; Han, Baoyu; Hu, Huajun; Liu, Jun; Liu, Yang

    2015-07-01

    The aim of this study was to examine the effects of epigallocatechin-3-O-gallate (EGCG) on hepatic damage and testicular toxicity in male mice exposed to daily oral administration of di-(2-ethylhexyl) phthalate (DEHP). A mouse model was used to assess the effects of daily intraperitoneal EGCG injection on hepatic and testicular damage. Histological and mitochondrial membrane potential results revealed that EGCG treatment significantly arrested the progression of hepatic damage. EGCG treatment resulted in significant suppression of liver injury (i.e., reduced activities of alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). The development of DEHP-induced hepatic and testicular damage altered the testosterone concentration in mouse serum, which could affect the reproductive ability of male mice. Moreover, EGCG treatment markedly attenuated testes lesions, sperm deformity, and spermatogenic cell apoptosis. At the molecular level, hepatic CYP3A4 expression was substantially reduced by EGCG treatment in mice exposed to DEHP compounds, whereas testicular aromatase expression was increased significantly in testes. Thus, these results demonstrate that EGCG administration may protect against liver damage and reproductive toxicity in males exposed to DEHP. PMID:25789634

  8. A statistical description of the evolution of cloud condensation nuclei activity during the heterogeneous oxidation of squalane and bis(2-ethylhexyl) sebacate aerosol by hydroxyl radicals.

    PubMed

    Harmon, Christopher W; Ruehl, Christopher R; Cappa, Christopher D; Wilson, Kevin R

    2013-06-28

    The heterogeneous reaction of hydroxyl radicals with chemically reduced organic aerosol comprised of either squalane or bis(2-ethylhexyl) sebacate are used as model systems to examine how cloud condensation nuclei (CCN) activity evolves with photochemical oxidation. Over the course of the reaction, the critical super-saturation evolves both by the formation of new oxygen functional groups and by changes in aerosol size through the formation of gas phase reaction products. A statistical model of the heterogeneous reaction reveals that it is the formation, volatilization, solubility, and surface activity of many generations of oxidation products that together control the average changes in aerosol hygroscopicity. The experimental observations and model demonstrate the importance of considering the underlying population or subpopulation of species within a particle and how they each uniquely contribute to the average hygroscopicity of a multi-component aerosol. To accurately predict changes in CCN activity upon oxidation requires a reduction in the surface tension of the activating droplet by a subpopulation of squalane reaction products. These results provide additional evidence that surface tension-concentration parameterizations based on macroscopic data should be modified for microscopic droplets.

  9. Effects of exposure of pre-pubertal boars to di(2-ethylhexyl) phthalate on their frozen-thawed sperm viability post-puberty.

    PubMed

    Spjuth, L; Saravia, F; Johannisson, A; Lundeheim, N; Rodríguez-Martínez, H

    2006-10-01

    Late effects of pre-pubertal oral exposure to di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in, for example, polyvinyl chloride-products, on semen quality in young boars have not been clear-cut. The aim of this study was to determine whether stress imposed on spermatozoa would reveal such effects. Semen was collected from post-pubertal boars (8-9 months of age), which had been exposed to 300 mg kg(-1) body weight of DEHP per os three times a week from 3 to 7 weeks of age and from control siblings given placebo (water). The semen was cryopreserved and examined for plasma membrane integrity post-thaw using the short hypo-osmotic swelling test and flow cytometry (propidium iodide /SYBR-14). Sperm motility was assessed by computer-assisted sperm analysis. No significant difference in plasma membrane integrity could be found between the groups. The DEHP-exposed group had a significantly lower percentage of linearly motile spermatozoa at 30 min (P < 0.05) and 120 min (P < 0.001) after thawing, and a larger amplitude of lateral displacement of the head 120 min after thawing (P < 0.05), compared with controls. In summary, spermatozoa from boars pre-pubertally exposed to low doses of DEHP, showed kinematic deviations post-thaw that could be related to DEHP exposure. PMID:16961572

  10. Cytotoxic Activity of Bioactive Compound 1, 2- Benzene Dicarboxylic Acid, Mono 2- Ethylhexyl Ester Extracted from a Marine Derived Streptomyces sp. VITSJK8

    PubMed Central

    Krishnan, Kannabiran; Mani, Abirami; Jasmine, Subashini

    2014-01-01

    Marine Streptomyces are prolific producers of majority of bioactive secondary metabolites which are used in pharmaceutical industry as effective drugs against life threatening diseases. The cytotoxic activity of the pure compound 1, 2- benzene dicarboxylic acid, mono 2- ethylhexyl ester (DMEHE) from marine derived actinomycete Streptomyces sp. VITSJK8 was investigated against mouse embryonic fibroblast (NIH 3T3) and human keratinocyte (HaCaT) normal cell lines, human hepatocellular liver carcinoma (HepG 2) and human breast adenocarcinoma (MCF-7) cell lines by using MTT assay. The compound DMEHE exhibited IC 50 values of 42, 100, 250 and 500 µg/ ml against HepG2, MCF-7, HaCaT and NIH 3T3 cell lines, respectively. The effect of DMEHE on the growth of cancer cell lines was expressed as the % of viability. Cell viability was recorded as 67.7%, 78.14%, 82.23% and 96. 11% in HepG2, MCF-7, HaCaT and NIH 3T3 cells, respectively. The results of the study conclude that the bioactive compound isolated from the potential isolate Streptomyces sp. VITSJK8 exhibited cytotoxic activity against HepG2 and MCF- 7 cancer cell lines and low toxicity against normal HaCaT and NIH 3T3 cell lines. PMID:25635251

  11. Acrylic AB and ABA block copolymers based on poly(2-ethylhexyl acrylate) (PEHA) and poly(methyl methacrylate) (PMMA) via ATRP.

    PubMed

    Haloi, Dhruba J; Ata, Souvik; Singha, Nikhil K; Jehnichen, Dieter; Voit, Brigitte

    2012-08-01

    Acrylic block copolymers have several advantages over conventional styrenic block copolymers, because of the presence of a saturated backbone and polar pendant groups. This investigation reports the preparation and characterization of di- and triblock copolymers (AB and ABA types) of 2-ethylhexyl acrylate (EHA) and methyl methacrylate (MMA) via atom transfer radical polymerization (ATRP). A series of block copolymers, PEHA-block-PMMA(AB diblock) and PMMA-block-PEHA-block-PMMA(ABA triblock) were prepared via ATRP at 90 °C using CuBr as catalyst in combination with N,N,N',N″,N″-pentamethyl diethylenetriamine (PMDETA) as ligand and acetone as additive. The chemical structure of the macroinitiators and molar composition of block copolymers were characterized by (1)H NMR analysis, and molecular weights of the polymers were analyzed by GPC analysis. DSC analysis showed two glass transition temperatures (T(g)), indicating formation of two domains, which was corroborated by AFM analysis. Small-angle X-ray scattering (SAXS) analysis of AB and ABA block copolymers showed scattering behavior inside the measuring limits indicating nanophase separation. However, SAXS pattern of AB diblock copolymers indicated general phase separation only, whereas for ABA triblock copolymer an ordered or mixed morphology could be deduced, which is assumed to be the reason for the better mechanical properties achieved with ABA block copolymers than with the AB analogues.

  12. Thymic Stromal Lymphopoietin Neutralization Inhibits the Immune Adjuvant Effect of Di-(2-Ethylhexyl) Phthalate in Balb/c Mouse Asthma Model

    PubMed Central

    Wei, Chenxi; Chen, Shaohui; Mao, Lin; Zhang, Zhenye; Yang, Xu

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, has an adjuvant effect in combination with ovalbumin (OVA). The adjuvant effect of DEHP has already been verified in our previous studies. In this study, to further investigate whether thymic stromal lymphopoietin (TSLP) was involved in the DEHP-adjuvant effect, DEHP was administered through a daily gavage exposure route. Mice were sensitized with ovalbumin (OVA) to trigger allergic responses, and an anti-TSLP monoclonal antibody was used to neutralize the effect of TSLP. Biomarkers including cytokines in bronchoalveolar lavage fluid (BALF), serum total IgE and TSLP content in the lung were detected. In addition, airway hyperreactivity and lung sections were examined. Collectively, these data indicated a salient Th2 response which was characterized by the upregulation of Th2-type cytokines, such as interleukin 4 (IL-4), IL-5 and IL-13. Moreover, the eosinophil number in BALF and the eosinophil cationic protein (ECP) in the lung were seen to have increased significantly. However, neutralization of TSLP with an anti-TSLP mAb reversed the adjuvant effect of DEHP on airway inflammation, structural alterations in the airway wall and increased airway hyperresponsiveness (AHR) to methacholine induced by the OVA allergen, suggesting that TSLP was an effective target site for suppressing the adjuvant effect of DEHP co-exposure. PMID:27467143

  13. Different effects by sex on hypothalamic-pituitary axis of prepubertal offspring rats produced by in utero and lactational exposure to di-(2-ethylhexyl) phthalate (DEHP).

    PubMed

    Carbone, S; Samaniego, Y A; Cutrera, R; Reynoso, R; Cardoso, N; Scacchi, P; Moguilevsky, J A; Ponzo, O J

    2012-01-01

    This study investigated the effect of pre and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in prepubertal male and female rats. DEHP at doses of 3 and 30mg/kgbw/day was administered orally in the drinking water to dam rats since pregnancy onset until the moment of pups sacrifice at 15 days of age. In these animals gonadotropin serum level and the hypothalamic contents of the amino acids aspartate, glutamate and gamma-aminobutyric acid were determined. No changes in gonadotropin levels and amino acid neurotransmitters were detected at the low dose in both sexes. However, DEHP administered at high dose (30mg/kgbw/day) to dams produced a significant decrease in the inhibitory neurotransmitter GABA and an increase in the stimulatory neurotransmitter aspartate in prepubertal male offspring rats. These modifications were accompanied by gonadotropin serum levels increase. On the contrary, in treated female rats this chemical increased both, aspartate and GABA, which exert a characteristic stimulatory action on gonadotropin in 15-day-old normal females. This study provides new data about changes produced by DEHP on the hypothalamic amino acid neurotransmitters involved in the neuroendocrine reproductive regulation, in prepubertal male and female rat offspring from dams exposed during gestational and lactational periods. These alterations induced by DEHP exposure could be related to the gonadotropin modifications also described in this work, and with changes in the production of sexual hormones previously reported by other authors.

  14. Adiabatic compressibility of AOT [sodium bis(2-ethylhexyl)sulfosuccinate] reverse micelles: Analysis of a simple model based on micellar size and volumetric measurements

    NASA Astrophysics Data System (ADS)

    Amararene, A.; Gindre, M.; Le Huérou, J.-Y.; Urbach, W.; Valdez, D.; Waks, M.

    2000-01-01

    The self-assembly of amphiphilic molecules into supramolecular aggregates involves a number of complex phenomena and forces. Recent developments of highly sensitive, densimetric and acoustic methods on small volume samples have provided novel sensitive probes to explore the physical properties of these complex fluids. We have investigated, by high precision densimetry and ultrasound velocimetry, reverse micelles of [sodium bis(2-ethylhexyl)sulfosuccinate] in oil (isooctane and decane), at increasing water concentration and at variable micellar volume fractions. The size of these spherical micelles has been determined by small angle x-ray scattering. Using these results, in the framework of the effective medium theory, we have developed a simple model of micellar compressibility, allowing the calculation of physical parameters (aggregation number, volume, and compressibility) of the surfactant monomolecular film as well as that of the micellar waters. In particular, we show that the central aqueous core designated as ``free'' water, located at a distance from the oil-water interacting interface, is twice as compressible as ``bulk'' water. One notable feature of this work is the influence of the nature of the oil on the above parameters.

  15. Comparative pharmacokinetics and subacute toxicity of di(2-ethylhexyl) phthalate (DEHP) in rats and marmosets: extrapolation of effects in rodents to man

    SciTech Connect

    Rhodes, C.; Orton, T.C.; Pratt, I.S.; Batten, P.L.; Bratt, H.; Jackson, S.J.; Elcombe, C.R.

    1986-03-01

    Certain phthalate esters and hypolipidemic agents are known to induce morphological and biochemical changes in the liver of rodents, which have been associated with an increased incidence of hepatocellular tumors in these species. There is evidence that hypolipidemic agents do not induce these effects in either subhuman primates or man. The oral and intraperitoneal administration of di(2-ethylhexyl) phthalate (DEHP) to the marmoset monkey at doses up to 5 mmole DEHP/kg body weight/day for 14 days did not induce morphological or biochemical changes in the liver or testis comparable with those obtained in rats given the same amount of DEHP. In the marmoset, the excretion profile of (/sup 14/C)-DEHP following oral, IP, and IV administration and the lower tissue levels of radioactivity demonstrated a considerably reduced absorption in this species compared to the rat. The urinary metabolite pattern in the marmoset was in many respects qualitatively similar to but quantitatively different from that in the rat. The pharmacokinetic differences between these two species indicate that the tissues of the marmoset are exposed to a level of DEHP metabolites equivalent to the complete absorption of a dose of Ca. 0.1 to 0.25 mmole DEHP/kg body weight/day without significant toxicological effects. The evidence suggests that in some nonrodent species the hepatocellular and testicular response to DEHP is considerably less than that in rodents and is dose-dependent.

  16. The influence of humidity on the emission of di-(2-ethylhexyl) phthalate (DEHP) from vinyl flooring in the emission cell "FLEC"

    NASA Astrophysics Data System (ADS)

    Clausen, Per Axel; Xu, Ying; Kofoed-Sørensen, Vivi; Little, John C.; Wolkoff, Peder

    Asthma in children appears to be associated with both phthalate esters and dampness in buildings. An important question is whether the concentrations of phthalate esters correlate with dampness (expressed as relative humidity—RH) in indoor air. The objective was to study the influence of RH on the specific emission rate (SER) of di-(2-ethylhexyl)phthalate (DEHP) from one type of vinyl flooring in the well characterized Field and Laboratory Emission Cell (FLEC). The vinyl flooring with ca. 17% (w/w) DEHP as plasticizer was tested in 6 FLECs at 22 °C. The RH in the 6 FLECs was 10%, 30%, 50% (in triplicate) and 70%. The RH was changed after 248 d in 2 of the 50%-FLECs to 10% and 70%, and to 50% in the 10%-and 70%-FLECs. The data show that the SER of DEHP from vinyl flooring in FLECs during a 1 yr period is independent of the RH. A new physically based emission model for semivolatile organic compounds was found to be consistent with the experimental data and independent of the RH. The model helps to explain the RH results, because it appears that RH does not significantly influence any of the identified controlling mechanisms.

  17. Emission of di-2-ethylhexyl phthalate from PVC flooring into air and uptake in dust: emission and sorption experiments in FLEC and CLIMPAQ.

    PubMed

    Clausen, Per Axel; Hansen, Vivi; Gunnarsen, Lars; Afshari, Alireza; Wolkoff, Peder

    2004-05-01

    The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and Air Quality). The loading of the CLIMPAQs was varied but was constant in the FLECs. The sorption properties of FLEC and CLIMPAQ were investigated using different methods. In addition, the uptake of DEHP by office floor dust on the PVC flooring was studied in CLIMPAQ experiments. The concentration versus time curves in both FLECs and CLIMPAQs increased slowly over about 150 days and reached a quasi-static equilibrium at 1 microg m(-3). The main conclusions were that (i) the emission rate of DEHP was limited by gas-phase mass transport and (ii) the dust layer increased the emission rate by increasing the external concentration gradient above the surface of the PVC. These conclusions were based on the facts that the specific emission rate was inversely proportional to the loading and that the dust had sorbed about four times as much DEHP over a 68-day period as emitted in the gas-phase experiments. About one-half of the emitted DEHP was deposited on the internal surfaces of both the FLEC and the CLIMPAQ. PMID:15180047

  18. Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide and bis-(2-ethylhexyl)phosphoric acid extractants for recovering transuranic elements from irradiated nuclear fuel

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Gelis, Artem V.; Vandegrift, George F.

    2009-10-14

    Advanced concepts for closing the nuclear fuel cycle include separating Am and Cm from other fuel components. Separating these elements from the lanthanide elements at an industrial scale remains a significant technical challenge. We describe here a chemical system in which a neutral extractant--octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO)--is combined with an acidic extractant--bis-(2-ethylhexyl)phosphoric acid (HDEHP)--to form a single process solvent (with dodecane as the diluent) for separating Am and Cm from the other components of irradiated nuclear fuel. Continuous variation experiments in which the relative CMPO and HDEHP concentrations are varied indicate a synergistic relationship between the two extractants in the extraction of Am from buffered diethylenetriaminepentaacetic acid (DTPA) solutions. A solvent mixture consisting or 0.1 M CMPO + 1 M HDEHP in dodecane offers acceptable extraction efficiency for the trivalent lanthanides and actinides from 1 M HNO3 while maintaining good lanthanide/actinide separation factors in the stripping regime (buffered DTPA solutions with pH 3.5 to 4). Using citrate buffer instead of lactate buffer results in improved lanthanide/actinide separation factors.

  19. Complete degradation of the endocrine disruptor di-(2-ethylhexyl) phthalate by a novel Agromyces sp. MT-O strain and its application to bioremediation of contaminated soil.

    PubMed

    Zhao, Hai-Ming; Du, Huan; Lin, Jing; Chen, Xue-Bin; Li, Yan-Wen; Li, Hui; Cai, Quan-Ying; Mo, Ce-Hui; Qin, Hua-Ming; Wong, Ming-Hung

    2016-08-15

    A newly isolated strain Agromyces sp. MT-O could utilize various phthalates and efficiently degraded di-(2-ethylhexyl) phthalate (DEHP). Response surface methodology was successfully employed for the optimization of culture conditions including pH (7.2), temperature (29.6), and inoculum size (OD600 of 0.2), resulting in almost complete degradation of DEHP (200mgL(-1)) within 7days. At different initial concentrations (50-1000mgL(-1)), DEHP degradation curves were fitted well with the first-order kinetic model, and the half-life of DEHP degradation ranged from 0.83 to 2.92days. Meanwhile, the substrate inhibition model was used to describe the special degradation rate with qmax, Ks, and Ki of 0.6298day(-1), 86.78mgL(-1), and 714.3mgL(-1), respectively. The GC-MS analysis indicated that DEHP was degraded into mono-ethylhexyl phthalate and phthalate acid before its complete mineralization. Bioaugmentation of DEHP-contaminated soils with strain MT-O has greatly enhanced DEHP disappearance rate in soils, providing great potential for efficiently remediating DEHP-contaminated environment.

  20. Basic Characteristics of Bis(2-ethylhexyl)phosphate-impregnated Adsorbent Used for Separation of Minor Actinides from FBR-Spent Fuel

    NASA Astrophysics Data System (ADS)

    Oda, Ryohei; Arai, Tsuyoshi; Nagayama, Katsuhisa; Watanabe, Sou; Sano, Yuichi; Myouchin, Munetaka

    FBR-spent nuclear fuel includes a great deal of minor actinides (MA: Am and Cm), which become febrile. Radioactive wastes including MA require a large area of ground for dumping and result in high cost. In Fast Reactor Cycel System Technology Development Project (FaCT) in Japan, we have been investigating extraction chromatography for separation of long-lived MA and specific fission products (FP) from high-level liquid wastes (HLLW). This method is expected to allow us to reduce an organic solvent use and to realize compact equipment. In this work, we have studied the static and dynamic adsorption behavior of representative FP contained in HLLW, Mo(VI), Zr(IV), Nd(III) and EU(III), on a bis(2-ethylhexyl)phosphate (HDEHP)-impregnated adsorbent. Such fundamental data should facilitate the efficient design of efficient MA recovery processes. Column adsorption experiments with the HDEHP-impregnated adsorbent have revealed that an increase in a flow rate results in a short breakthrough time and reduces the adsorption capacity of the column for all the elements tested. These results strongly suggest that a lower flow rate is preferable to enhance the adsorption capacity of the adsorbent.

  1. The adjuvant effect induced by di-(2-ethylhexyl) phthalate (DEHP) is mediated through oxidative stress in a mouse model of asthma.

    PubMed

    You, Huihui; Chen, Shaohui; Mao, Lin; Li, Bing; Yuan, Ye; Li, Rui; Yang, Xu

    2014-09-01

    Di-(2-ethylhexyl) phthalate, as the most commonly used plasticizer, is considered to be related to the asthma prevalence. There are studies affirming that the DEHP has an adjuvant effect in the pathogenesis of allergy asthma. Oxidative stress is one possible pathway for DEHP-adjuvant effect. Thus, this study explored whether DEHP could induce adjuvant effect in mouse asthma model via oxidative stress pathway. Male BALB/c mice were randomly divided into six groups: (1) saline group, (2) DEHP group, (3) ovalbumin (OVA) group, (4) DEHP+OVA group, (5) OVA+vitamin E (Vit E) group, (6) DEHP+OVA+Vit E group. The exposure dose of DEHP was 30 mg/kg body weight (bw)/day. After 18 days of the exposure protocol. Reactive oxygen species (ROS), glutathione (GSH) and malonaldehyde (MDA) levels and biomarkers related to asthma model were measured. Collectively, these data indicated higher ROS and MDA levels and lower GSH contents in DEHP+OVA group than that in OVA group, while Vit E, an antioxidant, could restore ROS, MDA and GSH levels to control levels and attenuate the DEHP and/or OVA effects. Our observations suggested that there was a relationship between oxidative stress and the adjuvant effect induced by DEHP in this mouse asthma model.

  2. Study of the photochemical transformation of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) under conditions relevant to surface waters.

    PubMed

    Calza, P; Vione, D; Galli, F; Fabbri, D; Dal Bello, F; Medana, C

    2016-01-01

    We studied the aquatic environmental fate of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA), a widespread sunscreen, to assess its environmental persistence and photoinduced transformation. Direct photolysis is shown to play a key role in phototransformation, and this fast process is expected to be the main attenuation route of OD-PABA in sunlit surface waters. The generation of transformation products (TPs) was followed via HPLC/HRMS. Five (or four) TPs were detected in the samples exposed to UVB (or UVA) radiation, respectively. The main detected TPs of OD-PABA, at least as far as HPLC-HRMS peak areas are concerned, would involve a dealkylation or hydroxylation/oxidation process in both direct photolysis and indirect phototransformation. The latter was simulated by using TiO2-based heterogeneous photocatalysis, involving the formation of nine additional TPs. Most of them resulted from the further degradation of the primary TPs that can also be formed by direct photolysis. Therefore, these secondary TPs might also occur as later transformation intermediates in natural aquatic systems.

  3. Prenatal Exposures of Male Rats to the Environmental Chemicals Bisphenol A and Di(2-Ethylhexyl) Phthalate Impact the Sexual Differentiation Process.

    PubMed

    Abdel-Maksoud, Fatma M; Leasor, Khrystyna R; Butzen, Kate; Braden, Timothy D; Akingbemi, Benson T

    2015-12-01

    The increasing incidence of reproductive anomalies, described as testicular dysgenesis syndrome, is thought to be related to the exposure of the population to chemicals in the environment. Bisphenol A (BPA) and di(2-ethylhexyl)phthalate (DEHP), which have hormonal and antihormonal activity, have attracted public attention due to their presence in consumer products. The present study investigated the effects of BPA and DEHP on reproductive development. Timed-pregnant female rats were exposed to BPA and DEHP by gavage from gestational days 12 to 21. Results showed that prenatal exposures to test chemicals exerted variable effects on steroidogenic factor 1 and GATA binding protein 4 protein expression and increased (P < .05) sex-determining region Y-box 9 and antimüllerian hormone protein in the infantile rat testis compared with levels in the control unexposed animals. Pituitary LHβ and FSHβ subunit protein expression was increased (P < .05) in BPA- and DEHP-exposed prepubertal male rats but were decreased (P < .05) in adult animals relative to control. Exposure to both BPA and DEHP in utero inhibited (P < .05) global DNA hydroxymethylation in the adult testis in association with altered DNA methyltransferase protein expression. Together the present data suggest that altered developmental programming in the testes associated with chemical exposures are related to the disruption of sexual differentiation events and DNA methylation patterns. The chemical-induced effects impact the development of steroidogenic capacity in the adult testis. PMID:26372177

  4. Central metal ion exchange in a coordination polymer based on lanthanide ions and di(2-ethylhexyl)phosphoric acid: exchange rate and tunable affinity.

    PubMed

    Tasaki-Handa, Yuiko; Abe, Yukie; Ooi, Kenta; Tanaka, Mikiya; Wakisaka, Akihiro

    2014-01-01

    In this paper the exchange of lanthanide(III) ions (Ln(3+)) between a solution and a coordination polymer (CP) of di(2-ethylhexyl)phosphoric acid (Hdehp), [Ln(dehp)3], is studied. Kinetic and selectivity studies suggest that a polymeric network of [Ln(dehp)3] has different characteristics than the corresponding monomeric complex. The reaction rate is remarkably slow and requires over 600 h to reach in nearly equilibrium, and this can be explained by the polymeric crystalline structure and high valency of Ln(3+). The affinity of the exchange reaction reaches a maximum with the Ln(3+) possessing an ionic radius 7% smaller than that of the central Ln(3+), therefore, the affinity of the [Ln(dehp)3] is tunable based on the choice of the central metal ion. Such unique affinity, which differs from the monomeric complex, can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The latter likely becomes predominant for Ln(3+) exchange when the ionic radius of the ion in solution is smaller than the original Ln(3+) by more than 7%. Structural studies suggest that the incoming Ln(3+) forms a new phase though an exchange reaction, and this could plausibly cause the structural strain.

  5. Study of the photochemical transformation of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) under conditions relevant to surface waters.

    PubMed

    Calza, P; Vione, D; Galli, F; Fabbri, D; Dal Bello, F; Medana, C

    2016-01-01

    We studied the aquatic environmental fate of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA), a widespread sunscreen, to assess its environmental persistence and photoinduced transformation. Direct photolysis is shown to play a key role in phototransformation, and this fast process is expected to be the main attenuation route of OD-PABA in sunlit surface waters. The generation of transformation products (TPs) was followed via HPLC/HRMS. Five (or four) TPs were detected in the samples exposed to UVB (or UVA) radiation, respectively. The main detected TPs of OD-PABA, at least as far as HPLC-HRMS peak areas are concerned, would involve a dealkylation or hydroxylation/oxidation process in both direct photolysis and indirect phototransformation. The latter was simulated by using TiO2-based heterogeneous photocatalysis, involving the formation of nine additional TPs. Most of them resulted from the further degradation of the primary TPs that can also be formed by direct photolysis. Therefore, these secondary TPs might also occur as later transformation intermediates in natural aquatic systems. PMID:26512801

  6. Migration from plasticized films into foods. 2. Migration of di-(2-ethylhexyl)adipate from PVC films used for retail food packaging.

    PubMed

    Castle, L; Mercer, A J; Startin, J R; Gilbert, J

    1987-01-01

    A UK survey of di-(2-ethylhexyl)adipate (DEHA) levels in retail foods (83 samples) wrapped in plasticized PVC film has been carried out, examining a wide range of different food types obtained from retail and take-away outlets. Foodstuffs analysed included fresh meat and poultry, ready-cooked poultry, cheese, fruit, vegetables and baked goods such as cakes, bread rolls and sandwiches. Analysis by stable isotope dilution GC/MS showed DEHA levels ranging from 1.0 to 72.8 mg/kg in uncooked meat and poultry, 9.4 to 48.6 mg/kg in cooked chicken portions, 27.8 to 135.0 mg/kg in cheese, less than 2.0 mg/kg in fruit and vegetables and 11 to 212 mg/kg in baked goods and sandwiches. The level of DEHA migration correlated with the extent of contact between the film and exposed fatty portions of the food, whether that was the mayonnaise filling of a sandwich or the surface fat from a joint of uncooked meat. The level of DEHA in meat exposed to plasticized film was not reduced significantly by volatilization or chemical transformation on subsequent cooking by grilling or frying.

  7. Migration from plasticized films into foods. 1. Migration of di-(2-ethylhexyl)adipate from PVC films during home-use and microwave cooking.

    PubMed

    Startin, J R; Sharman, M; Rose, M D; Parker, I; Mercer, A J; Castle, L; Gilbert, J

    1987-01-01

    Migration of di-(2-ethylhexyl)adipate (DEHA) into a diverse range of foods arising from the domestic use of plasticized PVC films has been determined using a stable isotope dilution GC/MS procedure. Aspects of home use reported in this study include the wrapping and covering of foods such as cheese, cooked meats, sandwiches, cakes, fresh fruit and vegetables; the use of films during food preparation such as marinading; covering during microwave reheating of previously prepared foods, and covering during microwave cooking. Contact between film and foods was for differing temperatures and times, representative of the range of conditions likely to be experienced in practice in the home. Migration increased with both the length of contact time and temperature of exposure, with the highest levels observed where there was a direct contact between the film and food, and where the latter had a high fat content on the contact surface. Highest levels of migration were observed for cheese, cooked meats, cakes and for microwave-cooked foods, whilst lower levels were observed for wrapping of unfilled sandwiches, fruit and vegetables (except avocado), and for food preparation including microwave reheating where there was covering of the food in a container but little or no direct contact.

  8. Developmental exposure to di(2-ethylhexyl) phthalate impairs endocrine pancreas and leads to long-term adverse effects on glucose homeostasis in the rat.

    PubMed

    Lin, Yi; Wei, Jie; Li, Yuanyuan; Chen, Jun; Zhou, Zhao; Song, Liqiong; Wei, Zhengzheng; Lv, Ziquan; Chen, Xi; Xia, Wei; Xu, Shunqing

    2011-09-01

    -Di(2-ethylhexyl) phthalate (DEHP), a typical endocrine-disrupting chemical (EDC), is widely used as plasticizer. DEHP exposure in humans is virtually ubiquitous, and those undergoing certain medical procedures can be especially high. In this study, we investigated whether developmental DEHP exposure disrupted glucose homeostasis in the rat and whether this was associated with the early impairment in endocrine pancreas. Pregnant Wistar rats were administered DEHP (1.25 and 6.25 mg·kg(-1)·day(-1)) or corn oil throughout gestation and lactation by oral gavage. Body weight, glucose and insulin tolerance, and β-cell morphometry and function were examined in offspring during the growth. In this study, developmental DEHP exposure led to abnormal β-cell ultrastructure, reduced β-cell mass, and pancreatic insulin content as well as alterations in the expression of genes involved in pancreas development and β-cell function in offspring at weaning. At adulthood, female DEHP-exposed offspring exhibited elevated blood glucose, reduced serum insulin, impaired glucose tolerance, and insulin secretion. Male DEHP-exposed offspring had increased serum insulin, although there were no significant differences in blood glucose at fasting and during glucose tolerance test. In addition, both male and female DEHP-exposed offspring had significantly lower birth weight and maintained relatively lower body weight up to 27 wk of age. These results suggest that developmental exposure to DEHP gives rise to β-cell dysfunction and the whole body glucometabolic abnormalities in the rat. DEHP exposure in critical periods of development can be a potential risk factor, at least in part, for developing diabetes.

  9. The Effects of Di-(2-ethylhexyl)-phthalate Exposure on Fertilization and Embryonic Development In Vitro and Testicular Genomic Mutation In Vivo

    PubMed Central

    Gu, Yi-Hua; Liu, Miao; Xu, Yan; Yuan, Yao; Sun, Fei; Zhang, Hui-Qin; Shi, Hui-Juan

    2012-01-01

    The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ – at least in testes, are of great concern to human male reproductive health. PMID:23226291

  10. Genotypic variation in the uptake, accumulation, and translocation of di-(2-ethylhexyl) phthalate by twenty cultivars of rice (Oryza sativa L.).

    PubMed

    Cai, Quan-Ying; Xiao, Pei-Yun; Chen, Tong; Lü, Huixiong; Zhao, Hai-Ming; Zeng, Qiao-Yun; Li, Yan-Wen; Li, Hui; Xiang, Lei; Mo, Ce-Hui

    2015-06-01

    Agricultural soil in China contains high levels of di-(2-ethylhexyl) phthalate (DEHP), especially in paddy-field soil of Guangdong province of China, but the accumulation and translocation of DEHP by rice (Oryza sativa L.) remains unknown. In the present study, twenty rice cultivars were cultivated in paddy soil spiked with DEHP, and variations in DEHP accumulation and translocation among various cultivars were investigated. Our results showed that DEHP concentrations in roots and shoots of different rice cultivars at four growth stages (i.e., ripening, tillering, jointing, and flowering stages) varied greatly from 0.26 to 11.8 mg/kg (dry weight, dw) and 0.40 to 7.58 mg/kg (dw), respectively. No obvious change over time was observed. The greatest variation in DEHP concentrations among the rice cultivars occurred at ripening stage, whereas the lowest variation at flowering stage. During ripening stage, the largest variation in DEHP concentrations among cultivars were observed in stems (varying from 0.35 to 13.2 mg/kg), whereas the least one was observed in roots (ranging from 1.01 to 5.72 mg/kg). Significant differences in DEHP concentrations in the roots, stems, leaves and grains of most rice cultivars were found. The translocation factors of DEHP from roots to stems or stems to leaves were higher than those from shoots to grains. Overall, cultivars Tianfengyou 316, Wuyou 308, and Peizataifeng, which contained low levels of DEHP in grains but high levels in shoots, were ideal cultivars for simultaneous production of safe food and phytoremediation of contaminated soil.

  11. Features of the thermodynamics of trivalent lanthanide/actinide distribution reactions by tri-n-octylphosphine oxide and bis(2-ethylhexyl) phosphoric acid.

    PubMed

    Grimes, Travis S; Zalupski, Peter R; Martin, Leigh R

    2014-11-01

    A new methodology has been developed to study the thermochemical features of the biphasic transfer reactions of trisnitrato complexes of lanthanides and americium by a monofunctional solvating ligand (tri-n-octylphosphine oxide, TOPO). Stability constants for successive nitrato complexes (M(NO3)x(3-x)(aq) where M is Eu(3+), Am(3+), or Cm(3+)) were determined to assist in the calculation of the extraction constant, K(ex), for the metal ions under study. Enthalpies of extraction (ΔH(extr)) for the lanthanide series (excluding Pm(3+)) and Am(3+) by TOPO have been measured using isothermal titration calorimetry. The observed ΔH(extr) were found to be constant at ~29 kJ mol(-1) across the series from La(3+) to Er(3+), with a slight decrease observed from Tm(3+) to Lu(3+). These heats were found to be consistent with enthalpies determined using van't Hoff analysis of temperature dependent extraction studies. A complete set of thermodynamic parameters (ΔG, ΔH, ΔS) was calculated for Eu(NO3)3, Am(NO3)3, and Cm(NO3)3 extraction by TOPO and Am(3+) and Cm(3+) extraction by bis(2-ethylhexyl) phosphoric acid (HDEHP). A discussion comparing the energetics of these systems is offered. The measured biphasic extraction heats for the transplutonium elements, ΔH(extr), presented in these studies are the first ever direct measurements offered using two-phase calorimetric techniques. PMID:25315891

  12. Possible Mechanisms of Di(2-ethylhexyl) Phthalate-Induced MMP-2 and MMP-9 Expression in A7r5 Rat Vascular Smooth Muscle Cells

    PubMed Central

    Shih, Mei-Fen; Pan, Kuang-Hung; Cherng, Jong Yuh

    2015-01-01

    Proliferation and migration of vascular smooth muscle cells (VSMC) are important in the development and/or progression of many cardiovascular diseases, including atherosclerosis. Evidence shows that matrix metalloproteinase (MMP)-2 and MMP-9 are related to the pathogenesis of atherosclerosis. The expressions of MMP-2 and MMP-9 in atherosclerosis are regulated via various pathways, such as p38 mitogen activated protein kinase (MAPK), extracellular signal regulated kinase 1 and 2 (ERK1/2), Akt, and nuclear factor kappa (NF-κB). Di(2-ethylhexyl) phthalate (DEHP) has been shown to induce atherosclerosis by increasing tumor necrosis factor (TNF)-α, interleukin (IL)-6, and intercellular adhesion molecule (ICAM) productions. However, whether DEHP poses any effects on MMP-2 or MMP-9 expression in VSMC has not yet been answered. In our studies, rat aorta VSMC was treated with DEHP (between 2 and 17.5 ppm) and p38 MAPK, ERK1/2, Akt, NF-κB, and MMP-2 and MMP-9 proteins and activities were measured. Results showed that the presence of DEHP can induce higher MMP-2 and MMP-9 expression than the controls. Similar results on MMP-regulating proteins, i.e., p38 MAPK, ERK1/2, Akt, and NF-κB, were also observed. In summary, our current results have showed that DEHP can be a potent inducer of atherosclerosis by increasing MMP-2 and MMP-9 expression at least through the regulations of p38 MAPK, ERK1/2, Akt, and NF-κB. PMID:26690114

  13. Effects of uterine and lactational exposure to di-(2-ethylhexyl) phthalate on spatial memory and NMDA receptor of hippocampus in mice.

    PubMed

    Dai, Yuhua; Yang, Yanling; Xu, Xiaohong; Hu, Yizhong

    2015-05-01

    Di-(2-ethylhexyl) phthalate (DEHP) is an environmental endocrine disrupter. Currently, little is known about neurodevelopmental toxicity of DEHP in wildlife and humans. The present study investigated the effects of DEHP, focusing on the changes in the behavior of offspring mice at the ages of 6 and 12w, respectively, following utero and lactational exposure to DEHP (10, 50, and 200mg/kg/d) from gestation day 7 through postnatal day 21. The results of open field tasks showed that DEHP increased the grooming of males at age 6w and females at age 12w but decreased the frequency of rearing of 6-w-old females and the number of grid crossings of 12-w-old females. In the Morris water maze task, 50 and 200mg/kg/d DEHP significantly prolonged the time of searching the hidden platform in water maze and reduced the time staying in the target quadrant during a probe trial of 6-w-old male mice, but not of 6-w-old females nor 12-w-old mice of both sexes, suggesting an impaired spatial learning and memory among younger males after perinatal exposure to DEHP. Western blot analyses further showed that DEHP at 50 and 200mg/kg/d decreased the levels of the N-methyl-d-aspartic acid (NMDA) receptor subunits NR1 and NR2B in the hippocampus of 6-w-old males. These results suggest that uterine and lactational exposure to low doses of DEHP sex-specifically impacted behaviors, including locomotion activity and spatial memory, via the concomitant inhibition of the NMDA receptor of the hippocampus in offspring mice.

  14. Kinetics of the phthalate metabolites mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) in male subjects after a single oral dose.

    PubMed

    Mittermeier, Astrid; Völkel, Wolfgang; Fromme, Hermann

    2016-06-11

    Humans have been exposed to dialkyl ortho-phthalates for decades. Due to degradation the phthalate monoesters, responsible for the toxic effects, are additionally found in environmental media as well as food samples. Nevertheless, the toxicokinetic properties of the monoesters are not known. Therefore, metabolism of the phthalate monoesters mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) was studied in four male volunteers (23-58 years of age) after ingestion of a single dose of 50μg/kg bw D4-MEHP or 10μg/kg bw D4-MnBP. The main metabolites in urine were determined up to 46h after administration. In the MEHP-study, more than 90% of each metabolite appeared in the urine within the first 22h, and the average excreted amount of D4-MEHP and its four secondary metabolites was 62% of the administered dose. The highest value of 15% was observed for mono-2-ethyl-5-carboxy-pentyl phthalate (D4-5cx-MEPP). The mean elimination half-life of D4-MEHP was estimated to be 3.5±1.4h. In the MnBP-study, the total recovered values of D4-MnBP and its secondary metabolites ranged from 52% to 130%. The monoester itself, with a half-life of 1.9±0.5h, accounted for the majority of the ingested dose (92%), while the secondary metabolites D4-mono-3-hydroxy-n-butyl phthalate (D4-3OH-MnBP) and D4-3-carboxy-mono-propyl phthalate (D4-3cx-MPP) represented only 7.1% and 1.0% of the ingested dose, respectively. Overall, this study determined that the kinetics of the phthalate monoesters MEHP and MnBP after oral dosage are comparable to the properties of their diesters.

  15. Possible Mechanisms of Di(2-ethylhexyl) Phthalate-Induced MMP-2 and MMP-9 Expression in A7r5 Rat Vascular Smooth Muscle Cells.

    PubMed

    Shih, Mei-Fen; Pan, Kuang-Hung; Cherng, Jong Yuh

    2015-12-04

    Proliferation and migration of vascular smooth muscle cells (VSMC) are important in the development and/or progression of many cardiovascular diseases, including atherosclerosis. Evidence shows that matrix metalloproteinase (MMP)-2 and MMP-9 are related to the pathogenesis of atherosclerosis. The expressions of MMP-2 and MMP-9 in atherosclerosis are regulated via various pathways, such as p38 mitogen activated protein kinase (MAPK), extracellular signal regulated kinase 1 and 2 (ERK1/2), Akt, and nuclear factor kappa (NF-κB). Di(2-ethylhexyl) phthalate (DEHP) has been shown to induce atherosclerosis by increasing tumor necrosis factor (TNF)-α, interleukin (IL)-6, and intercellular adhesion molecule (ICAM) productions. However, whether DEHP poses any effects on MMP-2 or MMP-9 expression in VSMC has not yet been answered. In our studies, rat aorta VSMC was treated with DEHP (between 2 and 17.5 ppm) and p38 MAPK, ERK1/2, Akt, NF-κB, and MMP-2 and MMP-9 proteins and activities were measured. Results showed that the presence of DEHP can induce higher MMP-2 and MMP-9 expression than the controls. Similar results on MMP-regulating proteins, i.e., p38 MAPK, ERK1/2, Akt, and NF-κB, were also observed. In summary, our current results have showed that DEHP can be a potent inducer of atherosclerosis by increasing MMP-2 and MMP-9 expression at least through the regulations of p38 MAPK, ERK1/2, Akt, and NF-κB.

  16. In vivo chronic and in vitro acute effects of di(2-ethylhexyl) phthalate on pseudopregnant rabbit corpora lutea: possible involvement of peroxisome proliferator-activated receptor gamma.

    PubMed

    Parillo, Francesco; Maranesi, Margherita; Brecchia, Gabriele; Gobbetti, Anna; Boiti, Cristiano; Zerani, Massimo

    2014-02-01

    The in vivo chronic and in vitro acute effects of di(2-ethylhexyl) phthalate (DEHP) on the reproductive function of peroxisome proliferator-activated receptor gamma (PPARG) were studied in rabbit corpora lutea (CL) at early stage (Day 4), midstage (Day 9), and late stage (Day 13) of pseudopregnancy. The rabbits were in vivo treated with DEHP for 15 days before induction of pseudopregnancy. Immunohistochemistry provided evidence for the presence of PPARG, prostaglandin endoperoxide synthase 1 (PTGS1), PTGS2, prostaglandin E2-9-ketoreductase (PGE2-9-K), and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in all the luteal cells during pseudopregnancy. DEHP decreased progesterone plasma levels and CL production in all the luteal stages and PPARG protein and gene expressions in early and mid-CL. DEHP in vivo treatment reduced PTGS2 protein expression at the late stage and that of PGE2-9-K at all the stages, whereas PTGS1 and 3beta-HSD were not affected. In in vitro cultured CL, DEHP alone, the PPARG antagonist T0070907 alone, or DEHP plus T0070907 diminished progesterone production and 3beta-HSD activity and increased PGF2alpha and PTGS2 in early and mid-CL, whereas DEHP plus the PPARG agonist 15d-PGJ2 did not affect these hormones and enzymes. All the in vitro treatments did not affect PGE2 secretion as well as PTGS1 and PGE2-9-K enzymatic activities in all the luteal stages. These results provided evidence that DEHP favors functional luteolysis of pseudopregnant rabbit CL, with a mechanism that seems to involve PPARG expression down-regulation, an increase of PTGS2 activity and prostaglandin F2alpha secretion, 3beta-HSD down-regulation, and decrease in progesterone.

  17. Influence of temperature on the emission of di-(2-ethylhexyl)phthalate (DEHP) from PVC flooring in the emission cell FLEC.

    PubMed

    Clausen, Per Axel; Liu, Zhe; Kofoed-Sørensen, Vivi; Little, John; Wolkoff, Peder

    2012-01-17

    Emissions of di-(2-ethylhexyl) phthalate (DEHP) from one type of polyvinylchloride (PVC) flooring with approximately 13% (w/w) DEHP as plasticizer were measured in the Field and Laboratory Emission Cell (FLEC). The gas-phase concentrations of DEHP versus time were measured at air flow rate of 450 mL·min(-1) and five different temperatures: 23 °C, 35 °C, 47 °C, 55 °C, and 61 °C. The experiments were terminated two weeks to three months after steady-state was reached and the interior surface of the FLECs was rinsed with methanol to determine the surface concentration of DEHP. The most important findings are (1) DEHP steady-state concentrations increased greatly with increasing temperature (0.9 ± 0.1 μg·m(-3), 10 ± 1 μg·m(-3), 38 ± 1 μg·m(-3), 91 ± 4 μg·m(-3), and 198 ± 5 μg·m(-3), respectively), (2) adsorption to the chamber walls decreased greatly with increasing temperature (measured partition coefficient between FLEC air and interior surface are: 640 ± 146 m, 97 ± 20 m, 21 ± 5 m, 11 ± 2 m, and 2 ± 1 m, respectively), (3) gas-phase DEHP concentration in equilibrium with the vinyl flooring surface is close to the vapor pressure of pure DEHP, and (4) with an increase of temperature in a home from 23 to 35 °C, the amount of DEHP in the gas- and particle-phase combined is predicted to increase almost 10-fold. The amount in the gas-phase increases by a factor of 24 with a corresponding decrease in the amount on the airborne particles. PMID:22191658

  18. Plant-originated glycoprotein (24 kDa) has an inhibitory effect on proliferation of BNL CL.2 cells in response to di(2-ethylhexyl)phthalate.

    PubMed

    Lee, Jin; Lim, Kye-Taek

    2011-08-01

    Di(2-ethylhexyl)phthalate (DEHP) is one of the many environmental chemicals that are widely used in polyvinyl chloride products, vinyl flooring, food packaging and infant toys. They cause cell proliferation or dysfunction of human liver. The purpose of this study is to investigate the inhibitory effect of a glycoprotein (24 kDa) isolated from Zanthoxylum piperitum DC (ZPDC) on proliferation of liver cell in the DEHP-induced BNL CL. 2 cells. [³H]-thymidine incorporation, intracellular reactive oxygen species (ROS), intracellular Ca²⁺ mobilization and activity of protein kinase C (PKC) were measured using radioactivity and fluorescence method respectively. The expression of mitogen-activated protein kinases [extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK)], activator protein (AP)-1 (c-Jun and c-Fos), proliferating cell nuclear antigen (PCNA) and cell cycle-related factors (cyclin D1/cyclin-dependent kinase [CDK] 4) were evaluated using Western blotting or electrophoretic mobility shift assay. The results in this study showed that the levels of [³H]-thymidine incorporation, intracellular ROS, intracellular Ca²⁺ mobilization and activity of PKCα were inhibited by ZPDC glycoprotein (100 µg/ml) in the DEHP-induced BNL CL. 2 cells. Also, activities of ERK, JNK and AP-1 were reduced by ZPDC glycoprotein (100 µg/ml). With regard to cell proliferation, activities of PCNA and cyclin D1/CDK4 were significantly suppressed at treatment with ZPDC glycoprotein (100 µg/ml) in the presence of DEHP. Taken together, these findings suggest that ZPDC glycoprotein significantly normalized activities of PCNA and cyclin D1/CDK4, which relate to cell proliferation factors. Thus, ZPDC glycoprotein appears to be one of the compounds derived from natural products that are able to inhibit cell proliferation in the phthalate-induced BNL CL. 2 cells. PMID:21721021

  19. Kinetics of the phthalate metabolites mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) in male subjects after a single oral dose.

    PubMed

    Mittermeier, Astrid; Völkel, Wolfgang; Fromme, Hermann

    2016-06-11

    Humans have been exposed to dialkyl ortho-phthalates for decades. Due to degradation the phthalate monoesters, responsible for the toxic effects, are additionally found in environmental media as well as food samples. Nevertheless, the toxicokinetic properties of the monoesters are not known. Therefore, metabolism of the phthalate monoesters mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MnBP) was studied in four male volunteers (23-58 years of age) after ingestion of a single dose of 50μg/kg bw D4-MEHP or 10μg/kg bw D4-MnBP. The main metabolites in urine were determined up to 46h after administration. In the MEHP-study, more than 90% of each metabolite appeared in the urine within the first 22h, and the average excreted amount of D4-MEHP and its four secondary metabolites was 62% of the administered dose. The highest value of 15% was observed for mono-2-ethyl-5-carboxy-pentyl phthalate (D4-5cx-MEPP). The mean elimination half-life of D4-MEHP was estimated to be 3.5±1.4h. In the MnBP-study, the total recovered values of D4-MnBP and its secondary metabolites ranged from 52% to 130%. The monoester itself, with a half-life of 1.9±0.5h, accounted for the majority of the ingested dose (92%), while the secondary metabolites D4-mono-3-hydroxy-n-butyl phthalate (D4-3OH-MnBP) and D4-3-carboxy-mono-propyl phthalate (D4-3cx-MPP) represented only 7.1% and 1.0% of the ingested dose, respectively. Overall, this study determined that the kinetics of the phthalate monoesters MEHP and MnBP after oral dosage are comparable to the properties of their diesters. PMID:27091076

  20. Variability over 1 Week in the Urinary Concentrations of Metabolites of Diethyl Phthalate and Di(2-Ethylhexyl) Phthalate among Eight Adults: An Observational Study

    PubMed Central

    Preau, James L.; Wong, Lee-Yang; Silva, Manori J.; Needham, Larry L.; Calafat, Antonia M.

    2010-01-01

    Background Phthalates are metabolized and eliminated in urine within hours after exposure. Several reports suggest that concentrations of phthalate metabolites in a spot urine sample can provide a reliable estimation of exposure to phthalates for up to several months. Objectives We examined inter- and intraperson and inter- and intraday variability in the concentrations of monoethyl phthalate (MEP), the major metabolite of diethyl phthalate, commonly used in personal care products, and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), a metabolite of di(2-ethylhexyl) phthalate (DEHP), a polyvinyl chloride plasticizer of which diet is the principal exposure source, among eight adults who collected all urine voids (average, 7.6 samples/person/day) for 1 week. Methods We analyzed the urine samples using online solid-phase extraction coupled to isotope dilution–high-performance liquid chromatography–tandem mass spectrometry. Results Regardless of the type of void (spot, first morning, 24-hr collection), for MEP, interperson variability in concentrations accounted for > 75% of the total variance. By contrast, for MEHHP, within-person variability was the main contributor (69–83%) of the total variance. Furthermore, we observed considerable intraday variability in the concentrations of spot samples for MEHHP (51%) and MEP (21%). Conclusions MEP and MEHHP urinary concentrations varied considerably during 1 week, but the main contributors to the total variance differed (interday variability, MEHHP; interperson variability, MEP) regardless of the sampling strategy (spot, first morning, 24-hr collection). The nature of the exposure (diet vs. other lifestyle factors) and timing of urine sampling to evaluate exposure to phthalates should be considered. For DEHP and phthalates to which people are mostly exposed through diet, collecting 24-hr voids for only 1 day may not be advantageous compared with multiple spot collections. When collecting multiple spot urine samples

  1. Effects of the peroxisome proliferator di(2-ethylhexyl)phthalate on cell turnover and peroxisome proliferation in primary chick embryo hepatocytes.

    PubMed

    Arias, Elio

    2012-12-01

    The peroxisome proliferator (PP) di(2-ethylhexyl)phthalate (DEHP) is widely used as a plasticizer and can contaminate air, water, and soil. As yet, no data have been published on its potential to induce changes in cell growth of nonmammalian hepatocytes. In the present study, the effects of DEHP on cell turnover and induction of peroxisome proliferation were evaluated in primary hepatocyte cultures from chick embryos. Cells were treated after attachment with 0, 25, 50, 75, and 100 µM DEHP for up to 96 h. S-phase increased significantly (p < 0.01) from a background level of 5.5 ± 0.1% in solvent-control hepatocytes to a maximum level of 7.1 ± 0.1% in cells exposed for 48 h to 100 µM DEHP and decreased to near 6% by 96 h. Lower (p < 0.05) levels of induction were seen at 50 and 75 µM DEHP. Spontaneous apoptosis showed a slight (p < 0.05) decrease in hepatocytes treated with ≥75 µM dosages, as measured at 72 to 96 h. Induction of peroxisome proliferation was observed for cultures treated with ≥75 µM dosages at 48 h onwards. The results of the present study indicate that avian species may be responsive to the effects of PPs and may thus be affected by the presence of DEHP in the environment, but that this species is less sensitive than rodents.

  2. Adsorption and Fenton regeneration of SBA-15 for di-(2-ethylhexyl) phthalate leached from PVC sheets by Gram-positive strains LHM1 and LHM2

    NASA Astrophysics Data System (ADS)

    Hwang, S.; Latorre, I.; Caban, M.; Soto, B.; Montalvo-Rodríguez, R.; Hernández-Maldonado, A.

    2012-12-01

    Bioleaching of Di-(2-ethylhexyl) phthalate (DEHP) from PVC sheets was studied with newly isolated, Gram-positive strains LHM1 and LHM2 capable of growing on DEHP as the sole carbon source. According to 16S rRNA gene analysis, strains LHM1 and LHM2 were closely related (more than 97% similarity) to Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. The biodeteriorated PVC sheets by the strains LHM1 and LHM2 had thicker biofilm development. Despite their metabolic capability of degrading DEHP as the sole carbon source, the strains LHM1 and LHM2 did not metabolize all DEHP leached out of the PVC sheets. Thermogravimetric analysis (TGA) showed that the biodeterioration by strains LHM1 and LHM2 resulted in less amount of and weakly bonded DEHP present in PVC sheets, in comparison to the virgin PVC sheet. Therefore, PVC biodeterioration by strains LHM1 and LHM2 might play an important role in stability of PVC sheets and fate and effect of leached DEHP on the environmental receptors. In response to this, an advanced adsorption with SBA-15 was assessed as a potential alternative DEHP remediation with arsenic as a co-contaminant. SBA-15 had an excellent arsenic adsorption showing >90% arsenic removal when arsenic was present as a singular contaminant. Adsorption effectiveness was irrelevant to the solid/liquid (S/L) ratio. However, when arsenic was present together with DEHP, arsenic adsorption to bare SBA-15 was reduced by 10 - 40%, with lesser S/L ratio having greater arsenic removal. On the contrary, bare SBA-15 only adsorbed ~30% of DEHP on average. When DEHP was present as a co-solute with arsenic, DEHP adsorption to bare SBA-15 was increased. For SBA-15 regeneration, adsorbed arsenic was recovered with EDTA elution, whereas adsorbed DEHP was destructed with Fenton oxidation.

  3. Identification of toxicological biomarkers of di(2-ethylhexyl) phthalate in proteins secreted by HepG2 cells using proteomic analysis.

    PubMed

    Choi, Seonyoung; Park, So-Young; Jeong, Ji; Cho, Eunkyung; Phark, Sohee; Lee, Min; Kwak, Dongsub; Lim, Ji-Youn; Jung, Woon-Won; Sul, Donggeun

    2010-05-01

    The effects of di(2-ethylhexyl) phthalate (DEHP) on proteins secreted by HepG2 cells were studied using a proteomic approach. HepG2 cells were exposed to various concentrations of DEHP (0, 2.5, 5, 10, 25, 50, 100, and 250 microM) for 24 or 48 h. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and comet assays were then conducted to determine the cytotoxicity and genotoxicity of DEHP, respectively. The MTT assay showed that 10 microM DEHP was the maximum concentration that did not cause cell death. In addition, the DNA damage in HepG2 cells exposed to DEHP was found to increase in a dose- and time-dependent fashion. Proteomic analysis using two different pI ranges (4-7 and 6-9) and large size 2-DE revealed the presence of 2776 protein spots. A total of 35 (19 up- and 16 down-regulated) proteins were identified as biomarkers of DEHP by ESI-MS/MS. Several differentiated protein groups were also found. Proteins involved in apoptosis, transportation, signaling, energy metabolism, and cell structure and motility were found to be up- or down-regulated. Among these, the identities of cystatin C, Rho GDP inhibitor, retinol binding protein 4, gelsolin, DEK protein, Raf kinase inhibitory protein, triose phosphate isomerase, cofilin-1, and haptoglobin-related protein were confirmed by Western blot assay. Therefore, these proteins could be used as potential biomarkers of DEHP and human disease associated with DEHP.

  4. Lanthanide ion exchange properties of a coordination polymer consisting of di(2-ethylhexyl) phosphoric acid and trivalent metal ions (Ce3+, Fe3+, or Al3+).

    PubMed

    Ooi, Kenta; Tasaki-Handa, Yuiko; Abe, Yukie; Wakisaka, Akihiko

    2014-03-28

    Three kinds of coordination polymers ([M(dehp)3], M = Ce, Fe, or Al) were prepared by mixing the sodium form (Na(dehp)) of di(2-ethylhexyl) phosphoric acid and MCl3 in an ethanol-water binary mixture. They have monoclinic crystalline structure with similar lattice parameters. The lanthanide ion (Ln(3+) = La(3+), Sm(3+), Dy(3+), or Yb(3+)) exchange properties were studied in a 20 : 80 vol% ethanol-water binary mixture containing 2 mM Ln(NO3)3 at room temperature. The rate of Ln(3+) adsorption is relatively slow; it requires over 3 weeks to reach equilibrium. [M(dehp)3] has different Ln(3+) affinities depending on the kind of central metal ions: the affinity order at 3 week adsorption is Yb(3+) < La(3+) < Dy(3+) < Sm(3+) for [Ce(dehp)3], La(3+) < Sm(3+) < Dy(3+) < Yb(3+) for [Fe(dehp)3], and La(3+) < Sm(3+), Dy(3+), Yb(3+) for [Al(dehp)3]. The difference in affinity order can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The chemical and structural analyses suggested that the Ln(3+) adsorption progresses first by the central M(3+)/Ln(3+) exchange, followed by a morphological change to a rod-like or fibrous form by a solid phase reaction. In the case of [Fe(dehp)3], the eluted Fe(3+) may be hydrolyzed and precipitated as amorphous iron hydroxide.

  5. Di-(2-ethylhexyl) phthalate inhibits testosterone level through disturbed hypothalamic-pituitary-testis axis and ERK-mediated 5α-Reductase 2.

    PubMed

    Ha, Mei; Guan, Xie; Wei, Li; Li, Peng; Yang, Min; Liu, Changjiang

    2016-09-01

    Di-(2-ethylhexyl) phthalate (DEHP) has reproductive toxicity and can affect male reproductive development. In order to clarify adverse effects of DEHP on testicular physiology and testosterone production, Sprague-Dawley (SD) rats were dosed daily with DEHP by gavage for 30days; TM3 cells (mouse Leydig cell line) were treated with DEHP for 24h after pretreatment with vitamin C or U0126. Results indicated that the hypothalamic-pituitary-testis (HPT) axis was disturbed and serum testosterone, LH and FSH levels were decreased following DEHP exposure. Histomorphological changes of rat testes were also observed, such as deformed seminiferous tubules, aggregated chromatin, multiple vacuoles, swollen mitochondria, apoptotic germ cells and Sertoli cells, as well as increased Leydig cell numbers. Moreover, DEHP caused oxidative stress in vivo and in vitro and then induced the ERK pathway, which was required to mediate 5α-Reductase 2 and scavenger receptor class B-1 (SRB1) levels. However, levels of steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), P450 17α-hydroxylase/17.20 lyase (P450c17), and P450 side-chain cleavage enzyme (P450scc) were not significantly altered after DEHP exposure. Taken together, DEHP-disturbed HPT axis and induced 5α-Reductase 2 contribute to the reduction of serum testosterone level. The activated ERK pathway is required to modulate expressions of 5α-Reductase 2 and SRB1. PMID:27155079

  6. The effects of Di-(2-ethylhexyl)-phthalate exposure on fertilization and embryonic development in vitro and testicular genomic mutation in vivo.

    PubMed

    Huang, Xue-Feng; Li, Yan; Gu, Yi-Hua; Liu, Miao; Xu, Yan; Yuan, Yao; Sun, Fei; Zhang, Hui-Qin; Shi, Hui-Juan

    2012-01-01

    The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ - at least in testes, are of great concern to human male reproductive health.

  7. Preparation and characterization of molecularly imprinted polymer for di(2-ethylhexyl) phthalate: application to sample clean-up prior to gas chromatographic determination.

    PubMed

    Shaikh, Huma; Memon, Najma; Khan, Hamayun; Bhanger, M I; Nizamani, S M

    2012-07-20

    The molecularly imprinted polymer (MIP) selective for di(2-ethylhexyl) phthalate (DEHP) an environmental endocrine disruptor was prepared by suspension polymerization using methacrylamide as functional monomer and N,N'-methylene-bis-acrylamide as cross-linker. The imprinted polymer was employed for solid-phase extraction of DEHP from water samples of environmental importance and characterized by FT-IR and SEM. The adsorption properties of the imprinted polymer were demonstrated by equilibrium rebinding experiments, Pseudo-second-order kinetic model, Sips isotherm and Scatchard analysis. The reusability of MIP was checked for at least six repeated batch adsorption cycles and the results showed almost no deterioration in the adsorption capacity. The competitive recognition studies were performed with DEHP and structurally similar compounds; dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP). The imprinting factor (IF) of DEHP was found to be 12.86 which was much higher than the imprinting factors (IF) of other phthalates. A method constituted by molecularly imprinted solid-phase extraction (MISPE) with GC-FID was developed for DEHP analysis in water samples under very simple conditions. Sample loading and desorption conditions were also optimized. The MISPE method's linearity ranged from 0.035 to 3.0 μg ml⁻¹ with r² = 0.9998. Intra-assay, interassay precision and accuracy ranged from 0.0168% to 1.017%, 1.130% to 4.799% and 94.98% to 99.35%, respectively. The LOD and LOQ were found to be 0.011 and 0.035 μg ml⁻¹, respectively. Synthesized MIP was employed in MISPE for cleaning up the spiked river water samples prior to gas chromatographic analysis. The river samples were found to contain DEHP in the range of 1.4 × 10⁻³ to 0.349 μg ml⁻¹. PMID:22673816

  8. Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): kinetic and penetration study.

    PubMed

    Goulas, Antonios E; Zygoura, Panagiota; Karatapanis, Andreas; Georgantelis, Dimitris; Kontominas, Michael G

    2007-04-01

    Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25+/-1 degrees C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240h of contact (kinetic study) and a second group was cut into slices (1.5mm thick) after 240h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31mg/dm(2) film or 81.4mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3mg/dm(2) of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46mg/dm(2) (36.1mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5mm).

  9. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

  10. Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore.

    PubMed

    Biswas, Sujoy; Pathak, P N; Roy, S B

    2012-06-01

    An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λ(max)) for UO(2)(2+)-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol(-1)cm(-1)). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to > 24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO(2)(2+)-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is < 2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98-105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ± 2%. This method can be used to determine 2.5-250 μg mL(-1) uranium in ore leach solutions with high accuracy and precision. PMID:22381794

  11. Developmental profiles and expression of the DNA methyltransferase genes in the fathead minnow (Pimephales promelas) following exposure to di-2-ethylhexyl phthalate.

    PubMed

    Wood, Richard K; Crowley, Emma; Martyniuk, Christopher J

    2016-02-01

    DNA methylation is an epigenetic regulator of gene expression, and this process has been shown to be disrupted by environmental contaminants. Di-2-(ethylhexyl) phthalate (DEHP) and related phthalate esters have been shown to affect development in early life stages of fish and can alter genomic methylation patterns in vertebrates. The objectives of this study were the following: (1) Describe the expression patterns of the DNA methyltransferase (dnmt) genes during early fathead minnow (FHM) development. These genes are critical for methylation and imprinting during development. (2) Determine the effects of DEHP on the development of FHM larvae [1 and 14 days post-hatch (dph)]. (3) Determine the effect of DEHP on dnmt expression and global methylation status in larval FHM. FHMs were first collected over a developmental time course [1, 3, 5, 6, and 14 days post-fertilization (dpf)] to investigate the expression patterns of five dnmt isoforms. The expression of dnmt1 and dnmt7 was relatively high in embryos at 1 dpf but was variable in expression, and these transcripts were later expressed at a lower level (>3 dpf); dnmt3 was significantly higher in embryos at 1 dpf compared to those at 3 dpf. Dnmt6 showed more of a constitutive pattern of expression during the first 2 weeks of development, and the mRNA levels of dnmt8 were higher in embryos at 5 and 6 dpf compared to those at 1 and 3 dpf, corresponding to the hatching period of the embryos. A waterborne exposure to three concentrations of DEHP (1, 10 and 100 µg/L) was conducted on 1-day FHM embryos for 24 h and on larval fish for 2 weeks, ending at 14 dpf. DEHP did not negatively affect survival, hatch rate, or the expression of dnmt isoforms in FHMs. There were no differences in global cytosine methylation following DEHP treatments in 14 dpf larvae, suggesting that environmentally relevant levels of DEHP may not affect global methylation at this stage of FHM development. However, additional targeted methylome studies

  12. Transgenerational Effects of Di (2-Ethylhexyl) Phthalate in the Male CRL:CD(SD) Rat: Added Value of Assessing Multiple Offspring per Litter

    PubMed Central

    Gray, Leon Earl; Barlow, Norman J.; Howdeshell, Kembra L.; Ostby, Joseph S.; Furr, Johnathan R.; Gray, Clark L.

    2009-01-01

    In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis, gubernacular ligaments, epididymis, and other androgen-dependent tissues. In order to define the dose-response relationship between di(2-ethylhexyl) phthalate (DEHP) and the Phthalate Syndrome of reproductive alterations in F1 male rats, Sprague-Dawley (SD) rat dams were dosed by gavage from gestational day 8 to day 17 of lactation with 0, 11, 33, 100, or 300 mg/kg/day DEHP (71–93 males per dose from 12 to 14 litters per dose). Some of the male offspring continued to be exposed to DEHP via gavage from 18 days of age to necropsy at 63–65 days of age (PUB cohort; 16–20/dose). Remaining males were not exposed after postnatal day 17 (in utero-lactational [IUL] cohort) and were necropsied after reaching full maturity. Anogenital distance, sperm counts and reproductive organ weights were reduced in F1 males in the 300 mg/kg/day group and they displayed retained nipples. In the IUL cohort, seminal vesicle weight also was reduced at 100 mg/kg/day. In contrast, serum testosterone and estradiol levels were unaffected in either the PUB or IUL cohorts at necropsy. A significant percentage of F1 males displayed one or more Phthalate Syndrome lesions at 11 mg/kg/day DEHP and above. We were able to detect effects in the lower dose groups only because we examined all the males in each litter rather than only one male per litter. Power calculations demonstrate how using multiple males versus one male/litter enhances the detection of the effects of DEHP. The results at 11 mg/kg/day confirm those reported from a National Toxicology Program multigenerational study which reported no observed adverse effect levels-lowest observed adverse effect levels of 5 and 10 mg/kg/day DEHP, respectively, via the diet. PMID:19482887

  13. Effects of high di(2-ethylhexyl) phthalate (DEHP) exposure due to tainted food intake on pre-pubertal growth characteristics in a Taiwanese population.

    PubMed

    Tsai, Yen-An; Lin, Ching-Ling; Hou, Jia-Woei; Huang, Po-Chin; Lee, Meng-Chih; Chen, Bai-Hsiun; Wu, Ming-Tsang; Chen, Chu-Chih; Wang, Shu-Li; Lee, Ching-Chang; Hsiung, Chao Agnes; Chen, Mei-Lien

    2016-08-01

    On May 23, 2011, a major scandal involving the illegal use of phthalates as clouding agents in food products was reported. Specifically, di(2-ethylhexyl) phthalate (DEHP) was purposefully added to foods as a substitute emulsifier. The purpose of this study was to examine the effects of DEHP exposure on the growth characteristics of the child victims of this scandal. Eighty-eight victims, originating from northern, central, and southern Taiwan and ranging in age from 6.0 to 10.5 years, were invited to participate in this study during clinic visits. The participants underwent follow-up health examinations from August 2012 to February 2013. We collected information on each participant's history of exposure to tainted food products using a questionnaire, and we analyzed their urinary concentrations of DEHP metabolites using high-performance liquid chromatography/tandem mass spectrometry. These data were then used to estimate their daily DEHP intake (DIAll) during the scandal. We also measured physical development parameters (height, weight, and bone age) and hormone levels (thyroid, sex and growth hormones) to evaluate their overall growth characteristics. The average (SD) duration of DEHP intake from tainted nutrition supplements was 1.39 (1.01) years. The median DIAll values were 19.93 and 20.69μg/kg bw/day for boys and girls, respectively. Among the enrolled children, the DIAll values of 46.9% of boys and 51.3% of girls exceeded the reference dose (RfD) of 20μg/kg bw/day established by the US Environmental Protection Agency. Our results demonstrate that DIAll is negatively associated with the height percentile, weight percentile, bone age/chronological age, and insulin-like growth factor 1 (IGF-1) levels but not with IGF binding protein 3 (IGF-BP3) level, IGF-1/IGF-BP3, sex hormones, or thyroid hormone levels. The DEHP DIAll value exceeded the RfD at high rates among children of both genders. Our results suggest that high levels of DEHP exposure due to the

  14. Effects of high di(2-ethylhexyl) phthalate (DEHP) exposure due to tainted food intake on pre-pubertal growth characteristics in a Taiwanese population.

    PubMed

    Tsai, Yen-An; Lin, Ching-Ling; Hou, Jia-Woei; Huang, Po-Chin; Lee, Meng-Chih; Chen, Bai-Hsiun; Wu, Ming-Tsang; Chen, Chu-Chih; Wang, Shu-Li; Lee, Ching-Chang; Hsiung, Chao Agnes; Chen, Mei-Lien

    2016-08-01

    On May 23, 2011, a major scandal involving the illegal use of phthalates as clouding agents in food products was reported. Specifically, di(2-ethylhexyl) phthalate (DEHP) was purposefully added to foods as a substitute emulsifier. The purpose of this study was to examine the effects of DEHP exposure on the growth characteristics of the child victims of this scandal. Eighty-eight victims, originating from northern, central, and southern Taiwan and ranging in age from 6.0 to 10.5 years, were invited to participate in this study during clinic visits. The participants underwent follow-up health examinations from August 2012 to February 2013. We collected information on each participant's history of exposure to tainted food products using a questionnaire, and we analyzed their urinary concentrations of DEHP metabolites using high-performance liquid chromatography/tandem mass spectrometry. These data were then used to estimate their daily DEHP intake (DIAll) during the scandal. We also measured physical development parameters (height, weight, and bone age) and hormone levels (thyroid, sex and growth hormones) to evaluate their overall growth characteristics. The average (SD) duration of DEHP intake from tainted nutrition supplements was 1.39 (1.01) years. The median DIAll values were 19.93 and 20.69μg/kg bw/day for boys and girls, respectively. Among the enrolled children, the DIAll values of 46.9% of boys and 51.3% of girls exceeded the reference dose (RfD) of 20μg/kg bw/day established by the US Environmental Protection Agency. Our results demonstrate that DIAll is negatively associated with the height percentile, weight percentile, bone age/chronological age, and insulin-like growth factor 1 (IGF-1) levels but not with IGF binding protein 3 (IGF-BP3) level, IGF-1/IGF-BP3, sex hormones, or thyroid hormone levels. The DEHP DIAll value exceeded the RfD at high rates among children of both genders. Our results suggest that high levels of DEHP exposure due to the

  15. Rodent Thyroid, Liver, and Fetal Testis Toxicity of the Monoester Metabolite of Bis-(2-ethylhexyl) Tetrabromophthalate (TBPH), a Novel Brominated Flame Retardant Present in Indoor Dust

    PubMed Central

    Springer, Cecilia; Dere, Edward; Hall, Susan J.; McDonnell, Elizabeth V.; Roberts, Simon C.; Butt, Craig M.; Stapleton, Heather M.; Watkins, Deborah J.; McClean, Michael D.; Webster, Thomas F.; Schlezinger, Jennifer J.

    2012-01-01

    Background: Bis-(2-ethylhexyl) tetrabromophthalate (TBPH) is widely used as a replacement for polybrominated diphenyl ethers (PBDEs) in commercial flame retardant mixtures such as Firemaster 550. It is also used in a commercial mixture called DP 45. Mono-(2-ethyhexyl) tetrabromophthalate (TBMEHP) is a potentially toxic metabolite. Objectives: We used in vitro and rodent in vivo models to evaluate human exposure and the potential metabolism and toxicity of TBPH. Methods: Dust collected from homes, offices, and cars was measured for TBPH by gas chromatography followed by mass spectrometry. Pregnant rats were gavaged with TBMEHP (200 or 500 mg/kg) or corn oil on gestational days 18 and 19, and dams and fetuses were evaluated histologically for toxicity. We also assessed TBMEHP for deiodinase inhibition using rat liver microsomes and for peroxisome proliferator-activated receptor (PPAR) α and γ activation using murine FAO cells and NIH 3T3 L1 cells. Results: TBPH concentrations in dust from office buildings (median, 410 ng/g) were higher than in main living areas in homes (median, 150 ng/g). TBPH was metabolized by purified porcine esterases to TBMEHP. Two days of TBMEHP exposure in the rat produced maternal hypothyroidism with markedly decreased serum T3 (3,3´,5-triiodo-l-thyronine), maternal hepatotoxicity, and increased multinucleated germ cells (MNGs) in fetal testes without antiandrogenic effects. In vitro, TBMEHP inhibited deiodinase activity, induced adipocyte differentiation in NIH 3T3 L1 cells, and activated PPARα- and PPARγ-mediated gene transcription in NIH 3T3 L1 cells and FAO cells, respectively. Conclusions: TBPH a) is present in dust from indoor environments (implying human exposure) and b) can be metabolized by porcine esterases to TBMEHP, which c) elicited maternal thyrotoxic and hepatotoxic effects and d) induced MNGs in the fetal testes in a rat model. In mouse NIH 3T3 L1 preadipocyte cells, TBMEHP inhibited rat hepatic microsome deiodinase

  16. Relationship between the ability of sunscreens containing 2-ethylhexyl-4'-methoxycinnamate to protect against UVR-induced inflammation, depletion of epidermal Langerhans (Ia+) cells and suppression of alloactivating capacity of murine skin in vivo.

    PubMed

    Walker, S L; Morris, J; Chu, A C; Young, A R

    1994-01-01

    The UVB sunscreen 2-ethylhexyl-4'-methoxycinnamate was evaluated in hairless albino mouse skin for its ability to inhibit UVR-induced (i) oedema, (ii) epidermal Langerhans cell (Ia+) depletion and (iii) suppression of the alloactivating capacity of epidermal cells (mixed epidermal cell-lymphocyte reaction, MECLR). The sunscreen, prepared at 9% in ethanol or a cosmetic lotion, was applied prior to UVB/UVA irradiation. In some experiments there was a second application halfway through the irradiation. Single applications in both vehicles gave varying degrees of protection from oedema and Langerhans cell depletion but afforded no protection from suppression of MECLR. When the sunscreens were applied twice there was improved protection from oedema and Langerhans cell depletion and complete protection was afforded from suppression of MECLR. There was a clear linear relationship between Langerhans cell numbers and oedema with and without sunscreen application. The relationship between Langerhans cell numbers and MECLR was more complex. These data confirm published discrepancies between protection from oedema (a model for human erythema) and endpoints with immunological significance, but show that 2-ethylhexyl-4'-methoxycinnamate can afford complete immunoprotection, although protection is dependent on the application rate and vehicle.

  17. Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death

    SciTech Connect

    Guida, Natascia; Laudati, Giusy; Galgani, Mario; Santopaolo, Marianna; Montuori, Paolo; Triassi, Maria; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

    2014-10-01

    Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1–100 μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but not Sp3 mRNA, after 24 and 48 h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination. - Highlights: • Di(2-ethylhexyl)phthalate (DEHP) is cytotoxic to SH-SY5Y cells and cortical neurons. • DEHP-induced cytotoxicity is mediated by apoptosis. • DEHP-induced apoptotic cell death is inhibited by class II HDAC MC-1568. • DEHP neurotoxicity is caused by HDAC4-mediated Sp3 degradation by ubiquitin.

  18. Application of the OECD 301F respirometric test for the biodegradability assessment of various potential endocrine disrupting chemicals.

    PubMed

    Stasinakis, Athanasios S; Petalas, Anastasios V; Mamais, Daniel; Thomaidis, Nikolaos S

    2008-06-01

    The biodegradability of several potential endocrine disrupting compounds, namely 4-n-nonylphenol (4-n-NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), bisphenol A (BPA), triclosan (TCS), di-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) was evaluated in this study, using OECD method 301F (manometric respirometry test) and activated sludge as inoculum. According to the results, 4-n-NP and BPA meet the strict definition of ready biodegradability and they are not expected to be persistent during the activated sludge process. Partial biodegradation was observed for DEHP (58.7+/-5.7%, n=3), TCS (52.1+/-8.5%, n=3) and NP1EO (25.9+/-8.1%, n=3), indicating their possible biodegradation in wastewater treatment systems, while no biodegradation was observed for NP2EO, PFOA and PFNA. Experiments in the co-presence of a readily biodegradable compound showed the absence of co-metabolic phenomena during 4-n-NP, BPA and TCS biodegradation. Using first order kinetics to describe biodegradation of the target compounds, half-lives of 4.3+/-0.6, 1.3+/-0.2, 1.8+/-0.5, 6.9+/-2.6 days were calculated for 4-n-NP, BPA, TCS and DEHP, respectively. Toxicity tests using marine bacterium Vibrio fischeri showed that biodegradation of 4-n-NP, NP1EO, BPA and TCS is a simultaneous detoxification process, while possible abiotic or biotic transformations of NP2EO, DEHP, PFOA and PFNA during respirometric test resulted to significant increase of their toxicities. PMID:17881226

  19. Biodegradable synthetic bone composites

    DOEpatents

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  20. Effects of water content and chain length of n-alkane on the interaction enthalpy between the droplets in water/sodium bis(2-ethylhexyl)-sulfosuccinate/n-alkane microemulsions.

    PubMed

    Fan, Dashuang; Zheng, Peizhu; Ma, Yuanming; Yin, Tianxiang; Zhao, Jihua; Shen, Weiguo

    2015-04-14

    The concentration-dependent enthalpies of mixing for water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/n-alkane microemulsions with different water contents ω0 and chain lengths n of n-alkane were determined by isothermal titration microcalorimetry (ITC) and flow-mixing microcalorimetry at 298.15 K and used to calculate the interaction enthalpies (-ΔH(C)) between the droplets. It was found that -ΔH(C) increased with ω0, and changed from negative to positive at about ω0 = 10. The investigation of the dependence of -ΔH(C) on n revealed that the values of -ΔH(C) were negative and had a minimum for ω0 = 5; while they were positive and had a maximum for ω0 = 15. These phenomena were discussed based on the competition of the overlapping contribution of the surfactant tails between two neighbouring droplets and the penetration contribution of the solvent molecules into the surfactant tails. These results indicated the important role of entropy in the stability of the microemulsion systems.

  1. Efficient transport of Am(III) from nitric acid medium using a new conformationally constrained (N,N,N',N'-tetra-2-ethylhexyl)7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamide across a supported liquid membrane.

    PubMed

    Sharma, S; Panja, S; Ghosh, S K; Dhami, P S; Gandhi, P M

    2016-03-15

    Am(III) is one of the most hazardous radionuclide present in nuclear fuel cycle. A new conformationally constrained diamide, (N,N,N',N'-tetra-2-ethylhexyl)7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamide (OBDA) was studied for Am(III) transport from HNO3 medium across a Supported Liquid Membrane. Transport rate was observed to be significantly fast with ∼95% transport of Am(III) within 1h using 0.1M OBDA in the presence of 15% isodecyl alcohol (IDA)/n-dodecane as carrier. The mechanism of transport was investigated by studying various parameters like feed HNO3/NaNO3 concentration, OBDA concentration in the membrane, membrane pore size, membrane thickness etc. From these studies, the mechanism of transport was found to be diffusion controlled with diffusion co-efficient value of 5.1×10(-6)cm(2)/s. The membrane was found to be highly selective for tri- and tetra-valent actinides, and trivalent lanthanides. OBDA based membrane was found to be stable for at least for ten consecutive cycles of operation. PMID:26685064

  2. Measurements of octanol-air partition coefficients, vapor pressures and vaporization enthalpies of the (E) and (Z) isomers of the 2-ethylhexyl 4-methoxycinnamate as parameters of environmental impact assessment.

    PubMed

    Pegoraro, César N; Chiappero, Malisa S; Montejano, Hernán A

    2015-11-01

    2-Ethylhexyl 4-methoxycinnamate is one of the UVB blocking agents more widely used in a variety of industrial fields. There are more than one hundred industrial suppliers worldwide. Given the enormous annual consumption of octinoxate, problems that arise due to the accumulation of this compound in nature should be taken into consideration. The GC-RT was used in this work with the aim of determining the vapor pressure, enthalpies of vaporization and octanol-air partition coefficient, for the BBP, DOP, E- and Z-EHMC esters. The results showed that Z-EHMC is almost five times more volatile than E-EHMC. Moreover, BBP, Z-EHMC and E-EHMC can be classified as substances with a relatively low mobility since they lie within the range of 810 and log(PL/Pa)<-4, therefore, a low mobility can be expected. From these parameters, their particle-bound fraction and gas-particle partition coefficient were also derived. PMID:26210018

  3. Development of dispersive liquid-liquid microextraction technique using ternary solvents mixture followed by heating for the rapid and sensitive analysis of phthalate esters and di(2-ethylhexyl) adipate.

    PubMed

    Farajzadeh, Mir Ali; Khoshmaram, Leila

    2015-01-30

    In this study, for the first time, a dispersive liquid-liquid microextraction technique using a ternary solvent mixture is reported. In order to extract five phthalate esters and di(2-ethylhexyl) adipate with different polarities from aqueous samples, a simplex centroid experimental design method was used to select an optimal mixture of ternary solvents prior to gas chromatographyflame ionization detection. In this work, dimethyl formamide as a disperser solvent containing dichloromethane, chloroform, and carbon tetrachloride as a ternary extraction solvent mixture is injected into sample solution and a cloudy solution is formed. After centrifuging, 250μL of the obtained sedimented phase was transferred into another tube and 5μL DMF was added to it. Then, the tube was heated in a water bath at 75°C for 5min in order to evaporate the main portion of the extraction solvents. Finally, 2μL of the remained phase is injected into the separation system. Under the optimum extraction conditions, the method shows wide linear ranges and low limits of detection and quantification between 0.03-0.15 and 0.09-0.55μgL(-1), respectively. Enrichment factors and extraction recoveries are in the ranges of 980-4500 and 20-90%, respectively. The method is successfully applied in the determination of the target analytes in mineral water, soda, lemon juice, vinegar, dough, and yogurt packed in plastic packages.

  4. Involvement of a chromatin modifier in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell injury: Probably an indirect action via the regulation of NFκB/FasL circuitry

    SciTech Connect

    Chen, Shiwei; Dong, Yushu; Xu, Chun; Jiang, Liming; Chen, Yongjie; Jiang, Cheng; Hou, Wugang; Li, Wei

    2013-11-01

    Highlights: •MTA1 expression is upregulated in SCs upon MEHP treatment. •Knockdown of MTA1 in SCs impairs the MEHP-induced NFκB signaling activation. •Knockdown of MTA1 inhibits recruitment of NFκB onto FasL promoter in MEHP-treated SCs. -- Abstract: The Fas/FasL signaling pathway, controlled by nuclear factor-κB (NFκB) at the transcriptional level, is critical for triggering germ cell apoptosis in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell (SC) injury, but the exact regulation mechanism remain unknown. Here, we discovered that expression level of Metastasis associated protein 1 (MTA1), a component of the Mi-2/nucleosome remodeling and deacetylase complex, was upregulated in SCs during the early recovery after MEHP exposure. This expression change was in line with the dynamic changes in germ cell apoptosis in response to MEHP treatment. Furthermore, a knockdown of MTA1 by RNAi in SCs was found to impair the MEHP-induced early activation of NFκB pathway and abolish the recruitment of NFκB onto FasL promoter, which consequently diminished the MEHP-triggered FasL induction. Considering that Fas/FasL is a well characterized apoptosis initiating signaling during SCs injury, our results point to a potential “switch on” effect of MTA1, which may govern the activation of NFκB/FasL cascade in MEHP-insulted SCs. Overall, the MTA1/NFκB/FasL circuit may serve as an important defensive/repairing mechanism to help to control the germ cell quality after SCs injury.

  5. Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death.

    PubMed

    Guida, Natascia; Laudati, Giusy; Galgani, Mario; Santopaolo, Marianna; Montuori, Paolo; Triassi, Maria; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

    2014-10-01

    Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1-100μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but not Sp3 mRNA, after 24 and 48h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination.

  6. Daily Exposure to Di(2-ethylhexyl) Phthalate Alters Estrous Cyclicity and Accelerates Primordial Follicle Recruitment Potentially Via Dysregulation of the Phosphatidylinositol 3-Kinase Signaling Pathway in Adult Mice1

    PubMed Central

    Hannon, Patrick R.; Peretz, Jackye; Flaws, Jodi A.

    2014-01-01

    ABSTRACT Humans are exposed daily to di(2-ethylhexyl) phthalate (DEHP), a plasticizer found in many consumer, medical, and building products containing polyvinyl chloride. Large doses of DEHP disrupt normal ovarian function; however, the effects of DEHP at environmentally relevant levels, the effects of DEHP on folliculogenesis, and the mechanisms by which DEHP disrupts ovarian function are unclear. The present study tested the hypothesis that relatively low levels of DEHP disrupt estrous cyclicity as well as accelerate primordial follicle recruitment by dysregulating phosphatidylinositol 3-kinase (PI3K) signaling. Adult CD-1 mice were orally dosed with DEHP (20 μg/kg/day–750 mg/kg/day) daily for 10 and 30 days. Following dosing, the effects on estrous cyclicity were examined, and follicle numbers were histologically quantified. Further, the ovarian mRNA and protein levels of PI3K signaling factors that are associated with early folliculogenesis were quantified. The data indicate that 10- and 30-day exposure to DEHP prolonged the duration of estrus and accelerated primordial follicle recruitment. Specifically, DEHP exposure decreased the percentage of primordial follicles and increased the percentage of primary follicles counted following 10-day exposure and increased the percentage of primary follicles counted following 30-day exposure. DEHP exposure, at doses that accelerate folliculogenesis, increased the levels of 3-phosphoinositide-dependent protein kinase-1, mammalian target of rapamycin complex 1, and protein kinase B and decreased the levels of phosphatase and tensin homolog, potentially driving PI3K signaling. Collectively, relatively low levels of DEHP disrupt estrous cyclicity and accelerate primordial follicle recruitment potentially via a mechanism involving dysregulation of PI3K signaling. PMID:24804967

  7. Biomonitoring of the di(2-ethylhexyl) phthalate metabolites mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethyl-5-oxohexyl) phthalate in children and adults during the course of time and seasons.

    PubMed

    Hildenbrand, Sibylle; Wodarz, Roman; Gabrio, Thomas; Volland, Gerhard

    2009-11-01

    Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with ubiquitous spread. Its metabolites are suspected to impair endocrine functions and fertility in man. This study is aimed to assess the DEHP exposure in children and adults, to evaluate the intraindividual variability, the influence of seasons and to identify potential routes of intake. Urine samples were collected from 6 people (age 4-58) over 7 consecutive days 4-times during a year to test for seasonal factors. 5-OH-MEHP and 5-oxo-MEHP were quantified by GC-MS. Urine concentrations of both metabolites were highly correlated with each other. Both female subjects showed remarkably low and stable 5-OH-MEHP concentrations throughout the year (median

  8. Exercise prevents the increased anxiety-like behavior in lactational di-(2-ethylhexyl) phthalate-exposed female rats in late adolescence by improving the regulation of hypothalamus-pituitary-adrenal axis.

    PubMed

    Wang, Dean-Chuan; Chen, Tsan-Ju; Lin, Ming-Lu; Jhong, Yue-Cih; Chen, Shih-Chieh

    2014-09-01

    Both the detrimental effects of early life adversity and the beneficial effects of exercise on the hypothalamic-pituitary-adrenal (HPA) axis have been reported. Early life exposure to di-(2-ethylhexyl)-phthalate (DEHP) may impair the development of endocrine system. In this study, we investigated the effects of lactational DEHP exposure on stress responses in late adolescent female rats and examined the protective role of treadmill running. Sprague-Dawley dams were fed with DEHP (10mg/kg per day) or vehicle during lactation. After weaning, the female offspring rats were trained to exercise on a treadmill for 5 weeks and then stressed by exploring on an elevated plus maze. The activities of HPA axis were evaluated by measuring the plasma levels of ACTH and corticosterone, the expressions of adrenal enzymes cholesterol side-chain cleavage enzyme (CYP11A1) and cytochrome P-450 11β-hydroxylase (CYP11B1), and the expression of hypothalamic glucocorticoid receptors (GR). The results demonstrate that DEHP-exposed rats exhibited enhanced anxiety-like behaviors. Increased hypothalamic GR and plasma ACTH levels, but decreased adrenal CYP11A1 and corticosterone levels, were observed in DEHP-exposed animals under stressed condition. Importantly, in DEHP-exposed animals, exercise during childhood-adolescence reduced anxiety-like behaviors by normalizing stress-induced alterations in ACTH level and adrenal CYP11A1 expression. The findings of this study suggest that treadmill running may provide beneficial effects on ameliorating the dysregulation of HPA axis in lactational DEHP-exposed adolescent female rats.

  9. Epigenetic Effects of Di(2-ethylhexyl) Phthalate

    EPA Science Inventory

    Epidemiological and laboratory investigations suggest that, in addition to genetic changes, environmental pollutants can affect human health through altering epigenetic mechanisms including DNA methylation, histone modification, and microRNA expression. There is evidence in anima...

  10. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  11. Biodegradability of plastics.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  12. Comparative effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) on the aquatic larvae of Chironomus riparius based on gene expression assays related to the endocrine system, the stress response and ribosomes.

    PubMed

    Planelló, Rosario; Herrero, Oscar; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2011-09-01

    In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analysis of the alterations in gene expression profiles of selected inducible and constitutive genes related to the endocrine system, the cellular stress response and the ribosomal machinery. Fourth instar larvae, a model system in aquatic toxicology, were experimentally exposed to five increasing concentrations (0.01, 0.1, 1, 10, and 100mg/L) of DEHP and BBP for 24h. Gene expression was analysed by the changes in levels of transcripts, using RT-PCR techniques with specific gene probes. The exposures to DEHP or BBP were able to rapidly induce the hsp70 gene in a concentration-dependent manner, whereas the cognate form hsc70 was not altered by either of these chemicals. Transcription of ribosomal RNA as a measure of cell viability, quantified by the levels of ITS2, was not affected by DEHP, but was slightly, yet significantly, downregulated by BBP at the highest concentrations tested. Finally, as these phthalates are classified as endocrine disruptor chemicals (EDCs), their potential effect on the ecdysone endocrine system was studied by analysing the two genes, EcR and usp, of the heterodimeric ecdysone receptor complex. It was found that BBP provoked the overexpression of the EcR gene, with significant increases from exposures of 0.1mg/L and above, while DEHP significantly decreased the activity of this gene at the highest concentration. These data are relevant as they show for the first time the ability of phthalates to interfere with endocrine marker genes in invertebrates, demonstrating their potential capacity to alter the ecdysone signalling pathway. Overall, the study clearly shows a differential gene-toxin interaction

  13. Degradation of di(2-ethyl hexyl) phthalate by Fusarium culmorum: Kinetics, enzymatic activities and biodegradation pathway based on quantum chemical modelingpathway based on quantum chemical modeling.

    PubMed

    Ahuactzin-Pérez, Miriam; Tlecuitl-Beristain, Saúl; García-Dávila, Jorge; González-Pérez, Manuel; Gutiérrez-Ruíz, María Concepción; Sánchez, Carmen

    2016-10-01

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. The specific growth rate (μ), maximum biomass (Xmax), biodegradation constant of DEHP (k), half-life (t1/2) of DEHP biodegradation and removal efficiency of DEHP, esterase and laccase specific activities, and enzymatic yield parameters were evaluated for Fusarium culmorum grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L). The greatest μ and the largest Xmax occurred in media supplemented with 1000mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000mg/L) within 60h of growth. The k and t1/2 were 0.024h(-1) and 28h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500mg/L, respectively. Much higher specific esterase activity than specific laccase activity was observed in all media tested. The compounds of biodegradation of DEHP were identified by GC-MS. A DEHP biodegradation pathway by F. culmorum was proposed on the basis of the intermolecular flow of electrons of the identified intermediate compounds using quantum chemical modeling. DEHP was fully metabolized by F. culmorum with butanediol as the final product. This fungus offers great potential in bioremediation of environments polluted with DEHP.

  14. Grey water biodegradability.

    PubMed

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively.

  15. Editorial: biodegradable materials.

    PubMed

    Schaschke, Carl; Audic, Jean-Luc

    2014-11-21

    This Special Issue "Biodegradable Materials" features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  16. Editorial: Biodegradable Materials

    PubMed Central

    Schaschke, Carl; Audic, Jean-Luc

    2014-01-01

    This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment. PMID:25421242

  17. [Study on biodegradation of polyacrylamide].

    PubMed

    Han, Chang-Fu; Zheng, Ai-Fang; Li, Da-Ping

    2006-01-01

    Phanerochaete chrysosporium was introduced into biodegradation of polyacrylamide(PAM), and effects of glucose amount, pH, N concentration, Mn2+ concentration and biodegradation time on biodegradation of PAM were studied. Results show that Phanerochaete chrysosporium has special abilities of enzyme catalysis biodegradation of PAM. And the removal rate of PAM is 50%. Nitrogen limitation (NH4+ = 0.2 g/L) and Mn2+ concentration (Mn2+ = 0.017 5 g/L) are optima of producing PAM biodegradation enzyme.

  18. Systemic approaches to biodegradation.

    PubMed

    Trigo, Almudena; Valencia, Alfonso; Cases, Ildefonso

    2009-01-01

    Biodegradation, the ability of microorganisms to remove complex chemicals from the environment, is a multifaceted process in which many biotic and abiotic factors are implicated. The recent accumulation of knowledge about the biochemistry and genetics of the biodegradation process, and its categorization and formalization in structured databases, has recently opened the door to systems biology approaches, where the interactions of the involved parts are the main subject of study, and the system is analysed as a whole. The global analysis of the biodegradation metabolic network is beginning to produce knowledge about its structure, behaviour and evolution, such as its free-scale structure or its intrinsic robustness. Moreover, these approaches are also developing into useful tools such as predictors for compounds' degradability or the assisted design of artificial pathways. However, it is the environmental application of high-throughput technologies from the genomics, metagenomics, proteomics and metabolomics that harbours the most promising opportunities to understand the biodegradation process, and at the same time poses tremendous challenges from the data management and data mining point of view.

  19. Biodegradable Materials for Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for nonwovens is increasing globally, particularly in the disposable products area. As the consumption of nonwoven products with short life increases, the burden on waste disposal also rises. In this context, biodegradable nonwovens become more important today and for the future. Several new ...

  20. "Cirque du Freak."

    ERIC Educational Resources Information Center

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and child readers. (SG)

  1. Biodegradable analogues of DDT*

    PubMed Central

    Metcalf, Robert L.; Kapoor, Inder P.; Hirwe, Asha S.

    1971-01-01

    Despite the immense utility of DDT for vector control its usefulness is prejudiced by its stability in the environment and by the low rate at which it can be degraded biologically. Metabolic studies in insects, in mice, and in a model ecosystem with several food chains have shown that DDT analogues with substituent groups readily attacked by multifunction oxidases undergo a substantial degree of biological degradation and do not appear to be stored readily in animal tissues or concentrated in food chains. Detailed metabolic pathways have been worked out and it is clear that comparative biochemistry can be used to develop DDT analogues that are adequately persistent yet biodegradable. A number of new DDT analogues have been evaluated for insecticidal activity against flies and mosquitos and for their potential usefulness as safe, persistent, and biodegradable insecticides. PMID:5315354

  2. Biodegradation of cyanuric acid.

    PubMed

    Saldick, J

    1974-12-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO(2) and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand.

  3. Biodegradation of Cyanuric Acid

    PubMed Central

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  4. Safe biodegradable fluorescent particles

    DOEpatents

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  5. Integration of bioinformatics to biodegradation

    PubMed Central

    2014-01-01

    Bioinformatics and biodegradation are two primary scientific fields in applied microbiology and biotechnology. The present review describes development of various bioinformatics tools that may be applied in the field of biodegradation. Several databases, including the University of Minnesota Biocatalysis/Biodegradation database (UM-BBD), a database of biodegradative oxygenases (OxDBase), Biodegradation Network-Molecular Biology Database (Bionemo) MetaCyc, and BioCyc have been developed to enable access to information related to biochemistry and genetics of microbial degradation. In addition, several bioinformatics tools for predicting toxicity and biodegradation of chemicals have been developed. Furthermore, the whole genomes of several potential degrading bacteria have been sequenced and annotated using bioinformatics tools. PMID:24808763

  6. Biodegradable Polymers for the Environment

    NASA Astrophysics Data System (ADS)

    Gross, Richard A.; Kalra, Bhanu

    2002-08-01

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  7. Biodegradable polymers for the environment.

    PubMed

    Gross, Richard A; Kalra, Bhanu

    2002-08-01

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  8. Computational Framework for Predictive Biodegradation

    PubMed Central

    Finley, Stacey D.; Broadbelt, Linda J.

    2014-01-01

    As increasing amounts of anthropogenic chemicals are released into the environment, it is vital to human health and the preservation of ecosystems to evaluate the fate of these chemicals in the environment. It is useful to predict whether a particular compound is biodegradable and if alternate routes can be engineered for compounds already known to be biodegradable. In this work, we describe a computational framework (called BNICE) that can be used for the prediction of novel biodegradation pathways of xenobiotics. The framework was applied to 4-chlorobiphenyl, phenanthrene, γ-hexachlorocyclohexane, and 1,2,4-trichlorobenzene, compounds representing various classes of xenobiotics with known biodegradation routes. BNICE reproduced the proposed biodegradation routes found experimentally, and in addition, it expanded the biodegradation reaction networks through the generation of novel compounds and reactions. The novel reactions involved in the biodegradation of 1,2,4-trichlorobenzene were studied in depth, where pathway and thermodynamic analyses were performed. This work demonstrates that BNICE can be applied to generate novel pathways to degrade xenobiotic compounds that are thermodynamically feasible alternatives to known biodegradation routes and attractive targets for metabolic engineering. PMID:19650084

  9. Thermodynamic Analysis of Biodegradation Pathways

    PubMed Central

    Finley, Stacey D.; Broadbelt, Linda J.

    2014-01-01

    Microorganisms provide a wealth of biodegradative potential in the reduction and elimination of xenobiotic compounds in the environment. One useful metric to evaluate potential biodegradation pathways is thermodynamic feasibility. However, experimental data for the thermodynamic properties of xenobiotics is scarce. The present work uses a group contribution method to study the thermodynamic properties of the University of Minnesota Biocatalysis/Biodegradation Database. The Gibbs free energies of formation and reaction are estimated for 914 compounds (81%) and 902 reactions (75%), respectively, in the database. The reactions are classified based on the minimum and maximum Gibbs free energy values, which accounts for uncertainty in the free energy estimates and a feasible concentration range relevant to biodegradation. Using the free energy estimates, the cumulative free energy change of 89 biodegradation pathways (51%) in the database could be estimated. A comparison of the likelihood of the biotransformation rules in the Pathway Prediction System and their thermodynamic feasibility was then carried out. This analysis revealed that when evaluating the feasibility of biodegradation pathways, it is important to consider the thermodynamic topology of the reactions in the context of the complete pathway. Group contribution is shown to be a viable tool for estimating, a priori, the thermodynamic feasibility and the relative likelihood of alternative biodegradation reactions. This work offers a useful tool to a broad range of researchers interested in estimating the feasibility of the reactions in existing or novel biodegradation pathways. PMID:19288443

  10. Biodegradable pectin/clay aerogels.

    PubMed

    Chen, Hong-Bing; Chiou, Bor-Sen; Wang, Yu-Zhong; Schiraldi, David A

    2013-03-13

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. The addition of multivalent cations (Ca(2+) and Al(3+)) resulted in apparent cross-linking of the polymer and enhancement of aerogel properties. The compressive properties increased as the solid contents (both pectin and clay) increased; moduli in the range of 0.04-114 MPa were obtained for materials with bulk densities ranging from 0.03 g/cm(3) to 0.19 g/cm(3), accompanied by microstructural changes from a lamellar structure to a cellular structure. Biodegradability of the aerogels was investigated by detecting CO2 release for 4 weeks in compost media. The results revealed that pectin aerogels possess higher biodegradation rates than wheat starch, which is often used as a standard for effective biodegradation. The addition of clay and multivalent cations surprisingly increased the biodegradation rates. PMID:23406325

  11. Marine Oil Biodegradation.

    PubMed

    Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

    2016-03-01

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments. PMID:26698270

  12. Biodegradation of Polypropylene Nonwovens

    NASA Astrophysics Data System (ADS)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  13. Biodegradation of propellant ingredients

    SciTech Connect

    Zhang, Y.Z.; Sundaram, S.T.; Sharma, A.

    1995-12-31

    This paper summarizes efforts to degrade nitrocellulose (NC) and nitroglycerin (NG) with fungi. Screening experiments were performed to determine the ability of mycelial fungi to biodegrade NC. The greatest amount of NC degradation was obtained with Sclerotium rolfsii ATCC 24459 and Fusarium solani IFO 31093. These fungi were then tested for NG degradation. It was found that the combined culture aerobically degraded 100% of the NG to form a mixture of 55% dinitroglycerin (DNG) and 5% of mononitroglycerin (MNG) in two days, with no further change observed afterward. In the presence of 1.2% glucose and 0.05% ammonium nitrate, NG was completely degraded in two days and a mixture of 20% DNG and 16% MNG was formed after 11 days. Based on these results, it appears that the combination of the fungi in a one to one ratio can be used to degrade both of these energetic compounds.

  14. Lung toxicity of biodegradable nanoparticles.

    PubMed

    Fattal, Elias; Grabowski, Nadége; Mura, Simona; Vergnaud, Juliette; Tsapis, Nicolas; Hillaireau, Hervé

    2014-10-01

    Biodegradable nanoparticles exhibit high potentialities for local or systemic drug delivery through lung administration making them attractive as nanomedicine carriers. However, since particulate matter or some inorganic manufactured nanoparticles exposed to lung cells have provoked cytotoxic effects, inflammatory and oxidative stress responses, it becomes important to investigate nanomedicine toxicity towards the lungs. This is the reason why, in the present review, the behavior of biodegradable nanoparticles towards the different parts of the respiratory tract as well as the toxicological consequences, measured on several models in vitro, ex vivo or in vivo, are described. Taken all together, the different studies carried out so far conclude on no or slight toxicity of biodegradable nanoparticles.

  15. Biodegradation of biodiesel fuels

    SciTech Connect

    Zhang, X.; Haws, R.; Wright, B.; Reese, D.; Moeller, G.; Peterson, C.

    1995-12-31

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO{sub 2} evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO{sub 2} evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO{sub 2} evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO{sub 2}. The test substances were examined for BOD{sub 5} and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD{sub 5} and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD{sub 5} and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p << 0.01. RME was also significantly lower than REE (p < 0.05) and MS (p < 0.01) for BOD{sub 5} value.

  16. Biodegradation of PCBs

    SciTech Connect

    Kopec, R.I.

    1992-01-01

    PCBs were examined for biodegradability by a strain of Pseudomonas sp. designated E1, by a strain of Pseudomonas aeruginosa designated E2, and by a strain of Pseudomonas putida designated E3. The PCBs included Aroclor mixes from Aroclor 1221 to Aroclor 1268, and pure congeners ranging from monochlorobiphenyl to decachlorobiphenyl. These congeners represented all structural classes. Pure culture studies revealed that cells of E1 grew well on all structural classes of PCB congeners up to heptachlorobiphenyl, and all Aroclor mixes up to Aroclor 1260. Gas chromotographic analysis revealed that biphenyl/acetate grown resting cells of E1 degraded congeners up to octachlorobiphenyl. The degradative patterns for E2 and E3 were assessed using gas chromatographic techniques. E2 was found to be markedly inferior to E1, degrading only the mono-, di-, and tri-chlorobiphenyl tested. Pseudomonas putida strain E3 could not degrade any PCB congener. Mutations in both E2 and E3 that enabled them to utilize more highly chlorinated congeners of PCBs were obtained in nutritionally depleted environments. Such mutants could not be obtained by direct selection using minimal media and appear to be [open quotes]Cairnsian[close quotes] mutations. The Pseudomonas sp. strain E1 was tested in 15 prior or current National Priority List soil microcosms to assess its biodegradative ability in situ. E1 was able to completely degrade the 2,3,4,2[prime],3[prime],4[prime]-2,4,5,2[prime],4[prime],5[prime]-hexachlorobiphenyl congener in seven of the microcosms within two months as well.

  17. Biodegradable Peptide-Silica Nanodonuts.

    PubMed

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-01

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated.

  18. Biodegradable Peptide-Silica Nanodonuts.

    PubMed

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-01

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated. PMID:26880470

  19. Biodegradation of Polyethoxylated Nonylphenols

    PubMed Central

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEOx), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEOx and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO15, as unique carbon source, is described. The most efficient NPEO15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO15 medium. The NPEO15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively. PMID:23936727

  20. Injectable and biodegradable hydrogels: gelation, biodegradation and biomedical applications.

    PubMed

    Li, Yulin; Rodrigues, João; Tomás, Helena

    2012-03-21

    Injectable hydrogels with biodegradability have in situ formability which in vitro/in vivo allows an effective and homogeneous encapsulation of drugs/cells, and convenient in vivo surgical operation in a minimally invasive way, causing smaller scar size and less pain for patients. Therefore, they have found a variety of biomedical applications, such as drug delivery, cell encapsulation, and tissue engineering. This critical review systematically summarizes the recent progresses on biodegradable and injectable hydrogels fabricated from natural polymers (chitosan, hyaluronic acid, alginates, gelatin, heparin, chondroitin sulfate, etc.) and biodegradable synthetic polymers (polypeptides, polyesters, polyphosphazenes, etc.). The review includes the novel naturally based hydrogels with high potential for biomedical applications developed in the past five years which integrate the excellent biocompatibility of natural polymers/synthetic polypeptides with structural controllability via chemical modification. The gelation and biodegradation which are two key factors to affect the cell fate or drug delivery are highlighted. A brief outlook on the future of injectable and biodegradable hydrogels is also presented (326 references). PMID:22116474

  1. Biodegradation of news inks

    SciTech Connect

    Erhan, S.Z.; Bagby, M.O.

    1995-12-01

    Printing ink vehicles that require no petroleum components were prepared by modifying vegetable oil. Physical properties of inks formulated with these vehicles meet or exceed the industry standards for lithographic and letterpress newsprint applications. Elimination of petroleum-based resin and reduced pigment requirements, due to the light vehicle color, provide a competitively priced alternative to petroleum-based inks of equal quality. These ink vehicles, made exclusively from soybean oil, were subjected to biodegradation, and the results were compared with those obtained with commercial vehicles. Results show that they degrade faster and more completely than commercial hybrid (partial) soy or mineral oil based vehicles. Fermentations were allowed to proceed for 5, 12, and 25 days. Both mono-and mixed cultures of microorganisms commonly found in soil were used. In 25 days, commercial mineral oil based vehicles degraded 17-27%, while commercial hybrid soy oil based vehicles degraded 58-68% and our 100% soy oil based vehicles degrade 82-92%. Similar studies were conducted with commercial news inks consisting of soy or mineral oil with petroleum resins along with the four colored pigments and USDA`s 100% soy oil based ink consisting of modified soybean oil and pigment. Results show that pigment slowed the degradation of ink vehicles; however, neither time nor type of pigment played a significant role. Also these inks were degraded by using {open_quotes}Modified Sturm Test{close_quotes} (Organization for Economic Cooperation and Development). In this method, test organisms were obtained from activated sludge, and the extent of degradation was determined by measuring carbon dioxide evolution. In all cases USDA`s ink degraded faster and more completely (for all four colors) than either hybrid soy oil based or petroleum based inks.

  2. Testing biodegradability with standardized methods.

    PubMed

    Pagga, U

    1997-12-01

    Laboratory test methods are used by industry laboratories to determine biodegradability, an important parameter for the evaluation of the ecological behaviour of substances. Biodegradability has a key role due to the simple fact that a degradable substance will cause no long term risk in the environment. The great variety of biodegradation processes in the natural environment and in technical plants for treating waste water and solid wastes gave rise to a rather large number of test methods based on different test principles. To guarantee the acceptance of the test results by authorities and customers internationally standardized methods (ISO, OECD) and established quality criteria (GLP, EN 45,000, ISO 9000) are used. PMID:9415981

  3. Petroleum biodegradation in marine environments.

    PubMed

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  4. Petroleum biodegradation in marine environments.

    PubMed

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  5. Biodegradation and bioaccumulation of phthalates

    SciTech Connect

    Scholz, N.; Diefenbach, R.

    1995-12-31

    Phthalate esters very often are considered as persistent in the environment. This view is supported by an assumed lack of biodegradability, the high log K{sub ow} values and the assumed high bioaccumulation potential. Results are presented which show phthalates esters to be readily biodegradable even with a non-adapted inoculum. Combined with a lack of relevant bioaccumulation in aquatic organisms, a reconsideration of the environmental impact of these substances is necessary. Special prerequisites for testing poorly water soluble substances are also discussed.

  6. Biodegradation of gasoline ether oxygenates.

    PubMed

    Hyman, Michael

    2013-06-01

    Ether oxygenates such as methyl tertiary butyl ether (MTBE) are added to gasoline to improve fuel combustion and decrease exhaust emissions. Ether oxygenates and their tertiary alcohol metabolites are now an important group of groundwater pollutants. This review highlights recent advances in our understanding of the microorganisms, enzymes and pathways involved in both the aerobic and anaerobic biodegradation of these compounds. This review also aims to illustrate how these microbiological and biochemical studies have guided, and have helped refine, molecular and stable isotope-based analytical approaches that are increasingly being used to detect and quantify biodegradation of these compounds in contaminated environments.

  7. Synthesis and physical properties of coriander estolide 2-ethylhexyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coriander (Coriandrum sativum L.) is new crop that is currently being investigated for cultivation in Central Illinois by USDA-NCAUR. Coriander is an annual herb belonging to the Apiaceae (Umbelliferae) family and indigenous to the Mediterranean basin areas and the Near East. This plant is widely ...

  8. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... Findings In the Federal Register of August 22, 2012 (77 FR 50661) (FRL-9358- 9), EPA issued a document... review under Executive Order 12866, entitled ``Regulatory Planning and Review'' (58 FR 51735, October 4... Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001) or Executive Order...

  9. Biodegradable Pectin/clay Aerogels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  10. High-pressure nuclear-magnetic-resonance study of carbon-13 relaxation in 2-ethylhexyl benzoate and 2-ethylhexyl cyclohexanecarboxylate

    NASA Astrophysics Data System (ADS)

    Adamy, S. T.; Grandinetti, P. J.; Masuda, Y.; Campbell, D.; Jonas, J.

    1991-03-01

    Natural abundance carbon-13 spin-lattice relaxation times and 13G-1H nuclear Overhauser enhancement (NOE) times of 2-ethyl hexylbenzoate (EHB) and 2-ethyl hexylcyclohexanecarboxylate (EHC) have been measured along isotherms of -20, 0, 20, 40, and 80 °C at pressures of 1-5000 bars using high-pressure, high-resolution NMR techniques. The ability to use pressure as an experimental variable has allowed us to study a wide range of molecular motions from extreme narrowing into the slow motional regime. In addition, the high-resolution capability even at high pressure permits the measurement of 13C and NOE for each individual carbon in the molecules studied. Relaxation in both molecules is successfully analyzed in terms of a model assuming a Cole-Davidson distribution of correlation times. The comparison of parameters used in the model demonstrates the increased flexibility of the EHC ring over the EHB ring and also shows how the presence of the flexible ring contributes to the increased over-all mobility of the EHC molecule. The analysis of molecular reorientations in terms of activation volumes also indicates that EHB motion is highly restricted at low temperature.

  11. A kinetic model for predicting biodegradation.

    PubMed

    Dimitrov, S; Pavlov, T; Nedelcheva, D; Reuschenbach, P; Silvani, M; Bias, R; Comber, M; Low, L; Lee, C; Parkerton, T; Mekenyan, O

    2007-01-01

    Biodegradation plays a key role in the environmental risk assessment of organic chemicals. The need to assess biodegradability of a chemical for regulatory purposes supports the development of a model for predicting the extent of biodegradation at different time frames, in particular the extent of ultimate biodegradation within a '10 day window' criterion as well as estimating biodegradation half-lives. Conceptually this implies expressing the rate of catabolic transformations as a function of time. An attempt to correlate the kinetics of biodegradation with molecular structure of chemicals is presented. A simplified biodegradation kinetic model was formulated by combining the probabilistic approach of the original formulation of the CATABOL model with the assumption of first order kinetics of catabolic transformations. Nonlinear regression analysis was used to fit the model parameters to OECD 301F biodegradation kinetic data for a set of 208 chemicals. The new model allows the prediction of biodegradation multi-pathways, primary and ultimate half-lives and simulation of related kinetic biodegradation parameters such as biological oxygen demand (BOD), carbon dioxide production, and the nature and amount of metabolites as a function of time. The model may also be used for evaluating the OECD ready biodegradability potential of a chemical within the '10-day window' criterion.

  12. Biobased and biodegradable polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  13. Phthalate esters in the environment: A critical review of their occurrence, biodegradation, and removal during wastewater treatment processes.

    PubMed

    Gao, Da-Wen; Wen, Zhi-Dan

    2016-01-15

    Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.-10.4 ng/m(3), N.D.-31.7 μg/L, N.D.-316 μg/kg dry weight, and N.D.-200 μg/kg dry weight, N.D.-43.27 μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%-71% to 95%-97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment. PMID:26473701

  14. Phthalate esters in the environment: A critical review of their occurrence, biodegradation, and removal during wastewater treatment processes.

    PubMed

    Gao, Da-Wen; Wen, Zhi-Dan

    2016-01-15

    Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.-10.4 ng/m(3), N.D.-31.7 μg/L, N.D.-316 μg/kg dry weight, and N.D.-200 μg/kg dry weight, N.D.-43.27 μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%-71% to 95%-97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment.

  15. Use of surfactants and slurrying to enhance the biodegradation in soil of compounds initially dissolved in nonaqueous-phase liquids.

    PubMed

    Fu, M H; Alexander, M

    1995-07-01

    A study was conducted to find means of enhancing the biodegradation of hydrophobic organic compounds in nonaqueous-phase liquids (NAPLs). The effects of surfactants, identity of the NAPL and agitation was investigated. When present in NAPLs, phenanthrene, di-(2-ethylhexyl) phthalate (DEHP) and biphenyl were mineralized slowly in soil. Addition of Triton X-100 or Alfonic 810-60 did not enhance the degradation of phenanthrene initially in hexadecane or dibutyl phthalate. Slurrying the soil increased the rate and extent of mineralization of phenanthrene initially in hexadecane but not in dibutyl phthalate. Addition of either of the two surfactants to the slurries did not promote the transformation. Triton X-100, Alfonic 810-60 and Tergitol 15-S-9 below their critical micelle concentrations increased the rate and sometimes the extent of mineralization in soil slurries of phenanthrene initially in 2,2,4,4,6,8,8-heptamethylnonane, but other surfactants were not stimulatory. Slurrying the soil promoted the initial mineralization of DEHP initially in dibutyl phthalate, and Alfonic 810-60 and Triton X-100 further stimulated the rate and extent of degradation in the slurries. Alfonic 810-60 increased the extent of mineralization in slurries of biphenyl in hexadecane but not in dibutyl phthalate, cyclohexane, kerosene or two oils. Little mineralization of biphenyl or DEHP initially in dibutyl phthalate occurred in soil slurries, but Tween 80, Tergitol 15-S-40 and Tergitol 15-S-9 increased the extent of mineralization. However, vigorous agitation of the slurries of soil acclimated to DEHP or the use of small volumes of the NAPL resulted in marked enhancement of the degradation.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Recent advances in biodegradable nanocomposites.

    PubMed

    Pandey, Jitendra K; Kumar, A Pratheep; Misra, Manjusri; Mohanty, Amar K; Drzal, Lawrence T; Singh, Raj Pal

    2005-04-01

    There is growing interest in developing bio-based products and innovative process technologies that can reduce the dependence on fossil fuel and move to a sustainable materials basis. Biodegradable bio-based nanocomposites are the next generation of materials for the future. Renewable resource-based biodegradable polymers including cellulosic plastic (plastic made from wood), corn-derived plastics, and polyhydroxyalkanoates (plastics made from bacterial sources) are some of the potential biopolymers which, in combination with nanoclay reinforcement, can produce nanocomposites for a variety of applications. Nanocomposites of this category are expected to possess improved strength and stiffness with little sacrifice of toughness, reduced gas/water vapor permeability, a lower coefficient of thermal expansion, and an increased heat deflection temperature, opening an opportunity for the use of new, high performance, lightweight green nanocomposite materials to replace conventional petroleum-based composites. The present review addresses this green material, including its technical difficulties and their solutions.

  17. Membrane stabilization of biodegradable polymersomes.

    PubMed

    Katz, Joshua S; Levine, Dalia H; Davis, Kevin P; Bates, Frank S; Hammer, Daniel A; Burdick, Jason A

    2009-04-21

    Biodegradable polymersomes are promising vehicles for a range of applications. Their stabilization would improve many properties, including the retention and controlled release of polymersome contents, yet this has not been previously accomplished. Here, we present the first example of stabilizing fully biodegradable polymersomes through acrylation of the hydrophobic terminal end of polymersome-forming poly(caprolactone-b-ethylene glycol). Exposure of the resulting polymersomes loaded with a hydrophobic photoinitiator to ultraviolet light polymerized the acrylates, without affecting polymersome morphology or cell cytotoxicity. These stabilized polymersomes were more resistant to surfactant disruption and degradation. As an example of stabilized polymersome utility, the unintended release of doxorubicin (DOX) due to leakage from polymersomes decreased with membrane stabilization and slower sustained release was observed. Finally, DOX-loaded polymersomes retained their cytotoxicity following stabilization.

  18. Biodegradable stents with elastic memory.

    PubMed

    Venkatraman, Subbu S; Tan, Lay Poh; Joso, Joe Ferry D; Boey, Yin Chiang Freddy; Wang, Xintong

    2006-03-01

    This work reports, for the first time, the development of a fully biodegradable polymeric stent that can self-expand at body temperatures (approximately 37 degrees C), using the concept of elastic memory. This self-expansion is necessary in fully polymeric stents, to overcome the problem of elastic recoil following balloon expansion in a body vessel. Bi-layered biodegradable stent prototypes were produced from poly-L-lactic acid (PLLA) and poly glycolic acid (PLGA) polymers. Elastic memory was imparted to the stents by temperature conditioning. The thickness and composition of each layer in the stents are critical parameters that affect the rate of self-expansion at 37 degrees C, as well as the collapse strengths of the stents. The rate of self-expansion of the stents, as measured at 37 degrees C, exhibits a maximum with layer thickness. The Tg of the outer layer is another significant parameter that affects the overall rate of expansion.

  19. BSD: the Biodegradative Strain Database.

    PubMed

    Urbance, John W; Cole, James; Saxman, Paul; Tiedje, James M

    2003-01-01

    The Biodegradative Strain Database (BSD) is a freely-accessible, web-based database providing detailed information on degradative bacteria and the hazardous substances that they degrade, including corresponding literature citations, relevant patents and links to additional web-based biological and chemical data. The BSD (http://bsd.cme.msu.edu) is being developed within the phylogenetic framework of the Ribosomal Database Project II (RDPII: http://rdp.cme.msu.edu/html) to provide a biological complement to the chemical and degradative pathway data of the University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD: http://umbbd.ahc.umn.edu). Data is accessible through a series of strain, chemical and reference lists or by keyword search. The web site also includes on-line data submission and user survey forms to solicit user contributions and suggestions. The current release contains information on over 250 degradative bacterial strains and 150 hazardous substances. The transformation of xenobiotics and other environmentally toxic compounds by microorganisms is central to strategies for biocatalysis and the bioremediation of contaminated environments. However, practical, comprehensive, strain-level information on biocatalytic/biodegradative microbes is not readily available and is often difficult to compile. Similarly, for any given environmental contaminant, there is no single resource that can provide comparative information on the array of identified microbes capable of degrading the chemical. A web site that consolidates and cross-references strain, chemical and reference data related to biocatalysis, biotransformation, biodegradation and bioremediation would be an invaluable tool for academic and industrial researchers and environmental engineers.

  20. In vitro biodegradation of steranes

    SciTech Connect

    Chosson, P. ); Connan, J.

    1989-03-01

    The purpose of this paper is to report reproducible results on the in vitro biodegradation of steranes in various crude oils. 73 pure strains including Pseudomonadacea (33) and Actinomycetaceae (40) have been screened in order to test their capability to degrade steranes contained in total alkanes isolated from various crudes. Biodegradation of steranes has been observed with 7 strains belonging to Nocardia and Arthrobacter genera. 5{alpha}(H), 14{alpha}(H), 17{alpha}(H) and 5{alpha}(H), 14{beta}(H), 17{beta}(H) Steranes with the 20R configuration were degraded under reproducible laboratory conditions. Biodegradation of the sterane mixtures isolated from crude oils followed W. Seiferts rules established on the basis of geological observations. 5{alpha}(H), 14{alpha}(H), 17{alpha}(H) C{sub 27}-Steranes with the 20R configuration are degraded first and ends with the 5{alpha}(H), 14{alpha}(H), 17{alpha}(H) C{sub 29}steranes. Then 5{alpha}9h0, 14{beta}(H), and 17{beta}(H) steranes are attacked starting with the 20R configuration. Limited alteration of Tm and Ts terpane has also been observed.

  1. Biodegradation of dimethylsilanediol in soils.

    PubMed Central

    Sabourin, C L; Carpenter, J C; Leib, T K; Spivack, J L

    1996-01-01

    The biodegradation potential of [14C]dimethylsilanediol, the monomer unit of polydimethylsiloxane, in soils was investigated. Dimethylsilanediol was found to be biodegraded in all of the tested soils, as monitored by the production of 14CO2. When 2-propanol was added to the soil as a carbon source in addition to [14C]dimethylsilanediol, the production of 14CO2 increased. A method for the selection of primary substrates that support cometabolic degradation of a target compound was developed. By this method, the activity observed in the soils was successfully transferred to liquid culture. A fungus, Fusarium oxysporum Schlechtendahl, and a bacterium, an Arthrobacter species, were isolated from two different soils, and both microorganisms were able to cometabolize [14C]dimethylsilanediol to 14CO2 in liquid culture. In addition, the Arthrobacter sp. that was isolated grew on dimethylsulfone, and we believe that this is the first reported instance of a microorganism using dimethylsulfone as its primary carbon source. Previous evidence has shown that polydimethylsiloxane is hydrolyzed in soil to the monomer, dimethylsilanediol. Now, biodegradation of dimethylsilanediol in soil has been demonstrated. PMID:8953708

  2. Engineering Flame Retardant Biodegradable Nanocomposites

    NASA Astrophysics Data System (ADS)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  3. Biodegradation of high molecular weight polylactic acid

    NASA Astrophysics Data System (ADS)

    Stloukal, Petr; Koutny, Marek; Sedlarik, Vladimir; Kucharczyk, Pavel

    2012-07-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite expectations, no significant differences in resulting mineralizations were observed for fiber, film and powder sample forms with different specific surface areas. The clearly faster biodegradation was detected only for the thin coating on porous material with high specific surface area.

  4. A review of plastic waste biodegradation.

    PubMed

    Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

    2005-01-01

    With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

  5. Biodegradable stents in gastrointestinal endoscopy

    PubMed Central

    Lorenzo-Zúñiga, Vicente; Moreno-de-Vega, Vicente; Marín, Ingrid; Boix, Jaume

    2014-01-01

    Biodegradable stents (BDSs) are an attractive option to avoid ongoing dilation or surgery in patients with benign stenoses of the small and large intestines. The experience with the currently the only BDS for endoscopic placement, made of Poly-dioxanone, have shown promising results. However some aspects should be improved as are the fact that BDSs lose their radial force over time due to the degradable material, and that can cause stent-induced mucosal or parenchymal injury. This complication rate and modest clinical efficacy has to be carefully considered in individual patients prior to placement of BDSs. Otherwise, the price of these stents therefore it is nowadays an important limitation. PMID:24605020

  6. Here today, gone tomorrow: biodegradable soft robots

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Winfield, Jonathan; Ieropoulos, Ioannis

    2016-04-01

    One of the greatest challenges to modern technologies is what to do with them when they go irreparably wrong or come to the end of their productive lives. The convention, since the development of modern civilisation, is to discard a broken item and then procure a new one. In the 20th century enlightened environmentalists campaigned for recycling and reuse (R and R). R and R has continued to be an important part of new technology development, but there is still a huge problem of non-recyclable materials being dumped into landfill and being discarded in the environment. The challenge is even greater for robotics, a field which will impact on all aspects of our lives, where discards include motors, rigid elements and toxic power supplies and batteries. One novel solution is the biodegradable robot, an active physical machine that is composed of biodegradable materials and which degrades to nothing when released into the environment. In this paper we examine the potential and realities of biodegradable robotics, consider novel solutions to core components such as sensors, actuators and energy scavenging, and give examples of biodegradable robotics fabricated from everyday, and not so common, biodegradable electroactive materials. The realisation of truly biodegradable robots also brings entirely new deployment, exploration and bio-remediation capabilities: why track and recover a few large non-biodegradable robots when you could speculatively release millions of biodegradable robots instead? We will consider some of these exciting developments and explore the future of this new field.

  7. Biodegradable Materials: Anchors and Interference Screws.

    PubMed

    Barber, F Alan

    2015-09-01

    Biodegradable implants allow clarity in postoperative imaging, easier revision, and fewer concerns about associated tissue damage. It is important to appreciate that different biodegradable materials have different properties and different degradation rates. Faster degradation can be associated with a greater inflammatory response. However, inflammation is a normal part of the degradation process. The concern arises when the inflammation is clinically significant.

  8. Biodegradation of aliphatic and aromatic polycarbonates.

    PubMed

    Artham, Trishul; Doble, Mukesh

    2008-01-01

    Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.

  9. [Chlorinate solvents natural biodegradation in shallow groundwater].

    PubMed

    He, Jiang-tao; Li, Ye; Liu, Shi; Chen, Hong-han

    2005-03-01

    Chlorinated solvents contaminations are most popular in shallow groundwater. A serious local groundwater contamination of chlorinated solvents is founded in a north city of China during the organic pollution investigation. On the basis of the available data and the determining methods of chlorinated solvents biodegradation in groundwater under natural conditions, research on chlorinated solvents biodegrading potential is carried out. The results show that the ground water environment parameters, Eh and pH of the groundwater, indirect sign of biodegradation, i.e. NO3- changing, and concentration variation of biodegradation intermediate products of PCE and TCE all proved that chlorinated solvents can be degraded by microorganism in groundwater. The results of simulating experiment also reveal that, co-metabolism biodegradation of chlorinated solvent was possible under the groundwater circumstances in this sample. Therefore, admitting there is biotransformation from PCE to TCE can explain the present situation more reasonably.

  10. Biodegradable polymers for electrospinning: towards biomedical applications.

    PubMed

    Kai, Dan; Liow, Sing Shy; Loh, Xian Jun

    2014-12-01

    Electrospinning has received much attention recently due to the growing interest in nano-technologies and the unique material properties. This review focuses on recent progress in applying electrospinning technique in production of biodegradable nanofibers to the emerging field of biomedical. It first introduces the basic theory and parameters of nanofibers fabrication, with focus on factors affecting the morphology and fiber diameter of biodegradable nanofibers. Next, commonly electrospun biodegradable nanofibers are discussed, and the comparison of the degradation rate of nanoscale materials with macroscale materials are highlighted. The article also assesses the recent advancement of biodegradable nanofibers in different biomedical applications, including tissue engineering, drug delivery, biosensor and immunoassay. Future perspectives of biodegradable nanofibers are discussed in the last section, which emphasizes on the innovation and development in electrospinning of hydrogels nanofibers, pore size control and scale-up productions.

  11. Chemical dispersants: Oil biodegradation friend or foe?

    PubMed

    Rahsepar, Shokouh; Smit, Martijn P J; Murk, Albertinka J; Rijnaarts, Huub H M; Langenhoff, Alette A M

    2016-07-15

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodegradation by alkane and/or aromatic degrading bacterial culture in artificial seawater at different dispersant to oil ratios (DORs). Our results show that dispersant addition did not enhance oil biodegradation. At DOR 1:20, biodegradation was inhibited, especially when only the alkane degrading culture was present. With a combination of cultures, this inhibition was overcome after 10days. This indicates that initial inhibition of oil biodegradation can be overcome when different bacteria are present in the environment. We conclude that the observed inhibition is related to the enhanced dissolution of aromatic compounds into the water, inhibiting the alkane degrading bacteria. PMID:27156037

  12. Chemical dispersants: Oil biodegradation friend or foe?

    PubMed

    Rahsepar, Shokouh; Smit, Martijn P J; Murk, Albertinka J; Rijnaarts, Huub H M; Langenhoff, Alette A M

    2016-07-15

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodegradation by alkane and/or aromatic degrading bacterial culture in artificial seawater at different dispersant to oil ratios (DORs). Our results show that dispersant addition did not enhance oil biodegradation. At DOR 1:20, biodegradation was inhibited, especially when only the alkane degrading culture was present. With a combination of cultures, this inhibition was overcome after 10days. This indicates that initial inhibition of oil biodegradation can be overcome when different bacteria are present in the environment. We conclude that the observed inhibition is related to the enhanced dissolution of aromatic compounds into the water, inhibiting the alkane degrading bacteria.

  13. Biodegradable products by lipase biocatalysis.

    PubMed

    Linko, Y Y; Lämsä, M; Wu, X; Uosukainen, E; Seppälä, J; Linko, P

    1998-11-18

    The interest in the applications of biocatalysis in organic syntheses has rapidly increased. In this context, lipases have recently become one of the most studied groups of enzymes. We have demonstrated that lipases can be used as biocatalyst in the production of useful biodegradable compounds. A number of examples are given. 1-Butyl oleate was produced by direct esterification of butanol and oleic acid to decrease the viscosity of biodiesel in winter use. Enzymic alcoholysis of vegetable oils without additional organic solvent has been little investigated. We have shown that a mixture of 2-ethyl-1-hexyl esters can be obtained in a good yield by enzymic transesterification from rapeseed oil fatty acids for use as a solvent. Trimethylolpropane esters were also similarly synthesized as lubricants. Finally, the discovery that lipases can also catalyze ester syntheses and transesterification reactions in organic solvent systems has opened up the possibility of enzyme catalyzed production of biodegradable polyesters. In direct polyesterification of 1,4-butanediol and sebacic acid, polyesters with a mass average molar mass of the order of 56,000 g mol-1 or higher, and a maximum molar mass of about 130,000 g mol-1 were also obtained by using lipase as biocatalyst. Finally, we have demonstrated that also aromatic polyesters can be synthesized by lipase biocatalysis, a higher than 50,000 g mol-1 mass average molar mass of poly(1,6-hexanediyl isophthalate) as an example. PMID:9866859

  14. Cri du Chat syndrome

    PubMed Central

    Cerruti Mainardi, Paola

    2006-01-01

    The Cri du Chat syndrome (CdCS) is a genetic disease resulting from a deletion of variable size occurring on the short arm of chromosome 5 (5p-). The incidence ranges from 1:15,000 to 1:50,000 live-born infants. The main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds, micrognathia, abnormal dermatoglyphics, and severe psychomotor and mental retardation. Malformations, although not very frequent, may be present: cardiac, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism. Molecular cytogenetic analysis has allowed a cytogenetic and phenotypic map of 5p to be defined, even if results from the studies reported up to now are not completely in agreement. Genotype-phenotype correlation studies showed a clinical and cytogenetic variability. The identification of phenotypic subsets associated with a specific size and type of deletion is of diagnostic and prognostic relevance. Specific growth and psychomotor development charts have been established. Two genes, Semaphorin F (SEMAF) and δ-catenin (CTNND2), which have been mapped to the "critical regions", are potentially involved in cerebral development and their deletion may be associated with mental retardation in CdCS patients. Deletion of the telomerase reverse transcriptase (hTERT) gene, localised to 5p15.33, could contribute to the phenotypic changes in CdCS. The critical regions were recently refined by using array comparative genomic hybridisation. The cat-like cry critical region was further narrowed using quantitative polymerase chain reaction (PCR) and three candidate genes were characterised in this region. The diagnosis is based on typical clinical manifestations. Karyotype analysis and, in doubtful cases, FISH analysis will confirm the diagnosis. There is no specific therapy for CdCS but early rehabilitative and educational interventions improve the prognosis and considerable progress has been made in

  15. L'Aventure du LHC

    SciTech Connect

    2010-06-11

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  16. Aged refinery hydrocarbon biodegradation in soil

    SciTech Connect

    Drake, E.N.; Stokley, K.E.; Calcavecchio, P.

    1995-12-31

    Aged hydrocarbon biodegradation was investigated as a potential cleanup technology for refinery soil. Well-mixed field soil was amended with water and nutrients and tilled weekly for one year in laboratory mesocosms to stimulate biodegradation. Freon infrared analysis of total petroleum hydrocarbons (TPH), and gas chromatography/mass spectrometry (GC/MS) analysis of polynuclear aromatic hydrocarbons (PAHs) and triterpane biomarkers were used to determine the extent of biodegradation. Significant reductions in TPH (up to 68%) and methylene chloride extractable material (up to 55%) were observed. The combined trimethylated phenanthrene/anthracenes (C3P/A) were even more highly depleted than TPH. Nutrient amendment increased TPH, methylene chloride, and C3P/A removal, but not biomarker concentrations. Significant reduction of two to five ring PAHs occurred. Expected depletion patterns for PAHs were observed except in the case of naphthalene and derivatives, phenanthrene/anthracene and derivatives, and chrysene. A possible explanation is that the more readily degradable PAHs were already highly biodegraded before the study and the remaining portions were less available for biodegradation. These results are consistent with reports on the effects of aging on PAH biodegradation in soil. Biodegradation was influenced by PAH structure and molecular weight.

  17. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    PubMed Central

    Zhang, Yi; Yang, Jian

    2013-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology. PMID:23710326

  18. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials.

    PubMed

    Zhang, Yi; Yang, Jian

    2013-01-14

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology.

  19. Formulation of microbial cocktails for BTEX biodegradation.

    PubMed

    Nagarajan, Karthiga; Loh, Kai-Chee

    2015-02-01

    BTEX biodegradation by a mixed community of micro-organisms offers a promising approach in terms of cost-effectiveness and elimination of secondary pollution. Two bacterial strains, Pseudomonas putida F1 and Pseudomonas stutzeri OX1 were chosen to formulate synthetic consortia based on their ability to biodegrade the mono-aromatic compounds. Benzene and toluene supported the growth of both the strains; while ethyl benzene and o-xylene were only utilized as growth substrates by P. putida F1 and P. stutzeri OX1, respectively. In a mixed substrate system, P. putida F1 exhibited incomplete removal of o-xylene while P. stutzeri OX1 displayed cometabolic removal of ethyl benzene with dark coloration of the growth medium. The biodegradation potential of the two Pseudomonas species complemented each other and offered opportunities to explore their performance as a co-culture for enhanced BTEX biodegradation. Several microbial formulations were concocted and their BTEX biodegradation characteristics were evaluated. Mixed culture biodegradation ascertained the advantages of the co-culture over the individual Pseudomonas species. This study also emphasized the significance of inoculum density and species proportion while concocting preselected micro-organisms for enhanced BTEX biodegradation.

  20. Biodegradable and compostable alternatives to conventional plastics

    PubMed Central

    Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

    2009-01-01

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

  1. Biodegradable and compostable alternatives to conventional plastics.

    PubMed

    Song, J H; Murphy, R J; Narayan, R; Davies, G B H

    2009-07-27

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

  2. Biodegradable and compostable alternatives to conventional plastics.

    PubMed

    Song, J H; Murphy, R J; Narayan, R; Davies, G B H

    2009-07-27

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

  3. New perspectives in plastic biodegradation.

    PubMed

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution.

  4. Biomedical Applications of Biodegradable Polymers

    PubMed Central

    Ulery, Bret D.; Nair, Lakshmi S.; Laurencin, Cato T.

    2011-01-01

    Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. In order to fit functional demand, materials with desired physical, chemical, biological, biomechanical and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications. PMID:21769165

  5. Engineered biosynthesis of biodegradable polymers.

    PubMed

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

  6. Biodegradable polyesters from renewable resources.

    PubMed

    Tsui, Amy; Wright, Zachary C; Frank, Curtis W

    2013-01-01

    Environmental concerns have led to the development of biorenewable polymers with the ambition to utilize them at an industrial scale. Poly(lactic acid) and poly(hydroxyalkanoates) are semicrystalline, biorenewable polymers that have been identified as the most promising alternatives to conventional plastics. However, both are inherently susceptible to brittleness and degradation during thermal processing; we discuss several approaches to overcome these problems to create a balance between durability and biodegradability. For example, copolymers and blends can increase ductility and the thermal-processing window. Furthermore, chain modifications (e.g., branching/crosslinking), processing techniques (fiber drawing/annealing), or additives (plasticizers/nucleating agents) can improve mechanical properties and prevent thermal degradation during processing. Finally, we examine the impacts of morphology on end-of-life degradation to complete the picture for the most common renewable polymers.

  7. Engineered biosynthesis of biodegradable polymers.

    PubMed

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers. PMID:27260524

  8. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  9. Biodegradation of halogenated organic compounds.

    PubMed

    Chaudhry, G R; Chapalamadugu, S

    1991-03-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  10. Preparation and degradation mechanisms of biodegradable polymer: a review

    NASA Astrophysics Data System (ADS)

    Zeng, S. H.; Duan, P. P.; Shen, M. X.; Xue, Y. J.; Wang, Z. Y.

    2016-07-01

    Polymers are difficult to degrade completely in Nature, and their catabolites may pollute the environment. In recent years, biodegradable polymers have become the hot topic in people's daily life with increasing interest, and a controllable polymer biodegradation is one of the most important directions for future polymer science. This article presents the main preparation methods for biodegradable polymers and discusses their degradation mechanisms, the biodegradable factors, recent researches and their applications. The future researches of biodegradable polymers are also put forward.

  11. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation.

    PubMed

    Yang, Lihui; Zhang, Yongming; Bai, Qi; Yan, Ning; Xu, Hua; Rittmann, Bruce E

    2015-04-28

    Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P+B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B+NP, B+OA, and B+NP+OA); NP and OA were NB's main UV-photolysis products. Compared with B, the biodegradation rate P+B was lower by 13-29%, but intimately coupling (P&B) had a removal rate that was 10-13% higher; mineralization showed similar trends. B+OA gave results similar to P&B, B+NP gave results similar to P+B, and B+OA+NP gave results between P+B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P+B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA. PMID:25661172

  12. Biodegradation of the anionic surfactant dialkyl sulphosuccinate

    SciTech Connect

    Hales, S.G. . Port Sunlight Lab.)

    1993-10-01

    A range of Organization for Economic Cooperation and Development (OECD) guideline test systems was used to determine the extent and possible mechanisms of biodegradation of dialkyl sulphosuccinate (DASS, C[sub 6]/C[sub 8]). Primary biodegradation of DASS was virtually complete in OECD guideline tests and in simulations of activated sludge sewage treatment systems under both optimal and adverse conditions, and of an anaerobic digester. Ultimate biodegradation increased form about 50% in ready tests to 94% in more powerful inherent tests. [[sup 14]C]DASS was used to determine the fate of the surfactant in activated sludge and in surface waters. Mechanistic studies were performed to ascertain the biodegradative pathway of [[sup 14]C]DASS. A putative degradation pathway for DASS is proposed.

  13. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  14. OPTIMIZING BTEX BIODEGRADATION UNDER DENITRIFYING CONDITIONS

    EPA Science Inventory

    Laboratory tests were conducted to determine optimum conditions for benzene, toluene, ethylbenzene, and xylene (collectively known as BTEX) biodegradation by aquifer microorganisms under denitrifying conditions. Microcosms, constructed with aquifer samples from Traverse City, Mic...

  15. Polyaspartate scale inhibitors -- Biodegradable alternatives to polyacrylates

    SciTech Connect

    Ross, R.J.; Low, K.C.; Shannon, J.E.

    1997-04-01

    Polyaspartates are highly biodegradable alternatives to polyacrylate-based scale inhibitors. This article presents laboratory testing data on polyaspartate inhibitors of calcium and barium mineral scales. The optimum molecular weight (Mw) for polyaspartate inhibitors of calcium carbonate, calcium sulfate, and barium sulfate mineral scales was determined to be between 1,000 Mw and 4,000 Mw. For inhibition of calcium carbonate and barium sulfate, polyaspartates in the range of 3,000 Mw to 4,000 Mw were most effective. For calcium sulfate inhibition, the optimum Mw lies in the 1,000 Mw to 2,000 Mw range. Biodegradability data (OECD 301B Ready Biodegradability) on polyaspartates of a variety of Mw is also presented, which demonstrates the high biodegradability of this class of mineral scale inhibitors.

  16. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  17. Phyllosphere yeasts rapidly break down biodegradable plastics.

    PubMed

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-11-29

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

  18. Radical-based dephosphorylation and organophosphonate biodegradation

    SciTech Connect

    Frost, J.W.; Loo, S.; Cordeiro, M.L.; Li, D.

    1987-04-01

    Products resulting from the degradation of organophosphonates by Escherichia coli are identified and used as a basis for evaluating mechanisms which may be the chemical basis of the biodegradation. One mechanistic hypothesis which is consistent with the biodegradation products involves radical-based dephosphorylation. Chemical modeling of this process is achieved by the reaction of alkylphosphonic acids with lead(IV) tetraacetate and electrochemical oxidation at a platinum anode.

  19. Etude de l'affaiblissement du comportement mecanique du pergelisol du au rechauffement climatique

    NASA Astrophysics Data System (ADS)

    Buteau, Sylvie

    Le rechauffement climatique predit pour les prochaines decennies, aura des impacts majeurs sur le pergelisol qui sont tres peu documentes pour l'instant. La presente etude a pour but d'evaluer ces impacts sur les proprietes mecaniques du pergelisol et sa stabilite a long terme. Une nouvelle technique d'essai de penetration au cone a taux de deformation controle, a ete developpee pour caracteriser en place le pergelisol. Ces essais geotechniques et la mesure de differentes proprietes physiques ont ete effectues sur une butte de pergelisol au cours du printemps 2000. Le developpement et l'utilisation d'un modele geothermique 1D tenant compte de la thermodependance du comportement mecanique ont permis d'evaluer que les etendues de pergelisol chaud deviendraient instables a la suite d'un rechauffement de l'ordre de 5°C sur cent ans. En effet, la resistance mecanique du pergelisol diminuera alors rapidement jusqu'a 11,6 MPa, ce qui correspond a une perte relative de 98% de la resistance par rapport a un scenario sans rechauffement.

  20. Biodegradability of commercial and weathered diesel oils

    PubMed Central

    Mariano, Adriano Pinto; Bonotto, Daniel Marcos; de Franceschi de Angelis, Dejanira; Pirôllo, Maria Paula Santos; Contiero, Jonas

    2008-01-01

    This work aimed to evaluate the capability of different microorganisms to degrade commercial diesel oil in comparison to a weathered diesel oil collected from the groundwater at a petrol station. Two microbiological methods were used for the biodegradability assessment: the technique based on the redox indicator 2,6 -dichlorophenol indophenol (DCPIP) and soil respirometric experiments using biometer flasks. In the former we tested the bacterial cultures Staphylococcus hominis, Kocuria palustris, Pseudomonas aeruginosa LBI, Ochrobactrum anthropi and Bacillus cereus, a commercial inoculum, consortia obtained from soil and groundwater contaminated with hydrocarbons and a consortium from an uncontaminated area. In the respirometric experiments it was evaluated the capability of the native microorganisms present in the soil from a petrol station to biodegrade the diesel oils. The redox indicator experiments showed that only the consortia, even that from an uncontaminated area, were able to biodegrade the weathered diesel. In 48 days, the removal of the total petroleum hydrocarbons (TPH) in the respirometric experiments was approximately 2.5 times greater when the commercial diesel oil was used. This difference was caused by the consumption of labile hydrocarbons, present in greater quantities in the commercial diesel oil, as demonstrated by gas chromatographic analyses. Thus, results indicate that biodegradability studies that do not consider the weathering effect of the pollutants may over estimate biodegradation rates and when the bioaugmentation is necessary, the best strategy would be that one based on injection of consortia, because even cultures with recognised capability of biodegrading hydrocarbons may fail when applied isolated. PMID:24031193

  1. Evaluation of biodegradation-promoting additives for plastics.

    PubMed

    Selke, Susan; Auras, Rafael; Nguyen, Tuan Anh; Castro Aguirre, Edgar; Cheruvathur, Rijosh; Liu, Yan

    2015-03-17

    Biodegradation-promoting additives for polymers are increasingly being used around the world with the claim that they effectively render commercial polymers biodegradable. However, there is a lot of uncertainty about their effectiveness in degrading polymers in different environments. In this study, we evaluated the effect of biodegradation-promoting additives on the biodegradation of polyethylene (PE) and polyethylene terephthalate (PET). Biodegradation was evaluated in compost, anaerobic digestion, and soil burial environments. None of the five different additives tested significantly increased biodegradation in any of these environments. Thus, no evidence was found that these additives promote and/or enhance biodegradation of PE or PET polymers. So, anaerobic and aerobic biodegradation are not recommended as feasible disposal routes for nonbiodegradable plastics containing any of the five tested biodegradation-promoting additives.

  2. Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

    PubMed

    Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

    2011-03-01

    The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future.

  3. L'Aventure du LHC

    ScienceCinema

    None

    2016-07-12

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  4. Biomechanical Challenges to Polymeric Biodegradable Stents.

    PubMed

    Soares, Joao S; Moore, James E

    2016-02-01

    Biodegradable implants have demonstrated clinical success in simple applications (e.g., absorbable sutures) and have shown great potential in many other areas of interventional medicine, such as localized drug delivery, engineered tissue scaffolding, and structural implants. For endovascular stenting and musculoskeletal applications, they can serve as temporary mechanical support that provides a smooth stress-transfer from the degradable implant to the healing tissue. However, for more complex device geometries, in vivo environments, and evolving load-bearing functions, such as required for vascular stents, there are considerable challenges associated with the use of biodegradable materials. A biodegradable stent must restore blood flow and provide support for a predictable appropriate period to facilitate artery healing, and subsequently, fail safely and be absorbed in a controllable manner. Biodegradable polymers are typically weaker than metals currently employed to construct stents, so it is difficult to ensure sufficient strength to keep the artery open and alleviate symptoms acutely while keeping other design parameters within clinically acceptable ranges. These design challenges are serious, given the general lack of understanding of biodegradable polymer behavior and evolution in intimal operating conditions. The modus operandi is mainly empirical and relies heavily on trial-and-error methodologies burdened by difficult, resource-expensive, and time-consuming experiments. We are striving for theoretical advancements systematizing the empirical knowledge into rational frameworks that could be cast into in silico tools for simulation and product development optimization. These challenges are evident when one considers that there are no biodegradable stents on the US market despite more than 30 years of development efforts (and currently only a couple with CE mark). This review summarizes previous efforts at implementing biodegradable stents, discusses the

  5. Prediction of biodegradability from chemical structure: Modeling or ready biodegradation test data

    SciTech Connect

    Loonen, H.; Lindgren, F.; Hansen, B.

    1999-08-01

    Biodegradation data were collected and evaluated for 894 substances with widely varying chemical structures. All data were determined according to the Japanese Ministry of International Trade and Industry (MITI) I test protocol. The MITI I test is a screening test for ready biodegradability and has been described by Organization for Economic Cooperation and Development (OECD) test guideline 301 C and European Union (EU) test guideline C4F. The chemicals were characterized by a set of 127 predefined structural fragments. This data set was used to develop a model for the prediction of the biodegradability of chemicals under standardized OECD and EU ready biodegradation test conditions. Partial least squares (PLS) discriminant analysis was used for the model development. The model was evaluated by means of internal cross-validation and repeated external validation. The importance of various structural fragments and fragment interactions was investigated. The most important fragments include the presence of a long alkyl chain; hydroxy, ester, and acid groups (enhancing biodegradation); and the presence of one or more aromatic rings and halogen substituents (regarding biodegradation). More than 85% of the model predictions were correct for using the complete data set. The not readily biodegradable predictions were slightly better than the readily biodegradable predictions (86 vs 84%). The average percentage of correct predictions from four external validation studies was 83%. Model optimization by including fragment interactions improve the model predicting capabilities to 89%. It can be concluded that the PLS model provides predictions of high reliability for a diverse range of chemical structures. The predictions conform to the concept of readily biodegradable (or not readily biodegradable) as defined by OECD and EU test guidelines.

  6. Biodegradable compounds: Rheological, mechanical and thermal properties

    NASA Astrophysics Data System (ADS)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  7. Biodegradable lignin/polyolefin composite films

    SciTech Connect

    Kosikova, B.; Demjanova, V.; Mikulasova, M.; Lora, J.H.

    1993-12-31

    From the view point of environmental protection, the plastic wastes, especially from packing materials, represent a potential waste problem. Various approaches were examined to develop partially or completely biodegradable plastics. New type of partially biodegradable polyolefins was prepared by blending of polypropylene with lignin, which was recovered in the ALCELL process, an organosolv pulping process that uses ethanol-water as the delignifying agent. Films of blends with up to 10% wt ALCELL lignin, prepared in absence of commercial stabilizers, had acceptable mechanical strengths. The effect of lignin on biodegradability of the composite films was examined by comparison of behaviour of both pure and lignin containing films during treatment with fungus Phanerochaete chrysosporium. It was found that this fungus is able to grow and to produce lignolytic enzymes in the presence of the films containing lignin. Biodegradation of lignin in the composite film was confirmed by the releasing of lignin fragments into the extracellular fluid. Because of measurement of mechanical properties offers a mean of direct estimation of polymer degradation, the degree of biodegradation of the films tested was followed by monitoring of elongation at break. The changes of break at elongation in the course of enzymatic treatment revealed that the lignin/PP composite films are potentially environmentally nonpersisting. The micrographs of the lignin containing films obtained by scanning electron microscopy show the significant changes of the film surface upon degradation with Phanerochaete chrysosporium in contrast to unchanged lignin free film.

  8. Neutralization/biodegradation of HD

    SciTech Connect

    Beaudry, W.T.; Bossle, P.C.; Harvey, S.P.

    1995-06-01

    The reaction of sulfur mustard (2,2{prime}-dichlorodiethyl sulfide, HD) with NaOH was investigated with respect to the potential utilization of this reaction for the demilitarization of HD stockpiles. Initial studies with Chemical Agent Standard Analytical Reference Material (CASARM) and [{sup 13}C]HD defined the essential parameters of the HD/NaOH reaction with respect to the effects of temperature and NaOH concentration. A temperature increase from 30{degrees}C to 70{degrees}C resulted in a greater than 28-fold increase in the hydrolysis rate, corresponding to an enthalpy of activation value of 17.9 Kcal/mol. NaOH requirements were essentially stoichiometric (0.528 g NaOH per g HD). The effects of varied HD concentrations on the product yield were investigated. At lower HD concentrations, thiodiglycol (TDG) was the major product. As HD concentrations increased, the relative yield of ether and thioether products increased with a concomitant decrease of TDG. Material balance was performed by {sup 13}C NMR to determine the overall product distribution. Approximately 35% of the carbon from HD formed TDG, 60% formed ether-alcohol compounds and 5% formed thioxane and elimination products. Under typical conditions, hydrolysis was complete (no HD or chlorinated organics remained) as determined by both {sup 13}C NMR and GOMS. In order to determine if the process would have application to partially degraded samples which are frequently encountered in demilitarization operations, 64% HD recovered from a buried munition was tested. No chlorinated compounds were detectable in the hydrolysate and the basic distribution of products was similar to that seen with CASARM and munitions-grade material. Biodegradation experiments with hydrolyzed [{sup 14}C] HD as the sole source of carbon for growth demonstrated mineralization by the evolution of CO{sub 2}.

  9. Biodegradability of degradable plastic waste.

    PubMed

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  10. Introduction of Environmentally Degradable Parameters to Evaluate the Biodegradability of Biodegradable Polymers

    PubMed Central

    Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter (EdK) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept EdK was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated EdK was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the EdK values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of EdK for each material. The EdK values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the EdK was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  11. Biodegradable Photonic Melanoidin for Theranostic Applications.

    PubMed

    Lee, Min-Young; Lee, Changho; Jung, Ho Sang; Jeon, Mansik; Kim, Ki Su; Yun, Seok Hyun; Kim, Chulhong; Hahn, Sei Kwang

    2016-01-26

    Light-absorbing nanoparticles for localized heat generation in tissues have various biomedical applications in diagnostic imaging, surgery, and therapies. Although numerous plasmonic and carbon-based nanoparticles with strong optical absorption have been developed, their clearance, potential cytotoxicity, and long-term safety issues remain unresolved. Here, we show that "generally regarded as safe (GRAS)" melanoidins prepared from glucose and amino acid offer a high light-to-heat conversion efficiency, biocompatibility, biodegradability, nonmutagenicity, and efficient renal clearance, as well as a low cost for synthesis. We exhibit a wide range of biomedical photonic applications of melanoidins, including in vivo photoacoustic mapping of sentinel lymph nodes, photoacoustic tracking of gastrointestinal tracts, photothermal cancer therapy, and photothermal lipolysis. The biodegradation rate and renal clearance of melanoidins are controllable by design. Our results confirm the feasibility of biodegradable melanoidins for various photonic applications to theranostic nanomedicines. PMID:26623481

  12. Biodegradation of malachite green by Ochrobactrum sp.

    PubMed

    Vijayalakshmidevi, S R; Muthukumar, Karuppan

    2014-02-01

    This study presents the biodegradation of malachite green (MG), a triphenylmethane dye, using a novel microorganism isolated from textile effluent contaminated environment. The organism responsible for degradation was identified as Ochrobactrum sp JN214485 by 16S rRNA analysis. The effect of operating parameters such as temperature, pH, immobilized bead loading, and initial dye concentration on % degradation was studied, and their optimal values were found to be 30 °C, 6, 20 g/L and 100 mg/L, respectively. The analysis showed that the extracellular enzymes were responsible for the degradation. The biodegradation of MG was confirmed by UV-visible spectroscopic and FTIR analysis. The phytotoxicity test concluded that the degradation products were less toxic compared to MG. The kinetics of biodegradation was studied and the activation energy was found to be 10.65 kcal/mol.

  13. Biodegradable Polymers and Stem Cells for Bioprinting.

    PubMed

    Lei, Meijuan; Wang, Xiaohong

    2016-01-01

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  14. Biodegradable containers from green waste materials

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  15. Adhesion of biocompatible and biodegradable micropatterned surfaces.

    PubMed

    Kaiser, Jessica S; Kamperman, Marleen; de Souza, Emerson J; Schick, Bernhard; Arzt, Eduard

    2011-02-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PLGA) polymer systems. Micropatterned and non-patterned compliant PDMS did not show significant differences in adhesion on compliant mice ear skin or on gelatin-glycerin model substrates. However, adhesion measurements for micropatterned stiff PLGA on compliant gelatin-glycerin model substrates showed significant enhancement in pull-off strengths compared to non-patterned controls.

  16. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    NASA Astrophysics Data System (ADS)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  17. Prospective for biodegradable microstructured optical fibers

    NASA Astrophysics Data System (ADS)

    Dupuis, Alexandre; Guo, Ning; Gao, Yan; Godbout, Nicolas; Lacroix, Suzanne; Dubois, Charles; Skorobogatiy, Maksim

    2007-01-01

    We report fabrication of a novel microstructured optical fiber made of biodegradable and water soluble materials that features ˜1dB/cm transmission loss. Two cellulose butyrate tubes separated with hydroxypropyl cellulose powder were codrawn into a porous double-core fiber offering integration of optical, microfluidic, and potentially drug release functionalities.

  18. BIODEGRADATION OF ATRAZINE IN SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    The pesticide atrazine is frequently detected in ground water, including ground water used as drinking water. Little information is available on the fate of atrazine in the subsurface, including its biodegradability. The objectives of this study were to evaluate the biodegradabil...

  19. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  20. DEMONSTRATION BULLETIN: SLURRY BIODEGRADATION, International Technology Corporation

    EPA Science Inventory

    This technology uses a slurry-phase bioreactor in which the soil is mixed with water to form a slurry. Microorganisms and nutrients are added to the slurry to enhance the biodegradation process, which converts organic wastes into relatively harmless byproducts of microbial metabo...

  1. Biodegradation Of thermoplastic polyurethanes from vegetable oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration were prepared. Soft segment concentration was varied fro, 40 to 70 wt %. Biodegradation was studied by respirometry. Segmented polyurethanes with soft segments based ...

  2. Neuronal growth and differentiation on biodegradable membranes.

    PubMed

    Morelli, Sabrina; Piscioneri, Antonella; Messina, Antonietta; Salerno, Simona; Al-Fageeh, Mohamed B; Drioli, Enrico; De Bartolo, Loredana

    2015-02-01

    Semipermeable polymeric membranes with appropriate morphological, physicochemical and transport properties are relevant to inducing neural regeneration. We developed novel biodegradable membranes to support neuronal differentiation. In particular, we developed chitosan, polycaprolactone and polyurethane flat membranes and a biosynthetic blend between polycaprolactone and polyurethane by phase-inversion techniques. The biodegradable membranes were characterized in order to evaluate their morphological, physicochemical, mechanical and degradation properties. We investigated the efficacy of these different membranes to promote the adhesion and differentiation of neuronal cells. We employed as model cell system the human neuroblastoma cell line SHSY5Y, which is a well-established system for studying neuronal differentiation. The investigation of viability and specific neuronal marker expression allowed assessment that the correct neuronal differentiation and the formation of neuronal network had taken place in vitro in the cells seeded on different biodegradable membranes. Overall, this study provides evidence that neural cell responses depend on the nature of the biodegradable polymer used to form the membranes, as well as on the dissolution, hydrophilic and, above all, mechanical membrane properties. PCL-PU membranes exhibit mechanical properties that improve neurite outgrowth and the expression of specific neuronal markers.

  3. Mechanisms of biodegradation of dibenzoate plasticizers.

    PubMed

    Kermanshahi pour, Azadeh; Cooper, David G; Mamer, Orval A; Maric, Milan; Nicell, Jim A

    2009-09-01

    Biodegradation mechanisms were elucidated for three dibenzoate plasticizers: diethylene glycol dibenzoate (D(EG)DB), dipropylene glycol dibenzoate (D(PG)DB), both of which are commercially available, and 1,6-hexanediol dibenzoate, a potential green plasticizer. Degradation studies were done using Rhodococcus rhodochrous in the presence of pure alkanes as a co-substrate. As expected, the first degradation step for all of these systems was the hydrolysis of one ester bond with the release of benzoic acid and a monoester. Subsequent biodegradation of the monobenzoates of diethylene glycol (D(EG)MB) and dipropylene glycol (D(PG)MB) was very slow, leading to significant accumulation of these monoesters. In contrast, 1,6-hexanediol monobenzoate was quickly degraded and characterization of the metabolites indicated that the biodegradation proceeded by way of the oxidation of the alcohol group to generate 6-(benzoyloxy) hexanoic acid followed by beta-oxidation steps. This pathway was blocked for D(EG)MB and D(PG)MB by the presence of an ether function. The use of a pure hydrocarbon as a co-substrate resulted in the formation of another class of metabolites; namely the esters of the alcohols formed by the oxidation of the alkanes and the benzoic acid released by hydrolysis of the original diesters. These metabolites were biodegraded without the accumulation of any intermediates. PMID:19665165

  4. Biodegradable implant materials in fracture fixation.

    PubMed

    Illi, O E; Weigum, H; Misteli, F

    1992-01-01

    Based on our experiences in paediatric traumatology treated conservatively or with metallic implants, we looked for alternative fixation possibilities in the field of biodegradables. We designed a new driving system for screws consisting of an indwelling screw driver which transduces the torque force over the whole length of the thread. With this technical approach, the head and the neck of the screw as the most friable point for the fracture of the implant could be avoided. In 48 calves aged 6 weeks we performed a comparative study with either conservative treatment (repositioning and casting) or osteosynthesis with biodegradable screws made from polylactate acid or metallic screws (AO type) after an oblique osteotomy at a 45 degrees angle to the axis of the right metacarpal bone. Results from 1 to 6 weeks postoperatively were compared and good to excellent results obtained in equal amounts for PLA and steel screw osteosynthesis, whereas conservative treatment was only successful in one third of the cases. Clinical, radiological and histological follow-up proved the feasibility of biodegradable osteosynthesis in the growing skeleton. For clinical evaluation in children, the resorption time of biodegradable materials has to be lowered to 3 to 6 months. PMID:10149979

  5. Biodegradable electroactive materials for tissue engineering applications

    NASA Astrophysics Data System (ADS)

    Guimard, Nathalie Kathryn

    This dissertation focuses on the development of biomaterials that could be used to enhance the regeneration of severed peripheral nerves. These materials were designed to be electroactive, biodegradable, and biocompatible. To render the materials electroactive the author chose to incorporate conducting polymer (CP) units into the materials. Because CPs are inherently non-degradable, the key challenge was to create a CP-based material that was also biodegradable. Two strategies were explored to generate a biodegradable CP-based material. The first strategy centered around the incorporation of both electroactive and biodegradable subunits into a copolymer system. In the context of this approach, two bis(methoxyquaterthiophene)-co-adipic acid polyester (QAPE) analogues were successfully synthesized, one through polycondensation (giving undoped QAPE) and the second through oxidative polymerization (giving doped QAPE-2). QAPE was found to be electroactive by cyclic voltammetry, bioerodible, and cytocompatible with Schwann cells. QAPE was doped with ferric perchlorate, although only a low doping percentage was realized (˜8%). Oxidative polymerization of a bis(bithiophene) adipate permitted the direct synthesis of doped QAPE-2, which was found to have a higher doping level (˜24%). The second strategy pursued with the goal of generating an electroactive biodegradable material involved covalently immobilizing low molecular weight polythiophene chains onto the surface of crosslinked hyaluronic acid (HA) films. HA films are not only biodegradable and biocompatible, but they also provide mechanical integrity to bilayer systems. Dicyclocarbodiimide coupling of carboxylic acids to HA alcohol groups was used to functionalize HA films. The HA-polythiophene composite is still in the early stages of development. However, to date, thiophene has been successfully immobilized at the surface of HA films with a high degree of substitution. The author has also shown that thiophene

  6. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    PubMed

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  7. Development of biodegradable materials; balancing degradability and performance

    SciTech Connect

    Mayer, J.M.; Allen, A.L.; Dell, P.A.; McCassie, J.E.; Shupe, A.E.; Stenhouse, P.J. Stenhouse, Welch, E.A.; Kaplan, D.L.

    1993-12-31

    The development of biodegradable materials suitable for packaging must take into consideration various performance criteria such as mechanical and barrier properties, as well as rate of biodegradability in given environments. Individual or blended biopolymer films were obtained commercially or blown into film in the laboratory and tested for tensile strength, ultimate elongation and oxygen barrier. These films were then subjected to accelerated marine biodegradation tests as well as simulated marine respirometry. Starch/ethylene vinyl alcohol films exhibited good mechanical and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated marine environment. Polyhydroxyalkanoates had good mechanical properties, average oxygen barrier and good biodegradability. Data indicate that performance and biodegradability of packaging can be tailored to needs by combining individual biopolymers in different proportions in blends and laminates.

  8. Improving the biodegradative capacity of subsurface bacteria

    SciTech Connect

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  9. Approche de prise en charge du trouble du spectre de l’autisme

    PubMed Central

    Lee, Patrick F.; Thomas, Roger E.; Lee, Patricia A.

    2015-01-01

    Résumé Objectif Se pencher sur les critères diagnostiques du trouble du spectre de l’autisme (TSA) comme les définit le Manuel diagnostique et statistique des troubles mentaux, cinquième édition (DSM-V), et concevoir une approche de prise en charge du TSA à l’aide du cadre CanMEDS–Médecine familiale (CanMEDS-MF). Sources d’information Le DSM-V, publié par l’American Psychiatric Association en mai 2013, énonce de nouveaux critères diagnostiques du TSA. Le cadre CanMEDS-MF du Collège des médecins de famille du Canada fournit un plan d’orientation pour la prise en charge complexe du TSA. Nous avons utilisé des données recueillies par le Centers for Disease Control and Prevention afin de déterminer la prévalence du TSA, ainsi que la revue systématique et méta-analyse détaillée effectuée par le National Institute for Health and Care Excellence du R.-U. pour ses lignes directrices sur le TSA dans le but d’évaluer les données probantes issues de plus de 100 interventions. Message principal Selon les données du Centers for Disease Control and Prevention, la prévalence du TSA se chiffrait à 1 sur 88 en 2008 aux États-Unis. La classification du TSA dans la quatrième édition du DSM incluait l’autisme, le syndrome d’Asperger, le trouble envahissant du développement et le trouble désintégratif de l’enfance. La dernière révision du DSM-V réunit tous ces troubles sous la mention TSA, avec différents niveaux de sévérité. La prise en charge du TSA est complexe; elle exige les efforts d’une équipe multidisciplinaire ainsi que des soins continus. Les rôles CanMEDS-MF fournissent un cadre de prise en charge. Conclusion Les médecins de famille sont au cœur de l’équipe de soins multidisciplinaire pour le TSA, et le cadre CanMEDS-MF tient lieu de plan détaillé pour guider la prise en charge d’un enfant atteint de TSA et aider la famille de cet enfant.

  10. BTEX biodegradation by bacteria from effluents of petroleum refinery.

    PubMed

    Mazzeo, Dânia Elisa Christofoletti; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

    2010-09-15

    Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOD Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and

  11. BTEX biodegradation by bacteria from effluents of petroleum refinery.

    PubMed

    Mazzeo, Dânia Elisa Christofoletti; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

    2010-09-15

    Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOD Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and

  12. Les plaies du tendon patellaire

    PubMed Central

    Mechchat, Atif; Elidrissi, Mohammed; Mardy, Abdelhak; Elayoubi, Abdelghni; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les plaies du tendon patellaire sont peu fréquentes et sont peu rapportés dans la littérature, contrairement aux ruptures sous cutanées. Les sections du tendon patellaire nécessitent une réparation immédiate afin de rétablir l'appareil extenseur et de permettre une récupération fonctionnelle précoce. A travers ce travail rétrospectif sur 13 cas, nous analysons les aspects épidémiologiques, thérapeutiques et pronostiques de ce type de pathologie en comparant différents scores. L’âge moyen est de 25 ans avec une prédominance masculine. Les étiologies sont dominées par les accidents de la voie publique (68%) et les agressions par agent tranchant (26%) et contendant (6 %). Tous nos patients ont bénéficié d'un parage chirurgical avec suture tendineuse direct protégée par un laçage au fils d'aciers en légère flexion. La rééducation est débutée après sédation des phénomènes inflammatoires. Au dernier recul les résultats sont excellents et bon à 92%. Nous n'avons pas noté de différence de force musculaire et d'amplitude articulaire entre le genou sain et le genou lésé. Les lésions ouvertes du tendon patellaire est relativement rare. La prise en charge chirurgicale rapide donne des résultats assez satisfaisants. La réparation est généralement renforcée par un semi-tendineux, synthétique ou métallique en forme de cadre de renfort pour faciliter la réadaptation et réduire le risque de récidive après la fin de l'immobilisation. PMID:25170379

  13. Learning about Cri du Chat Syndrome

    MedlinePlus

    ... chat syndrome - also known as 5p- syndrome and cat cry syndrome - is a rare genetic condition that ... du chat syndrome usually include a high-pitched cat-like cry, mental retardation, delayed development, distinctive facial ...

  14. Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions.

    PubMed

    Mohee, R; Unmar, G D; Mudhoo, A; Khadoo, P

    2008-01-01

    A study was conducted on two types of plastic materials, Mater-Bi Novamont (MB) and Environmental Product Inc. (EPI), to assess their biodegradability under aerobic and anaerobic conditions. For aerobic conditions, organic fractions of municipal solid wastes were composted. For the anaerobic process, anaerobic inoculum from a wastewater treatment plant was used. Cellulose filter papers (CFP) were used as a positive control for both mediums. The composting process was monitored in terms of temperature, moisture and volatile solids and the biodegradation of the samples were monitored in terms of mass loss. Monitoring results showed a biodegradation of 27.1% on a dry basis for MB plastic within a period of 72 days of composting. Biodegradability under an anaerobic environment was monitored in terms of biogas production. A cumulative methane gas production of 245 ml was obtained for MB, which showed good degradation as compared to CFP (246.8 ml). However, EPI plastic showed a cumulative methane value of 7.6 ml for a period of 32 days, which was close to the blank (4.0 ml). The EPI plastic did not biodegrade under either condition. The cumulative carbon dioxide evolution after 32 days was as follows: CFP 4.406 cm3, MB 2.198 cm3 and EPI 1.328 cm3. The cumulative level of CO2 varying with time fitted sigmoid type curves with R2 values of 0.996, 0.996 and 0.995 for CFP, MB and EPI, respectively.

  15. Biodegradable Epoxy Networks Cured with Polypeptides

    NASA Astrophysics Data System (ADS)

    Nakamura, Shigeo; Kramer, Edward J.

    2006-03-01

    Epoxy resins are used widely for adhesives as well as coatings. However, once cured they are usually highly cross-linked and are not biodegradable. To obtain potentially biodegradable polypeptides that can cure with epoxy resins and achieve as good properties as the conventional phenol novolac hardeners, poly(succinimide-co-tyrosine) was synthesized by thermal polycondensation of L-aspartic acid and L-tyrosine with phosphoric acid under reduced pressure. The tyrosine/succinimide ratio in the polypeptide was always lower than the tyrosine/(aspartic acid) feed ratio and was influenced by the synthesis conditions. Poly(succinimide-tyrosine- phenylalanine) was also synthesized from L-aspartic acid, L- tyrosine and L-phenylalanine. The thermal and mechanical properties of epoxy resins cured with these polypeptides are comparable to those of similar resins cured with conventional hardeners. In addition, enzymatic degradability tests showed that Chymotrypsin or Subtilisin A could cleave cured films in an alkaline borate buffer.

  16. Enhanced biodegradation resistance of biomodified jute fibers.

    PubMed

    Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam; Das, Sancharini

    2013-04-01

    A bio-catalyzed process has been developed for treating jute fibers to enhance their tensile strength and resistance against biodegradation. Lipolytic bacteria were used in the process to transesterify jute fibers by replacing hydrophilic hydroxyl groups within cellulose chains with hydrophobic fatty acyl chains. Transesterification of some of the hydroxyl groups within the fiber was confirmed with FTIR, UV-vis spectroscopy, (13)C solid state NMR, gas chromatography and analytical determination of ester content. Biomodified fibers exhibited remarkably smaller affinity to water and moisture and retained 62% of their initial tensile strengths after being exposed to a composting environment over 21 days. The corresponding figure for untreated fibers was only 30%. Efficacy of the process reported herein in terms of tensile strength and biodegradation resistance enhancement of fibers achieved after treatment appears to be comparable with similar chemical processes and better than the enzyme-catalyzed alternatives.

  17. Modeling ready biodegradability of fragrance materials.

    PubMed

    Ceriani, Lidia; Papa, Ester; Kovarich, Simona; Boethling, Robert; Gramatica, Paola

    2015-06-01

    In the present study, quantitative structure activity relationships were developed for predicting ready biodegradability of approximately 200 heterogeneous fragrance materials. Two classification methods, classification and regression tree (CART) and k-nearest neighbors (kNN), were applied to perform the modeling. The models were validated with multiple external prediction sets, and the structural applicability domain was verified by the leverage approach. The best models had good sensitivity (internal ≥80%; external ≥68%), specificity (internal ≥80%; external 73%), and overall accuracy (≥75%). Results from the comparison with BIOWIN global models, based on group contribution method, show that specific models developed in the present study perform better in prediction than BIOWIN6, in particular for the correct classification of not readily biodegradable fragrance materials.

  18. Biodegradable inflatable balloons for tissue separation.

    PubMed

    Basu, Arijit; Haim-Zada, Moran; Domb, Abraham J

    2016-10-01

    Confining radiation to a specific region (during radiation therapy) minimizes damage to surrounding tissues. Biodegradable inflatable balloons (bio-balloons) were developed. The device protects the normal tissues by increasing the gap between radiation source and critical structures. The radiation fades away while passing through the inflated balloon preventing the surrounding tissues from harmful radiation. These bio-balloons have also found clinical use to treat massive rotator cuff tear. This review summarizes the chemistry, engineering, and clinical development of these biomedical devices. These balloons are made of biodegradable polymers folded into the edge of a trocar and inserted between the tissues to be separated, and inflated by normal saline in the site of the application. The inserted balloon protects the tissues from radiation or mechanical stress. They remain inflated on site for two months and are finally eliminated within 12 months. PMID:27521613

  19. Biodegradable foam plastics based on castor oil.

    PubMed

    Wang, Hong Juan; Rong, Min Zhi; Zhang, Ming Qiu; Hu, Jing; Chen, Hui Wen; Czigány, Tibor

    2008-02-01

    In this work, a simple but effective approach was proposed for preparing biodegradable plastic foams with a high content of castor oil. First of all, castor oil reacted with maleic anhydride to produce maleated castor oil (MACO) without the aid of any catalyst. Then plastic foams were synthesized through free radical initiated copolymerization between MACO and diluent monomer styrene. With changes in MACO/St ratio and species of curing initiator, mechanical properties of MACO foams can be easily adjusted. In this way, biofoams with comparable compressive stress at 25% strain as commercial polyurethane (PU) foams were prepared, while the content of castor oil can be as high as 61 wt %. The soil burial tests further proved that the castor oil based foams kept the biodegradability of renewable resources despite the fact that some petrol-based components were introduced. PMID:18163578

  20. Enhanced biodegradation resistance of biomodified jute fibers.

    PubMed

    Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam; Das, Sancharini

    2013-04-01

    A bio-catalyzed process has been developed for treating jute fibers to enhance their tensile strength and resistance against biodegradation. Lipolytic bacteria were used in the process to transesterify jute fibers by replacing hydrophilic hydroxyl groups within cellulose chains with hydrophobic fatty acyl chains. Transesterification of some of the hydroxyl groups within the fiber was confirmed with FTIR, UV-vis spectroscopy, (13)C solid state NMR, gas chromatography and analytical determination of ester content. Biomodified fibers exhibited remarkably smaller affinity to water and moisture and retained 62% of their initial tensile strengths after being exposed to a composting environment over 21 days. The corresponding figure for untreated fibers was only 30%. Efficacy of the process reported herein in terms of tensile strength and biodegradation resistance enhancement of fibers achieved after treatment appears to be comparable with similar chemical processes and better than the enzyme-catalyzed alternatives. PMID:23499101

  1. Biodegradable, hydrophobic coatings based on crosslinked polycaprolactone

    SciTech Connect

    Koenig, M.F.

    1993-12-31

    Crosslinked poly(caprolactone) (PCL) has been explored as a hydrophobic and biodegradable coating for hydrophilic substrates. Crosslinking of PCL is known to retard its degradation rate, but does not affect its biodegradability. The cross-linking efficiencies of several organic peroxides have been determined for PCL. This has been accomplished by calculating the crosslink density (M{sub c} from dynamic mechanical data) for a given molar concentration of organic peroxide. Various thicknesses of crosslinked PCL have been coated on several different hydrophilic substrates, including paper, MaterBi (regsign), and PCL/starch composites. The hydrophobicity of the coating has been measured by following the weight gain of the coated samples upon exposure to water and a high relative humidity for various lengths of time. Results show that a coating as thin as 10 {mu}m reduces water absorption of paper by a factor of five, and thicker coatings (0.25 mm) by more than two orders of magnitude.

  2. Biodegradable foam plastics based on castor oil.

    PubMed

    Wang, Hong Juan; Rong, Min Zhi; Zhang, Ming Qiu; Hu, Jing; Chen, Hui Wen; Czigány, Tibor

    2008-02-01

    In this work, a simple but effective approach was proposed for preparing biodegradable plastic foams with a high content of castor oil. First of all, castor oil reacted with maleic anhydride to produce maleated castor oil (MACO) without the aid of any catalyst. Then plastic foams were synthesized through free radical initiated copolymerization between MACO and diluent monomer styrene. With changes in MACO/St ratio and species of curing initiator, mechanical properties of MACO foams can be easily adjusted. In this way, biofoams with comparable compressive stress at 25% strain as commercial polyurethane (PU) foams were prepared, while the content of castor oil can be as high as 61 wt %. The soil burial tests further proved that the castor oil based foams kept the biodegradability of renewable resources despite the fact that some petrol-based components were introduced.

  3. Natural biodegradation of organic contaminants in groundwater

    SciTech Connect

    McNab, W W; Rice, D W

    1998-09-23

    There has recently been a growing awareness that natural processes are degrading contaminants of concern, and that the contribution these natural processes make to achieving cleanup goals needs to be formally considered during site-specific cleanup. Historical case data from a large number of releases has been used to evaluate the expectation for natural attenuation to contribute to the cleanup of petroleum hydrocarbons and chlorinated solvents. The use of historical case data has several advantages, among them: 1) sites can reduce characterization costs by sharing information on key hydrogeologic parameters controlling contaminant fate and transport, and 2) standard reference frameworks can be developed that individual sites can use as a basis of comparison regarding plume behavior. Definition of cleanup times must take into account basic constraints imposed by natural laws governing the transport and natural degradation process of petroleum hydrocarbons. The actual time to reach groundwater cleanup goals is determined by these laws and the limitations on residual subsurface contamination attenuation rates, through either active or natural biological processes. These limitations will practically constrain the time to achieve low concentration cleanup goals. Recognition is needed that sites will need to be transitioned to remediation by natural processes at some point following implementation of active remediation options. The results of an analysis of approximately 1800 California and 600 Texas fuel hydrocarbon (FHC) releases and 2.50 chlorinated volatile organic compound (CVOC) plumes will be summarized. Plume lengths and natural biodegradation potential were evaluated. For FHC releases, 90% of benzene groundwater plumes were less than 280 feet in length and evidence of natural biodegradation was found to be present at all sites studied in detail. For CVOC releases, source strength and groundwater flow velocity are dominant factors controlling groundwater plume

  4. Anaerobic biodegradation of surrogate naphthenic acids.

    PubMed

    Clothier, Lindsay N; Gieg, Lisa M

    2016-03-01

    Surface bitumen extraction from the Alberta's oil sands region generates large settling basins known as tailings ponds. The oil sands process-affected water (OSPW) stored in these ponds contain solid and residual bitumen-associated compounds including naphthenic acids (NAs) that can potentially be biodedgraded by indigenous tailings microorganisms. While the biodegradation of some NAs is known to occur under aerobic conditions, little is understood about anaerobic NA biodegradation even though tailings ponds are mainly anoxic. Here, we investigated the potential for anaerobic NA biodegradation by indigenous tailings microorganisms. Enrichment cultures were established from anoxic tailings that were amended with 5 single-ringed surrogate NAs or acid-extractable organics (AEO) from OSPW and incubated under nitrate-, sulfate-, iron-reducing, and methanogenic conditions. Surrogate NA depletion was observed under all anaerobic conditions tested to varying extents, correlating to losses in the respective electron acceptor (sulfate or nitrate) or the production of predicted products (Fe(II) or methane). Tailings-containing cultures incubated under the different electron-accepting conditions resulted in the enrichment and putative identification of microbial community members that may function in metabolizing surrogate NAs under the various anoxic conditions. In addition, more complex NAs (in the form of AEO) was observed to drive sulfate and iron reduction relative to controls. Overall, this study has shown that simple surrogate NAs can be biodegraded under a variety of anoxic conditions, a key first step in understanding the potential anaerobic metabolism of NAs in oil sands tailings ponds and other industrial wastewaters. PMID:26724449

  5. Polymer blends with biodegradable components and reinforcements

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Di Landro, Luca

    2014-05-01

    Polymeric blends based on ethylene vinyl acetate rubbers filled with high mol. wt. carboxymethyl cellulose were investigated in view of possible employment as biodegradable materials. The effect of vinyl acetate content and of addition of transesterification agent to increase interaction between EVA and cellulosic components was considered. Blends reinforced with cellulose microfibers in different amounts were also characterized in their mechanical, rheological and thermal behavior.

  6. Biodegradation of hexachlorocyclohexane (HCH) by microorganisms.

    PubMed

    Phillips, Theresa M; Seech, Alan G; Lee, Hung; Trevors, Jack T

    2005-08-01

    The organochlorine pesticide Lindane is the gamma-isomer of hexachlorocyclohexane (HCH). Technical grade Lindane contains a mixture of HCH isomers which include not only gamma-HCH, but also large amounts of predominantly alpha-, beta- and delta-HCH. The physical properties and persistence of each isomer differ because of the different chlorine atom orientations on each molecule (axial or equatorial). However, all four isomers are considered toxic and recalcitrant worldwide pollutants. Biodegradation of HCH has been studied in soil, slurry and culture media but very little information exists on in situ bioremediation of the different isomers including Lindane itself, at full scale. Several soil microorganisms capable of degrading, and utilizing HCH as a carbon source, have been reported. In selected bacterial strains, the genes encoding the enzymes involved in the initial degradation of Lindane have been cloned, sequenced, expressed and the gene products characterized. HCH is biodegradable under both oxic and anoxic conditions, although mineralization is generally observed only in oxic systems. As is found for most organic compounds, HCH degradation in soil occurs at moderate temperatures and at near neutral pH. HCH biodegradation in soil has been reported at both low and high (saturated) moisture contents. Soil texture and organic matter appear to influence degradation presumably by sorption mechanisms and impact on moisture retention, bacterial growth and pH. Most studies report on the biodegradation of relatively low (< 500 mg/kg) concentrations of HCH in soil. Information on the effects of inorganic nutrients, organic carbon sources or other soil amendments is scattered and inconclusive. More in-depth assessments of amendment effects and evaluation of bioremediation protocols, on a large scale, using soil with high HCH concentrations, are needed.

  7. Behaviour of biodegradable plastics in composting facilities.

    PubMed

    Körner, I; Redemann, K; Stegmann, R

    2005-01-01

    Composting is a preferred treatment strategy for biodegradable plastics (BDPs). In this sense, the collection of BDPs together with organic household wastes is a highly discussed possibility. Under the aspect of the behaviour of BDPs in composting facilities, a telephone survey was carried out with selected composting facility operators. They were interviewed with respect to treated wastes, content of impurities, processes for impurity separation, experiences with biodegradable plastics and assumptions to the behaviour of biodegradable plastics in their facility. Forty percent of the facilities had some experiences with BDPs due to test runs, and also since the occurrence of BDPs in their waste was known. The majority of the operators expressed apprehension regarding an increase of impurities resulting from a combined collection of biowaste and BDPs. In the facilities, measures for the impurity separation from the biowaste were used in common practice - in 33% of the cases, separation of disturbing plastics was done before composting, in 33% after composting, and in 13% before and after composting. The most important separation processes for conventional plastics were sieving and manual sorting. In two cases air classification was also used. When asked about the separation possibility of the conventional but not of the biodegradable plastics in their facilities, the majority of operators were not in a position to comment or they replied that it was not an option. No problems were seen in most cases if the impurity separation follows composting. If impurity separation takes place before composting it was often assumed that the BDPs are mainly separated by sieving. In conclusion, in more than half of the cases, BDPs would not be composted if delivered to a composting facility. Under the actual conditions regarding the collection and the treatment/disposal possibilities, an application of BDPs seems to only be reasonable for clean (i.e., source separated on their own

  8. Directions for environmentally biodegradable polymer research

    SciTech Connect

    Swift, G. )

    1993-03-01

    A major factor promoting interest in biodegradable polymers is the growing concern raised by the recalcitrance and unknown environmental fate of many of the currently used synthetic polymers. These polymers include both water-soluble and water-insoluble types. The former are generally specialty polymers with functional groups that effect water solubility such as carboxyl, hydroxyl, amido, etc.; the latter are usually nonfunctional polymers commonly referred to as commodity plastics. Both types of polymers are widely used in many applications. Water-soluble polymers are used, for example, in cosmetics, water treatment, dispersants, thickeners, detergents, and superabsorbents, and they include poly(acrylic acid), polyacrylamide, poly(vinyl alcohol), and poly(ethylene glycol). Plastics are used in packaging, disposable diaper backing, fishing nets, and agricultural film; they include polymers such as polyethylene, polypropylene, polystyrene, poly(vinyl chloride), poly(ethylene terephthalate), and Nylon 6.6. In this Account, the author presents a personal perspective on definitions and test protocols for biodegradable polymers as well as how they will influence the future direction and developments in the field. However, before doing so he digresses briefly to present a commentary on the role of biodegradable polymers in environmental waste management. This should be useful for those readers unfamiliar with the subject, and it will set the stage for the rest of the discussion. 36 refs., 3 figs.

  9. Biodegradation potential of a modified natural product

    SciTech Connect

    Sajjad, W.

    1996-12-31

    Biodegradation potential of a modified natural product for treating petroleum contaminated soils was investigated along with some commercially available microbial cultures in three different scales from a laboratory to pilot to case studies. The modified natural product is lignocellulosic in nature and proprietary product of a company in Iowa. The production process of this product involves mechanical size reduction, blending/coating, and aerobic digestion of hay, corn cob residue, straw or crop residue in presence of poultry manure. The degradation kinetics of the petroleum products in the contaminated soils were measured both directly and indirectly. Residual petroleum products in different soils (treated and untreated) at various time periods were quantified by gas chromatographic (GC) analysis on extracted samples. The indirect assessment of the kinetics of biological activity involved the measurement of CO{sub 2} evolved from flasks (250 ml capacity) containing contaminated soil (about 50 ml) with various treatments. The results indicated that the biodegradation kinetics of petroleum products in the contaminated soils were significantly improved by treatment with this modified natural product. In most cases tested, this product performed significantly better than the available commercial bacterial cultures for biological removal of petroleum products from contaminated soils. This study also demonstrated the significance of temperature and moisture content in biodegradation kinetics.

  10. Transport and biodegradation of perchlorate in soils.

    PubMed

    Tipton, Deborah K; Rolston, Dennis E; Scow, Kate M

    2003-01-01

    Perchlorate (ClO4-) contamination of ground water and surface water is a widespread problem, particularly in the western United States. This study examined the effect of biodegradation on perchlorate fate and transport in soils. Solute transport experiments were conducted on two surface soils. Pulses of solution containing perchlorate and Br- were applied to saturated soil columns at steady state water flow. Perchlorate behaved like a nonreactive tracer in Columbia loam (coarse-loamy, mixed, superactive, nonacid, thermic Oxyaquic Xerofluvent) but was degraded in Yolo loam (fine-silty, mixed, superactive, nonacid, thermic Mollic Xerofluvent). Batch experiments demonstrated that perchlorate removal from solution in Yolo loam was caused by biodegradation. Other batch experiments with Yolo loam surface and subsurface soils, Columbia loam surface soil, and dredge tailings demonstrated that perchlorate biodegradation required anaerobic conditions, an adequate carbon source, and an active perchlorate-degrading microbial population. The sequential reduction of perchlorate and NO3- by an indigenous soil microbial community in Yolo loam batch systems was also studied. Nitrate reduction occurred much sooner than perchlorate reduction in soils that had not been previously exposed to perchlorate, but NO3- and perchlorate were simultaneously reduced in soils previously exposed to perchlorate. The results of this study have implications for in situ remediation schemes and for agricultural soils that have been contaminated by perchlorate-tainted irrigation water. PMID:12549540

  11. Systematic approach for modeling tetrachloroethene biodegradation

    SciTech Connect

    Bagley, D.M.

    1998-11-01

    The anaerobic biodegradation of tetrachloroethene (PCE) is a reasonably well understood process. Specific organisms capable of using PCE as an electron acceptor for growth require the addition of an electron donor to remove PCE from contaminated ground waters. However, competition from other anaerobic microorganisms for added electron donor will influence the rate and completeness of PCE degradation. The approach developed here allows for the explicit modeling of PCE and byproduct biodegradation as a function of electron donor and byproduct concentrations, and the microbiological ecology of the system. The approach is general and can be easily modified for ready use with in situ ground-water models or ex situ reactor models. Simulations conducted with models developed from this approach show the sensitivity of PCE biodegradation to input parameter values, in particular initial biomass concentrations. Additionally, the dechlorination rate will be strongly influenced by the microbial ecology of the system. Finally, comparison with experimental acclimation results indicates that existing kinetic constants may not be generally applicable. Better techniques for measuring the biomass of specific organisms groups in mixed systems are required.

  12. Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

    PubMed

    Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

    2014-09-01

    Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed.

  13. Pru du 2S albumin or Pru du vicilin?

    PubMed

    Garino, Cristiano; De Paolis, Angelo; Coïsson, Jean Daniel; Arlorio, Marco

    2015-06-01

    A short partial sequence of 28 amino acids is all the information we have so far about the putative allergen 2S albumin from almond. The aim of this work was to analyze this information using mainly bioinformatics tools, in order to verify its rightness. Based on the results reported in the paper describing this allergen from almond, we analyzed the original data of amino acids sequencing through available software. The degree of homology of the almond 12kDa protein with any other known 2S albumin appears to be much lower than the one reported in the paper that firstly described it. In a publicly available cDNA library we discovered an expressed sequence tag which translation generates a protein that perfectly matches both of the sequencing outputs described in the same paper. A further analysis indicated that the latter protein seems to belong to the vicilin superfamily rather than to the prolamin one. The fact that also vicilins are seed storage proteins known to be highly allergenic would explain the IgE reactivity originally observed. Based on our observations we suggest that the IgE reactive 12kDa protein from almond currently known as Pru du 2S albumin is in reality the cleaved N-terminal region of a 7S vicilin like protein.

  14. Biokinetics and dosimetry of depleted uranium (DU) in rats implanted with DU fragments.

    SciTech Connect

    Guilmette, Ray A.; Hahn, Fletcher F.; Durbin, P. W.

    2004-01-01

    A number of U. S. veterans of the Persian Gulf War were wounded with depleted uranium (DU) metal fragments as a result of 'friendly fire' incidents, in which Abrams tanks and Bradley fighting vehicles were struck by DU anti-armor munitions. Some of the crew members who survived were left with multiple small fragments of DU in their muscles and soft tissues. The number, size and location of the fragments made them inoperable in general, and therefore subject to long-term retention. Because there was inadequate data to predict the potential carcinogenicity of DU fragments in soft tissues, Hahn et al. (2003) conducted a lifespan cancer study in rats. As part of that study, a number of rats were maintained to study the biokinetics and dosimetry of DU implanted intramuscularly in male Wistar rats. Typically, four metal fragments, either as cylindrical pellets or square wafers were implanted into the biceps femoris muscles of the rats. Urine samples were collected periodically during their lifespans, and DU was analyzed in kidneys and eviscerated carcass (minus the implant sites) at death. The daily DU urinary excretion rate increased steeply during the first 30 d after implantation peaking at about 90 d at 3-10 x 10{sup -3}%/d. During the first 150 d, the average excretion rate was 2.4 x 10{sup -3}%/d, decreasing thereafter to about 1 x 10{sup -3}%/d. Serial radiographs were made of the wound sites to monitor gross morphologic changes in the DU implant and the surrounding tissue. As early as 1 w after implantation, radiographs showed the presence of surface corrosion and small, dense bodies near the original implant, presumably DU. This corrosion from the surface of the implant continued with time, but did not result in an increasing amount of DU reaching the blood and urine after the first 3 mo. During this 3-mo period, connective tissue capsules formed around the implants, and are hypothesized to have reduced the access of DU to tissue fluids by limiting the diffusion

  15. Critical evaluation of biodegradable polymers used in nanodrugs.

    PubMed

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.

  16. Critical evaluation of biodegradable polymers used in nanodrugs

    PubMed Central

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  17. Résultats du traitement du synovialosarcome des members

    PubMed Central

    Lukulunga, Loubet Unyendje; Moussa, Abdou Kadri; Mahfoud, Mustapha; El Bardouni, Ahmed; Ismail, Farid; Kharmaz, Mohammed; Berrada, Mohamed Saleh; El Yaacoubi, Moradh

    2014-01-01

    Les synovialosarcomes, sarcomes de haut grade, sont de diagnostic tardif et le traitement est complexe et onéreux, nécessitant la mise en œuvre d'une équipe pluridisciplinaire. Le but de ce travail était d'apprécier les résultats de l'association de la chirurgie à la radio chimiothérapie des synovialosarcomes des membres. Il s'agissait d'une étude rétrospective portant sur des patients présentant de synovialosarcomes des membres pris en charge dans le service de chirurgie orthopédique et traumatologique du CHU Ibn SINA de Rabat allant de Janvier 2006 à Décembre 2011 (6 ans). Nous avons inclus les malades présentant de synovialosarcomes des membres dont la clinique et l'imagerie médicale étaient en faveur, confirmés par l'examen anatomopathologique et la prise en charge effectuée dans le service. Les patients ont été revus avec un recul moyen de 3 ans. Nous n'avons pas retenu les patients dont les dossiers étaient incomplets, perdus de vue. Nous avons apprécié les résultats selon les critères carcinologiques et le score MSTS (Musculoskeletal Tumor Society). La saisie et l'analyse des données ont été faites sur le logiciel SPSS Stastic 17.0 Nous avons colligé 20 cas de synovialosarcome des membres dans le Service de Chirurgie Orthopédique et Traumatologique au CHU Ibn SINA de Rabat Le sexe masculin a prédominé avec 65% (n = 13) avec un sex ratio 1,85. L’âge moyen a été de 42,6 ans avec des extrêmes allant de 20 ans et 70 ans. Notre délai moyen de consultation était de 14,42 mois. Tous les malades ont consulté pour une tuméfaction dans 100% (localisée au membre inférieur dans 65% (n = 13), membre supérieur dans 35% (n = 7). La douleur était associée à la tuméfaction dans 55% (n = 11), quant à l'altération de l’état général et l'ulcération de la masse, elles ont été notées dans 3 cas chacune. Nous avons réalisé un bilan d'imagerie médicale comprenant: radiographie standard, échographie, écho doppler

  18. Cirque du Monde as a health intervention

    PubMed Central

    Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

    2014-01-01

    Abstract Objective To present Cirque du Soleil’s social circus program, Cirque du Monde, to explore its potential as a primary health care tool for family physicians. Data sources A review of the literature in PubMed, the Cochrane Library, PsycINFO, LaPresse, Eureka, Google Scholar, and Érudit using the key words circus, social circus, Cirque du Monde, and Cirque du Soleil; a Montreal-based initiative, Espace Transition, modeled on Cirque du Monde; and personal communication with Cirque du Soleil’s Social Circus Training Advisor. Study selection The first 50 articles or websites identified for each key word in each of the databases were examined on the basis of their titles and abstracts in the case of articles, and on the basis of their titles and page content in the case of websites. Articles and websites that explored an aspect of social circuses or that described an intervention that involved circuses were then retained for analysis. Because all literature on social circuses was searched, no criterion for year of publication was used. Synthesis No articles on the social circus as a health intervention were found. One study on the use of the circus as an intervention in schools was identified. It demonstrated an increase in self-esteem in the children who took part. One study on the use of the circus in a First Nations community was found; it contained nonspecific, qualitative findings. The other articles identified were merely descriptions of social circuses. One website was identified on the use of the social circus to help youth who had been treated in a hospital setting for major psychiatric disorders to re-enter the community. The team in the pediatric psychiatry department at Centre Hospitalier Universitaire Sainte-Justine, the children’s hospital in Montreal, Que, was contacted; they were leading this project, called Espace Transition. The unpublished preliminary findings of its pilot project demonstrate substantial improvements in overall patient

  19. Isomer-specific biodegradation of nonylphenol in an activated sludge bioreactor and structure-biodegradability relationship.

    PubMed

    Lu, Zhijiang; Reif, Rubén; Gan, Jay

    2015-01-01

    Nonylphenol (NP), one of the priority hazardous substances, is in fact a mixture of numerous isomers. It is inconclusive whether or not biodegradation during wastewater treatment process is isomer-specific, leading to the environmental release of NP in different isomer profiles. In this study, we evaluated the isomer selectivity of 19 NP isomers in a laboratory-scale continuous flow conventional activated sludge bioreactor under various operational conditions. The removal efficiency of NP isomers ranged from 90 to 99%, depending on the operational conditions and isomer structures. Isomer selective biodegradation resulted in the increase of composition of recalcitrant isomers, such as, NP₁₉₃a/b, NP₁₁₀a and NP₁₉₄ in the effluent. Moreover, biodegradability was related to the bulkiness of α-substituents and followed α-dimethyl > α-ethyl-α-methyl > α-methyl-α-n-propyl > α-iso-propyl-α-methyl. Steric effect index, a quantitative descriptor of steric hindrance, was linearly correlated with residues of NP isomers in the effluent (R² = 0.76). Decrease of temperature to 10 °C decreased the overall biodegradability and also enhanced the relative enrichment of recalcitrant isomers. These findings suggest that isomer compositions of NP entering the environment may be different from those in technical mixtures and that isomeric selectivity should be taken into account to better understand the occurrence, fate, and ecological risks of NP.

  20. Heterostereocomplexation between biodegradable and optically active polyesters as a versatile preparation method for biodegradable materials.

    PubMed

    Tsuji, Hideto; Yamamoto, Satomi; Okumura, Ayaka; Sugiura, Yu

    2010-01-11

    The thermal properties and crystallization of biodegradable and optically active poly[(S)-2-hydroxybutyrate] [P(S-2HB)], poly(l-lactide) (PLLA), poly(d-lactide) (PDLA) and their blends were investigated. The results of differential scanning calorimetry, wide-angle X-ray scattering (WAXS), and polarized optical microscopy first indicated heterostereocomplexation between biodegradable and optically active polyesters having different chemical structures and opposite configurations, that is, P(S-2HB) and PDLA. The melting temperature of the heterostereocomplex was higher than those of pure polymers. Such cocrystallization was not observed for P(S-2HB)/PLLA blends having identical configurations. The WAXS profile of P(S-2HB)/PDLA heterostereocomplex was very similar to those of the PLLA/PDLA and P(S-2HB)/P(R-2HB) homostereocomplexes and each crystalline diffraction peak of the heterostereocomplex was located between those of the homostereocomplexes. The present study strongly suggests that heterostereocomplexation will provide a novel versatile method for preparing biodegradable polyester materials with a wide range of physical properties and biodegradability.

  1. Isomer-specific biodegradation of nonylphenol in an activated sludge bioreactor and structure-biodegradability relationship.

    PubMed

    Lu, Zhijiang; Reif, Rubén; Gan, Jay

    2015-01-01

    Nonylphenol (NP), one of the priority hazardous substances, is in fact a mixture of numerous isomers. It is inconclusive whether or not biodegradation during wastewater treatment process is isomer-specific, leading to the environmental release of NP in different isomer profiles. In this study, we evaluated the isomer selectivity of 19 NP isomers in a laboratory-scale continuous flow conventional activated sludge bioreactor under various operational conditions. The removal efficiency of NP isomers ranged from 90 to 99%, depending on the operational conditions and isomer structures. Isomer selective biodegradation resulted in the increase of composition of recalcitrant isomers, such as, NP₁₉₃a/b, NP₁₁₀a and NP₁₉₄ in the effluent. Moreover, biodegradability was related to the bulkiness of α-substituents and followed α-dimethyl > α-ethyl-α-methyl > α-methyl-α-n-propyl > α-iso-propyl-α-methyl. Steric effect index, a quantitative descriptor of steric hindrance, was linearly correlated with residues of NP isomers in the effluent (R² = 0.76). Decrease of temperature to 10 °C decreased the overall biodegradability and also enhanced the relative enrichment of recalcitrant isomers. These findings suggest that isomer compositions of NP entering the environment may be different from those in technical mixtures and that isomeric selectivity should be taken into account to better understand the occurrence, fate, and ecological risks of NP. PMID:25462736

  2. Development of aliphatic biodegradable photoluminescent polymers

    PubMed Central

    Yang, Jian; Zhang, Yi; Gautam, Santosh; Liu, Li; Dey, Jagannath; Chen, Wei; Mason, Ralph P.; Serrano, Carlos A.; Schug, Kevin A.; Tang, Liping

    2009-01-01

    None of the current biodegradable polymers can function as both implant materials and fluorescent imaging probes. The objective of this study was to develop aliphatic biodegradable photoluminescent polymers (BPLPs) and their associated cross-linked variants (CBPLPs) for biomedical applications. BPLPs are degradable oligomers synthesized from biocompatible monomers including citric acid, aliphatic diols, and various amino acids via a convenient and cost-effective polycondensation reaction. BPLPs can be further cross-linked into elastomeric cross-linked polymers, CBPLPs. We have shown representatively that BPLP-cysteine (BPLP-Cys) and BPLP-serine (BPLP-Ser) offer advantages over the traditional fluorescent organic dyes and quantum dots because of their preliminarily demonstrated cytocompatibility in vitro, minimal chronic inflammatory responses in vivo, controlled degradability and high quantum yields (up to 62.33%), tunable fluorescence emission (up to 725 nm), and photostability. The tensile strength of CBPLP-Cys film ranged from 3.25 ± 0.13 MPa to 6.5 ± 0.8 MPa and the initial Modulus was in a range of 3.34 ± 0.15 MPa to 7.02 ± 1.40 MPa. Elastic CBPLP-Cys could be elongated up to 240 ± 36%. The compressive modulus of BPLP-Cys (0.6) (1:1:0.6 OD:CA:Cys) porous scaffold was 39.60 ± 5.90 KPa confirming the soft nature of the scaffolds. BPLPs also possess great processability for micro/nano-fabrication. We demonstrate the feasibility of using BPLP-Ser nanoparticles (“biodegradable quantum dots”) for in vitro cellular labeling and noninvasive in vivo imaging of tissue engineering scaffolds. The development of BPLPs and CBPLPs represents a new direction in developing fluorescent biomaterials and could impact tissue engineering, drug delivery, bioimaging. PMID:19506254

  3. Biodegradation of brominated and organophosphorus flame retardants.

    PubMed

    Waaijers, Susanne L; Parsons, John R

    2016-04-01

    Brominated flame retardants account for about 21% of the total production of flame retardants and many of these have been identified as persistent, bioaccumulative and toxic. Nevertheless, debromination of these chemicals under anaerobic conditions is well established, although this can increase their toxicity. Consequently, the production and use of these chemicals has been restricted and alternative products have been developed. Many of these are brominated compounds and share some of the disadvantages of the chemicals they are meant to replace. Therefore, other, nonbrominated, flame retardants such as organophosphorus compounds are also being used in increasing quantities, despite the fact that knowledge of their biodegradation and environmental fate is often lacking.

  4. Biodegradable Long-Circulating Polymeric Nanospheres

    NASA Astrophysics Data System (ADS)

    Gref, Ruxandra; Minamitake, Yoshiharu; Peracchia, Maria Teresa; Trubetskoy, Vladimir; Torchilin, Vladimir; Langer, Robert

    1994-03-01

    Injectable nanoparticulate carriers have important potential applications such as site-specific drug delivery or medical imaging. Conventional carriers, however, cannot generally be used because they are eliminated by the reticulo-endothelial system within seconds or minutes after intravenous injection. To address these limitations, monodisperse biodegradable nanospheres were developed from amphiphilic copolymers composed of two biocompatible blocks. The nanospheres exhibited dramatically increased blood circulation times and reduced liver accumulation in mice. Furthermore, they entrapped up to 45 percent by weight of the drug in the dense core in a one-step procedure and could be freeze-dried and easily redispersed without additives in aqueous solutions.

  5. Biodegradable and Renal Clearable Inorganic Nanoparticles

    PubMed Central

    Ehlerding, Emily B.; Chen, Feng; Cai, Weibo

    2016-01-01

    Personalized treatment plans for cancer therapy have been at the forefront of oncology research for many years. With the advent of many novel nanoplatforms, this goal is closer to realization today than ever before. Inorganic nanoparticles hold immense potential in the field of nano-oncology, but have considerable toxicity concerns that have limited their translation to date. In this review, an overview of emerging biologically safe inorganic nanoplatforms is provided, along with considerations of the challenges that need to be overcome for cancer theranostics with inorganic nanoparticles to become a reality. The clinical and preclinical studies of both biodegradable and renal clearable inorganic nanoparticles are discussed, along with their implications. PMID:27429897

  6. Biosynthesis and biodegradation of wood components

    SciTech Connect

    Higuchi, T.

    1985-01-01

    A textbook containing 22 chapters by various authors covers the structure of wood, the localization of polysaccharides and lignins in wood cell walls, metabolism and synthetic function of cambial tissue, cell organelles and their function in the biosynthesis of cell wall components, biosynthesis of plant cell wall polysaccharides, lignin, cutin, suberin and associated waxes, phenolic acids and monolignols, quinones, flavonoids, tannins, stilbenes and terpenoid wood extractives, the occurrence of extractives, the metabolism of phenolic acids, wood degradation by micro-organisms and fungi, and biodegradation of cellulose, hemicelluloses, lignin, and aromatic extractives of wood. An index is included.

  7. Biodegradable long-circulating polymeric nanospheres.

    PubMed

    Gref, R; Minamitake, Y; Peracchia, M T; Trubetskoy, V; Torchilin, V; Langer, R

    1994-03-18

    Injectable nanoparticulate carriers have important potential applications such as site-specific drug delivery or medical imaging. Conventional carriers, however, cannot generally be used because they are eliminated by the reticulo-endothelial system within seconds or minutes after intravenous injection. To address these limitations, monodisperse biodegradable nanospheres were developed from amphiphilic copolymers composed of two biocompatible blocks. The nanospheres exhibited dramatically increased blood circulation times and reduced liver accumulation in mice. Furthermore, they entrapped up to 45 percent by weight of the drug in the dense core in a one-step procedure and could be freeze-dried and easily redispersed without additives in aqueous solutions.

  8. Biodegradation of petroleum hydrocarbons in hypersaline environments

    PubMed Central

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  9. Biodegradable and Renal Clearable Inorganic Nanoparticles

    PubMed Central

    Ehlerding, Emily B.

    2015-01-01

    Personalized treatment plans for cancer therapy have been at the forefront of oncology research for many years. With the advent of many novel nanoplatforms, this goal is closer to realization today than ever before. Inorganic nanoparticles hold immense potential in the field of nano‐oncology, but have considerable toxicity concerns that have limited their translation to date. In this review, an overview of emerging biologically safe inorganic nanoplatforms is provided, along with considerations of the challenges that need to be overcome for cancer theranostics with inorganic nanoparticles to become a reality. The clinical and preclinical studies of both biodegradable and renal clearable inorganic nanoparticles are discussed, along with their implications. PMID:27429897

  10. Compared in vivo toxicity in mice of lung delivered biodegradable and non-biodegradable nanoparticles.

    PubMed

    Aragao-Santiago, Letícia; Hillaireau, Hervé; Grabowski, Nadège; Mura, Simona; Nascimento, Thais L; Dufort, Sandrine; Coll, Jean-Luc; Tsapis, Nicolas; Fattal, Elias

    2016-01-01

    To design nanoparticle (NP)-based drug delivery systems for pulmonary administration, biodegradable materials are considered safe, but their potential toxicity is poorly explored. We here explore the lung toxicity in mice of biodegradable nanoparticles (NPs) and compare it to the toxicity of non-biodegradable ones. NP formulations of poly(d,l-lactide-co-glycolide) (PLGA) coated with chitosan (CS), poloxamer 188 (PF68) or poly(vinyl alcohol) (PVA), which renders 200 nm NPs of positive, negative or neutral surface charge respectively, were analyzed for their biodistribution by in vivo fluorescence imaging and their inflammatory potential after single lung nebulization in mice. After exposure, analysis of bronchoalveolar lavage (BAL) cell population, protein secretion and cytokine release as well as lung histology were carried out. The inflammatory response was compared to the one induced by non-biodegradable counterparts, namely, TiO2 of rutile and anatase crystal form and polystyrene (PS). PLGA NPs were mostly present in mice lungs, with little passage to other organs. An increase in neutrophil recruitment was observed in mice exposed to PS NPs 24 h after nebulization, which declined at 48 h. This result was supported by an increase in interleukin (IL)-6 and tumor necrosis factor α (TNFα) in BAL supernatant at 24 h. TiO2 anatase NPs were still present in lung cells 48 h after nebulization and induced the expression of pro-inflammatory cytokines and the recruitment of polymorphonuclear cells to BAL. In contrast, regardless of their surface charge, PLGA NPs did not induce significant changes in the inflammation markers analyzed. In conclusion, these results point out to a safe use of PLGA NPs regardless of their surface coating compared to non-biodegradable ones.

  11. KINETICS OF ETHANOL BIODEGRADATION UNDER METHANOGENIC CONDITIONS IN GASOLINE SPILLS

    EPA Science Inventory

    Ethanol is commonly used as a fuel oxygenate. A concern has been raised that biodegradation of ethanol from a spill of gasoline may inhibit the natural biodegradation of fuel hydrocarbons, including benzene. Ethanol is miscible in water, and ethanol is readily metabolized by mi...

  12. SCREENING OF BACTERIAL PRODUCTS FOR THEIR CRUDE OIL BIODEGRADATION EFFECTIVENESS

    EPA Science Inventory

    Although petroleum hydrocarbons have been known to be biodegradable for decades (1-5), use of microbial cultures to enhance natural biodegradation (bioaugmentation) has met with limited success (6-10). Despite the paucity of controlled field studies demonstrating the effectivene...

  13. Biodegradation of Petroleum Hydrocarbon in the Vadose Zone

    EPA Science Inventory

    There are two major impediments to a better understanding of the influence of biodegradation on the risk of intrusion of petroleum vapors. We describe the contribution of biodegradation as an attenuation factor between the source and the receptor. The use of attenuation factors...

  14. A Sensitive and Biodegradable Pressure Sensor Array for Cardiovascular Monitoring.

    PubMed

    Boutry, Clementine M; Nguyen, Amanda; Lawal, Qudus Omotayo; Chortos, Alex; Rondeau-Gagné, Simon; Bao, Zhenan

    2015-11-18

    An array of highly sensitive pressure sensors entirely made of biodegradable materials is presented, designed as a single-use flexible patch for application in cardiovascular monitoring. The high sensitivity in combination with fast response time is unprecedented when compared to recent reports on biodegradable pressure sensors (sensitivity three orders of magnitude higher), as illustrated by pulse wave velocity measurements, toward hypertension detection.

  15. Unilateral hyperhydrosis in Pourfour du Petit syndrome.

    PubMed

    Kara, Murat; Dikmen, Erkan; Akarsu, Cengiz; Birol, Ahu

    2004-08-01

    Upper limp hyperhydrosis is an idiopathic disease with bilateral involvement. However, Pourfour du Petit syndrome, the opposite of Horner syndrome, may result in unilateral upper limb hyperhydrosis. It occurs following hyperactivity of the sympathetic cervical chain as a consequence of irritation secondary to trauma. We report herein two cases with Pourfour du Petit syndrome showing unilateral upper limb hyperhydrosis. The patients presented with right-sided mydriasis and ipsilateral hemifacial hyperhydrosis. The onset of disease was followed by a trauma in both patients. They underwent upper thoracic sympathectomy with favorable outcome. A history of an antecedent trauma in patients with unilateral upper limb hyperhydrosis and anisocoria may imply a possible diagnosis of Pourfour du Petit syndrome. PMID:15296919

  16. [Progress on biodegradation of polylactic acid--a review].

    PubMed

    Li, Fan; Wang, Sha; Liu, Weifeng; Chen, Guanjun

    2008-02-01

    Polylactic acid is a high molecular-weight polyester made from renewable resources such as corn or starch. It is a promising biodegradable plastic due to its mechanical properties, biocompatibility and biodegradability. To achieve natural recycling of polylactic acid, relative microorganisms and the underlying mechanisms in the biodegradation has become an important issue in biodegradable materials. Up to date, most isolated microbes capable of degrading polylactic acid belong to actinomycetes. Proteases secreted by these microorganisms are responsible for the degradation. However, subtle differences exist between these polylactic acid degrading enzymes and typical proteases with respect to substrate binding and catalysis. Amino acids relative to catalysis are postulated to be highly plastic allowing their catalytic hydrolysis of polylactic acid. In this paper we reviewed current studies on biodegradation of polylactic acid concerning its microbial, enzymatic reactions and the possible mechanisms. We also discussed the probability of biologically recycling PLA by applying highly efficient strains and enzymes.

  17. Best conditions for biodegradation of diesel oil by chemometric tools

    PubMed Central

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for “lower” alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  18. Porous Biodegradable Metals for Hard Tissue Scaffolds: A Review

    PubMed Central

    Yusop, A. H.; Bakir, A. A.; Shaharom, N. A.; Abdul Kadir, M. R.; Hermawan, H.

    2012-01-01

    Scaffolds have been utilized in tissue regeneration to facilitate the formation and maturation of new tissues or organs where a balance between temporary mechanical support and mass transport (degradation and cell growth) is ideally achieved. Polymers have been widely chosen as tissue scaffolding material having a good combination of biodegradability, biocompatibility, and porous structure. Metals that can degrade in physiological environment, namely, biodegradable metals, are proposed as potential materials for hard tissue scaffolding where biodegradable polymers are often considered as having poor mechanical properties. Biodegradable metal scaffolds have showed interesting mechanical property that was close to that of human bone with tailored degradation behaviour. The current promising fabrication technique for making scaffolds, such as computation-aided solid free-form method, can be easily applied to metals. With further optimization in topologically ordered porosity design exploiting material property and fabrication technique, porous biodegradable metals could be the potential materials for making hard tissue scaffolds. PMID:22919393

  19. Biodegradation of PuEDTA and Impacts on Pu Mobility

    SciTech Connect

    Xun, Luying; Bolton, Jr., Harvey

    2001-06-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation.

  20. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2001-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  1. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2003-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  2. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2002-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  3. Biodegradable plastic agricultural mulches and key features of microbial degradation.

    PubMed

    Brodhagen, Marion; Peyron, Mark; Miles, Carol; Inglis, Debra Ann

    2015-02-01

    The development of biodegradable plastic mulch films for use in agriculture has been ongoing for decades. These films consist of mixtures of polymers with various additives. As a result, their physical and chemical properties differ from those of the pure polymers often used for in vitro enzymatic and microbial degradation studies, raising questions about the biodegradation capability of mulch films. Currently, standards exist for the biodegradation of plastics in composting conditions but not in soil. Biodegradation in soil or compost depends on a complex synergy of biological and abiotic degradative processes. This review discusses the physicochemical and structural properties of biodegradable plastic mulches, examines their potential for on-site decomposition in light of site-to-site variance due to environmental and biological conditions, and considers the potential for long-term effects on agroecosystem sustainability and functionality.

  4. Tailoring the biodegradability of porous silicon nanoparticles.

    PubMed

    Hon, Nick K; Shaposhnik, Zory; Diebold, Eric D; Tamanoi, Fuyuhiko; Jalali, Bahram

    2012-12-01

    Porous silicon nanoparticles (PSiNPs) are attractive carriers for targeted drug delivery in nanomedicine. For in vivo applications, the biodegradation property of PSiNPs provides a pathway for their safe clearance from the body. Particles sizes of 80-120 nm are of particular interest as they are important for cellular applications, such as drug delivery for cancer therapy, because these nanoparticles can take advantage of the enhanced permeability and retention effect to deliver drug preferentially to tumors with leaky vasculature, yet large enough to avoid renal clearance. However, the biodegradability rate of such particles is often too fast, which limits particle half-life and potentially reduces their in vivo delivery efficiency. In this work, we focus on the degradation of nanoscale particles and study the effect of both thermal oxidation and silica coating on the stability of PSiNPs in phosphate buffered saline solution (a close mimic of a basic biological fluid). Using thermal oxidation, the half-life of PSiNPs can be varied from 10 min up to 3 h. Using silica coating, the half-life can be extended further to 8 h. The particles produced using both these techniques can be functionalized using standard silica surface chemistries developed for applications in drug delivery.

  5. Wood biodegradation in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; De la Cruz, Florentino B; Barlaz, Morton A

    2011-08-15

    The objective of this research was to characterize the anaerobic biodegradability of major wood products in municipal waste by measuring methane yields, decay rates, the extent of carbohydrate decomposition, carbon storage, and leachate toxicity. Tests were conducted in triplicate 8 L reactors operated to obtain maximum yields. Measured methane yields for red oak, eucalyptus, spruce, radiata pine, plywood (PW), oriented strand board (OSB) from hardwood (HW) and softwood (SW), particleboard (PB) and medium-density fiberboard (MDF) were 32.5, 0, 7.5, 0.5, 6.3, 84.5, 0, 5.6, and 4.6 mL CH(4) dry g(-1), respectively. The red oak, a HW, exhibited greater decomposition than either SW (spruce and radiata), a trend that was also measured for the OSB-HW relative to OSB-SW. However, the eucalyptus (HW) exhibited toxicity. Thus, wood species have unique methane yields that should be considered in the development of national inventories of methane production and carbon storage. The current assumption of uniform biodegradability is not appropriate. The ammonia release from urea formaldehyde as present in PB and MDF could contribute to ammonia in landfill leachate. Using the extent of carbon conversion measured in this research, 0-19.9%, predicted methane production from a wood mixture using the Intergovernmental Panel for Climate Change waste model is only 7.9% of that predicted using the 50% carbon conversion default. PMID:21749061

  6. Endothelial Cellular Responses to Biodegradable Metal Zinc

    PubMed Central

    Ma, Jun; Zhao, Nan; Zhu, Donghui

    2016-01-01

    Biodegradable zinc (Zn) metals, a new generation of biomaterials, have attracted much attention due to their excellent biodegradability, bioabsorbability, and adaptability to tissue regeneration. Compared with magnesium (Mg) and iron (Fe), Zn exhibits better corrosion and mechanical behaviors in orthopedic and stent applications. After implantation, Zn containing material will slowly degrade, and Zn ions (Zn2+) will be released to the surrounding tissue. For stent applications, the local Zn2+concentration near endothelial tissue/cells could be high. However, it is unclear how endothelia will respond to such high concentrations of Zn2+, which is pivotal to vascular remodeling and regeneration. Here, we evaluated the short-term cellular behaviors of primary human coronary artery endothelial cells (HCECs) exposed to a concentration gradient (0−140 μM) of extracellular Zn2+. Zn2+ had an interesting biphasic effect on cell viability, proliferation, spreading, and migration. Generally, low concentrations of Zn2+ promoted viability, proliferation, adhesion, and migration, while high concentrations of Zn2+ had opposite effects. For gene expression profiles, the most affected functional genes were related to cell adhesion, cell injury, cell growth, angiogenesis, inflammation, vessel tone, and coagulation. These results provide helpful information and guidance for Zn-based alloy design as well as the controlled release of Zn2+in stent and other related medical applications. PMID:27689136

  7. Endothelial Cellular Responses to Biodegradable Metal Zinc

    PubMed Central

    Ma, Jun; Zhao, Nan; Zhu, Donghui

    2016-01-01

    Biodegradable zinc (Zn) metals, a new generation of biomaterials, have attracted much attention due to their excellent biodegradability, bioabsorbability, and adaptability to tissue regeneration. Compared with magnesium (Mg) and iron (Fe), Zn exhibits better corrosion and mechanical behaviors in orthopedic and stent applications. After implantation, Zn containing material will slowly degrade, and Zn ions (Zn2+) will be released to the surrounding tissue. For stent applications, the local Zn2+concentration near endothelial tissue/cells could be high. However, it is unclear how endothelia will respond to such high concentrations of Zn2+, which is pivotal to vascular remodeling and regeneration. Here, we evaluated the short-term cellular behaviors of primary human coronary artery endothelial cells (HCECs) exposed to a concentration gradient (0−140 μM) of extracellular Zn2+. Zn2+ had an interesting biphasic effect on cell viability, proliferation, spreading, and migration. Generally, low concentrations of Zn2+ promoted viability, proliferation, adhesion, and migration, while high concentrations of Zn2+ had opposite effects. For gene expression profiles, the most affected functional genes were related to cell adhesion, cell injury, cell growth, angiogenesis, inflammation, vessel tone, and coagulation. These results provide helpful information and guidance for Zn-based alloy design as well as the controlled release of Zn2+in stent and other related medical applications.

  8. Wood biodegradation in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; De la Cruz, Florentino B; Barlaz, Morton A

    2011-08-15

    The objective of this research was to characterize the anaerobic biodegradability of major wood products in municipal waste by measuring methane yields, decay rates, the extent of carbohydrate decomposition, carbon storage, and leachate toxicity. Tests were conducted in triplicate 8 L reactors operated to obtain maximum yields. Measured methane yields for red oak, eucalyptus, spruce, radiata pine, plywood (PW), oriented strand board (OSB) from hardwood (HW) and softwood (SW), particleboard (PB) and medium-density fiberboard (MDF) were 32.5, 0, 7.5, 0.5, 6.3, 84.5, 0, 5.6, and 4.6 mL CH(4) dry g(-1), respectively. The red oak, a HW, exhibited greater decomposition than either SW (spruce and radiata), a trend that was also measured for the OSB-HW relative to OSB-SW. However, the eucalyptus (HW) exhibited toxicity. Thus, wood species have unique methane yields that should be considered in the development of national inventories of methane production and carbon storage. The current assumption of uniform biodegradability is not appropriate. The ammonia release from urea formaldehyde as present in PB and MDF could contribute to ammonia in landfill leachate. Using the extent of carbon conversion measured in this research, 0-19.9%, predicted methane production from a wood mixture using the Intergovernmental Panel for Climate Change waste model is only 7.9% of that predicted using the 50% carbon conversion default.

  9. Optimization of low ring polycylic aromatic biodegradation

    NASA Astrophysics Data System (ADS)

    Othman, N.; Abdul-Talib, S.; Tay, C. C.

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are recalcitrance and persistence that finally turn into problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment due to its organic criteria. This study is carried out to optimize degradation process of low ring PAHs. Bacteria used in this study was isolated from sludge collected from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Working condition namely, substrate concentration, bacteria concentration, pH and temperature were optimized. PAHs in the liquid sample was extracted by using solid phase microextractio equipped with a 7 µm polydimethylsiloxane (PDMS) SPME fibr. Removal of PAHs were assessed by measuring PAHs concentration using GC-FID. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mgL-1 of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. These working condition had proved the effectiveness of using bacteria in biodegradation process of PAHs.

  10. Monitoring Biodegradation of Magnesium Implants with Sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  11. Biodegradability of industrial textile wastewater - batch tests.

    PubMed

    Paździor, Katarzyna; Klepacz-Smółka, Anna; Wrębiak, Julita; Liwarska-Bizukojć, Ewa; Ledakowicz, Stanisław

    2016-01-01

    Following new trends we applied oxygen uptake rate (OUR) tests as well as long-term tests (in two batch bioreactors systems) in order to assess the biodegradability of textile wastewater. Effluents coming from a dyeing factory were divided into two streams which differed in inorganic and organic contaminants loads. Usefulness of the stream division was proved. Biodegradation of the low-loaded stream led to over 97% reduction of biochemical oxygen demand (BOD5) together with 80% reduction of chemical oxygen demand (COD) and total organic carbon (TOC). Most of the controlled parameter values were below the levels allowed by legislation for influents to surface water, whereas the high-loaded stream was so contaminated with recalcitrant organic compounds that despite the reduction of BOD5 by over 95%, COD, TOC, total nitrogen and total phosphorus levels exceeded permissible values. OUR tests were aimed at determination of the following kinetic parameters: maximum specific growth rate (μMax), half-saturation constant, hydrolysis constant and decay coefficient for activated sludge biomass for both types of textile wastewater studied. The values of kinetic parameters will be applied in activated sludge models used for prediction and optimisation of biological treatment of textile wastewater. PMID:27642827

  12. Nitroaromatic Compounds, from Synthesis to Biodegradation

    PubMed Central

    Ju, Kou-San; Parales, Rebecca E.

    2010-01-01

    Summary: Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed. PMID:20508249

  13. Immunological Response to Biodegradable Magnesium Implants

    NASA Astrophysics Data System (ADS)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  14. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  15. Neutralization and biodegradation of sulfur mustard

    SciTech Connect

    Harvey, S.P.; Beaudry, W.T.; Szafraniec, L.L.

    1995-12-31

    One technology recommended for consideration for the disposal of the U.S. Chemical Stockpile is chemical neutralization followed by biodegradation. In the case of sulfur mustard ({open_quotes}mustard gas{close_quotes}, 2,2{prime}-dichlorodiethyl sulfide), alkaline hydrolysis yields a detoxified and biodegradable product. The hydrolysis reaction was studied with respect to the effects of temperature and sulfur mustard concentration on the rate and products of the reaction. A 28-fold overall rate enhancement was observed at 70{degrees}C vs. 30{degrees}C corresponding to an enthalpy of activation value of 17.9 Kcal/mole. Material balance studies conducted by {sup 1}H Nuclear Magnetic Resonance analysis showed that the products of the reaction consisted of thiodiglycol was relatively greater at lower sulfur mustard concentrations and higher temperatures. As temperatures were decreased or sulfur mustard concentrations was increased, the proportion of ether-type compounds increased accordingly. Conditions of 1% (vol//vol) sulfur mustard, 5% stoichiometric excess of NaOH and 90{degrees}C were selected for generation of the hydrolyzed bioreactor influent material. The bioreactor was seeded with activated sludge and was initially operated as 5 liter sequencing batch reactor with a hydraulic residence time of approximately days. Early results show total organic carbon removal of greater than 90%.

  16. Isotopic fractionation indicates anaerobic monochlorobenzene biodegradation.

    PubMed

    Kaschl, Arno; Vogt, Carsten; Uhlig, Sylvia; Nijenhuis, Ivonne; Weiss, Holger; Kästner, Matthias; Richnow, Hans H

    2005-06-01

    The concentration and isotopic composition of monochlorobenzene (MCB) was monitored in the plume of an anaerobic, contaminated aquifer in Bitterfeld, Germany. An enrichment in the carbon isotopic composition of more than 4 delta units was found at the fringes of the plume relative to the center (-26.5 %), suggesting the occurrence of in situ biodegradation of MCB. A similar enrichment was measured in a detailed cross-section of the plume and in depth-specific samples obtained in a multilevel sampling well. The latter samples gave a good correlation of MCB concentrations and respective isotopic composition according to the Rayleigh equation. On the other hand, batch experiments using the aerobic MCB-degrading strains Ralstonia sp. DSM 8910, Acidovorax facilis UFZ B517, Rhodococcus erythropolis UFZ B528, and Pseudomonas veronii UFZ B547 showed that the known aerobic pathway initiated by dioxygenases does not result in a significant isotopic fractionation. Thus, a novel anaerobic pathway resulting in an isotopic fractionation appears to be the predominant process of MCB degradation in this aquifer. The study also clearly demonstrates the usefulness of isotopic fractionation analysis to prove biodegradation directly in the field, even when microcosm studies are not available and a metabolic pathway has not yet been elucidated.

  17. Nitroaromatic compounds, from synthesis to biodegradation.

    PubMed

    Ju, Kou-San; Parales, Rebecca E

    2010-06-01

    Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed.

  18. Sign Communication in Cri du Chat Syndrome

    ERIC Educational Resources Information Center

    Erlenkamp, Sonja; Kristoffersen, Kristian Emil

    2010-01-01

    This paper presents findings from a study on the use of sign supported Norwegian (SSN) in two individuals with Cri du chat syndrome (CCS). The study gives a first account of some selected aspects of production and intelligibility of SSN in CCS. Possible deviance in manual parameters, in particular inter- and/or intra-subject variation in the use…

  19. Prejudice: From Allport to DuBois.

    ERIC Educational Resources Information Center

    Gaines, Stanley O., Jr.; Reed, Edward S.

    1995-01-01

    Examines the differences between Gordon Allport's and W. E. B. DuBois's theories on the origins of prejudice and the impact of discrimination on the personality and social development of blacks. The article argues that prejudice is a historically developed process, not a universal feature of human psychology. Implications for U.S. race relations…

  20. Research approach to teaching groundwater biodegradation in karst aquifers

    USGS Publications Warehouse

    King, L.; Byl, T.; Painter, R.

    2006-01-01

    TSU in partnership with the USGS has conducted extensive research regarding biode??gradation of contaminants in karst aquifers. This research resulted in the development of a numerical approach to modeling biodegradation of contaminants in karst aquifers that is taught to environmental engineering students in several steps. First, environmental engineering students are taught chemical-reaction engineering principles relating to a wide variety of environmental fate and transport issues. Second, as part of TSU's engineering course curriculum, students use a non-ideal flow laboratory reactor system and run a tracer study to establish residence time distribution (RTD). Next, the students couple that formula to a first-order biodegradation rate and predict the removal of a biodegradable contaminant as a function of residence time. Following this, students are shown data collected from karst bedrock wells that suggest that karst aquifers are analogous to non-ideal flow reactors. The students are challenged to develop rates of biodegradation through lab studies and use their results to predict biodegradaton at an actual contaminated karst site. Field studies are also conducted to determine the accuracy of the students' predictions. This academic approach teaches biodegradation processes, rate-kinetic processes, hydraulic processes and numerical principles. The students are able to experience how chemical engineering principles can be applied to other situations, such as, modeling biodegradation of contaminants in karst aquifers. This paper provides background on the chemical engineering principles and karst issues used in the research-enhanced curriculum. ?? American Society for Engineering Education, 2006.

  1. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    PubMed Central

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

  2. [Biodegradation Coefficients of Typical Pollutants in the Plain Rivers Network].

    PubMed

    Feng, Shuai; Li, Xu-yongl; Deng, Jian-cai

    2016-05-15

    Biodegradation is a significant part of pollutant integrated degradation, the process rate of which is represented by the biodegradation coefficient. To investigate the biodegradation law of typical pollutants in the plain rivers network located in the upstream of the Lake Taihu, experiments were conducted in site in September 2015, one order kinetics model was used to measure the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus, and influencing factors of the biodegradation coefficients were also analyzed. The results showed that the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus were 0.008 3-0.126 4 d⁻¹, 0.002 1-0.213 8 d⁻¹, 0.002 1-0.090 5 d⁻¹ and 0.011 0- 0.152 8 d⁻¹, respectively. The influencing factors of the biodegradation coefficients for permanganate index were permanganate index and pH; those for ammonia were ammonia concentration and pH; those for total nitrogen were inorganic nitrogen concentration, total dissolved solid concentration and nitrite concentration; and those for total phosphorus were background concentration and pH. The research results were of important guiding significance for pollutants removal and ecological restoration of the plain rivers network located in the unstream of the Lake Taihu. PMID:27506025

  3. [Biodegradation Coefficients of Typical Pollutants in the Plain Rivers Network].

    PubMed

    Feng, Shuai; Li, Xu-yongl; Deng, Jian-cai

    2016-05-15

    Biodegradation is a significant part of pollutant integrated degradation, the process rate of which is represented by the biodegradation coefficient. To investigate the biodegradation law of typical pollutants in the plain rivers network located in the upstream of the Lake Taihu, experiments were conducted in site in September 2015, one order kinetics model was used to measure the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus, and influencing factors of the biodegradation coefficients were also analyzed. The results showed that the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus were 0.008 3-0.126 4 d⁻¹, 0.002 1-0.213 8 d⁻¹, 0.002 1-0.090 5 d⁻¹ and 0.011 0- 0.152 8 d⁻¹, respectively. The influencing factors of the biodegradation coefficients for permanganate index were permanganate index and pH; those for ammonia were ammonia concentration and pH; those for total nitrogen were inorganic nitrogen concentration, total dissolved solid concentration and nitrite concentration; and those for total phosphorus were background concentration and pH. The research results were of important guiding significance for pollutants removal and ecological restoration of the plain rivers network located in the unstream of the Lake Taihu.

  4. Effects of carbon nanotubes on atrazine biodegradation by Arthrobacter sp.

    PubMed

    Zhang, Chengdong; Li, Mingzhu; Xu, Xu; Liu, Na

    2015-04-28

    The environmental risks of engineered nanoparticles have attracted attention. However, little is known regarding the effects of carbon nanotubes (CNTs) on the biodegradation and persistence of organic contaminants in water. We investigated the impacts of pristine and oxidized multiwalled CNTs on the atrazine biodegradation rate and efficiency using Arthrobacter sp. At a concentration of 25mg/L, the CNTs enhanced the biodegradation rate by up to 20%; however, at a concentration of 100mg/L, the CNTs decreased the biodegradation rate by up to 50%. The stimulation effects resulted from enhanced bacterial growth and the overexpression of degradation genes. The inhibitory effects resulted from the toxicity of the CNTs at high concentrations. The differences between the two CNTs at tested concentrations were not significant. The biodegradation efficiency was not impacted by adsorption, and the pre-adsorbed atrazine on the CNTs was fully biodegraded when the CNT concentration was ≤25mg/L. This finding was consistent with the lack of observable desorption hysteresis for atrazine on the tested CNTs. Our results indicate that CNTs can enhance or inhibit biodegradation through a balance of two effects: the toxic effects on microbial activity and the effects of the changing bioavailability that result from adsorption and desorption.

  5. Elevated dissolved organic carbon biodegradability from thawing and collapsing permafrost

    NASA Astrophysics Data System (ADS)

    Abbott, Benjamin W.; Larouche, Julia R.; Jones, Jeremy B.; Bowden, William B.; Balser, Andrew W.

    2014-10-01

    As high latitudes warm, a portion of the large organic carbon pool stored in permafrost will become available for transport to aquatic ecosystems as dissolved organic carbon (DOC). If permafrost DOC is biodegradable, much will be mineralized to the atmosphere in freshwater systems before reaching the ocean, accelerating carbon transfer from permafrost to the atmosphere, whereas if recalcitrant, it will reach marine ecosystems where it may persist over long time periods. We measured biodegradable DOC (BDOC) in water flowing from collapsing permafrost (thermokarst) on the North Slope of Alaska and tested the role of DOC chemical composition and nutrient concentration in determining biodegradability. DOC from collapsing permafrost was some of the most biodegradable reported in natural systems. However, elevated BDOC only persisted during active permafrost degradation, with a return to predisturbance levels once thermokarst features stabilized. Biodegradability was correlated with background nutrient concentration, but nutrient addition did not increase overall BDOC, suggesting that chemical composition may be a more important control on DOC processing. Despite its high biodegradability, permafrost DOC showed evidence of substantial previous microbial processing, and we present four hypotheses explaining this incongruity. Because thermokarst features form preferentially on river banks and lake shores and can remain active for decades, thermokarst may be the dominant short-term mechanism delivering sediment, nutrients, and biodegradable organic matter to aquatic systems as the Arctic warms.

  6. Biodegradation of hydrocarbon cuts used for diesel oil formulation.

    PubMed

    Penet, Sophie; Marchal, Rémy; Sghir, Abdelghani; Monot, Frédéric

    2004-11-01

    The biodegradability of various types of diesel oil (DO), such as straight-run DO, light-cycle DO, hydrocracking DO, Fischer-Tropsch DO and commercial DO, was investigated in biodegradation tests performed in closed-batch systems using two microflorae. The first microflora was an activated sludge from an urban wastewater treatment plant as commonly used in biodegradability tests of commercial products and the second was a microflora from a hydrocarbon-polluted soil with possible specific capacities for hydrocarbon degradation. Kinetics of CO(2) production and extent of DO biodegradation were obtained by chromatographic procedures. Under optimised conditions, the polluted-soil microflora was found to extensively degrade all the DO types tested, the degradation efficiencies being higher than 88%. For all the DOs tested, the biodegradation capacities of the soil microflora were significantly higher than those of the activated sludge. Using both microflora, the extent of biodegradation was highly dependent upon the type of DO used, especially its hydrocarbon composition. Linear alkanes were completely degraded in each test, whereas identifiable branched alkanes such as farnesane, pristane or phytane were degraded to variable extents. Among the aromatics, substituted mono-aromatics were also variably biodegraded.

  7. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    PubMed

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

  8. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB.

    PubMed

    Torlapati, Jagadish; Boufadel, Michel C

    2014-01-01

    We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al., 2010). In that study, samples were collected from three different islands: Eleanor Island (EL107), Knight Island (KN114A), and Smith Island (SM006B), and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA). The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with that of the overall polycyclic aromatic hydrocarbons

  9. Biodegradability of fluorinated fire-fighting foams in water.

    PubMed

    Bourgeois, A; Bergendahl, J; Rangwala, A

    2015-07-01

    Fluorinated fire-fighting foams may be released into the environment during fire-fighting activities, raising concerns due to the potential environmental and health impacts for some fluorinated organics. The current study investigated (1) the biodegradability of three fluorinated fire-fighting foams, and (2) the applicability of current standard measures used to assess biodegradability of fluorinated fire-fighting foams. The biodegradability of three fluorinated fire-fighting foams was evaluated using a 28-day dissolved organic carbon (DOC) Die-Away Test. It was found that all three materials, diluted in water, achieved 77-96% biodegradability, meeting the criteria for "ready biodegradability". Defluorination of the fluorinated organics in the foam during biodegradation was measured using ion chromatography. It was found that the fluorine liberated was 1-2 orders of magnitude less than the estimated initial amount, indicating incomplete degradation of fluorinated organics, and incomplete CF bond breakage. Published biodegradability data may utilize biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) metrics to quantify organics. COD and TOC of four fluorinated compounds were measured and compared to the calculated carbon content or theoretical oxygen demand. It was found that the standard dichromate-based COD test did not provide an accurate measure of fluorinated organic content. Thus published biodegradability data using COD for fluorinated organics quantification must be critically evaluated for validity. The TOC measurements correlated to an average of 91% of carbon content for the four fluorinated test substances, and TOC is recommended for use as an analytical parameter in fluorinated organics biodegradability tests.

  10. Biodegradability of fluorinated fire-fighting foams in water.

    PubMed

    Bourgeois, A; Bergendahl, J; Rangwala, A

    2015-07-01

    Fluorinated fire-fighting foams may be released into the environment during fire-fighting activities, raising concerns due to the potential environmental and health impacts for some fluorinated organics. The current study investigated (1) the biodegradability of three fluorinated fire-fighting foams, and (2) the applicability of current standard measures used to assess biodegradability of fluorinated fire-fighting foams. The biodegradability of three fluorinated fire-fighting foams was evaluated using a 28-day dissolved organic carbon (DOC) Die-Away Test. It was found that all three materials, diluted in water, achieved 77-96% biodegradability, meeting the criteria for "ready biodegradability". Defluorination of the fluorinated organics in the foam during biodegradation was measured using ion chromatography. It was found that the fluorine liberated was 1-2 orders of magnitude less than the estimated initial amount, indicating incomplete degradation of fluorinated organics, and incomplete CF bond breakage. Published biodegradability data may utilize biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) metrics to quantify organics. COD and TOC of four fluorinated compounds were measured and compared to the calculated carbon content or theoretical oxygen demand. It was found that the standard dichromate-based COD test did not provide an accurate measure of fluorinated organic content. Thus published biodegradability data using COD for fluorinated organics quantification must be critically evaluated for validity. The TOC measurements correlated to an average of 91% of carbon content for the four fluorinated test substances, and TOC is recommended for use as an analytical parameter in fluorinated organics biodegradability tests. PMID:25813673

  11. Advances in our knowledge of biodegradation of hydrocarbons in reservoirs

    SciTech Connect

    Connan, J. )

    1993-09-01

    Biodegradation of hydrocarbons in reservoirs is a widespread phenomenon that is currently observed by petroleum organic geochemists in most sedimentary basins. This basic phenomenon is responsible for the occurrence of large, heavy oil deposits referred to as tar mats or tar belts. Biodegradation of crude oils takes place in reservoirs in which oil-eating bacteria may thrive. For this reason, effective and present biodegradation effects are not observed at subsurface temperatures higher than 70-80[degrees]C. Significant compositional changes, especially at a molecular level, still remain linked to the aerobic biodegradation of crude oils. Under favorable circumstances, both alkanes and aromatics are degraded, but when nutrients (N, P, O[sup 2]) are impoverished, aromatics seem to be preferentially removed. Biodegradation extends also to sulfur-bearing aromatics with a preferential removal of alkylated structures. Changes in molecular patterns are used to assess degrees of biodegradation in crude oils. The most bacterially resistant structures are polycyclic alkanes and aromatics. The in-reservoir biodegradation of hydrocarbons does not generate new hydrocarbons, e.g., 25-norhopanes as proposed by several authors. In fact, the selective removal of less resistant structures concentrates preexisting minor families that were not detected on the unaltered crude due to their low absolute concentration. Consequently, the molecular spectrum found in severely biodegraded oils may be considered as highly diagnostic of a part of the primary genetic spectrum of each oil. In outcrop samples, biodegradation is associated with other complementary phenomena such as photooxidation, oxidation, inspissation, evaporation, water washing, etc. Of particular importance are weathering effects linked to oxidation, which entail drastic compositional changes, with neogenesis of resins, asphaltenes, and even insoluble residue.

  12. Biodegradable polymer adhesives, hybrids and nanomaterials

    NASA Astrophysics Data System (ADS)

    Mylonakis, Andreas

    Biodegradable polymeric products and organic-inorganic hybrid materials for a diversity of applications are the two main fields on which this research has been focused. A novel biodegradable adhesive, which mimics marine adhesive proteins, has been synthesized by the covalent incorporation of 3,4-dihydroxybenzoic acid onto the chitosan backbone. The adhesive strength of these materials varies with the molecular weight of the polysaccharide, the amount of diphenolics present and the curing time. Infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR) and ultraviolet-visible spectroscopy (UV) have been used to qualitatively and quantitatively establish the amount of the diphenolic moiety present on the backbone of the biodegradable polymers. The as synthesized polymers combine both the adhesive capability of the diphenolic function and the healing effect of chitosan. The biocompatibility and biodegradability of these modified chitosans offer the promise of utility of these novel materials in dental and medical applications. Organic-inorganic hybrid materials with low volume shrinkage and excellent mechanical properties were synthesized by the covalent incorporation of 2-hydroxyethyl methacrylate and glycidyl methacrylate on pre-hydrolyzed sol-gel silica. These hybrid materials exhibited low volume shrinkage during polymerization and were crack-free during storage for about twelve months. The mechanical properties of these materials are composition dependent. Incorporation of silica effectively increased the compressive yield stress and modulus of the obtained poly(HEMAGMA-silica) hybrid materials. A series of new electroactive hybrid materials have been synthesized by covalent incorporation of polyaniline into polyacrylate-silica hybrids. The formulation involves the radical co-polymerization of glycidyl methacrylate-polyaniline (GMA-PANi) and glycidyl methacrylate2-hydroxyethyl methacrylate-silica (GMA-HEMA-silica) to yield poly

  13. Biodegradable thermogelling polymers: working towards clinical applications.

    PubMed

    Dou, Qing Qing; Liow, Sing Shy; Ye, Enyi; Lakshminarayanan, Rajamani; Loh, Xian Jun

    2014-07-01

    As society ages, aging medical problems such as organ damage or failure among senior citizens increases, raising the demand for organ repair technologies. Synthetic materials have been developed and applied in various parts of human body to meet the biomedical needs. Hydrogels, in particular, have found extensive applications as wound healing, drug delivery and controlled release, and scaffold materials in the human body. The development of the next generation of soft hydrogel biomaterials focuses on facile synthetic methods, efficacy of treatment, and tunable multi-functionalities for applications. Supramolecular 3D entities are highly attractive materials for biomedical application. They are assembled by modules via various non-covalent bonds (hydrogen bonds, p-p stacking and/or van der Waals interactions). Biodegradable thermogels are a class of such supramolecular assembled materials. Their use as soft biomaterials and their related applications are described in this Review.

  14. Biodegradation of lignin by Agaricus Bisporus

    SciTech Connect

    Vane, C.H.; Abbott, G.D.; Head, I.M.

    1996-12-31

    The lignolytic activity of Agaricus bisporus will be addressed in this paper. Sound and fungally degraded lignins were characterized by Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS), Fourier Transform Infrared Spectroscopy (FnR) and elemental analysis. Fungally degraded lignins displayed increased wt%N, wt%H and wt%O content and decreased wt%C content The FTIR spectrum of decayed lignin showed an increase in the relative intensity of absorption bands assigned to carbonyl and carboxyl functional groups located on the aliphatic side chain and a decrease in absorption bands assigned to aromatic skeletal vibration modes. Semiquantitative Py-GC-MS revealed an 82% decrease in lignin derived pyrolysis products upon biodegradation. No significant increase in pyrolysis products with an oxygenated aliphatic side chain were detected in the fungally degraded lignin however shortening of the aliphatic side chain via cleavage at the {alpha}, {beta} and {gamma} positions was observed.

  15. Enhancement of BTX biodegradation by benzoate

    SciTech Connect

    Rotert, K.H.; Cronkhite, L.A.; Alvarez, P.J.J.

    1995-12-31

    Aquifer microcosms were used to investigate the effect of adding environmentally benign aromatic substrates on the phenotypic composition of indigenous microbial communities. Addition of aromatic compounds (i.e., benzoate or phenylalanine) exerted preferential selective pressure for benzene, toluene and xylene (BTX) degraders. Addition of a non-aromatic substrate (i.e., acetate), however, did not stimulate a significant increase in the fraction of total heterotrophs capable of degrading BTX. A selective proliferation of BTX degraders would enhance biodegradation kinetics, which should decrease the duration (and cost) of BTX bioremediation. Proof of concept was obtained with laboratory aquifer columns that were continuously fed benzene, toluene, and o-xylene. Benzoate addition to the column`s influent enhanced aerobic BTX degradation and attenuated BTX breakthrough relative to acetate-amended or unamended control columns.

  16. Biodegradation of the nitramine explosive CL-20.

    PubMed

    Trott, Sandra; Nishino, Shirley F; Hawari, Jalal; Spain, Jim C

    2003-03-01

    The cyclic nitramine explosive CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) was examined in soil microcosms to determine whether it is biodegradable. CL-20 was incubated with a variety of soils. The explosive disappeared in all microcosms except the controls in which microbial activity had been inhibited. CL-20 was degraded most rapidly in garden soil. After 2 days of incubation, about 80% of the initial CL-20 had disappeared. A CL-20-degrading bacterial strain, Agrobacterium sp. strain JS71, was isolated from enrichment cultures containing garden soil as an inoculum, succinate as a carbon source, and CL-20 as a nitrogen source. Growth experiments revealed that strain JS71 used 3 mol of nitrogen per mol of CL-20. PMID:12620886

  17. Recent advances in the biodegradation of chlorothalonil.

    PubMed

    Wang, Guangli; Liang, Bin; Li, Feng; Li, Shunpeng

    2011-11-01

    Chlorothalonil (TPN; 2,4,5,6-tetrachloroisophthalonitrile) has been widely used as a broad-spectrum chlorinated aromatic fungicide and its application resulted in global pollution commonly detected in the diverse ecosystems. Recently, microbial degradation of TPN has been studied extensively as an effective and environmental-friendly method to reduce TPN residue levels in the environment. This review summarizes the current knowledge of recent developments in the biodegradation of TPN. Diverse pure culture strains capable of degrading TPN were widely distributed among Proteobacteria and several metabolic pathways of TPN biotransformation were discovered. The two key genes (glutathione S-transferase and chlorothalonil hydrolytic dehalogenase coding gene) responsible for the conversion of TPN and recent findings for future practical bioremediation of TPN-contaminated ecosystem are also discussed.

  18. Biodegradable thermogelling polymers: working towards clinical applications.

    PubMed

    Dou, Qing Qing; Liow, Sing Shy; Ye, Enyi; Lakshminarayanan, Rajamani; Loh, Xian Jun

    2014-07-01

    As society ages, aging medical problems such as organ damage or failure among senior citizens increases, raising the demand for organ repair technologies. Synthetic materials have been developed and applied in various parts of human body to meet the biomedical needs. Hydrogels, in particular, have found extensive applications as wound healing, drug delivery and controlled release, and scaffold materials in the human body. The development of the next generation of soft hydrogel biomaterials focuses on facile synthetic methods, efficacy of treatment, and tunable multi-functionalities for applications. Supramolecular 3D entities are highly attractive materials for biomedical application. They are assembled by modules via various non-covalent bonds (hydrogen bonds, p-p stacking and/or van der Waals interactions). Biodegradable thermogels are a class of such supramolecular assembled materials. Their use as soft biomaterials and their related applications are described in this Review. PMID:24488805

  19. Biodegradation and flushing of MBT wastes.

    PubMed

    Siddiqui, A A; Richards, D J; Powrie, W

    2013-11-01

    Mechanical-biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratory experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320g/kg dry matter for raw MSW to between 183 and 195g/kg dry matter for the MBT wastes. PMID:23973052

  20. Biodegradation of the Nitramine Explosive CL-20

    PubMed Central

    Trott, Sandra; Nishino, Shirley F.; Hawari, Jalal; Spain, Jim C.

    2003-01-01

    The cyclic nitramine explosive CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) was examined in soil microcosms to determine whether it is biodegradable. CL-20 was incubated with a variety of soils. The explosive disappeared in all microcosms except the controls in which microbial activity had been inhibited. CL-20 was degraded most rapidly in garden soil. After 2 days of incubation, about 80% of the initial CL-20 had disappeared. A CL-20-degrading bacterial strain, Agrobacterium sp. strain JS71, was isolated from enrichment cultures containing garden soil as an inoculum, succinate as a carbon source, and CL-20 as a nitrogen source. Growth experiments revealed that strain JS71 used 3 mol of nitrogen per mol of CL-20. PMID:12620886

  1. Evaluation and Optimization of MTBE Biodegradation in Aquifers, Final Report

    SciTech Connect

    Legler, T; Balser, L; Koester, C; Wilson, W

    2004-02-13

    This study was focused on meeting the following objectives concerning the process of methyl tertiary butyl ether (MTBE) biodegradation, with the goal of optimizing this process in situ: 1. Assess whether intrinsic bioattenuation of MTBE is feasible under aerobic conditions across several contaminated sites. 2. Determine the effect of co-contaminants, specifically water-soluble gasoline components (most notably benzene, toluene, ethylbenzene and xylenes [BTEX]) on MTBE biodegradation. 3. Determine whether microbial and/or chemical factors contribute to different MTBE degradative activities. 4. Isolate and characterize MTBE-degrading microorganisms from sediments in which MTBE biodegradation was observed.

  2. Biodegradation of carbon nanohorns in macrophage cells

    NASA Astrophysics Data System (ADS)

    Zhang, Minfang; Yang, Mei; Bussy, Cyrill; Iijima, Sumio; Kostarelos, Kostas; Yudasaka, Masako

    2015-02-01

    With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the nanomaterials rather than in an inflammatory pathway induction.With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the

  3. Biodegradation of crystal violet by Agrobacterium radiobacter.

    PubMed

    Parshetti, G K; Parshetti, S G; Telke, A A; Kalyani, D C; Doong, R A; Govindwar, S P

    2011-01-01

    Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr (10 mg/L) at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4C1 has shown 100% decolorization of Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated addition (10 mg/L). When the effect of increasing inoculum concentration on decolorization of Crystal Violet (100 mg/L) was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase (184%) and aminopyrine N-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography and mass spectroscopy (GC/MS). It was detected the presence of N,N,N',N"-tetramethylpararosaniline, [N, N-dimethylaminophenyl] [N-methylaminophenyl] benzophenone, N, N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing to soil fertility and for four kinds of plants (Sorghum bicolor Vigna radiata, Lens culinaris and Triticum aestivum) which are most sensitive, fast growing and commonly used in Indian agriculture.

  4. Antibacterial biodegradable Mg-Ag alloys.

    PubMed

    Tie, D; Feyerabend, F; Müller, W D; Schade, R; Liefeith, K; Kainer, K U; Willumeit, R

    2013-06-16

    The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4) and aging (T6) heat treatment. The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH)₂ and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7), revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231) and Staphylococcus epidermidis (DSMZ 3269), and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  5. Biodegradable nano-films for capture and non-invasive release of circulating tumor cells

    PubMed Central

    Park, Myoung-Hwan; Castleberry, Steven; Deng, Jason Z.; Hsu, Bryan; Mayner, Sarah; Jensen, Anne E.; Sequist, Lecia V.; Maheswaran, Shyamala; Haber, Daniel A.; Toner, Mehmet; Stott, Shannon L.; Hammond, Paula T.

    2016-01-01

    Selective isolation and purification of circulating tumor cells (CTCs) from whole blood is an important capability for both clinical medicine and biological research. Current techniques to perform this task place the isolated cells under excessive stresses that reduce cell viability, and potentially induce phenotype change, therefore losing valuable information about the isolated cells. We present a biodegradable nano-film coating on the surface of a microfluidic chip, which can be used to effectively capture as well as non-invasively release cancer cell lines such as PC-3, LNCaP, DU 145, H1650 and H1975. We have applied layer-by-layer (LbL) assembly to create a library of ultrathin coatings using a broad range of materials through complementary interactions. By developing an LbL nano-film coating with an affinity-based cell-capture surface that is capable of selectively isolating cancer cells from whole blood, and that can be rapidly degraded on command, we are able to gently isolate cancer cells and recover them without compromising cell viability or proliferative potential. Our approach has the capability to overcome practical hurdles and provide viable cancer cells for downstream analyses, such as live cell imaging, single cell genomics, and in vitro cell culture of recovered cells. Furthermore, CTCs from cancer patients were also captured, identified, and successfully released using the LbL-modified microchips. PMID:26142780

  6. BIOPLUME MODEL FOR CONTAMINANT TRANSPORT AFFECTED BY OXYGEN LIMITED BIODEGRADATION

    EPA Science Inventory

    Many of the organic pollutants entering ground water are potentially biodegradable in the subsurface. This potential has been demonstrated in aquifers contaminated by wood-creosoting process wastes. The persistence of many of these organic compounds in the subsurface indicated ...

  7. Fade to Green: A Biodegradable Stack of Microbial Fuel Cells.

    PubMed

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Stinchcombe, Andrew; Walter, X Alexis; Greenman, John; Ieropoulos, Ioannis

    2015-08-24

    The focus of this study is the development of biodegradable microbial fuel cells (MFCs) able to produce useful power. Reactors with an 8 mL chamber volume were designed using all biodegradable products: polylactic acid for the frames, natural rubber as the cation-exchange membrane and egg-based, open-to-air cathodes coated with a lanolin gas diffusion layer. Forty MFCs were operated in various configurations. When fed with urine, the biodegradable stack was able to power appliances and was still operational after six months. One useful application for this truly sustainable MFC technology includes onboard power supplies for biodegradable robotic systems. After operation in remote ecological locations, these could degrade harmlessly into the surroundings to leave no trace when the mission is complete.

  8. Impact of metals on the biodegradation of organic pollutants.

    PubMed Central

    Sandrin, Todd R; Maier, Raina M

    2003-01-01

    Forty percent of hazardous waste sites in the United States are co-contaminated with organic and metal pollutants. Data from both aerobic and anaerobic systems demonstrate that biodegradation of the organic component can be reduced by metal toxicity. Metal bioavailability, determined primarily by medium composition/soil type and pH, governs the extent to which metals affect biodegradation. Failure to consider bioavailability rather than total metal likely accounts for much of the enormous variability among reports of inhibitory concentrations of metals. Metals appear to affect organic biodegradation through impacting both the physiology and ecology of organic degrading microorganisms. Recent approaches to increasing organic biodegradation in the presence of metals involve reduction of metal bioavailability and include the use of metal-resistant bacteria, treatment additives, and clay minerals. The addition of divalent cations and adjustment of pH are additional strategies currently under investigation. PMID:12826480

  9. COMPARING STABLE CARBON ISOTOPE AND RESPIROMETRIC TECHNIQUES FOR EVALUATING BIODEGRADATION

    EPA Science Inventory

    Biodegradation of petrochemical contaminants such as crude oil and polychlorinated biphenyls has been determined to remove these contaminants from the environment. The biological processes that result in the contaminant degradation have been determined primarily through bench-sc...

  10. Biodegradable elastomers for biomedical applications and regenerative medicine.

    PubMed

    Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W; Poot, André A

    2014-05-01

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After implantation in the body, biomedical devices may be subjected to degradation and erosion. Understanding the mechanisms of these processes is essential for the development of biomedical devices or implants with a specific function, for example, scaffolds for tissue-engineering applications. For the engineering and regeneration of soft tissues (e.g., blood vessels, cardiac muscle and peripheral nerves), biodegradable polymers are needed that are flexible and elastic. The scaffolds prepared from these polymers should have tuneable degradation properties and should perform well under long-term cyclic deformation conditions. The required polymers, which are either physically or chemically crosslinked biodegradable elastomers, are reviewed in this article.

  11. [Biodegradable synthetic implant materials : clinical applications and immunological aspects].

    PubMed

    Witte, F; Calliess, T; Windhagen, H

    2008-02-01

    In the last decade biodegradable synthetic implant materials have been established for various clinical applications. Ceramic materials such as calcium phosphate, bioglass and polymers are now routinely used as degradable implants in the clinical practice. Additionally these materials are now also used as coating materials or as microspheres for controlled drug release and belong to a series of examples for applications as scaffolds for tissue engineering. Because immense local concentrations of degradation products are produced during biodegradation, this review deals with the question whether allergic immune reactions, which have been reported for classical metallic and organic implant materials, also play a role in the clinical routine for synthetic biodegradable materials. Furthermore, possible explanatory theories will be developed to clarify the lack of clinical reports on allergy or sensitization to biodegradable synthetic materials.

  12. Complications of Biodegradable Materials: Anchors and Interference Screws.

    PubMed

    Barber, F Alan

    2015-09-01

    Metal, plastic, and biodegradable implants can all cause problems. The advantage of the biodegradable implant is clarity in postoperative imaging, easier revision, and fewer concerns about associated tissue damage. Although biodegradable implants do degrade over time, this time varies considerably, depends upon the polymer present, and is often measured in years. Before that occurring, the implant is a rigid device. Problems in the operative or immediate postoperative period include implant breakage during insertion, loss of initial fixation, incompletely buried or "proud" implants within a joint that could damage articular cartilage, and possible implant migration. Later occurring problems include the development of inflammatory reactions leading to lytic changes, cyst formation, intra-articular granuloma formation along with swelling, and sterile pretibial abscesses. Despite this list of potential problems on balance biodegradable implants are safe and effective and present no greater concerns (and arguably fewer ones) than metal or plastic implants.

  13. Sediment bacterial communities associated with anaerobic biodegradation of bisphenol A.

    PubMed

    Yang, Yuyin; Wang, Zhao; He, Tao; Dai, Yu; Xie, Shuguang

    2015-07-01

    Bisphenol A (BPA) is one of the endocrine-disrupting chemicals that are ubiquitous in aquatic environments. Biodegradation is a major way to clean up the BPA pollution in sediments. However, information on the effective BPA biodegradation in anaerobic sediments is still lacking. The present study investigated the biodegradation potential of BPA in river sediment under nitrate- or sulfate-reducing conditions. After 120-day incubation, a high removal of BPA (93 or 89%) was found in sediment microcosms (amended with 50 mg kg(-1) BPA) under these two anaerobic conditions. Illumina MiSeq sequencing analysis indicated that Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatimonadetes, and Actinobacteria were the major bacterial groups in BPA-degrading sediments. The shift in bacterial community structure could occur with BPA biodegradation.

  14. INFLUENCE OF PROTOZOAN GRAZING ON CONTAMINANT BIODEGRADATION. (R825418)

    EPA Science Inventory

    The influence of protozoan grazing on biodegradation rates in samples from contaminated aquifer sediment was evaluated under aerobic and anaerobic conditions. Predator¯prey biomass ratios suggested that protozoan grazing might be influencing bacterial populations....

  15. Trichloroethylene Biodegradation by a Methane-Oxidizing Bacterium †

    PubMed Central

    Little, C. Deane; Palumbo, Anthony V.; Herbes, Stephen E.; Lidstrom, Mary E.; Tyndall, Richard L.; Gilmer, Penny J.

    1988-01-01

    Trichloroethylene (TCE), a common groundwater contaminant, is a suspected carcinogen that is highly resistant to aerobic biodegradation. An aerobic, methane-oxidizing bacterium was isolated that degrades TCE in pure culture at concentrations commonly observed in contaminated groundwater. Strain 46-1, a type I methanotrophic bacterium, degraded TCE if grown on methane or methanol, producing CO2 and water-soluble products. Gas chromatography and 14C radiotracer techniques were used to determine the rate, methane dependence, and mechanism of TCE biodegradation. TCE biodegradation by strain 46-1 appears to be a cometabolic process that occurs when the organism is actively metabolizing a suitable growth substrate such as methane or methanol. It is proposed that TCE biodegradation by methanotrophs occurs by formation of TCE epoxide, which breaks down spontaneously in water to form dichloroacetic and glyoxylic acids and one-carbon products. Images PMID:16347616

  16. Fade to Green: A Biodegradable Stack of Microbial Fuel Cells.

    PubMed

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Stinchcombe, Andrew; Walter, X Alexis; Greenman, John; Ieropoulos, Ioannis

    2015-08-24

    The focus of this study is the development of biodegradable microbial fuel cells (MFCs) able to produce useful power. Reactors with an 8 mL chamber volume were designed using all biodegradable products: polylactic acid for the frames, natural rubber as the cation-exchange membrane and egg-based, open-to-air cathodes coated with a lanolin gas diffusion layer. Forty MFCs were operated in various configurations. When fed with urine, the biodegradable stack was able to power appliances and was still operational after six months. One useful application for this truly sustainable MFC technology includes onboard power supplies for biodegradable robotic systems. After operation in remote ecological locations, these could degrade harmlessly into the surroundings to leave no trace when the mission is complete. PMID:26212495

  17. Prenatal exposure to di-(2-ethylhexyl) phthalate (DEHP) affects reproductive outcomes in female mice

    PubMed Central

    Niermann, Sarah; Rattan, Saniya; Brehm, Emily; Flaws, Jodi A.

    2015-01-01

    This study tested the hypothesis that prenatal DEHP exposure affects female reproduction. To test this hypothesis, pregnant female CD-1 mice were orally dosed daily with tocopherol-stripped corn oil (vehicle control) or DEHP (20μg/kg/day-750mg/kg/day) from gestation day 11-birth. Pups were counted, weighed, and sexed at birth, ovaries were subjected to evaluations of follicle numbers on postnatal days (PNDs) 8 and 21, and fertility was evaluated at 3-9 months. The results indicate that prenatal DEHP exposure increased male-to-female ratio compared to controls. Prenatal DEHP exposure also increased preantral follicle numbers at PND 21 compared to controls. Further, 22.2% of the 20 μg/kg/day treated animals took longer than 5 days to get pregnant at 3 months and 28.6% of the 750 mg/kg/day treated animals lost some of their pups at 6 months. Thus, prenatal DEHP exposure alters F1 sex ratio, increases preantral follicle numbers, and causes some breeding abnormalities PMID:25765777

  18. 76 FR 64810 - Beverages: Bottled Water Quality Standard; Establishing an Allowable Level for di(2-ethylhexyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... FR 41612), FDA published a proposal (``the 1993 proposed rule'') to revise the bottled water quality... adopting the allowable level for DEHP in the bottled water quality standard as proposed (58 FR 41612... be found in bottled water in levels above the standard. C. Benefits In the Economic Impact...

  19. Transgenerational Effects of Di(2-ethylhexyl) Phthalate in the SD Male Rat

    EPA Science Inventory

    In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis, gubernacular ligaments, epididymis and other androgen-dependent tissues. In ...

  20. Molecular Order and Dynamics of Tris(2-ethylhexyl)phosphate Confined in Uni-Directional Nanopores

    SciTech Connect

    Kipnusu, Wycliffe Kiprop; Kossack, Wilhelm; Iacob, Ciprian; Jasiurkowska, Malgorzata; Sangoro, Joshua R; Kremer, Friedrich

    2012-01-01

    Infrared Transition Moment Orientational Analysis (IR-TMOA) and Broadband Dielectric Spectroscopy (BDS) are combined to study molecular order and dynamics of the glass-forming liquid Tris(2-ethylhexy)phosphate (TEHP) confined in uni-directional nanopores with diameters of 4, 8, and 10.4 nm. The former method enables one to determine the molecular order parameter of specific IR transition moments. It is observed that the central P=O moiety of TEHP has a weak orientational effect (molecular order parameter Sz = 0.1 0.04) due the nanoporous confinement, in contrast to the terminal C H groups. BDS traces the dynamic glass transition of the guest molecules in a broad spectral range and at widely varying temperature. An enhancement of the mobility takes place when approaching the glass transition temperature and becomes more pronounced with decreasing pore diameter. This is attributed to a slight reduction of the density of the confined liquid caused by the 2-dimensional geometrical constraint.

  1. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL... requirement of a tolerance for residues in grain, aspirated fractions; barley, grain, barley, hay,...

  2. Chromatographic extraction with di(2-ethylhexyl)orthophosphoric acid for production and purification of promethium-147

    DOEpatents

    Boll, Rose A [Knoxville, TN

    2008-10-14

    A method of producing and purifying promethium-147 including the steps of: irradiating a target material including neodymium-146 with neutrons to produce promethium-147 within the irradiated target material; dissolving the irradiated target material to form an acidic solution; loading the acidic solution onto a chromatographic separation apparatus containing HDEHP; and eluting the apparatus to chromatographically separate the promethium-147 from the neodymium-146.

  3. Fate of di-2-(ethylhexyl)phthalate in three sludge-amended New Mexico soils

    SciTech Connect

    Fairbanks, B.C.; O'Connor, G.A.; Smith, S.E.

    1985-01-01

    Di-3-(ethylhexyl)phthalate (DEHP) is a toxic organic of concern limiting the reuse of sewage sludge on agricultural lands. The degradation, volatilization, and adsorption of DEHP-/sup 14/C were monitored in three calcareous soils from New Mexico amended or unamended with sewage sludge. Evolution of /sup 14/CO/sub 2/ was the only mechanism of loss of DEPH from these soils. No volatilization of parent compound or organic metabolites was detected. The effects of sewage sludge on DEHP degradation varied with soil, DEHP concentration, and sludge incubation time. As a result, 50% disappearance time varied from 8 to 72 d, depending on treatment interactions. After 146 d, 76 to 93% of the DEHP-/sup 14/C was evolved as CO/sub 2/. In general, DEHP persistence was reduced by previous exposure of the soil to sludge, but was increased or unaffected by fresh additions of sludge. Increasing DEHP concentration from 2 to 20 mg kg/sup -1/ soil increased DEHP persistence. Degradation of DEHP was greater in two sandy loams (Typic Haplargids and petrocalcic Paleustolls) than in a clay soil (Typic Torrifluvents). Preliminary data suggest extensive adsorption of DEHP by all soils with no effect of sewage sludge additions.

  4. Integral physicochemical properties of reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT)

    NASA Astrophysics Data System (ADS)

    Fedyaeva, O. A.; Shubenkova, E. G.; Poshelyuzhnaya, E. G.; Lutaeva, I. A.

    2016-08-01

    The effect the degree of hydration has on optical and electrophysical properties of water/AOT/ n-hexane system is studied. It is found that AOT reverse micelles form aggregates whose dimensions grow along with the degree of hydration and temperature. Aggregation enhances their electrical conductivity and shifts the UV spectrum of AOT reverse emulsions to the red region. Four states of water are found in the structure of AOT reverse micelles.

  5. Prenatal exposure to di-(2-ethylhexyl) phthalate (DEHP) affects reproductive outcomes in female mice.

    PubMed

    Niermann, Sarah; Rattan, Saniya; Brehm, Emily; Flaws, Jodi A

    2015-06-01

    This study tested the hypothesis that prenatal DEHP exposure affects female reproduction. To test this hypothesis, pregnant female CD-1 mice were orally dosed daily with tocopherol-stripped corn oil (vehicle control) or DEHP (20 μg/kg/day-750 mg/kg/day) from gestation day 11-birth. Pups were counted, weighed, and sexed at birth, ovaries were subjected to evaluations of follicle numbers on postnatal days (PNDs) 8 and 21, and fertility was evaluated at 3-9 months. The results indicate that prenatal DEHP exposure increased male-to-female ratio compared to controls. Prenatal DEHP exposure also increased preantral follicle numbers at PND 21 compared to controls. Further, 22.2% of the 20 μg/kg/day treated animals took longer than 5 days to get pregnant at 3 months and 28.6% of the 750 mg/kg/day treated animals lost some of their pups at 6 months. Thus, prenatal DEHP exposure alters F1 sex ratio, increases preantral follicle numbers, and causes some breeding abnormalities. PMID:25765777

  6. Sterilization techniques for biodegradable scaffolds in tissue engineering applications

    PubMed Central

    Dai, Zheng; Ronholm, Jennifer; Tian, Yiping; Sethi, Benu; Cao, Xudong

    2016-01-01

    Biodegradable scaffolds have been extensively studied due to their wide applications in biomaterials and tissue engineering. However, infections associated with in vivo use of these scaffolds by different microbiological contaminants remain to be a significant challenge. This review focuses on different sterilization techniques including heat, chemical, irradiation, and other novel sterilization techniques for various biodegradable scaffolds. Comparisons of these techniques, including their sterilization mechanisms, post-sterilization effects, and sterilization efficiencies, are discussed. PMID:27247758

  7. Biodegradable kinetics of plastics under controlled composting conditions.

    PubMed

    Leejarkpai, Thanawadee; Suwanmanee, Unchalee; Rudeekit, Yosita; Mungcharoen, Thumrongrut

    2011-06-01

    This study models and evaluates the kinetics of C-CO(2) evolution during biodegradation of plastic materials including Polyethylene (PE), PE/starch blend (PE/starch), microcrystalline cellulose (MCE), and Polylactic acid (PLA). The aerobic biodegradation under controlled composting conditions was monitorated according to ISO 14855-1, 2004. The kinetics model was based on first order reaction in series with a flat lag phase. A non-linear regression technique was used to analyze the experimental data. SEM studies of the morphology of the samples before and after biodegradation testing were used to confirm the biodegradability of plastics and the accuracy of the model. The work showed that MCE and PLA produced the high amounts of C-CO(2) evolution, which gave readily hydrolysable carbon values of 55.49% and 40.17%, respectively with readily hydrolysis rates of 0.338 day(-1) and 0.025 day(-1), respectively. Whereas, a lower amount of C-CO(2) evolution was found in PE/starch, which had a high concentration of moderately hydrolysable carbon of 97.74% and a moderate hydrolysis rate of 0.00098 day(-1). The mineralization rate of PLA was 0.500 day(-1) as a lag phase was observed at the beginning of the biodegradability test. No lag phase was observed in the biodegradability testing of the PE/starch and MCE. The mineralization rates of the PE/starch and MCE were found to be 1.000 day(-1), and 1.234 day(-1), respectively. No C-CO(2) evolution was observed during biodegradability testing of PE, which was used for reference as a non-biodegradable plastics sample.

  8. Saponification of fatty slaughterhouse wastes for enhancing anaerobic biodegradability.

    PubMed

    Battimelli, Audrey; Carrère, Hélène; Delgenès, Jean-Philippe

    2009-08-01

    The thermochemical pretreatment by saponification of two kinds of fatty slaughterhouse waste--aeroflotation fats and flesh fats from animal carcasses--was studied in order to improve the waste's anaerobic degradation. The effect of an easily biodegradable compound, ethanol, on raw waste biodegradation was also examined. The aims of the study were to enhance the methanisation of fatty waste and also to show a link between biodegradability and bio-availability. The anaerobic digestion of raw waste, saponified waste and waste with a co-substrate was carried out in batch mode under mesophilic and thermophilic conditions. The results showed little increase in the total volume of biogas, indicating a good biodegradability of the raw wastes. Mean biogas volume reached 1200 mL/g VS which represented more than 90% of the maximal theoretical biogas potential. Raw fatty wastes were slowly biodegraded whereas pretreated wastes showed improved initial reaction kinetics, indicating a better initial bio-availability, particularly for mesophilic runs. The effects observed for raw wastes with ethanol as co-substrate depended on the process temperature: in mesophilic conditions, an initial improvement was observed whereas in thermophilic conditions a significant decrease in biodegradability was observed.

  9. Calcium orthophosphate coatings on magnesium and its biodegradable alloys.

    PubMed

    Dorozhkin, Sergey V

    2014-07-01

    Biodegradable metals have been suggested as revolutionary biomaterials for bone-grafting therapies. Of these metals, magnesium (Mg) and its biodegradable alloys appear to be particularly attractive candidates due to their non-toxicity and as their mechanical properties match those of bones better than other metals do. Being light, biocompatible and biodegradable, Mg-based metallic implants have several advantages over other implantable metals currently in use, such as eliminating both the effects of stress shielding and the requirement of a second surgery for implant removal. Unfortunately, the fast degradation rates of Mg and its biodegradable alloys in the aggressive physiological environment impose limitations on their clinical applications. This necessitates development of implants with controlled degradation rates to match the kinetics of bone healing. Application of protective but biocompatible and biodegradable coatings able to delay the onset of Mg corrosion appears to be a reasonable solution. Since calcium orthophosphates are well tolerated by living organisms, they appear to be the excellent candidates for such coatings. Nevertheless, both the high chemical reactivity and the low melting point of Mg require specific parameters for successful deposition of calcium orthophosphate coatings. This review provides an overview of current coating techniques used for deposition of calcium orthophosphates on Mg and its biodegradable alloys. The literature analysis revealed that in all cases the calcium orthophosphate protective coatings both increased the corrosion resistance of Mg-based metallic biomaterials and improved their surface biocompatibility.

  10. Biodegradable and edible gelatine actuators for use as artificial muscles

    NASA Astrophysics Data System (ADS)

    Chambers, L. D.; Winfield, J.; Ieropoulos, I.; Rossiter, J.

    2014-03-01

    The expense and use of non-recyclable materials often requires the retrieval and recovery of exploratory robots. Therefore, conventional materials such as plastics and metals in robotics can be limiting. For applications such as environmental monitoring, a fully biodegradable or edible robot may provide the optimum solution. Materials that provide power and actuation as well as biodegradability provide a compelling dimension to future robotic systems. To highlight the potential of novel biodegradable and edible materials as artificial muscles, the actuation of a biodegradable hydrogel was investigated. The fabricated gelatine based polymer gel was inexpensive, easy to handle, biodegradable and edible. The electro-mechanical performance was assessed using two contactless, parallel stainless steel electrodes immersed in 0.1M NaOH solution and fixed 40 mm apart with the strip actuator pinned directly between the electrodes. The actuation displacement in response to a bias voltage was measured over hydration/de-hydration cycles. Long term (11 days) and short term (1 hour) investigations demonstrated the bending behaviour of the swollen material in response to an electric field. Actuation voltage was low (<10 V) resulting in a slow actuation response with large displacement angles (<55 degrees). The stability of the immersed material decreased within the first hour due to swelling, however, was recovered on de-hydrating between actuations. The controlled degradation of biodegradable and edible artificial muscles could help to drive the development of environmentally friendly robotics.

  11. DU-AGG pilot plant design study

    SciTech Connect

    Lessing, P.A.; Gillman, H.

    1996-07-01

    The Idaho National Engineering Laboratory (INEL) is developing new methods to produce high-density aggregate (artificial rock) primarily consisting of depleted uranium oxide. The objective is to develop a low-cost method whereby uranium oxide powder (UO[sub 2], U[sub 3]O[sub ]8, or UO[sub 3]) can be processed to produce high-density aggregate pieces (DU-AGG) having physical properties suitable for disposal in low-level radioactive disposal facilities or for use as a component of high-density concrete used as shielding for radioactive materials. A commercial company, G-M Systems, conducted a design study for a manufacturing pilot plant to process DU-AGG. The results of that study are included and summarized in this report. Also explained are design considerations, equipment capacities, the equipment list, system operation, layout of equipment in the plant, cost estimates, and the proposed plan and schedule.

  12. Mars' 1995 opposition from PIC du Midi

    NASA Astrophysics Data System (ADS)

    Erard, S.

    1997-03-01

    The last Martian apparition was observed from Pic du Midi between October 1994 and March 1995. Earth-based observation remains the only practicable way to perform continuous surveys of the planets, as opposed to orbital (HST) or space-borne observation. A good planetary site with limited demand for observational time like the 1-m telescope at Pic du Midi provides the optimal opportunity to monitor planetary activity, including atmospheric phenomena, surface variations, and polar caps recession. For instance, HST observations of Mars during this period, though yielding a much better spatial resolution, are limited to very few sessions and do not make it possible to monitor quick processes along a whole Martian season.

  13. An adsorption-release-biodegradation system for simultaneous biodegradation of phenol and ammonium in phenol-rich wastewater.

    PubMed

    Wang, Ying; Chen, Hu; Liu, Yu-Xiang; Ren, Rui-Peng; Lv, Yong-Kang

    2016-07-01

    The feasibility of simultaneous biodegradation of phenol and ammonium in phenol-rich wastewater was evaluated in a reusable system, which contained macroporous adsorption resin and Alcaligenes faecalis strain WY-01. In the system, up to 6000mg/L phenol could be completely degraded by WY-01; meanwhile, 99.03±3.95% of ammonium was removed from the initial concentration of 384mg/L. This is the first study to show the capability of single strain in simultaneous removal of ammonium and phenol in wastewater containing such high concentrations of phenol. Moreover, the resin was regenerated during the biodegradation process without any additional manipulations, indicating the system was reusable. Furthermore, enzyme assay, gene expression patterns, HPLC-MS and gas chromatography analysis confirmed that phenol biodegradation accompanied with aerobic nitrifier denitrification process. Results imply that the reusable system provides a novel strategy for more efficient biodegradation of phenol and ammonium contained in some particular industrial wastewater. PMID:27060247

  14. Sustainable growth, the DuPont way.

    PubMed

    Holliday, C

    2001-09-01

    Like many manufacturers, DuPont traditionally has grown by making more and more "stuff." And its business growth has been proportional to the amount of raw materials and energy used--as well as the resulting waste and emissions from operations. Over the years, though, DuPont became aware that cheap supplies of nonrenewable resources wouldn't be endlessly available and that the earth's ecosystems couldn't indefinitely absorb the waste and emissions of production and consumption. Chad Holliday, chairman and CEO of DuPont, believes strongly in the challenge of sustainable growth and makes the business case for it: By using creativity and scientific knowledge effectively, he says, companies can provide strong returns for shareholders and grow their businesses--while also meeting the human needs of societies around the world and reducing the environmental footprint of their operations and products. In fact, a focus on sustainability can help identify new products, markets, partnerships, and intellectual property and lead to substantial business growth. Holliday describes how DuPont developed a three-pronged strategy to translate the concept of sustainability into nuts-and-bolts business practices. Focusing on integrated science, knowledge intensity, and productivity improvement, the strategy was accompanied by a new way to measure progress quantitatively. Sustainable growth should be viewed not as a program for stepped-up environmental performance but as a comprehensive way of doing business, one that delivers tremendous economic value and opens up new opportunities. Ultimately, companies will find that they can generate substantial business value through sustainability while both enhancing the quality of life around the world and protecting the environment.

  15. Sustainable growth, the DuPont way.

    PubMed

    Holliday, C

    2001-09-01

    Like many manufacturers, DuPont traditionally has grown by making more and more "stuff." And its business growth has been proportional to the amount of raw materials and energy used--as well as the resulting waste and emissions from operations. Over the years, though, DuPont became aware that cheap supplies of nonrenewable resources wouldn't be endlessly available and that the earth's ecosystems couldn't indefinitely absorb the waste and emissions of production and consumption. Chad Holliday, chairman and CEO of DuPont, believes strongly in the challenge of sustainable growth and makes the business case for it: By using creativity and scientific knowledge effectively, he says, companies can provide strong returns for shareholders and grow their businesses--while also meeting the human needs of societies around the world and reducing the environmental footprint of their operations and products. In fact, a focus on sustainability can help identify new products, markets, partnerships, and intellectual property and lead to substantial business growth. Holliday describes how DuPont developed a three-pronged strategy to translate the concept of sustainability into nuts-and-bolts business practices. Focusing on integrated science, knowledge intensity, and productivity improvement, the strategy was accompanied by a new way to measure progress quantitatively. Sustainable growth should be viewed not as a program for stepped-up environmental performance but as a comprehensive way of doing business, one that delivers tremendous economic value and opens up new opportunities. Ultimately, companies will find that they can generate substantial business value through sustainability while both enhancing the quality of life around the world and protecting the environment. PMID:11550629

  16. Du Pont Classifications of 6 Supernovae

    NASA Astrophysics Data System (ADS)

    Morrell, N.; Shappee, Benjamin J.

    2016-06-01

    We report optical spectroscopy (range 370-910 nm) of six supernovae from the Backyard Observatory Supernova Search (BOSS) and the All-Sky Automated Survey for Supernovae (ASAS-SN) using the du Pont 2.5-m telescope (+ WFCCD) at Las Campanas Observatory on June 17 2016 UT. We performed a cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J.

  17. Biofilm formation and partial biodegradation of polystyrene by the actinomycete Rhodococcus ruber: biodegradation of polystyrene.

    PubMed

    Mor, Roi; Sivan, Alex

    2008-11-01

    Polystyrene, which is one of the most utilized thermoplastics, is highly durable and is considered to be non-biodegradable. Hence, polystyrene waste accumulates in the environment posing an increasing ecological threat. In a previous study we have isolated a biofilm-producing strain (C208) of the actinomycete Rhodococcus ruber that degraded polyethylene films. Formation of biofilm, by C208, improved the biodegradation of polyethylene. Consequently, the present study aimed at monitoring the kinetics of biofilm formation by C208 on polystyrene, determining the physiological activity of the biofilm and analyzing its capacity to degrade polystyrene. Quantification of the biofilm biomass was performed using a modified crystal violet (CV) staining or by monitoring the protein content in the biofilm. When cultured on polystyrene flakes, most of the bacterial cells adhered to the polystyrene surface within few hours, forming a biofilm. The growth of the on polystyrene showed a pattern similar to that of a planktonic culture. Furthermore, the respiration rate, of the biofilm, exhibited a pattern similar to that of the biofilm growth. In contrast, the respiration activity of the planktonic population showed a constant decline with time. Addition of mineral oil (0.005% w/v), but not non-ionic surfactants, increased the biofilm biomass. Extended incubation of the biofilm for up to 8 weeks resulted in a small reduction in the polystyrene weight (0.8% of gravimetric weight loss). This study demonstrates the high affinity of C208 to polystyrene which lead to biofilm formation and, presumably, induced partial biodegradation. PMID:18401686

  18. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB.

    PubMed

    Torlapati, Jagadish; Boufadel, Michel C

    2014-01-01

    We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al., 2010). In that study, samples were collected from three different islands: Eleanor Island (EL107), Knight Island (KN114A), and Smith Island (SM006B), and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA). The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with that of the overall polycyclic aromatic hydrocarbons

  19. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB

    PubMed Central

    Torlapati, Jagadish; Boufadel, Michel C.

    2014-01-01

    We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al., 2010). In that study, samples were collected from three different islands: Eleanor Island (EL107), Knight Island (KN114A), and Smith Island (SM006B), and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA). The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with that of the overall polycyclic aromatic hydrocarbons

  20. Biodegradation and surfactant-mediated biodegradation of diesel fuel by 218 microbial consortia are not correlated to cell surface hydrophobicity.

    PubMed

    Owsianiak, Mikołaj; Szulc, Alicja; Chrzanowski, Łukasz; Cyplik, Paweł; Bogacki, Mariusz; Olejnik-Schmidt, Agnieszka K; Heipieper, Hermann J

    2009-09-01

    In this study, we elucidated the role of cell surface hydrophobicity (microbial adhesion to hydrocarbons method, MATH) and the effect of anionic rhamnolipids and nonionic Triton X-100 surfactants on biodegradation of diesel fuel employing 218 microbial consortia isolated from petroleum-contaminated soils. Applied enrichment procedure with floating diesel fuel as a sole carbon source in liquid cultures resulted in consortia of varying biodegradation potential and diametrically different cell surface properties, suggesting that cell surface hydrophobicity is a conserved parameter. Surprisingly, no correlations between cell surface hydrophobicity and biodegradation of diesel fuel were found. Nevertheless, both surfactants altered cell surface hydrophobicity of the consortia in similar manner: increased for the hydrophilic and decreased for the hydrophobic cultures. In addition to this, the surfactants exhibited similar influence on diesel fuel biodegradation: Increase was observed for initially slow-degrading cultures and the opposite for fast degraders. This indicates that in the surfactant-mediated biodegradation, effectiveness of surfactants depends on the specification of microorganisms and not on the type of surfactant. In contrary to what was previously reported for pure strains, cell surface hydrophobicity, as determined by MATH, is not a good descriptor of biodegrading potential for mixed cultures.

  1. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    PubMed

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides.

  2. Hydrolytic kinetics of biodegradable polyester monolayers

    SciTech Connect

    Lee, W.K.; Gardella, J.A. Jr.

    2000-04-04

    The rate of hydrolysis of Langmuir monolayer films of a series of biodegradable polyesters was investigated at the air/water interface. The present study investigated parameters such as degradation medium, pH, and time. The hydrolysis of polyester monolayers strongly depended on both the degradation medium used to control subphase pH and the concentration of active ions. Under the conditions studied here, polymer monolayers showed faster hydrolysis when they were exposed to a basic subphase rather than that of acidic or neutral subphase. The basic (pH = 10) hydrolysis of [poly(l-lactide)/polycaprolactone](l-PLA/PCL 1/1 by mole) blend was faster than that of each homopolymer at the initial stage. This result is explained by increasing numbers of base attack sites per unit area owing to the very slow hydrolysis of PCL, a dilution effect on the concentration of l-PLA monolayers. Conversely the hydrolytic behavior of l-lactide-co-caprolactone (1/1 by mole) was similar to that of PCL even though the chemical compositions of the blend and the copolymer are very similar to each other. The resistance of the copolymer to hydrolysis might be attributed to the hydrophobicity and the steric hindrance of caprolactone unit in the copolymer.

  3. [Biodegradable polyhydroxyalkanoates as carriers for antitumor agents].

    PubMed

    Shishatskaia, E I; Zhemchugova, A V; Volova, T G

    2005-01-01

    The possible use of biodegradable polyethers of microbial origin (polyhydroxyalkanoates) as matrices for deposition of daunorubicin (rubomycin), an antitumor anthracycline, was studied. The tablet dosage form of various rubomycin load (from 1 to 60% w/w) was prepared by cold compaction under pressure. The in vitro kinetics of the rubomycin release from the polymer matrix was investigated. It was shown that the rubomycin release to the medium resulted from the drug solution and diffusion within various periods, from tens hours to several weeks and months depending on the load. When the rubomycin load was under 20% w/w the drug release was prolonged and directly proportional to the observation time. When the rubomycin concentration was under 5%, the drug release kinetics corresponded to the type of the zero order reaction with prolonged release without sharp efflux at the initial stage of the observation. The findings showed that the polyhydroxyalkanoates were applicable as matrices for deposition of rubomycin and preparation of drugs with prolonged action.

  4. Pharmacokinetics and biodegradation of chitosan in rats

    NASA Astrophysics Data System (ADS)

    Li, Hui; Jiang, Zhiwen; Han, Baoqin; Niu, Shuyi; Dong, Wen; Liu, Wanshun

    2015-10-01

    Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate (FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 kDa. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

  5. Melt electrospinning of biodegradable polyurethane scaffolds.

    PubMed

    Karchin, Ari; Simonovsky, Felix I; Ratner, Buddy D; Sanders, Joan E

    2011-09-01

    Electrospinning from a melt, in contrast to from a solution, is an attractive tissue engineering scaffold manufacturing process as it allows for the formation of small diameter fibers while eliminating potentially cytotoxic solvents. Despite this, there is a dearth of literature on scaffold formation via melt electrospinning. This is likely due to the technical challenges related to the need for a well-controlled high-temperature setup and the difficulty in developing an appropriate polymer. In this paper, a biodegradable and thermally stable polyurethane (PU) is described specifically for use in melt electrospinning. Polymer formulations of aliphatic PUs based on (CH(2))(4)-content diisocyanates, polycaprolactone (PCL), 1,4-butanediamine and 1,4-butanediol (BD) were evaluated for utility in the melt electrospinning process. The final polymer formulation, a catalyst-purified PU based on 1,4-butane diisocyanate, PCL and BD in a 4/1/3M ratio with a weight-average molecular weight of about 40kDa, yielded a nontoxic polymer that could be readily electrospun from the melt. Scaffolds electrospun from this polymer contained point bonds between fibers and mechanical properties analogous to many in vivo soft tissues. PMID:21640853

  6. Biodegradation and flushing of MBT wastes

    SciTech Connect

    Siddiqui, A.A.; Richards, D.J.; Powrie, W.

    2013-11-15

    Highlights: • Stabilization was achieved for MBT wastes of different degrees of pretreatment. • About 92% reduction in the gas generation compared with raw MSW. • Pretreatment resulted in reduced TOC, nitrogen and heavy metals in leachate. • A large proportion of carbon and nitrogen remained in the waste material. - Abstract: Mechanical–biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratory experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320 g/kg dry matter for raw MSW to between 183 and 195 g/kg dry matter for the MBT wastes.

  7. Biodegradable magnesium-hydroxyapatite metal matrix composites.

    PubMed

    Witte, Frank; Feyerabend, Frank; Maier, Petra; Fischer, Jens; Störmer, Michael; Blawert, Carsten; Dietzel, Wolfgang; Hort, Norbert

    2007-04-01

    Recent studies indicate that there is a high demand to design magnesium alloys with adjustable corrosion rates and suitable mechanical properties. An approach to this challenge might be the application of metal matrix composite (MMC) based on magnesium alloys. In this study, a MMC made of magnesium alloy AZ91D as a matrix and hydroxyapatite (HA) particles as reinforcements have been investigated in vitro for mechanical, corrosive and cytocompatible properties. The mechanical properties of the MMC-HA were adjustable by the choice of HA particle size and distribution. Corrosion tests revealed that HA particles stabilised the corrosion rate and exhibited more uniform corrosion attack in artificial sea water and cell solutions. The phase identification showed that all samples contained hcp-Mg, Mg(17)Al(12), and HA before and after immersion. After immersion in artificial sea water CaCO3 was found on MMC-HA surfaces, while no formation of CaCO3 was found after immersion in cell solutions with and without proteins. Co-cultivation of MMC-HA with human bone derived cells (HBDC), cells of an osteoblasts lineage (MG-63) and cells of a macrophage lineage (RAW264.7) revealed that RAW264.7, MG-63 and HBDC adhere, proliferate and survive on the corroding surfaces of MMC-HA. In summary, biodegradable MMC-HA are cytocompatible biomaterials with adjustable mechanical and corrosive properties.

  8. Biodegradation of sulfanilic acid by Pseudomonas paucimobilis.

    PubMed

    Perei, K; Rákhely, G; Kiss, I; Polyák, B; Kovács, K L

    2001-01-01

    An aerobic bacterium, isolated from a contaminated site, was able to degrade sulfanilic acid (4-aminobenzenesulfonic acid) and was identified as Pseudomonas paucimobilis. The isolate could grow on sulfanilic acid (SA) as its sole carbon and nitrogen source and metabolized the target compound to biomass. The bioconversion capacity depended on the sulfanilic acid concentration; greater than 98% elimination of the hazardous compound was achieved at low (10 mM) sulfanilic acid concentration, and the yield was greater than 70% at 50 mM concentration of the contaminant. The maximum conversion rate was 1.5 mmol sulfanilic acid/h per mg wet cells at 30 degrees C. Ca-alginate-phytagel proved a good matrix for immobilization of P. paucimobilis, with essentially unaltered biodegradation activity. Removal of sulfanilic acid from contaminated industrial waste water was demonstrated. SDS-PAGE analysis of the crude extract revealed novel proteins appearing upon induction with sulfanilic acid and related compounds, which indicated alternative degradation mechanisms involving various inducible enzymes.

  9. Biodegradation characteristics of imazaquin and imazethapyr

    SciTech Connect

    Cantwell, J.R.; Liebl, R.A.; Slife, F.W.

    1989-11-01

    The extent of {sup 14}C-imazaquin and {sup 14}C-imazethapyr abiotic vs biotic degradation in soil was investigated. Degradation was measured in an in vitro system which allowed 90% recovery of applied herbicide. Triallate biodegradation is well documented and therefore used as a standard. Herbicide degradation was compared in two soils, a Cisne silt loam and a Drummer silty clay loam. Herbicide degradation in gamma-irradiated soil was compared to fresh soil. Biomass quantities were measured for the duration of the experiments. {sup 14}CO{sub 2} evolution, extractable parent, metabolites, and unextractable residue were measured. After 12 weeks of incubation, 95% of the radioactivity could be extracted as parent from sterilized soil. In unsterilized soil, imazaquin and imazethapyr degraded at a similar rate which was dependent upon soil type. All herbicides degraded slower in the Drummer soil and triallate degraded two to three times faster than the imidazolinones in either soil. {sup 14}C-imazaquin degradation products included {sup 14}CO{sub 2} and unextractable residues. The major product from {sup 14}C-imazethapyr degradation was {sup 14}CO{sub 2}. Evolution of {sup 14}CO{sub 2} from an imazethapyr-treated Cisne soil, containing a serial dilution of activated charcoal, demonstrated that adsorption of herbicide was negatively correlated with degradation. Therefore imidazolinone microbial degradation is regulated by the amount of herbicide in soil solution as determined by soil characteristics.

  10. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    PubMed

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides. PMID:26837064

  11. Biodegradation of cellulose acetate by Neisseria sicca.

    PubMed

    Sakai, K; Yamauchi, T; Nakasu, F; Ohe, T

    1996-10-01

    Bacteria capable of assimilating cellulose acetate, strains SB and SC, were isolated from soil on a medium containing cellulose acetate as a carbon source, and identified as Neisseria sicca. Both strains degraded cellulose acetate membrane filters (degree of substitution, DS, mixture of 2.8 and 2.0) and textiles (DS, 2.34) in a medium containing cellulose acetate (DS, 2.34) or its oligomer, but were not able to degrade these materials in a medium containing cellobiose octaacetate. Biodegradation of cellulose acetate (DS, 1.81 and 2.34) on the basis of biochemical oxygen demand reached 51 and 40% in the culture of N. sicca SB and 60 and 45% in the culture of N. sicca SC within 20 days. A decrease in the acetyl content of degraded cellulose acetate films and powder was confirmed by infrared and nuclear magnetic resonance analyses. After 10-day cultivation of N. sicca SB and SC, the number-average molecular weight of residual cellulose acetate decreased by 9 and 5%, respectively. Activities of enzymes that released acetic acid and produced reducing sugars from cellulose acetate were mainly present in the culture supernatant. Reactivity of enzymes for cellulose acetate (DS, 1.81) was higher than that for cellulose acetate (DS, 2.34).

  12. Biodegradation of sugarcane bagasse by Pleurotus citrinopileatus.

    PubMed

    Pandey, V K; Singh, M P; Srivastava, A K; Vishwakarma, S K; Takshak, S

    2012-12-22

    The chemically as well as hot water treated agrowaste sugarcane bagasse was subjected to degradation by Pleurotus citrinopileatus. The fungus degraded lignin, cellulose, hemicellulose, and carbon content of both chemically as well as hot water treated waste and produced in turn the edible and nutritious fruiting body. Biodegradation of the waste in terms of loss of lignin, cellulose and hemicellulose showed positive correlation with cellulases, xylanase, laccase and polyphenol oxidase (PPO) activity of the fungus. During mycelial growth of the fungus, lignin degradation was faster and during fructification, lignin degradation was slower than cellulose and hemicellulose. The carbon content of the sugarcane bagasse decreased while, nitrogen content increased during degradation of the waste. Hot water treated substrate supported better production of enzymatic activity and degraded more efficiently than chemically sterilized substrate. The total yield and biological efficiency of the mushroom was maximum on the hot water treated substrates. Degradation of the hot water treated sugarcane bagasse was better and faster than chemically treated substrates.

  13. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions.

    PubMed

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C12E9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C12E9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C12E9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C12E9, C12E8, C12E7 and C12E6. Apart from the substrate, the homologues C12E8, C12E7 and C12E6, being metabolites of C12E9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C12E8COOH, C12E7COOH, C12E6COOH and C12E5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C12E9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. PMID:27037882

  14. Aerobic biodegradation of iso-butanol and ethanol and their relative effects on BTEX biodegradation in aquifer materials.

    PubMed

    Schaefer, Charles E; Yang, Xiaomin; Pelz, Oliver; Tsao, David T; Streger, Sheryl H; Steffan, Robert J

    2010-11-01

    The aerobic biodegradability of iso-butanol, a new biofuel, and its impact on benzene, toluene, ethylbenzene and xylenes (BTEX) degradation was investigated in aerobic microcosms consisting of groundwater and sediment from a California site with a history of gasoline contamination. To the best of our knowledge this is the first study directly examining the effects of iso-butanol on BTEX degradation. Microcosms that received either low (68 μM) or high (3400 μM) concentrations of iso-butanol showed complete biodegradation of iso-butanol within 7 and 23 d, respectively, of incubation at 15°C under aerobic conditions. A maximum utilization rate coefficient of 2.3±0.1×10⁻⁷ μmol cell⁻¹ h⁻¹ and a half saturation constant of 610±54 μM were regressed from the iso-butanol data. Iso-butanol biodegradation resulted in transient formation of the degradation intermediate products iso-butylaldehyde and iso-butyric acid, and both compounds were subsequently degraded within the timeframe of the experiments. Ethanol was biodegraded more slowly than iso-butanol. Ethanol also exhibited greater adverse impacts on BTEX biodegradation than iso-butanol. Results of the study suggest that iso-butanol added to fuels will be readily biodegraded in the environment under aerobic conditions without the accumulation of major intermediate products (iso-butylaldehyde and iso-butyric acid), and that it will pose less impacts on BTEX biodegradation than ethanol.

  15. BTE-OX biodegradation kinetics with MTBE through bioaugmentation.

    PubMed

    Acuna-Askar, K; Villarreal-Chiu, J F; Gracia-Lozano, M V; Garza-Gonzalez, M T; Chavez-Gomez, B; Rodriguez-Sanchez, I P; Barrera-Saldana, H A

    2004-01-01

    The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of bioaugmented bacterial populations as high as 880 mg/L VSS was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. Benzene and o-xylene biodegradation followed a first-order one-phase kinetic model, whereas toluene and ethylbenzene biodegradation was well described by a first-order two-phase kinetic model in all samples. MTBE followed a zero-order removal kinetic model in all samples. The presence of soil in aqueous samples retarded BTE-oX removal rates, with the highest negative effect on o-xylene. The presence of soil enhanced MTBE removal rate. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged from 95.4-99.7% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged from 55.9-90.1% and 15.6-30.1%, respectively. PMID:15497834

  16. Adsorption and biodegradation of antidiabetic pharmaceuticals in soils.

    PubMed

    Mrozik, Wojciech; Stefańska, Justyna

    2014-01-01

    Pharmaceuticals are emerging contaminants in the natural environment. Most studies of the environmental fate of these chemicals focus on their behavior in wastewater treatment processes and in sewage sludge. Little is known about their behavior in soils. In this study adsorption and biodegradation of four antidiabetic pharmaceuticals - glimepiride, glibenclamide, gliclazide and metformin - were examined in three natural soils. The sorption of sulfonylurea derivatives was high (higher than sulfonylurea herbicides for example), whereas metformin showed high mobility. Desorption rates were highest for metformin. Sorption isotherms in two of three soils fitted best to the Freundlich model. Despite their high affinity to for soil surfaces, biodegradation studies revealed that transformation of the drugs occurred. Biodegradation results were described by pseudo-first order kinetics with half-life values from 5 to over 120 d (under aerobic conditions) and indicate that none of the tested drugs can be classified as quickly biodegradable. Biodegradation under anoxic conditions was much slower; often degrading by less than 50% during time of the experiment.

  17. Biodegradation of imidazolium ionic liquids by activated sludge microorganisms.

    PubMed

    Liwarska-Bizukojc, Ewa; Maton, Cedric; Stevens, Christian V

    2015-11-01

    Biological properties of ionic liquids (ILs) have been usually tested with the help of standard biodegradation or ecotoxicity tests. So far, several articles on the identification of intermediate metabolites of microbiological decay of ILs have been published. Simultaneously, the number of novel ILs with unrecognized characteristics regarding biodegradability and effect on organisms and environment is still increasing. In this work, seven imidazolium ionic liquids of different chemical structure were studied. Three of them are 1-alkyl-3-methyl-imidazolium bromides, while the other four are tetra- or completely substituted imidazolium iodides. This study focused on the identification of intermediate metabolites of the aforementioned ionic liquids subjected to biodegradation in a laboratory activated sludge system. Both fully substituted ionic liquids and 1-ethyl-3-methyl-imidazolium bromide were barely biodegradable. In the case of two of them, no biotransformation products were detected. The elongation of the alkyl side chain made the IL more susceptible for microbiological decomposition. 1-Decyl-3-methyl-imidazolium bromide was biotransformed most easily. Its primary biodegradation up to 100 % could be achieved. Nevertheless, the cleavage of the imidazolium ring has not been observed.

  18. Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3

    PubMed Central

    Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

    2015-01-01

    Background: Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. Objectives: This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative agent that decomposes PAA. Materials and Methods: Primarily, DNA-DNA hybridization between TBZ3, Halomonas denitrificans DSM18045T and Halomonas saccharevitans LMG 23976T was carried out. Para-amino acetanilide biodegradation was assessed using spectrophotometry and confirmed by gas chromatography-mass spectroscopy (GC-MS). Parameters effective on biodegradation of PAA were optimized by the Response Surface Methodology (RSM). Results: The DNA-DNA hybridization experiments between isolate TBZ3, H. denitrificans and H. saccharevitans revealed relatedness levels of 57% and 65%, respectively. According to GC-MS results, TBZ3 degrades PAA to benzene, hexyl butanoate, 3-methyl-1-heptanol and hexyl hexanoate. Temperature 32.92°C, pH 6.76, and salinity 14% are the optimum conditions for biodegradation with a confidence level of 95% (at level α = 0.05). Conclusions: According to our results, Halomonas sp. TBZ3 could be considered as a biological agent for bioremediation of PAA and possibly other similar aromatic compounds. PMID:26495103

  19. High throughput and miniaturised systems for biodegradability assessments.

    PubMed

    Cregut, Mickael; Jouanneau, Sulivan; Brillet, François; Durand, Marie-José; Sweetlove, Cyril; Chenèble, Jean-Charles; L'Haridon, Jacques; Thouand, Gérald

    2014-01-01

    The society demands safer products with a better ecological profile. Regulatory criteria have been developed to prevent risks for human health and the environment, for example, within the framework of the European regulation REACH (Regulation (EC) No 1907, 2006). This has driven industry to consider the development of high throughput screening methodologies for assessing chemical biodegradability. These new screening methodologies must be scalable for miniaturisation, reproducible and as reliable as existing procedures for enhanced biodegradability assessment. Here, we evaluate two alternative systems that can be scaled for high throughput screening and conveniently miniaturised to limit costs in comparison with traditional testing. These systems are based on two dyes as follows: an invasive fluorescent dyes that serves as a cellular activity marker (a resazurin-like dye reagent) and a noninvasive fluorescent oxygen optosensor dye (an optical sensor). The advantages and limitations of these platforms for biodegradability assessment are presented. Our results confirm the feasibility of these systems for evaluating and screening chemicals for ready biodegradability. The optosensor is a miniaturised version of a component already used in traditional ready biodegradability testing, whereas the resazurin dye offers an interesting new screening mechanism for chemical concentrations greater than 10 mg/l that are not amenable to traditional closed bottle tests. The use of these approaches allows generalisation of high throughput screening methodologies to meet the need of developing new compounds with a favourable ecological profile and also assessment for regulatory purpose.

  20. Implications of fullerene-60 upon in-vitro LDPE biodegradation.

    PubMed

    Sah, Aditi; Kapri, Anil; Zaidi, M G H; Negi, Harshita; Goel, Reeta

    2010-05-01

    Fullerene-60 nanoparticles were used for studying their influence upon the LDPE biodegradation efficiency of two potential polymer-degrading consortia comprising of three bacterial strains each. At a concentration of 0.01% (w/v) in minimal broth lacking dextrose, fullerene did not have any negative influence upon the consortial growth. However, fullerene was found to be detrimental for bacterial growth at higher concentrations (viz. 0.25%, 0.5% and 1%). Although, addition of 0.01% fullerene into the biodegradation assays containing 5 mg/ml LDPE subsided growth-curves significantly, but subsequent analysis of degraded products revealed enhanced biodegradation. Fourier transform infrared spectroscopy (FT-IR) revealed breakage and formation of chemical bonds along with introduction of nu C-O frequencies into hydrocarbon backbone of LDPE. Further, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) revealed higher number of decomposition steps along with a 1,000-fold decrease in the heat of reactions (DeltaH) in fullerene-assisted biodegraded LDPE suggesting probable formation of multiple, macromolecular by-products. This is the first report whereby fullerene-60, which is otherwise considered toxic, has helped to alleviate polymer biodegradation process of bacterial consortia. PMID:20519915