藻类水体Cd2+毒性快速监测新方法研究

采用藻类生长抑制试验和光合活性抑制试验两种方法对蛋白核小球藻受不同浓度Cd2+胁迫作用下叶绿素浓度及藻活性荧光参数进行测量,依据Sigmoidal曲线拟合及单因素方差分析(one-way ANOVA)的方法对Cd2+不同胁迫时间下藻活性抑制率和96 h比生长率抑制率的相关性进行研究.结果表明,48、53、72、77和96 h的藻活性抑制率和96 h比生长率抑制率间具有较好的S函数关系(R2>0.95),因此可采用藻活性抑制率48 h-EC10和53 h-EC10来代替96 h的藻类半数比生长率抑制率EC50进行Cd2+藻类毒性实验评价.进一步分析了蛋白核小球藻受Cd2+胁迫48 h和53 h藻活性抑制率和Cd2+毒性当量的剂量-效应关系.该方法为实验室内单一Cd2+毒性的监测提供了一种快速有效的新方法,为水环境综合毒性预警提供了一种切实可行的方法依据.     

微小小环藻对双酚A的富集与降解

对深圳福田红树林优势藻种微小小环藻(Cyclotella caspia)对BPA的生物富集与降解进行了研究.结果显示,微小小环藻对BPA具有较弱的富集能力,当BPA浓度为6.00、8.00、10.00 mg·L-1时,藻细胞在16d时分别达到最大富集量0.01、0.13、0.14 mg·g-1和最大生物富集系数(BCF)0.15%、1.18%、0.16%.微小小环藻对BPA亦具有一定的降解能力,浓度为6.00、8.00、10.00 mg·L-1的BPA在16d内分别有22.39%、36.44%和10.28%被藻降解,日平均生物降解量分别为0.08、0.18和0.06 mg·L-1.     

Sensitivity of green and blue-green algae to methyl tert-butyl ether

The toxicity of methyl tert-butyl ether (MTBE) to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high (2.00×104 mg/L) to low (2 mg/L). The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00×104-2.00×104 mg/L (the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5). Low concentrations (2-500 mg/L) stimulated algal growth up to the greatest effect of 85%-200% w...     

直链烷基苯磺酸钠(LAS)的可生物处理性及其对大型溞毒性的试验研究

合成洗涤剂是现代化学工业发展的重要产物之一,它广泛应用于家庭和工业部门,近年来我国合成洗涤剂工业迅猛发展,1986年总产量已达115万吨,居世界第二位。我国目前生产的洗涤剂中LAS占有较大比重。从世界发展趋势看,在今后相当的一段时期内,LAS仍是使用和发展的重点。因此,必须对LAS给水环境带来的污染及其潜在危害要有高度的重视,并采取相应的有效措施,以控制     

蛋白核小球藻与DEP的相互作用

运用评价化学品对藻类毒性的标准实验方法,得出邻苯二甲酸二乙酯抑制蛋白核小球藻生长的９６ｈＥＣ５０为８０ｍｇ／Ｌ。实验结果表明,蛋白核小球藻对ＥＤＰ有明显的富集与降解作用,富集量和浓缩系数（ＢＣＦ）都在１２ｈ达到最大,分别为９．８ｍｇ／ｇ和２０５。此后富集量随时间的延长而逐渐降低,９６ｈ降到１．８ｍｇ／ｇ。ＢＣＦ在７２ｈ内也随时间的延长而逐渐减小,并在７２ｈ降到最小８０,７２ｈ以后又随时间的延长而升     

铜、锌和锰抑制蛋白核小球藻生长的毒性效应

运用评价化学品毒性藻类测试的标准实验方法 ,得到铜、锌和锰对蛋白核小球藻生长的安全浓度分别为31.8μg/L、65.0μg/L和 5.5mg/L ,抑制蛋白核小球藻生长的 96h EC₅₀ 分别为 67.3μg/L、473.0 μg/L和 17.0mg/L .实验结果表明无论从安全浓度还是从 96h EC₅₀ 考虑 ,都证明抑制蛋白核小球藻生长的毒性由大到小的顺序是铜 >锌 >锰 .不同金属离子与藻细胞的不同亲和性是导致金属离子抑制蛋白核小球藻生长毒性差异的主要原因 .     

Comparative cytotoxicity of nanoparticles and ions to Escherichia coli in binary mixtures

The objective of this study was to understand toxicity of mixture of nanoparticles (NPs) (ZnO and TiO₂) and their ions to Escherichia coli. Results indicated the decrease in percentage growth of E. coli with the increase in concentration of NPs both in single and mixture setups. Even a small concentration of 1 mg/L was observed to be significantly toxic to E. coli in binary mixture setup (exposure concentration: 1 mg/L ZnO and 1 mg/L TiO₂; 21.15% decrease in plate count concentration with respect to control). Exposure of E. coli to mixture of NPs at 1000 mg/L (i.e., 1000 mg/L ZnO and 1000 mg/L TiO₂) resulted in 99.63% decrease in plate count concentration with respect to control. Toxic effects of ions to E. coli were found to be lesser than their corresponding NPs. The percentage growth reduction was found to be 36% for binary mixture of zinc and titanium ions at the highest concentration (i.e., 803.0 mg/L Zn and 593.3 mg/L Ti where ion concentrations are equal to the Zn ions present in 1000 mg/L ZnO NP solution and Ti^+ 4 ions present in 1000 mg/L TiO₂ NP solution). Nature of mixture toxicity of the two NPs to E. coli was found to be antagonistic. The alkaline phosphatase (Alp) assay indicated that the maximum damage was observed when E. coli was exposed to 1000 mg/L of mixture of NPs. This study tries to fill the knowledge gap on information of toxicity of mixture of NPs to bacteria which has not been reported earlier.     

藻源性黑水团环境效应:对水-沉积物界面氮磷变化的驱动作用

利用自制的静态模拟实验装置,通过连续抽取间隙水来研究藻细胞沉降在沉积物表面后对水-沉积物界面处的N、P变化的驱动作用及影响效果.结果表明,藻细胞沉降后,在50 min内就完全消耗掉水-沉积物界面处的溶解氧,同时水体出现严重的发黑、发臭现象;形成的厌氧、强还原环境,使得死亡的藻细胞在界面处发生强烈的厌氧矿化作用,界面处的水溶性PO34--P、NH 4+-N在实验的第2 d开始向上覆水中扩散,含量不断增加.至实验结束时(实验第8 d),界面处PO34--P、NH 4+-N的含量分别达到4.00 mg/L、39.45 mg/L,分别为同期对照实验样柱中的10倍和241倍(对照样柱中的PO43--P、NH 4+-N的含量分别为0.42 mg/L、0.16 mg/L).藻细胞的厌氧矿化加剧了氮磷营养盐向上覆水的扩散,在加重水体营养盐含量的同时,也为藻华的再次发生提供了物质基础.     

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。     

镉与S-异丙甲草胺对斜生栅藻的联合毒性作用

采用毒性标准实验方法研究了Cd2+与S-异丙甲草胺单独及联合作用对斜生栅藻急性毒性、总可溶性蛋白含量、超氧化物歧化酶(SOD)活性和细胞膜通透性的影响.结果表明Cd2+与S-异丙甲草胺单独作用时EC50均随时间的延长而减小,且S-异丙甲草胺的急性毒性大于Cd2+;Cd2+、S-异丙甲草胺的EC50-24h分别为0.27 mg·L-1、0.24 mg·L-1,EC50-96h分别为0.16mg·L-1、0.13 mg·L-1.Cd2+与S-异丙甲草胺联合作用时低浓度表现为协同作用,高浓度表现为拮抗作用.暴露96 h后,Cd2+与S-异丙甲草胺单独及联合作用下,随有毒物质浓度升高,斜生栅藻总可溶性蛋白含量降低,SOD酶活性先激活后抑制,细胞膜通透性逐渐增大.     

我国典型土壤中铜对白符跳(Folsomia candida)的毒性阈值及其预测模型

为确定我国土壤中Cu对白符跳的毒性阈值并建立其预测模型,以外源添加的方式研究了我国9种典型土壤（江西红壤、安徽黄棕壤、重庆紫色土、云南黄红壤、湖南水稻土、山东潮土、黑龙江黑土、新疆灰漠土、陕西垆土）中Cu对模式生物——白符跳（Folsomia candida）存活率与繁殖率的影响.结果表明:白符跳存活率对Cu毒害的敏感性远低于繁殖率.9种土壤中基于w（TCu）实测值推导的土壤Cu对白符跳繁殖率的EC₅₀（半数效应浓度）变化范围为65~668 mg/kg,表明不同土壤中Cu的毒性阈值差异显著,但基于w（Cu_Ca）（Cu_Ca为CaCl₂溶液提取的Cu）推导的不同土壤中EC₅₀的差异有所减小.相关性分析表明,基于w（TCu）实测值推导的EC₅₀值与土壤pH、w（CaCO₃）均呈显著正相关,相关系数分别为0.801和0.670.进一步利用回归分析建立了基于pH和w（OM）的土壤Cu对白符跳繁殖的EC₅₀预测模型——lg（EC₅₀）=0.213+0.288pH+0.016 w（OM）,基于该模型预测与推导的EC₅₀值之间相关性较好.研究显示,氯化钙提取态Cu的存在能在一定程度上解释不同土壤中Cu对白符跳繁殖的EC₅₀值的差异,pH和w（OM）可较好地预测不同土壤中Cu对白符跳繁殖的EC₅₀值.      

除草剂百草枯对蓝藻和绿藻的毒性

为评估除草剂百草枯对藻类生态系统的环境毒害效应,测定了百草枯对4株蓝藻:铜绿微囊藻(M.aeruginosa XW01,M.aeruginosa 7806)、平裂藻(Merismopedia sp.)、集胞藻(Synechocystis PCC 6803),以及两株绿藻:蛋白核小球藻(Chlorella pyrenoidosa)和绿球藻(Chlorococcum sp.472)的毒害效应,采用半效抑制浓度EC5o值、无观察效应浓度(NOEC)、最低观察效应浓度(LOEC)及慢性值(ChV)评价了百草枯对6株藻的毒性.结果表明:蓝藻对百草枯的敏感性显著大于绿藻,蛋白核小球藻的96 h-EC50值是铜绿微囊藻XW01的96 h-EC50值的7.4倍.百草枯毒害作用具有时间效应,暴露时间越长,毒害作用越强.     

氧化石墨烯对邻苯二甲酸二丁酯藻毒性的影响

以海洋微藻青岛大扁藻(Platymonas helgolanidica var.tingtaoensis)为受试对象,研究了氧化石墨烯(graphene oxide,GO)与邻苯二甲酸二丁酯(dibutyl phthalate,DBP)单独及共同对青岛大扁藻的急性毒性效应,考察了藻细胞的生长状况,光合色素产量,细胞通透性,氧化应激指标及扫描电镜,以探讨GO的加入对DBP藻毒性的影响.结果表明,低浓度GO(0.1~10 mg·L~(-1))对青岛大扁藻的藻密度和叶绿素产量无明显影响,但藻细胞通透性随GO浓度升高显著增加(P0.05),10mg·L~(-1)时达到空白组的2.2倍.DBP对青岛大扁藻的EC50,96 h为(11.14±0.80)mg·L~(-1),其毒性远大于GO(EC50,96 h大于100mg·L~(-1)).1 mg·L~(-1)GO的加入使DBP的EC50,96 h降低到(4.93±2.14)mg·L~(-1),低浓度GO对DBP藻毒性表现出一定的增强作用.1 mg·L~(-1)的GO加入时,对低浓度DBP组(0.1~2 mg·L~(-1))的藻密度、叶绿素产量、细胞通透性水平没有显著性影响,但加剧了高浓度DBP组(4 mg·L~(-1))对藻密度、叶绿素产量的抑制,使单个藻细胞内ROS和SOD平均增加了21%和7%.扫描电镜结果发现GO对藻细胞具有覆盖,包裹及聚集作用,这些可能是DBP藻毒性增强的主要原因.该结果为揭示新型污染物碳纳米材料对海洋生物的风险提供了数据支持.     

Allelopathic effects of gallic acid from Aegiceras corniculatum on Cyclotella caspia

High abundance of algae and eutrophication were observed in mangrove wetlands and these were estimated to be associated with root exudates of some specific mangrove plants to a certain extent.Root exudates form allelopathic effects from mangroves.The main secondary metabolites of Aegiceras corniculatum had been detected to be organic phenolic acids.Gallic acid had been isolated and identified from A.corniculatum.The half-maximal inhibitory concentration of gallic acid on alge Cyclotella caspia was tested as 15.46mg/L.The effects on algal cell morphology were mainly shown as elongated cells,with no apparent cell inclusions,such as oil droplets,chloroplast.At a dose of 2mg/L,gallic acid had a stimulative effect on the specific growth rate of algae on day 3.The contents of malondialdehyde,superoxide dismutase,soluble carbohydrates and chlorophyll a in algal cells showed an overall "low promotion and high suppression".Our results could provide preliminary and valuable reference on the complex influences of mangroves on microecology and microbial communities in the rhizosphere system.     

磷矿浮选剂S-808及其尾矿水对鱼类和胚胎的毒性

S-808是我国选矿科技工作者研制的一种新型磷矿浮选剂。湖北省荆襄磷矿矿务局王集矿,在选矿过程中采用S-808作为抑制剂直接浮选中低品位钙质磷块岩,获得特殊的选矿效果。为此化工部矿山局委托我们开展磷矿浮选剂S-808对鱼类的毒性和毒理学的研究。     

Effects of silica nanoparticles on growth and photosynthetic pigment contents of Scenedesmus obliquus

To assess the aquatic ecosystem safety for silica (SiO2) nanoparticles (NPs), the growth inhibition and photosynthetic pigment contents of Scenedesmus obliquus in logarithm growth phase exposed to SiO2 NPs and SiO2 bulk particles (BPs) suspensions were measured. SiO2 NPs with 10-20 nm diameters were found to be toxic. The 20% effective concentration (EC20) values for 72 and 96 hr were 388.1 and 216.5 mg/L, respectively. The contents of chlorophyll decreased significantly under moderate and high concentratio...     

锑对土壤跳虫(Folsomia candida)的毒性效应

为了解Sb（锑）对土壤无脊椎动物的毒性效应及对比不同类型土壤中Sb毒性的差异,选取死亡率、逃避率、繁殖数三组个体水平的评价指标研究了3种典型土壤（海伦黑土、祁阳红壤、北京潮土）中外源添加Sb对模式生物——跳虫（Folsomia candida）的急性毒性和慢性毒性效应.结果表明,基于实测w（Sb_总）求得的上述3种土壤中Sb影响跳虫逃避的2 d-EC₅₀（EC₅₀为半数效应浓度）分别为298、>431[高于土壤中最高w（Sb_总）]和132 mg/kg;影响跳虫死亡的7 d-LC₅₀（LC₅₀为半数致死浓度）分别为3 352、4 007、2 105 mg/kg;影响跳虫死亡的28 d-LC₅₀分别为2 271、1 865、703 mg/kg,影响跳虫繁殖的28 d-EC₅₀分别为1 799、1 323、307 mg/kg.由上述毒性阈值大小可知,跳虫逃避率的敏感性高于死亡率和繁殖数的敏感性,不同土壤中Sb对跳虫的毒性大小具有显著差异,北京潮土中Sb对跳虫的毒性与海伦黑土、祁阳红壤相比最大差别接近6倍,表明不同土壤理化性质对Sb生态毒性效应具有显著影响.但基于w（Sb_水提）求得的上述3种土壤中Sb的毒性阈值差异减小,说明水提态Sb与其毒性具有显著相关性,可以较好地解释不同土壤间Sb毒性的差异.该研究结果可为建立我国土壤中Sb的毒性预测模型及制订Sb的质量标准值提供依据.      

壬基酚对胶州湾典型微藻的毒性效应

以胶州湾常见优势藻种中肋骨条藻(Skeletonema costatum)和旋链角毛藻(Chaetoceros curvisetus)为受试生物,考察了壬基酚(NP)对两种海洋微藻的急性毒性效应,同时以超氧化歧化酶(SOD)活性和丙二醛(MDA)含量为指标,研究了两种海洋微藻细胞内抗氧化系统对NP氧化胁迫的响应。结果表明,NP对中肋骨条藻和旋链角毛藻生长抑制的96 h-EC50分别为0.13 mg/L和0.22 mg/L,中肋骨条藻对NP的毒性更为敏感。当中肋骨条藻培养体系中NP浓度在0.04～0.16 mg/L和旋链角毛藻培养体系中NP浓度在0.05～0.20 mg/L时,两种海洋微藻体内SOD活性均呈现出先诱导上升后抑制降低的变化趋势,MDA含量则随NP浓度的增大而增大;而在低浓度NP(<0.05 mg/L)胁迫下,96 h实验周期内,两种微藻细胞内SOD活性和MDA含量与不添加NP的对照组相比无显著差异(P>0.05),表明低浓度的NP胁迫下微藻体内诱导产生的抗氧化酶能够及时清除活性氧自由基,防止细胞受到损伤。暴露实验72 h后,两种微藻细胞内的SOD活性和MDA含量与NP作用浓度呈现显著的浓度-效应关系,这表明微藻细胞内SOD活性和MDA含量可以作为生物标志物用于近海水体中NP生态风险评价。     

芦苇抑藻化感物质的分离及其抑制蛋白核小球藻效果研究

采用乙醇提取、溶剂萃取法从芦苇中分离出2组能抑制蛋白核小球藻生长的化感物质. 该2组化感物质对蛋白核小球藻的半效应浓度(EC₅₀)分别为0.68mg/L和2.65mg/L. 将前者用碱性氧化铝层析柱分离得到一组抑藻活性更强的化感物质和一组能够促进蛋白核小球藻生长的化感物质: 前者对蛋白核小球藻的EC₅₀为0.50mg/L, 是目前报道的抑藻能力最强的化感物质; 后者在浓度为0.63mg/L时能显著促进蛋白核小球藻的生长. 芦苇化感物质可以用来控制淡水中有害藻类.     

Toxic effects of enrofloxacin on Scenedesmus obliquus

In this article, the toxic effects of Enrofloxacin (ENFX) on Scenedesmus obliquus were studied, through investigating the growth, photosynthetic pigments, and protein contents. The possible toxic mechanisms of ENFX were analyzed by determining the superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, proline content, and superoxide anion (O₂⁻) generation rate. Results showed that the growth of algae was inhibited by ENFX and the 50% effective concentration (EC₅₀) values for 24, 48, 72, and 96 h of ENFX were 88.39, 63.86, 45.10, and 59.16 mg·L⁻¹, respectively. After treated with ENFX for 96 h, the contents of photosynthetic pigments decreased with the increase of ENFX concentration, the content of soluble protein and the activity of SOD increased and then decreased, and the generation rate of superoxide anion (O₂⁻) increased continually. The contents of MDA and proline changed little in lower ENFX concentration groups, but increased rapidly when treated with higher concentration groups. These results suggested that ENFX affected the growth of S. obliquus, and the main toxicity mechanism was that algal cells generated the reactive oxygen species under ENFX stress, and then the reactive oxygen species (ROS) induced the oxidation damages of biologic macromolecules and changed the biomembrane permeability further.