赤子爱胜蚯蚓体液中几种抗菌成分的比较研究

目的对赤子爱胜蚯蚓体液纯化的几种抗菌组分进行比较研究。方法将蚯蚓体液分别经反相柱、分子筛和阴离子交换柱色谱后 ,得到相应活性组分 ,用分光光度法、甲基红四唑 /吩嗪二甲基硫酸盐 (MTS/PMS)比色分析法和双层琼脂抑菌圈法进行抗菌活力筛选。结果在被检测的 3种色谱组分中 ,只有分子筛色谱组分对巨大芽孢杆菌有抗菌活力 ;阴离子交换柱色谱组分对铜绿假单胞菌的抗菌活力最大。其它色谱组分也有一定抗菌活力。结论MTS/PMS比色分析法和双层琼脂抑菌圈法相结合 ,能为纯化和筛选新的抗菌成分提供一个良好的实验平台。     

Bioavailability of cobalt and silver nanoparticles to the earthworm Eisenia fetida

Due to difficulties in tracing engineered nanoparticles (ENPs) in complex media, there are few data on the exposure of soil biota to ENPs. This study used neutron activated cobalt (Co NPs) and silver (Ag NPs) nanoparticles, as well as soluble cobalt and silver salts, to assess the uptake, excretion and biodistribution in the earthworm Eisenia fetida. Concentrations of cobalt in worms after four weeks exposure reached 88% and 69% of the Co ions and Co NPs concentrations in food, respectively, while corresponding values for Ag ions and Ag NPs were 2.3% and 0.4%. Both Ag ions and Ag NPs in earthworms were excreted rapidly, while only 32% of the cobalt accumulated from Co ions and Co NPs were excreted within four months. High accumulation of cobalt was found in blood and in the digestive tract. Metal characterization in the exposure medium was assessed by sequential extraction and ultrafiltration. The Co NPs showed significant dissolution and release of ions, while Ag ions and particularly Ag NPs were more inert.     

Limit-test toxicity screening of selected inorganic nanoparticles to the earthworm Eisenia fetida

The toxicity of a range of inorganic (Ag, Cu, Ni, Al₂O₃, SiO₂, TiO₂ and ZrO₂) nanoparticles (NP) and their corresponding metal salt or bulk metal oxide were screened for toxicity toward the earthworm Eisenia fetida using the limit-test design (1000 mg/kg). This study provides the first ecotoxicological life history trait data on earthworms for each these NPs, as well as for AgNO₃, Al₂O₃, SiO₂, TiO₂ and ZrO₂. Significant effects were observed on survival for AgNO₃ (2.5% of controls), CuCl₂ (17.5% of controls) and NiCl₂ (32.5% of controls) and on reproduction (AgNO₃, CuCl₂, NiCl₂, Ag-NP, Cu-NP, TiO₂-NP); with total reproductive failure in both silver treatments. Ag-NP, Cu-NP and TiO₂-NP were the only NPs that caused toxic effects to E. fetida. The toxicity could not be singularly related to particle size or zeta potential or to the inherent element constituting the NPs (e.g. Ag).     

Oxidative damage of naphthenic acids on the Eisenia fetida earthworm

Naphthenic acids (NAs) have been gaining recognition in recent years as potentially harmful environmental contaminants. Few studies have focused on the potential ecotoxicity of NAs to terrestrial environment. In this study, the responses of antioxidant system and lipid peroxidation and DNA damage were investigated after exposing Eisenia fetida to soil contaminated with NAs. The results indicated that NAs induced a significant increase (p < 0.05) in superoxide dismutase and catalase enzyme activities. The glutathione peroxidase enzyme activities were significantly inhibited (p < 0.05) in the medium and high dose treatments. An increase in malondialidehyde indicated that NAs could cause cellular lipid peroxidation in the tested earthworms. The percentage of DNA in the tail of comet assay of coelomocytes as an indication of DNA damage increased after treatment with different doses of NAs, and a dose‐dependent DNA damage of coelomocytes was found. In conclusion, oxidative stress caused by NAs exposure induces physiological responses and genotoxicity on earthworms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1337–1343, 2016.     

Combined effects of oxytetracycline and Pb on earthworm Eisenia fetida

Combined effects of oxytetracycline (OTC) and Pb on lysosomal membrane stability and coelomocyte apoptosis of earthworm were studied in the paper. Compared with control, the lysosomal membrane stability decreased and coelomocyte apoptosis increased in the treatments of single OTC and Pb contamination. As for compound pollution, combined effect of (5 mg/kg OTC + 50 mg/kg Pb) treatment on earthworm lysosomal was synergistic (except 28 d). However, it was antagonistic at higher concentration of (10 mg/kg OTC + 50 mg/kg Pb) and (20 mg/kg OTC + 50 mg/kg Pb) treatment. In addition, coelomocyte apoptosis of earthworm decreased significantly compared with single OTC, indicating an antagonistic reaction. And joint toxicity of OTC and Pb decreased significantly with the increasing OTC concentration.     

Avoidance behavior of Eisenia fetida in oxytetracycline- and heavy metal-contaminated soils

To determine the behavior of oxytetracycline (OTC) and heavy metals in soil, this study assessed the pollutant-induced avoidance behavior of earthworms (E. fetida) exposed to zinc (Zn²⁺), lead (Pb²⁺), and OTC in soil. The results showed a clear avoidance response within 48 h of exposure to the highest concentrations of pollutants. Moreover, E. fetida was shown to be more sensitive to Zn²⁺ than to Pb²⁺ and OTC. Compared with OTC alone, the net response of earthworms increased in the OTC-Zn²⁺ and OTC-Pb²⁺ combined treatments, indicating a synergistic effect. Moreover, the net response (NR) of the earthworms was higher for OTC-Zn²⁺ than it was for OTC-Pb²⁺, possibly reflecting the differences in essential characteristics of Zn and Pb.     

Both released silver ions and particulate Ag contribute to the toxicity of AgNPs to earthworm Eisenia fetida

Abstract

To disentangle the contribution of ionic and nanoparticulate Ag to the overall toxicity to the earthworm Eisenia fetida, a semi-permeable membrane strategy was used to separate Ag⁺ released from silver nanoparticles (AgNPs) in an aqueous exposure. Internal Ag fractionation, activities of antioxidant enzymes and metabolites in E. fetida were determined after 96?h of exposure to two sizes of polyvinylpyrrolidone-coated AgNPs. The response of the antioxidant system combined with the content of malondialdehyde indicated that the Ag⁺ released from AgNPs induced significant oxidative stress to the earthworms. Ag accumulated from AgNPs was predominantly associated with the granules and cell membrane compartments, whereas dissolved Ag was localized in the cytosol-containing fraction. In both Ag⁺ exposures, two intermediates in the Krebs cycle, succinate and fumarate, were significantly elevated and depleted, respectively. A similar alteration pattern was seen in groups exposed to both smaller AgNPs (S AgNP, 10?nm) and larger AgNP (L AgNP, 40?nm), indicating that these effects in E. fetida were induced by exposure to released Ag⁺. In addition, unique metabolic responses including decreased malate and glucose levels in S AgNP-exposed earthworms could be associated with exposure to nanoparticulate silver. Increased leucine and arginine and decreased ATP and inosine levels were observed in L AgNP exposures only, which clearly demonstrated a size-specific effect of AgNPs. Collectively, this study provided strong evidence that nanosilver acts by a different mechanism than ionic silver to cause acute toxicity to E. fetida, but further verification under different environmental conditions is needed.     

Content and distribution of arsenic in soils, sediments and groundwater environments of the southern Pampa region, Argentina

The health of a large rural population in the southern Pampa (Argentina) is at risk owing to newly detected areas where As-groundwater exceeds 0.01 mg/L standard (WHO (1995) Guidelines for drinking water quality, 2nd edition. pp 43-45). Currently, devitrification of volcanic glass is invoked to interpret the origin of arsenic in the aquifers hosted in a sequence of pampean loess (Plio-Pleistocene) juxtaposed with postpampean loess (Holocene). Our data suggest that arsenic is not specifically associated with volcanic glass and that other minerals contribute to As-release into groundwater. The goals were (1) to understand As-groundwater spatial variability, (2) to explore soils/sediments/water relationships and to identify the probable As-provenance. Comparable As concentrations of the light and the heavy sand fractions suggest that though detrital glass is a major light constituent, other existing primary minerals are As-bearers that contribute to As-release into groundwater. Grouping of materials according to their As-content indicated spatial variability in the sedimentary distribution pattern leading to differences in the frequencies of occurrence of As-bearing minerals. Phreatic waters were Ca + Mg bicarbonate and devoid of As in the intake areas (Ventania System) and Na-carbonate but As-rich towards the discharge (Atlantic coast and local depressions). As-groundwater reflects a patchy distribution within the pampean landscape. A correspondence between As-high groundwater, EC >1 dSm, CO(3)H(-), alkaline pH and a longer water residence time do exist triggering As extraction from the loess sand fraction and desorption from charged fine particles which lead to As-toxicity towards groundwater discharge.     

The hydroxyl radical generation and oxidative stress for the earthworm Eisenia fetida exposed to tetrabromobisphenol A

Biochemical effects of tetrabromobisphenol A (TBBPA) on the earthworm Eisenia fetida, including superoxide dismutase, catalase, glutathione-S-transferase, reduced glutathione, oxidized glutathione, GSH/GSSG ratio and malondialdehyde (MDA) level, were measured to assess ecological toxicity of TBBPA. With OECD standard filter-paper contact test method, earthworms were exposed to TBBPA of a range of concentrations (0.00, 0.01, 0.05, 0.1, 0.5 and 1.0 mg L⁻¹). According to the electron paramagnetic resonance spectrum, reactive oxygen species (ROS) generated in the earthworm was identified as the hydroxyl radical (^•OH) which was significantly induced at all TBBPA concentrations. With the increasing of TBBPA concentration, the antioxidant enzymes, glutathione and MDA levels varied significantly. The results showed that TBBPA exerts its toxic effects on E. fetida by inducing the generation of ROS and resulting in oxidative damage. The results show that the ^•OH production leads to oxidative stress in the tissues of the earthworm E. fetida.     

氟氯氰菊酯、溴氰菊酯和联苯菊酯对赤子爱胜蚓的急性毒性

目的探讨氟氯氰菊酯、溴氰菊酯和联苯菊酯3种典型拟除虫菊酯农药对赤子爱胜蚓(Eisenia fetida)的急性毒性效应。方法以赤子爱胜蚓为模式生物,通过滤纸接触法(48 h)和土壤培养法(7 d和14 d)分别研究了3种拟除虫菊酯农药的蚯蚓急性毒性响应,并计算蚯蚓的半致死剂量LC50。结果 3种拟除虫菊酯农药对蚯蚓的毒性效应与染毒时间和染毒浓度相关。采用接触滤纸法测得氟氯氰菊酯、溴氰菊酯和联苯菊酯的48 h LC50分别为16.2、485.8、3637.8μg·cm~(-2),采用土壤培养法测得氟氯氰菊酯、溴氰菊酯和联苯菊酯的14 d LC_(50)分别为134.7、196.6、3440.9 mg·kg~(-1)。结论通过滤纸接触法和土壤培养法测得氟氯氰菊酯、溴氰菊酯和联苯菊酯3种拟除虫菊酯农药的毒性效应表现一致,毒性顺序均为氟氯氰菊酯>溴氰菊酯>联苯菊酯。     

Biochemical and genotoxic effect of triclosan on earthworms (Eisenia fetida) using contact and soil tests

Triclosan (TCS) is a broad‐spectrum bactericide that is used for a variety of antimicrobial functions. TCS is frequently detected in the terrestrial environment due to application of sewage sludge to agricultural land. In the present study, 48‐h paper contact and 28‐day spiked soil tests were conducted to examine the toxic effects of TCS on the antioxidative and genetic indices of earthworms (Eisenia fetida). The activity of antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT) and the content of the lipid peroxidation product (malondialdehyde, MDA) were determined as biomarkers of oxidative stress in E. fetida. Moreover, single cell gel electrophoresis (SCGE) was used as a biomarker of genotoxicity. The results showed that triclosan induced a significant increase (P < 0.05) in antioxidative enzyme activities and MDA content. Of all of the biomarkers examined, CAT activity was most sensitive to TCS, and the CAT activity increased significantly (P < 0.05) at bactericidal concentrations of 7.86 ng cm^?2 in the contact test and 10 mg kg^?1 in the spiked soil test. The comet assay showed that TCS treatments significantly induced (P < 0.05) DNA damage in E. fetida, and that 78.6 ng cm^?2 caused significant genotoxic effects in the acute test (48 h). Clear dose‐dependent DNA damage to E. fetida was observed both in contact and spiked soil tests. These results imply that TCS may have potential biochemical and genetic toxicity toward earthworms (E. fetida). A battery of biomarkers covering multiple molecular targets of acute toxicity can be combined to better understand the impacts of TCS on E. fetida. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.     

Soil pH effects on the comparative toxicity of dissolved zinc,non-nano and nano ZnO to the earthworm Eisenia fetida

To determine how soil properties influence nanoparticle (NP) fate, bioavailability and toxicity, this study compared the toxicity of nano zinc oxide (ZnO NPs), non-nano ZnO and ionic ZnCl₂ to the earthworm Eisenia fetida in a natural soil at three pH levels. NP characterisation indicated that reaction with the soil media greatly controls ZnO properties. Three main conclusions were drawn. First that Zn toxicity, especially for reproduction, was influenced by pH for all Zn forms. This can be linked to the influence of pH on Zn dissolution. Secondly, that ZnO fate, toxicity and bioaccumulation were similar (including relationships with pH) for both ZnO forms, indicating the absence of NP-specific effects. Finally, earthworm Zn concentrations were higher in worms exposed to ZnO compared to ZnCl₂, despite the greater toxicity of the ionic form. This observation suggests the importance of considering the relationship between uptake and toxicity in nanotoxicology studies.     

Responses of Daphnia magna to pulsed exposures of arsenic

Research on the toxicity of arsenic has focused on sublethal effects that do not provide sufficient information for risk estimation. While most studies have focused on organism response to constant arsenic exposures, organisms in nature are exposed to fluctuating As concentrations. Consequently, results obtained from standardized bioassays with constant exposures may not adequately characterize risk to indigenous biota. This research was designed to characterize the response of Daphnia magna to fluctuating arsenic exposures during 21-day experiments. At concentrations > or =3000 microg/L As, 21-day pulsed exposure mortality increased as a function of exposure concentration and duration. In addition, 21-day pulsed exposure mortality increased with increasing recovery time. Pulsed As exposure did not affect the growth of D. magna over 21 days. Twenty-one day accumulative reproduction of D. magna was only affected by pulsed exposures of high As concentration and long durations.     

Effect of temperature on heavy metal toxicity to earthworm Lumbricus terrestris (Annelida: Oligochaeta)

Earthworms (Lumbricus terrestris) acclimated at 2 degrees C above their habitat temperature (10-12 degrees C) showed about 5% increase in basal rate of oxygen consumption, which increased to about 38% in 14-16 degrees C- and 40% in 16-18 degrees C-, but decreased by 84% in 20-22 degrees C-acclimated worms. Temperature also increased the blood hemoglobin (Hb) concentration, which decreased slightly in 20-22 degrees C-acclimated worms. The worms acclimated at 20-22 degrees C showed their blood to be hypovolemic than that of 10-12 degrees C worms indicating dehydration. Pre-exposure of 10-14 degrees C-acclimated worms to sublethal concentrations of zinc, copper, and lead did not significantly affect the rate of respiration. However, at higher temperatures all these metals inhibited oxygen consumption; zinc, lead, and cadmium by approximately 11% and copper by approximately 18% of that at 14-16 degrees C. At 20-22 degrees C, the respiration was further inhibited, 36% by copper, 18% by cadmium, and approximately 10% by lead and zinc. Copper, lead, and zinc decreased the temperature-enhanced increase in blood Hb concentration at all temperatures. In 20-22 degrees C-acclimated worms heavy metal exposure slightly lowered the oxygen affinity of Hb as well as caused shifts in carbon monoxide difference spectra. The acute toxicity of these metals was not affected by a 2 degrees C rise in acclimation temperature but increased by 17% (lead), 33% (copper), and 5% (zinc) in 14-16 degrees C- and by 40% (lead), 149% (copper), and 132% (zinc) in 20-22 degrees C-acclimated worms. The increase in toxicity of metals caused by high temperatures may be due to limiting the scope of aerobic metabolism (oxygen extraction, transport, and utilization) via quantitative and qualitative effects on Hb. This terrestrial species appears to be tolerant of slight increases in habitat temperature, such as that expected with current global climate change.     

蚯蚓纤溶酶的纯化及pH值、温度和胰蛋白酶对其纤溶活性的影响

目的纯化并鉴定蚯蚓纤溶酶 ,研究pH、温度和胰蛋白酶对其纤溶活性的影响。方法以赤子爱胜蚓为材料 ,采用硫酸铵盐析、DEAESepharoseCL 6B离子交换色谱、SephadexG 75凝胶过滤和制备电泳等分离技术纯化蚯蚓纤溶酶 ;利用纤维平板和聚丙烯酰胺凝胶电泳研究pH、温度和胰蛋白酶对蚯蚓纤溶酶纤溶活性的影响。结果分离得到纤溶酶 4种单一组分 :EFE 1、EFE 2、EFE 3、EFE 4 ;分子量分别为 2 70 0 0、2 80 0 0、2 30 0 0、330 0 0 ;4种组分对温度的适应范围较广 ;pH值对其纤溶活性的影响不尽相同 ,但都在pH低于 1.5时纤溶活性完全丧失 ;胰蛋白酶对纤溶酶 4种组分均无降解作用 ,对其纤溶活性无影响。结论纤溶酶口服药制剂宜制成肠溶型     

Effect of triclosan on reproduction,DNA damage and heat shock protein gene expression of the earthworm Eisenia fetida

Triclosan (TCS) is released into the terrestrial environment via the application of sewage sludge and reclaimed water to agricultural land. More attention has been paid to its effect on non-target soil organisms. In the present study, chronic toxic effects of TCS on earthworms at a wide range of concentrations were investigated. The reproduction, DNA damage, and expression levels of heat shock protein (Hsp70) gene of earthworms were studied as toxicity endpoints. The results showed that the reproduction of earthworms were significantly reduced (p < 0.05) after exposure to the concentrations ranges from 50 to 300 mg kg^?1, with a half-maximal effective concentration (EC₅₀) of 142.11 mg kg^?1. DNA damage, detected by the comet assay, was observed and there was a clear significant (R² = 0.941) relationship between TCS concentrations and DNA damage, with the EC₅₀ value of 8.85 mg kg^?1. The expression levels of Hsp70 gene of earthworms were found to be up-regulated under the experimental conditions. The expression level of hsp70 gene increased, up to about 2.28 folds that in the control at 50 mg kg^?1. The EC₅₀ value based on the Hsp70 biomarker was 1.79 mg kg^?1. Thus, among the three toxicity endpoints, the Hsp70 gene was more sensitive to TCS in soil.     

Uptake route and resulting toxicity of silver nanoparticles in Eisenia fetida earthworm exposed through Standard OECD Tests

Ecotoxicology - Despite the increasing interest in silver nanoparticles toxicity still few works dealt with the hazards of nanosized Ag in soils (either dissolved in pore water or coupled to...     

Interaction of citrate‐coated silver nanoparticles with earthworm coelomic fluid and related cytotoxicity in Eisenia andrei

Understanding the interaction of nanoparticles with biological fluid is important for predicting the behavior and toxicity of nanoparticles in living systems. The earthworm Eisenia andrei was exposed to citrate‐coated silver nanoparticles (cAgNPs), and the interaction of cAgNPs with earthworm coelomic fluid (ECF), the cytotoxicity of cAgNPs in earthworm coelomocytes was assessed. The neutral red retention assay showed a reduction in lysosomal stability after exposure. The toxicity of silver ions dissolved from cAgNPs in the soil medium was not significant. The aggregation and dissolution of cAgNPs increased in ECF, which contains various electrolytes that alter the properties of nanoparticles, and their subsequent toxicity. Microscopic and dissolution studies demonstrated that the aggregation of cAgNPs rapidly increased, and readily dissolved in ECF. The bioavailability of cAgNPs to earthworms induced lysosomal cytotoxicity. This is the first report to test the interaction and lysosomal cytotoxicity of nanoparticles in earthworm biofluids. Copyright © 2014 John Wiley & Sons, Ltd.     

Developmental toxicity assessment of arsenic acid in mice and rabbits

To evaluate potential effects of exposure to inorganic arsenic throughout major organogenesis, CD-1 mice and New Zealand White rabbits were gavaged with arsenic acid dosages of 0, 7.5, 24, or 48 mg/kg/d on gestation days (GD) 6 through 15 (mice) or 0, 0.19, 0.75, or 3.0 mg/kg/d on GD 6 through 18 (rabbits) and examined at sacrifice (GD 18, mice; GD 29, rabbits) for evidence of toxicity. Two high-dose mice died, and survivors at the high and intermediate doses had decreased weight gains. High-dose-group fetal weights were decreased; no significant decreases in fetal weight or increases in prenatal mortality were seen at other dosages. Similar incidences of malformations occurred in all groups of mice, including controls. At the high dose in rabbits, seven does died or became moribund, and prenatal mortality was increased; surviving does had signs of toxicity, including decreased body weight. Does given lower doses appeared unaffected. Fetal weights were unaffected by treatment, and there were no effects at other doses. These data revealed an absence of dose-related effects in both species at arsenic exposures that were not maternally toxic. In mice, 7.5 mg/kg/d was the maternal No-Observed-Adverse-Effect-Level (NOAEL); the developmental toxicity NOAEL, while less well defined, was judged to be 7.5 mg/kg/d. In rabbits, 0.75 mg/kg/d was the NOAEL for both maternal and developmental toxicity.     

Effect of silver nanoparticle surface coating on bioaccumulation and reproductive toxicity in earthworms (Eisenia fetida)

Abstract

The purpose of this study was to investigate the effect of surface coating on the toxicity of silver nanoparticles (Ag NPs) soil. Earthworms (Eisenia fetida) were exposed to AgNO₃ and Ag NPs with similar size ranges coated with either polyvinylpyrrolidone (hydrophilic) or oleic acid (amphiphilic) during a standard sub-chronic reproduction toxicity test. No significant effects on growth or mortality were observed within any of the test treatments. Significant decreases in reproduction were seen in earthworms exposed to AgNO3, (94.21 mg kg^-1) as well as earthworms exposed to Ag NPs with either coating (727.6 mg kg^-1 for oleic acid and 773.3 mg kg^-1 for polyvinylpyrrolidone). The concentrations of Ag NPs at which effects were observed are much higher than predicted concentrations of Ag NPs in sewage sludge amended soils; however, the concentrations at which adverse effects of AgNO₃ were observed are similar to the highest concentrations of Ag presently observed in sewage sludge in the United States. Earthworms accumulated Ag in a concentration-dependent manner from all Ag sources, with more Ag accumulating in tissues from AgNO₃ compared to earthorms exposed to equivalent concentrations of Ag NPs. No differences were observed in Ag accumulation or toxicity between earthworms exposed to Ag NPs with polyvinylpyrrolidone or oleic acid coatings.