排序方式： 共有55条查询结果，搜索用时 31 毫秒
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从红树植物红海榄叶片中分离一株对芘具有较好降解作用的海洋细菌,命名为B11,并对其菌体特征、生长条件及降解效能等进行了系统研究。结果发现该菌株为革兰氏阴性菌,结合其生理生化特征和16S rDNA序列比对,表明此菌株属于交替单胞菌属(Alteromonas sp.)。菌株在芘的起始浓度为100 mg/L,pH为中性或偏碱性条件下,盐度35时对芘的降解作用最强。外加碳源对B11对芘的降解效果都具有一定的抑制作用,其中水杨酸的抑制作用更为显著。综合菌株B11的生长特性和降解效能,初步认为B11菌株较适合用于降解多环芳烃芘,可用于红树植物多环芳烃生态污染的原位修复。 相似文献
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海洋环境中微塑料和多环芳烃(PAHs)污染日益严重,以滤食动物菲律宾蛤仔(Ruditapes philippinarum)为研究对象,探讨了聚苯乙烯微塑料和芘单一及联合暴露对菲律宾蛤仔的毒性效应.分别采用两个聚苯乙烯微塑料粒径(0.3μm和6μm,20 μg/L)和两个芘浓度水平(10 μg/L和100μg/L)单独和联合暴露21d,测定其对菲律宾蛤仔生理活动(肥满度和摄食率)、免疫防御、氧化应激等相关生物标志物的影响.研究结果表明,除芘单一暴露组外,其余暴露组菲律宾蛤仔的摄食率与对照组相比都显著降低,但这两种污染物对菲律宾蛤仔的肥满度没有显著影响.微塑料和芘暴露均导致菲律宾蛤仔免疫功能受损,表现为血细胞凋亡率增加和吞噬活性被抑制;其中,在小粒径微塑料和高浓度芘存在的暴露组血细胞凋亡率均显著高于对照组,并且二者联合暴露组血细胞凋亡率最高;除大粒径微塑料暴露组外,各暴露组血细胞吞噬活性均显著低于对照组.菲律宾蛤仔抗氧化酶系统不能及时清除体内产生的自由基,导致机体出现氧化损伤现象,表现为抗氧化酶活性变化和丙二醛(MDA)含量升高.微塑料和芘联合暴露导致鳃组织谷胱甘肽疏基转移酶(GST)活性显著升高,消化腺组织过氧化氡酶(CAT)和超氧化物歧化酶(SOD)活性显著降低.综合生物标志物指数(IBR)结果显示,联合暴露对菲律宾蛤仔造成的胁迫压力高于单一暴露组. 相似文献
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苯并[a]芘(Ba P)是一类典型多环芳烃(PAHs)污染物。为了定量评价Ba P对脊尾白虾(Exopalaemon carinicauda)的毒性效应,采用水体暴露实验,研究了脊尾白虾肝胰脏、肌肉组织的5种生物标志物(EROD、GST、SOD、CAT、MDA)对Ba P暴露的响应,并应用综合生物标志物响应(IBR)定量评价了Ba P对肝胰脏、肌肉组织的毒性差异。结果显示:肝胰脏、肌肉组织的EROD、GST、SOD、CAT活性整体呈现诱导-抑制的规律性变化,除了0.05μg/L实验组CAT外,其余各实验组肝胰脏组织生物标志物活性在实验结束时均显著高于对照组(P0.05),除了0.45μg/L实验组EROD、CAT外,其余各浓度组肌肉组织生物标志物活性在实验结束时均与对照组无显著性差异(P0.05),MDA含量呈现持续上升的趋势,在实验结束时各实验组均显著高于对照组(P0.05);IBR值存在时间效应和剂量效应。研究结果表明,肝胰脏、肌肉组织对Ba P的暴露响应存在差异性,肝胰脏生物标志物综合应激活性高于肌肉组织。 相似文献
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Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days
in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing
BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase
(GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations.
Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with
oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect)
between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in
detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed
to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant
mixtures in the marine environment.
Supported by the Technology Development Program of Shandong (No. 2008GG1005010) and the Program of Introducing Talents of
Discipline of Universities (111 Project, No. B08049) 相似文献
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The toxic effects of benzo[α]pyrene （B[α]P） at different concentrations （0.1, 0.5, 1, 2.5 and 7.5 μgL^-1） on scallop （Chlamys farreri） immune system were studied. The results showed that B[α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity （P〈0.05）, while the seawater control and acetone control had no significant differences. The haemocyte counts, neutral red uptake, phagocytosis and bacteriolytic activity in all B[α]P treatment groups as well as antibacterial activity in groups of 0.5, 1, 2.5 and 7.5 μgL^-1·B[α]P decreased significantly （P〈0.05）. Some of these indices tended to be stable on the sixth day and others on the ninth day, and the indices showed clear time- and concentration-response to B[α]E Bactenolytic activity in 0.1 μgL^-1 B[α]P treatment group and antibacterial activity in 0.1 ggLl and 0.5 μgL^-1 B[α]P treatment groups increased at the beginning of exposure and reached their peaks on day 1 and day 6, respectively. Following that, both activities decreased gradually and became stable after day 9. When all the indices reached stability, they were significantly lower than those in control group （P〈0.05）, except for antibacterial activity in 0.1 μgLl B[α]P treatment group （P〉0.05）. Thus, B[α]P has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and lmmunomodulation in aquatic organisms. 相似文献
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近年来超临界CO2在环境地球科学领域应用广泛,在这些研究应用中,CO2流体在超临界状态下的溶剂化特性起到了十分重要的作用。在超临界高密度压缩区域里,体系温度和压力的稍许变化都会导致流体密度的突变,因此通过有效的探针分子研究超临界CO2流体的异常溶剂化行为具有重要的理论和应用价值。文中从新的角度运用荧光探针分子芘在温度308.15K和不同压力下研究超临界CO2性质,与以往采用的参照线方法有所不同,文中所提出的参照点模型手段引入序参量方法和新定义的溶剂化作用参量,测定近临界区超临界CO2流体局域密度增强的变化。文中同时讨论了3段密度区域模型(three-density regionmodel)、局域密度不均一性以及探针芘在超临界CO2中的分子间相互作用。将荧光探针分子研究的流体局域密度增强与热力学测试的流体等温压缩系数进行综合对比,有助于更好地从微观和宏观两方面理解超临界CO2的特性。 相似文献
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Glutathione S-transferases (GSTs) are a class of enzymes that facilitate the detoxification of xenobiotics, and also play important roles in antioxidant defense. We identified two glutathione S-transferase isoforms (VpGSTS, sigma GST; VpGSTO, omega GST) from Venerupis philippinarum by RACE approaches. The open reading frames of VpGSTS and VpGSTO were of 612 bp and 729 bp, encoding 203 and 242 amino acids with an estimated molecular mass of 22.88 and 27.94 kDa, respectively. The expression profiles of VpGSTS and VpGSTO responded to heavy metals and benzo[a]pyrene (B[a]P) exposure were investigated by quantitative real-time RT-PCR. The expression of VpGSTS and VpGSTO were both rapidly up-regulated, however, they showed differential expression patterns to different toxicants. Cd displayed stronger induction of VpGSTS expression with an approximately 12-fold increase than that of VpGSTO with a maximum 6.4-fold rise. Cu exposure resulted in similar expression patterns for both VpGSTS and VpGSTO. For B[a]P exposure, the maximum induction of VpGSTO was approximately two times higher than that of VpGSTS. Altogether, these findings implied the involvement of VpGSTS and VpGSTO in host antioxidant responses, and highlighted their potential as a biomarker to Cd and B[a]P exposure. 相似文献
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A microbial consortium was obtained by enrichment culture of sea water samples collected from Botan oil port in Xiamen, China, using the persistent high concentration of a mixture of polycyclic aromatic hydrocarbons enrichment strategy. Denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial composition and community dynamic changes based on PCR amplification of 16S rRNA genes during batch culture enrichment. Using the spray-plate method, three bacteria, designated as BL01, BL02 and BL03, which corresponded to the dominant bands in the DGGE profiles, were isolated from the consortium. Sequence analysis showed that BL01, BL02 and BL03 were phylogenetically close to Ochrobactrum sp., Stenotrophomonas maltophilia and Pseudomonas fluorescens, respectively. The degradation of benzo(a)pyrene (BaP), a model high-molecular-weight polycyclic aromatic hydrocarbon (HMW PAH) compound was investigated using individual isolates, a mixture of the three isolates, and the microbial consortium (BL) originally isolated from the oil port sea water. Results showed that the order of degradative ability was BL > the mixture of the three isolates > individual isolates. BL degraded 44.07% of the 10 ppm BaP after 14 days incubation, which showed the highest capability for HMW PAH compound degradation.Our results revealed that this high selective pressure strategy was feasible and effective in enriching the HMW PAH-degraders from the original sea water samples. 相似文献