Formation of the metabolic intermediate 2,4,4-trimethyl-2-pentanol during incubation of a shape Sphingomonas sp. strain with the xeno-estrogenic octylphenol

Degradation of branched octylphenol was studied in abacterial culture of a Sphingomonas sp. strain.Octylphenol is considered to be the most stabledegradation intermediate formed from the correspondingnonionic octylphenol polyethoxylates surfactantsduring biological wastewater treatment. Sinceoctylphenol can exert estrogenic effects in wildlife,a detailed study of its biodegradation is warranted.The aerobic microbiological transformation ofoctylphenol was examined with and without the additionof the easily assimilable sodium acetate. In bothcases the formation of the metabolite2,4,4-trimethyl-2-pentanol, representing the intactalkyl chain as a tertiary alcohol, was observed. Sincethe octylphenol degradation rate was not affected bythe presence of acetate, this strain did not show anydiauxic metabolic behaviour when incubated withoctylphenol and sodium acetate as the sources ofcarbon and energy. As a result of thebiotransformation of octylphenol, its estrogenicpotency was removed because it is the phenolic moietythat interacts with the estrogen receptors. Thisfeature opens perspectives for the use of this strainin the framework of an adequate treatment ofwastewater with high levels of alkylphenolpolyethoxylates.     

辛基酚胁迫对雄性泥鳅抗氧化酶及卵黄蛋白原的影响

为研究辛基酚(OP)对雄性泥鳅抗氧化酶活性及血清卵黄蛋白原(VTG)含量的影响,将雄性泥鳅分别暴露于4种不同质量浓度OP(0.12、0.19、0.32、0.52 mg/L)中持续7、14、21 d和28 d,采用试剂盒检测肝脏超氧化物歧化酶(SOD)与过氧化氢酶(CAT)的含量,采用碱不稳定性蛋白结合磷法检测血清VTG的含量。结果表明,0.12 mg/L OP胁迫14 d,肝脏SOD和CAT含量均无显著变化,但是随着胁迫剂量增大和时间延长,SOD和CAT含量降低极其显著,在0.52 mg/L OP胁迫28 d时降到最低水平;泥鳅在0.12 mg/L OP中暴露7 d时,血清VTG含量就有极其显著升高,且随着胁迫剂量增大和时间的延长,VTG含量呈升高趋势。提示OP胁迫对SOD和CAT活性有显著的抑制作用,并随胁迫剂量增大和时间延长而抑制加剧,造成氧化损伤;OP胁迫可诱导VTG合成,并随暴露剂量增大和时间延长而诱导增强,具有明显的雌激素效应,这可能与其氧化损伤有密切关系。     

Research for the effect of octylphenol on spermatogenesis and proteomic analysis in octylphenol-treated mice testes

OP (octylphenol), an environmental oestrogen was administered, and differentially expressed proteins were analysed in mice testes to clarify its mechanism of action in male sterility. Male Kunming suckling mice (10 days old) were subcutaneously injected with OP at a dose of 10 μg/kg per day, 50 μg/kg per day and 100 μg/kg per day as low-, medium- and high-dose groups, respectively, for 35 days. Animals in the control group received subcutaneous injections of olive oil at a dose of 10 μl/mouse per day. Serum oestradiol, testosterone, FSH (follicle stimulating hormone) and LH (luteinizing hormone) levels were measured on day 45. The left testes were removed for tissue analysis, and the right testes were analysed for differentially expressed proteins by using two-dimensional gel electrophoresis and MS. Tissue analysis showed that mice spermatogenesis was blocked at the round spermatid stage in the high-dose group, whereas no such changes were found in the medium- and low-dose groups. Higher serum oestradiol (P<0.05) and lower testosterone (P<0.05) levels were found in the medium- and high-dose groups. There was no significant difference in serum oestradiol and testosterone levels in the low-dose and control groups. No significant influence of OP was seen on serum FSH and LH levels in all OP-treated animals. The results from four differentially expressed proteins such as PPIA (peptidyl-prolyl cis-trans isomerase A), PEBP1 (phosphatidylethanolamine-binding protein1), TPI (triose-phosphate isomerase) and TCP-1 (T-complex protein 1) in the high-dose and control groups showed up-regulation of PPIA expression and down-regulation in PEBP1, TPI and TCP-1 expressions. These findings will contribute to clarify the mechanism of male sterility by environmental oestrogens.     

Posthatch Oral Estrogen Exposure Impairs Adult Reproductive Performance of Zebra Finch in a Sex-Specific Manner

We determined whether short-term, posthatch oral exposure to estradiol benzoate (EB) or the industrial surfactant octylphenol (OP) could impair the reproductive performance of zebra finches. If so, naturally occurring phytoestrogens and xenoestrogens might influence reproduction in wild populations. Chicks were given oral administration of 10 or 100 nmol EB per gram of body mass (earlier work showed the latter to be the minimum oral dose required to maximally masculinize female song nuclei) or an equimolar amount of OP daily from 5 through 11 days of age. Canola oil was used as a vehicle and control. Reproductive testing was done either in individual pair cages or in communal cages that permitted self-selection of mates, N = 10 pairs per group. Pairs consisted of EB-treated males and females, EB-treated males paired with canola-treated females, vice versa, and canola-treated males and females. Posthatch EB treatment produced sex-specific impairments in reproduction that, in some instances, were additive when both sexes were treated. Egg production was reduced and egg breakage was increased in 100 nmol/g EB-treated male and female pairs. The incidence of missing eggs was increased in 10 nmol/g EB-treated male and female pairs. Candled fertility was reduced in both groups containing 100 nmol/g EB-treated males. The number of hatched chicks was severely reduced in all EB-treated groups. No adverse effects of OP treatment were detected. These significant treatment effects (all P < 0.05) show that posthatch EB treatment profoundly disrupts the reproductive performance of zebra finches, suggesting that exposure to estrogens in the wild could impair the reproductive performance of wild populations.     

Review of the Potential Environmental and Human Health–Related Hazards and Risks from Long-Term Exposure to p-tert-Octylphenol

Para-tert-octylphenol (OP) is an important chemical intermediate mainly used for production of phenolic resins and lacquers. OP has weak estrogen-like activity in vitro, with induction of vitellogenin in fish hepatocytes and competitive estrogen receptor binding and estrogen-responsive gene expression in mammalian systems. Induction of vitellogenin in fish plasma and liver, in vivo, has also been measured and weak estrogen-like activity in rodent screening assays occurs but at much lower potency than predicted by the in vitro activity. Conventional aquatic wildlife toxicity testing shows effects on survival, growth and development, and reproduction occurring at concentrations lower than the estrogen-like responses predicted from screening assays. Studies in rodents have provided evidence of metabolic saturation at high doses of OP, and a multigeneration reproductive study confirms the lack of estrogen-like activity below this metabolic saturation as well as the lack of reproductive toxicity. This article reviews the weight of evidence for the aquatic and mammalian data and compares the results of the definitive assays to those of the screening tests. The results show that the estrogen-like activity in screening tests is not predictive of results from definitive testing, and that risk assessment decisions should be made using conventional toxicity endpoints.     

Naphthalene,phenanthrene and surfactant biodegradation

The impact of surfactants on naphthalene and phenanthrene biodegradation and vice versa after surfactant flushing were evaluated using two anionic surfactants: sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS); and two nonionic surfactants: POE (20) sorbitan monooleate (T-maz-80) and octylphenol poly(ethyleneoxy) ethanol (CA-620). Naphthalene and phenanthrene biodegradation varied differently in the presence of different surfactants. Naphthalene biodegradation was not impacted by the presence of SDS. In the presence of T-maz-80 and CA-620, naphthalene biodegradation occurred at a lower rate (0.14 d^-1 for T-maz-80 and 0.19 d^-1 for CA-620) as compared to un-amended control (0.29 d^-1). Naphthalene biodegradation was inhibited by the presence of SDBS. In the presence of SDS, phenanthrene biodegradation occurred at a lower rate (0.10 d^-1 as compared to un-amended control of 0.17 d^-1) and the presence of SDBS, CA-620 and T-maz-80 inhibited phenanthrene biodegradation. The surfactants also responded differently to the presence of naphthalene and phenanthrene. In the presence of naphthalene, SDS biodegradation was inhibited; SDBS and T-maz-80 depleted at a lower rate (0.41d^-1 and 0.12 d^-1 as compared to 0.48 d^-1 and 0.22 d^-1). In the absence of naphthalene, CA-620 was not degradable, while in the presence of naphthalene, CA-620 began to degrade at a comparatively low rate (0.12 d^-1). In the presence of phenanthrene, SDS biodegradation occurred at a lower rate (1.2 d^-1 as compared to 1.68 d^-1) and a similar trend was observed for T-maz-80. The depletion of SDBS and CA-620 did not change significantly. The choice of SDS for naphthalene-contaminated sites would not adversely affect the natural attenuation of naphthalene, in addition, naphthalene was preferentially utilized to SDS by naphthalene-acclimated microorganisms. Therefore, SDS was the best choice. T-maz-80 was also found to be usable in naphthalene-contaminated sites. For phenanthrene contaminated sites, SDS was the only choice.     

Attachment Sites of Carbohydrate Moieties to Peptide Chain of Bovine κ-Casein from Normal Milk

The attachment site of the carbohydrate moiety to the peptide chain of normal κ-casein was investigated with κ-casein component P-6 containing the most carbohydrates. Three short glycopeptides 6-IB₁, 6-IB_{2 ? 1} and 6-IB_{2 ? 2} were prepared by cyanogen bromide cleavage and digestion of proteases (pronase P and thermolysin). Glycopeptides 6-IB₁, 6-IB_{2? 1} and 6-IB_{2 ? 2} corresponded to residues 128–139 (Gly-Glu-Pro-Thr-Ser-Thr-Pro-Thr-Thr-Glu-Ala-Val), residues 128–132 (or 127–131) and residues 135–139 of κ-casein A, respectively, and contained threonine and/or serine, but not asparagine. Glycopeptide 6-IB₁ was considered to have three carbohydrate chains because it contained three galactosamine residues. The results of alkali treatment of 6-IB, under reduction condition excluded serine residue as the binding site, and confirmed the existence of three binding sites in the carbohydrate moieties. The carbohydrate moiety was shown to attach to threonine residue No. 131 from analysis of 6-IB_{2? 1} and to threonine residue No. 135 (or 136) from analysis of 6-IB_{2 ? 2}. It was concluded that the carbohydrate chains attached to threonine residues No. 131, 133 and 135 (or 136).     

Oral estrogen masculinizes female zebra finch song system

It is well established that parenteral treatment of female zebra finch chicks with estradiol masculinizes their song control nuclei and that as adults they are capable of song. Concern over the widespread use of putative environmental estrogens caused us to ask whether oral exposure to estrogens (a natural route of exposure) could produce similar effects. We dosed chicks orally with estradiol benzoate (EB; 1, 10, 100, and 1000 nmol/g of body mass per day, days 5-11 posthatch), the non-ionic surfactant octylphenol (100 and 1000 nmol/g), or the pesticides methoxychlor (100 and 1000 nmol/g) and dicofol (100 nmol/g) and measured their song control nuclei as adults. EB treatment produced increases in song nuclei comparable to that induced by parenteral administration of estrogens. This is the first study of which we are aware to use an oral route of administration, which simulates the natural process of parent birds feeding their nestlings. We conclude that oral exposure to estradiol alters song control nuclei and we report in a related paper (Millam et al., 2001) that such exposure severely disrupts reproductive performance. Although we detected no influence of xenobiotics on induction of song control nuclei the possibility remains that oral exposure to xenoestrogens in high enough doses could affect development.     

酚类物质对中国林蛙蝌蚪生长发育的毒性效应

中国林蛙蝌蚪对水环境有极强的依赖性,水环境中的酚类物质可以通过中国林蛙蝌蚪的呼吸系统和皮肤进入其体内,影响蝌蚪的存活状况、生长发育和生理生化指标。因此中国林蛙蝌蚪可以用作监测水体环境的指示物种。从壬基酚、辛基酚和双酚A等酚类物质对中国林蛙蝌蚪生长发育的毒性效应进行阐述,为酚类污染物对两栖动物生长发育影响机理的深入研究奠定基础,为中国林蛙蝌蚪的生态保护和水环境监测提供科学依据。