Phytoremediation potential of charophytes: Bioaccumulation and toxicity studies of cadmium, lead and zinc

The ability for usage of common freshwater charophytes,Chara aculeolata and Nitella opaca in removal of cadmium (Cd),lead (Pb) and zinc (Zn) from wastewater was examined.C.aculeolata and N.opaca were exposed to various concentrations of Cd (0.25 and 0.5 mg/L),Pb (5 and 10 mg/L) and Zn (5 and 10 mg/L) solutions under hydroponic conditions for 6 days.C.aculeolata was more tolerant of Cd and Pb than N.opaca.The relative growth rate of N.opaca was drastically reduced at high concentrations of Cd and Pb although both were tolerant of Zn.Both macroalgae showed a reduction in chloroplast,chlorophyll and carotenoid content after Cd and Pb exposure,while Zn exposure had little effects.The bioaccumulation of both Cd and Pb was higher in N.opaca (1544.3 μg/g at 0.5 mg/L Cd,21657.0 μg/g at 10 mg/L Pb) whereas higher Zn accumulation was observed in C.aculeolata (6703.5 μg/g at 10 mg/L Zn).In addition,high bioconcentration factor values (> 1000) for Cd and Pb were observed in both species.C.aculeolata showed higher percentage of Cd and Pb removal (> 95%) than N.opaca and seemed to be a better choice for Cd and Pb removal from wastewater due to its tolerance to these metals.     

Using lysosomal membrane stability of haemocytes in Ruditapes philippinarum as a biomarker of cellular stress to assess contamination by caffeine, ibuprofen, carbamazepine and novobiocin

Although pharmaceuticals have been detected in the environment only in the range from ng/L to g/L, it has been demonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability (LMS) has previously been applied as an indicator of cellular well-being to determine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay (NRRA). Clams were exposed in laboratory conditions to caffeine (0.1, 5, 15, 50 μg/L), ibuprofen (0.1, 5, 10, 50 μg/L), carbamazepine and novobiocin (both at 0.1, 1, 10, 50 μg/L) for 35 days. Results show a dose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassay was significantly reduced by 50% after exposure to environmental concentrations (p < 0.05) (caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L), compared to controls. Clams exposed to these pharmaceuticals were considered to present a diminished health status (retention time < 45 min), significantly worse than controls (96 min) (p < 0.05). The predicted no environmental effect concentration (PNEC) results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.     

Histological observation on unique phenotypes of malformation induced in Xenopus tropicalis larvae by tributyltin

Tributyltin (TBT), a biocide used in antifouling paints, has shown strong teratogenic effects on Xenopus tropicalis embryos at environmentally relevant concentrations. X. tropicalis embryos were exposed to 50, 100 and 200 ng/L tributyltin chloride for 72 hr. The histological changes were further observed on abnormal eyes, enlarged trunks, enlarged proctodaeums and absence of fins induced by TBT. The lens and the retinal layers of abnormal eyes were slightly or barely differentiated, and that the pigment epithelium was neither continuous nor smooth. The abdomens were full of undifferentiated gut tissue with yolk-rich inclusions in the tadpoles with enlarged trunks. The proctodaeums formed a bump-like or columnar structure. The mass of yolk-rich cells occupied the lumen, blocked the opening and even turned inside out of the proctodaeum. Both the ventral and dorsal fins in trunks and tails became narrow or even disappeared totally. Our results suggest that great changes of histology took place corresponding to the unique phenotypes. The gut tissue was poorly differentiated, which led to the failed elongation of the guts and subsequently the enlarged trunks. The enlarged proctodaeums were due to the undifferentiation of inner layer, the expansion of outer epidermal part and the absence of fins around them. In brief, the histological observations provided insights into the reason of the unique external malformations in some degree.     

球形红假单胞菌对三苯基锡的降解性能研究

以1株对三苯基锡(triphenyltin,TPT)有高耐受性的球形红假单胞菌(Rhodopseudomonos spheroids)X-5为对象,进行TPT的微生物降解实验,研究了R.spheroids对TPT降解特性.结果表明,R.spheroids对TPT有良好降解效果.30℃是其最佳生长温度,对TPT的降解活性...     

Effects of phenanthrene on hepatic enzymatic activities in tilapia (Oreochromis niloticus♂×O. aureus♀)

The effects of phenanthrene (Phe) on hepatosomatic index (HSI) and hepatic enzymatic activities in hybrid tilapia (Oreochromis niloticus O. aureus ) were investigated via the static freshwater exposure at dosage of 50, 100, and 400 g/L for 4–14 d. Compared with the control group, HSI was significantly decreased (P < 0.05) at 400 g/L at day 14. Increased enzymatic activities (P < 0.05) were observed for catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) at either 100 or 400 g/L at day 8 and 14, as well as for CAT at 50 g/L at day 14, except for GPx at 400 g/L at day 8. Ethoxyresorufin O-deethylase (EROD) activity was significantly increased (P < 0.05) at all dosage at day 4 as well as at 50 g/L at day 8, but significantly decreased at either 100 or 400 g/L at day 14 (P < 0.05). Glutathione-S-transferase (GST) activity was not a ected. The results suggest that CAT, GPx, SOD and EROD, as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons (PAHs) such as Phe.     

海水中原油对双齿围沙蚕(Perinereis aibuhitensis)的急性毒性效应及其体内抗氧化酶活性的影响

近年来海洋溢油事故频发,增加了溢油污染对海洋生物及海洋生态系统的暴露风险.为阐明海洋溢油事故对海洋生物的毒性效应,以双齿围沙蚕（Perinereis aibuhitensis）为受试生物,研究了不同质量浓度的海水原油溶液对双齿围沙蚕的急性毒性效应及抗氧化酶活性的影响.结果表明:双齿围沙蚕的死亡率与海水中原油暴露浓度呈正相关,暴露24、48及72 h的LC₅₀（半致死浓度）分别为13.08、9.80和8.37 g/L;暴露72 h后,双齿围沙蚕组织液中MDA（丙二醛）的含量均高于对照组,其中1.0 g/L暴露组显著高于对照组（P < 0.05）,且随暴露浓度的增大而升高;GST（谷胱甘肽巯基转移酶）的活性被显著诱导,且随暴露浓度的增大而升高;0.1 g/L原油暴露下,CAT（过氧化氢酶）和SOD（超氧化物歧化酶）的活性被显著诱导,当暴露浓度达到0.5 g/L时,CAT的诱导程度减弱,而SOD则受到抑制.研究显示,海水中的原油对双齿围沙蚕具有显著急性毒性效应,且0.1 g/L的原油暴露即可导致双齿围沙蚕产生脂质过氧化,脂质过氧化程度随暴露浓度的升高而增强;0.1 g/L原油暴露能显著诱导双齿围沙蚕体内抗氧化酶的活性,且随着海水中原油暴露浓度的增加,GST的诱导程度增强,CAT的诱导程度减弱,SOD的活性则受到抑制.      

Effects of nitrogen and phosphorus concentrations on the bioaccumulation of polybrominated diphenyl ethers by Prorocentrum donghaiense

The growth, cellular total lipids, bioaccumulation amount, and bioaccumulation factors (BAFs) of 2,4,4 ′ -tribromodiphenyl ether (BDE28), 2,2 ′ ,4,4 ′ -tetrabromodiphenyl ether (BDE47), and 2,2 ′ ,4,4 ′ ,5-pentabromodiphenyl ether (BDE99) in a semi-continuous culture of Prorocentrum donghaiense were studied in relation to nitrate (0, 128, and 512 μmol/L) and phosphate (0, 8, and 32 μmol/L) concentrations. The BDE28, BDE47, and BDE99 content per cell under 0 μmol N/L were 3.77 × 10 6 , 3.95 × 10 6 , and 4.32 × 10 6 ng/cell, respectively, which were significantly higher than those under 128 and 512 μmol N/L. A nearly 5-fold increase in polybrominated diphenyl ether (PBDE) content per algal cell was found between 0 and 8 μmol P/L and between 8 and 32 μmol P/L. With increasing N and P concentrations, the PBDE content per volume of algal culture and the accumulation percentage of available PBDEs declined slightly. The BAFs for the PBDEs based on lipids showed that the logBAF lip under 0 μmol N/L was higher than those under 128 and 512 μmol N/L. The logBAF lip under 0 μmol P/L was higher than that under 8 μmol P/L but lower than that under 32 μmol P/L. Correlation analysis indicated a significant negative correlation between nutrient concentration and cellular total lipids, as well as the PBDE content per cell. The results indicate that different N and P concentrations change the total lipids content of P. donghaiense, thereby resulting in varying PBDE accumulation.     

重金属对秀丽隐杆线虫繁殖的影响

为了探究重金属单独及联合暴露对秀丽隐杆线虫(Caenorhabditis elegans)繁殖的影响及其作用机制,采用96孔板液相暴露试验,以环境相关浓度(0.1~50.0 μg/L)的Cd、Hg、Pb暴露同步化处理秀丽隐杆线虫,24 h后统计其怀卵数及阴门畸形率,以及连续记录72 h内子一代秀丽隐杆线虫的个体数,最后利用2×2析因设计方差分析阐明重金属的两两联合作用模式. 结果表明:与对照组相比,Cd、Hg、Pb单独及联合暴露对秀丽隐杆线虫的繁殖具有显著抑制作用,ρ(Cd)为50.0 μg/L、ρ(Hg)为10.0 μg/L、ρ(Pb)为50.0 μg/L暴露组秀丽隐杆线虫子一代数量分别降低了43.5%、33.8%、51.0%;Cd-Hg暴露组〔当ρ(Cd)、ρ(Hg)分别为50.0、10.0 μg/L时〕、Hg-Pb暴露组〔当ρ(Hg)、ρ(Pb)分别为10.0、50.0 μg/L时〕、Cd-Pb暴露组〔当ρ(Cd)、ρ(Pb)分别为50.0、50.0 μg/L时〕秀丽隐杆线虫子一代个体数分别降低了44.7%、61.0%、53.3%. 进一步研究发现,Cd、Hg、Pb单独及联合暴露会引起秀丽隐杆线虫子宫内受精卵数量降低以及产卵器阴门结构畸形率升高. 2×2析因设计方差分析结果发现,Cd、Hg、Pb两两联合暴露对秀丽隐杆线虫的繁殖表现为没有交互作用或者交互方式为拮抗. 研究显示,秀丽隐杆线虫子宫内怀卵数的降低是其子一代数量显著减少的主要原因,而阴门结构的损伤可能使产卵行为受损,从而进一步加剧重金属对秀丽隐杆线虫繁殖的抑制作用.      

Chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin

With the increasing use of synthetic pyrethroids (SPs), the significance of ecological safety and health risk is an emerging concern. In this study, we evaluated the chronic aquatic toxicity of cis-bifenthrin (cis-BF) in Daphnia magna and its cytotoxicity in Chinese hamster ovary (CHO) cells as well as human cervical carcinoma (Hela) cells. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 μg/L, respectively, and the chronic value was 0.014 μg/L. The intrinsic rate of natural increase was significantly decreased (p < 0.05) to 0.02 μg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration-and time-dependent manner. The IC₅₀ values for Hela and CHO cells were 4.0 × 10⁻⁵ and 3.2 × 10⁻⁵ mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.     

Sulfide-driven nitrous oxide recovery during the mixotrophic denitrification process

We propose a novel sulfide-driven process to recover N₂O during the traditional denitrification process. The optimum initial sulfide concentration was 120 mg/L, and the N₂O percentage in the gaseous products (N₂O+N₂) was up to 82.9%. Moreover, sulfide involved in denitrification processes could substitute for organic carbon as an electron donor, e.g., 1 g sulfide was equivalent to 0.5-2 g COD when sulfide was oxidized to sulfur and sulfate. The accumulation of N₂O was mainly due to the inhibiting effect of sulfide on nitrous oxide reductase (N₂OR), which was induced by the supply insufficiency of electrons from cytochrome c (cyt c) to N₂OR. When the initial sulfide concentration was 120 mg/L, the N₂OR activity was only 36.8% of its original level. According to the results of cyclic voltammetry, circular dichroism spectra and fluorescence spectra, significant changes in the conformations and protein structures of cyt c were caused by sulfide, and cyt c completely lost its electron transport capacity. This study provides a new concept for N₂O recovery driven by sulfide in the denitrification process. In addition, the findings regarding the mechanism of the inhibition of N₂OR activity have important implications both for reducing emissions of N₂O and recovering N₂O in the sulfide-driven denitrification process.     

A flow cytometer based protocol for quantitative analysis of bloom-forming cyanobacteria (Microcystis) in lake sediments

A quantitative protocol for the rapid analysis of Microcystis cells and colonies in lake sediment was developed using a modified flow cytometer, the CytoSense. For cell enumeration, diluted sediment samples containing Microcystis were processed with sonication to disintegrate colonies into single cells. An optimized procedure suggested that 5 mg dw (dry weight)/mL dilution combined with 200 W × 2 min sonication yielded the highest counting efficiency. Under the optimized determination conditions, the quantification limit of this protocol was 3.3×10⁴ cells/g dw. For colony analysis, Microcystis were isolated from the sediment by filtration. Colony lengths measured by flow cytometry were similar to those measured by microscopy for the size range of one single cell to almost 400 μupm in length. Moreover, the relationship between colony size and cell number was determined for three Microcystis species, including Microcystis flos-aquae, M. aeruginosa and M. wessenbergii. Regression formulas were used to calculate the cell numbers in different-sized colonies. The developed protocol was applied to field sediment samples from Lake Taihu. The results indicated the potential and applicability of flow cytometry as a tool for the rapid analysis of benthic Microcystis. This study provided a new capability for the high frequency monitoring of benthic overwintering and population dynamics of this bloom-forming cyanobacterium.     

Development of indirect competitive fluorescence immunoassay for 2,2′,4,4′-tetrabromodiphenyl ether using DNA/dye conjugate as antibody multiple labels

An indirect competitive fluorescence immunoassay using a DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in aqueous samples. A hapten, 2,4,2′-tribromodiphenyl ether-4′-aldehyde, was synthesized, and was conjugated to bovine serum albumin to form a coating antigen. Specific recognition of the antigen by anti-PBDE antiserum was confirmed by a surface plasmon resonance measurement. In the immunoassay, the coating antigen was adsorbed on a 96-well plate first, and a sample, antiserum and biotinylated goat anti-rabbit secondary antibody were then added and reacted sequentially. A biotinylated, double-stranded DNA with 219 base pairs was attached to the secondary antibody by using streptavidin as a molecular bridge. In situ multiple labeling of the antibody was accomplished after addition of a DNA-binding fluorescent dye, SYBR Green I. The working range of the immunoassay for the BDE-47 standard was 3.1-390 μg/L, with an IC₅₀ value of 15.6 μg/L. The calculated LOD of the immunoassay is 0.73 μg/L. The immunoassay demonstrated relatively high selectivity for BDE-47, showing very low cross-reactivity (< 3%) with BDE-15, BDE-153 and BDE-209. With a spiked river water sample containing 50 μup g/L BDE-47, quantification by the immunoassay was 41.9 μg/L, which compared well with the standard GC-ECD method (45.7 μg/L). The developed immunoassay provides a rapid screening tool for polybrominated diphenyl ethers in environmental samples.     

Effect of cadmium on photosynthetic pigments, lipid peroxidation, antioxidants, and artemisinin in hydroponically grown Artemisia annua

The effects of different cadmium (Cd) concentrations (0, 20, 60, and 100 μmol/L) on hydroponically grown Artemisia annua L. were investigated. Cd treatments applied for 0, 4, 12, 24, 72, 144, 216, and 336 hr were assessed by measuring the changes in photosynthetic pigments, electrolyte leakage, malondialdehyde (MDA) and antioxidants (ascorbic acid and glutathione), while the artemisinin content was tested after 0, 12, 144, 216, and 336 hr. A significant decrease was observed in photosynthetic pigment levels over time with increasing Cd concentration. Chlorophyll b levels were more affected by Cd than were chlorophyll a or carotenoid levels. The cell membrane was sensitive to Cd stress, as MDA content in all treatment groups showed insignificant differences from the control group, except at 12 hr treatment time. Ascorbic acid (AsA) content changed slightly over time, while glutathione (GSH) content took less time to reach a maximum as Cd concentration increased. Cd was found to promote synthesis and accumulation of artemisinin, especially at concentrations of 20 and 100 μmol/L. In conclusion, Cd stress can damage to photosynthetic pigments, and vigorously growing A. annua showed a strong tolerance for Cd stress. Appropriate amounts of added Cd aided synthesis and accumulation of artemisinin.     

柱孢藻毒素对草鱼淋巴细胞毒效应及氧化损伤机理研究

针对淡水水体拟柱孢藻水华产生的柱孢藻毒素,以我国典型食用鱼种草鱼(Ctenophar yngodon idellus)为实验材料,研究了其对鱼体免疫细胞毒效应及机理.结果表明,随着体外暴露剂量的增加,草鱼淋巴细胞活性逐渐降低,暴露24h后100μg·L-1柱孢藻毒素诱导组细胞活性仅为对照组的20%;对诱导组淋巴细胞的DNA检测发现呈现阶梯状电泳的典型细胞凋亡特征;应用流式细胞仪进一步检测了细胞凋亡率,表明1～100μg·L-1柱孢藻毒素均能够诱导细胞凋亡,并且其凋亡毒效应呈现明显的时间-效应和剂量-效应关系;诱导12h后,氧化应激产物活性氧(ROS)和丙二醛(MDA)含量均明显上升,100μg·L-1柱孢藻毒素诱导组ROS含量为对照组的2.5倍,MDA含量为对照组的2倍,诱导24h后,1、10、50和100μg·L-1实验组氧化应激产物含量仍然明显上升,这说明氧化应激是柱孢藻毒素导致草鱼淋巴细胞DNA损伤的重要原因;RT-PCR技术对重要凋亡基因的检测表明,1～100μg·L-1实验组凋亡促进基因Bax表达显著增强(p<0.05),50和100μg·L-1高剂量组凋亡抑制基因Bcl-2表达显著降低(p<0.01).本研究从细胞水平揭示柱孢藻毒素对草鱼免疫细胞具有明显的毒性,该毒效应通过氧化应激介导的DNA损伤表现,凋亡是柱孢藻毒素对草鱼免疫细胞毒性的主要机制.     

太湖双酚A的水质基准研究及风险评价

水质基准是制定水质标准的重要科学依据,制定符合我国实际情况的水质基准已成为当前的迫切需求.BPA（bisphenol A,双酚A）是一种典型的内分泌干扰物,基于太湖流域的人群暴露参数和生物累积系数,采用HJ 837-2017《人体健康水质基准制定技术指南》推荐方法,推导出太湖BPA的人体健康水质基准为0.738 μg/L,通过太湖儿童暴露参数得到保护儿童BPA的人体健康基准为0.628 μg/L（6~ < 9岁）、0.821 μg/L（9~ < 12岁）、0.620 μg/L（12~ < 15岁）,与成人基准差异不大.基于太湖流域水生生物的毒性数据,采用SSD（species sensitivity distribution,物种敏感度分布）法得到水生生物慢性基准为0.189 μg/L.使用RQ（risk quotient,风险商值）法评价太湖水体中BPA暴露所造成的健康与生态风险,结果表明,太湖中有0.03%区域面积水体存在较高健康风险,有2.03%区域面积水体存在较高的生态风险.另外,采用联合概率曲线法进一步分析生态风险发现,太湖水体中BPA对1%与5%的水生生物造成危害的概率分别为0.71%和0.33%.研究显示,我国太湖水体中BPA暴露造成的健康与生态风险处于可接受水平.      

巢湖沉积物有效磷的原位高分辨分析研究

将两种原位被动采样技术——高分辨平衡式间隙水(HR-Peeper)与氧化锆薄膜梯度扩散技术(Zr-oxide DGT)相结合,分别对巢湖西半湖7个点位溶解态反应性磷(cPW)和有效磷(cDGT)进行原位测定分析,cPW和cDGT在大部分沉积物剖面的分布相似或局部相似,说明不同深度沉积物固相有效磷组分对间隙水SRP的缓冲能力较接近.利用界面扩散通量和cDGT/cPW比值(R)表征沉积物磷的活性,从巢湖湖心向南淝河入湖口方向,界面以下6 mm的cPW、cDGT和扩散通量的变化基本一致,均呈递增趋势,表明沉积物磷的污染水平在增加;R值变化较小,说明沉积物界面处的缓冲能力差异不明显.     

Characterization of Methylocystis strain JTA1 isolated from aged refuse and its tolerance to chloroform

To accelerate the efficiency of methane biodegradation in landfills,a Gram-negative,rod-shaped,non-motile,non-spore-forming bacterium,JTA1,which can utilize methane as well as acetate,was isolated from the Laogang MSW landfills,Shanghai,China.Strain JTA1 was a member of genus Methylocystis on the basis of 16S rRNA and pmoA gene sequence similarity.The maximum specific cell growth rates(μmax=0.042 hr-1,R2=0.995) was derived through Boltzmann simulation,and the apparent half-saturation constants(Km(app)=7.08mmol/L,R2=0.982) was calculated according to Michaelis-Menton hyperbolic model,indicating that Methylocystis strain JTA1 had higher-affinity potential for methane oxidation than other reported methanotrophs.By way of adding the strain JTA1 culture,the methane consumption of aged refuse reached 115mL,almost two times of control experiment.In addition,high tolerance of Methylocystis strain JTA1 to chloroform could facilitate the methane oxidation of aged refuse bio-covers.At the chloroform concentration of 50mg/L,the methane-oxidation rate of bio-cover reached 0.114mL/(day·g),much higher than the highest rate,0.0135mL/(day·g),of reported bio-covers.In conclusion,strain JTA1 opens up a new possibility for environmental biotechnology,such as soil or landfills bioremediation and wastewater decontamination.     

环境浓度下邻苯二甲酸二乙酯对秀丽隐杆线虫的生态毒理效应

DEP (diethyl phthalate,邻苯二甲酸二乙酯)是一种在环境中普遍存在的具有潜在神经和生殖毒性的增塑剂,其会干扰环境生物的发育水平、运动行为及生化水平.以秀丽隐杆线虫的体长、体宽、头部摆动频率及生化指标作为测试终点,评估环境中DEP对秀丽隐杆线虫的生态毒理效应.在不同环境浓度(0、0.000 2、0.002、0.02、0.2、2 mg/L)的DEP溶液中,对秀丽隐杆线虫进行不同时间(24 h、72 h和10 d)的暴露试验.结果表明:①在不同浓度DEP溶液中暴露24 h后,秀丽隐杆线虫的发育水平均未受到显著影响(P>0.05).②在不同浓度DEP溶液中暴露72 h后,秀丽隐杆线虫的发育水平受到干扰.与对照组相比,在DEP浓度最高(2 mg/L)时,秀丽隐杆线虫体长下降了3.21%(P < 0.05);在DEP浓度为0.000 2 mg/L时,秀丽隐杆线虫的体宽呈上升趋势,且头部摆动频率明显加快了5.52%(P < 0.01),秀丽隐杆线虫的发育水平受到显著抑制.③在不同浓度DEP溶液中暴露10 d后,与对照组相比,秀丽隐杆线虫的体长、体宽和头摆频率均出现下降;在DEP浓度为2 mg/L时,秀丽隐杆线虫体内活性氧自由基、脂褐素和细胞凋亡水平累积均增长显著,出现氧化应激损伤.研究显示,不同环境浓度的DEP溶液会对秀丽隐杆线虫产生一定的毒性影响,且不同暴露时间和暴露浓度产生的毒性影响也存在一定差异.      

有机锡化合物对萝卜螺的毒性作用

研究了氯化三丁基锡（ＴＢＴ）对折叠萝卜螺Ｒａｄｉｘｐｌｉｃａｔｕｌａ的毒性作用,结果表明,ＴＢＴ对萝卜螺的９６ｈ半数数致死浓度（ＬＣ５０）为１．１７μｇ／Ｌ,在４０ｄ中,ＴＢＴ对萝卜螺放卵量的ＥＣ５０为０．１０μｇ／Ｌ,螺卵孵化率的ＬＣ５０为０．１７μｇ／Ｌ。     

混合抗生素对铜绿微囊藻的生物效应

选取SP(螺旋霉素)和AM(阿莫西林)为目标化合物,研究二者的混合物对铜绿微囊藻的生长、Chla(叶绿素a)合成及微囊藻毒素合成与释放的影响. 结果表明:SP与AM以等毒性〔ρ(SP)∶ρ(AM)为1∶7,ρ(SP+AM)为4~15 μg/L〕混合时,铜绿微囊藻的生长及Chla的合成均受到抑制,并且ρ(SP+AM)越高,抑制作用越明显,在ρ(SP+AM)为15 μg/L时生长抑制率最大,为109.86%;SP与AM以等浓度〔ρ(SP)∶ρ(AM)为1∶1,ρ(SP+AM)为1~10 μg/L〕混合,ρ(SP+AM)≤4 μg/L时促进铜绿微囊藻的生长,ρ(SP+AM)为1 μg/L时促进作用最明显,铜绿微囊藻的比生长率高出对照组39.13%;ρ(SP+AM)≥5 μg/L时则抑制铜绿微囊藻生长;而Chla的合成在各试验浓度下均受到抑制. SP与AM对铜绿微囊藻的联合毒性表现为拮抗作用. 混合抗生素在各试验浓度和混合配比条件下,均导致藻细胞内藻毒素合成量的上升,并引起胞外藻毒素的释放量增加,ρ(SP)∶ρ(AM)为1∶7且ρ(SP+AM)为5 μg/L组释放比例最高,达到37.96%. 因此,混合抗生素的存在可导致铜绿微囊藻对水环境的危害进一步加深.