诺氟沙星对芽期玉米的毒性和氧化损伤研究

畜禽养殖废弃物的农田处置,使大量抗生素进入环境,从而对环境生物产生潜在危害.为了研究诺氟沙星(norfloxacin,Nor)对玉米发芽和幼苗生长的影响,采用水培发芽实验,测定了不同浓度下,诺氟沙星对玉米种子的发芽率和玉米幼苗对诺氟沙星的吸收与传输的影响;另外还研究了诺氟沙星对玉米幼苗生物量、自由基水平、丙二醛(MDA)含量、抗氧化酶活性的影响.结果显示,诺氟沙星能被玉米根吸收并传输到地上部分.0.5mg·L-1～50mg·L-1的诺氟沙星暴露均不影响玉米的发芽率.当诺氟沙星浓度大于1mg·L-1时,幼苗的生长受到抑制,其敏感指标依次为根重>根长>芽长>芽重.诺氟沙星暴露使玉米根、芽中MDA含量明显增加,玉米根中谷胱甘肽硫转移酶(GST),过氧化物酶(POD),超氧化物歧化酶(SOD)和过氧化氢酶(CAT)等抗氧化酶的活度有显著改变,这表明诺氟沙星暴露能够引起玉米体内的氧化损伤.用电子自旋共振结合二级自由基自旋捕获技术测定了玉米根中自由基水平,发现诺氟沙星能够引起玉米根中大量羟基自由基的产生,为诺氟沙星引起玉米幼苗的氧化损伤提供了直接的证据.     

环丙沙星对3种作物的毒性

为了研究环丙沙星对作物的毒性效应,为其可能对农业生产带来的风险提供评价依据,采用急性毒性实验方法,研究了环丙沙星对3种作物(玉米、萝卜和小白菜)种子发芽、根伸长及芽伸长的影响。结果表明,在环丙沙星作用下,3种作物的根伸长抑制率和芽伸长抑制率与药物浓度显著相关(P<0.05),发芽抑制率与药物浓度不相关(P>0.05);药物对根伸长及芽伸长的抑制高于对种子发芽的抑制;环丙沙星对玉米、萝卜和小白菜的根伸长和芽伸长的ID50(抑制率为50%时污染物浓度)分别为7.97、2.51、1.48mg·kg-1和11.23、2.90、1.95mg·kg-1,3种作物在环丙沙星的胁迫下,其敏感性顺序为:小白菜>萝卜>玉米。     

3种抗生素对黑麦草种子萌发的生态毒性效应

为探明四环素、环丙沙星和磺胺嘧啶3种抗生素对黑麦草种子萌发的影响,为评价抗生素污染的生态影响提供科学依据,采用保湿培养法研究了它们对黑麦草种子萌发的影响,比较分析了抗生素的生态毒性差异和相对敏感的指标。结果表明,在种子萌发期,一定浓度范围的抗生素胁迫会引发植物种子抵抗逆境的应激反应,因此,3种抗生素在1 mg·L~(-1)处理水平下均能促进种子发芽。超过该浓度,四环素对黑麦草种子发芽仍有一定的促进作用,而环丙沙星和磺胺嘧啶则表现为抑制作用。四环素对种子发芽率的最大无作用浓度(NOEC)为5 mg·L~(-1),而环丙沙星和磺胺嘧啶对种子发芽率的NOEC为1 mg·L~(-1)。实验结束时,3种抗生素在1 mg·L~(-1)处理水平下的种子发芽率最高。3种抗生素浓度超过0.1 mg·L~(-1)时,种子根长和芽长即受到抑制,因此,它们对种子根长和芽长的NOEC均为0～0.1 mg·L~(-1)。其中,磺胺嘧啶的抑制作用最为显著。根长受到抑制的程度强于芽长。黑麦草种子萌发受3种抗生素影响程度依次为磺胺嘧啶环丙沙星四环素。     

诺氟沙星对芽期玉米的毒性和氧化损伤研究（Phytotoxicity and Oxidative Stress of Norfloxacin on Maize（Zea mays L.）Germination Stage）

畜禽养殖废弃物的农田处置,使大量抗生素进入环境,从而对环境生物产生潜在危害. 为了研究诺氟沙星（norfloxacin, Nor）对玉米发芽和幼苗生长的影响,采用水培发芽实验,测定了不同浓度下,诺氟沙星对玉米种子的发芽率和玉米幼苗对诺氟沙星的吸收与传输的影响;另外还研究了诺氟沙星对玉米幼苗生物量、自由基水平、丙二醛（MDA）含量、抗氧化酶活性的影响. 结果显示,诺氟沙星能被玉米根吸收并传输到地上部分. 0.5mg·L-1~50mg·L-1的诺氟沙星暴露均不影响玉米的发芽率. 当诺氟沙星浓度大于1mg·L-1时,幼苗的生长受到抑制,其敏感指标依次为根重>根长>芽长>芽重. 诺氟沙星暴露使玉米根、芽中MDA含量明显增加,玉米根中谷胱甘肽硫转移酶（GST）,过氧化物酶（POD）,超氧化物歧化酶（SOD）和过氧化氢酶（CAT）等抗氧化酶的活度有显著改变,这表明诺氟沙星暴露能够引起玉米体内的氧化损伤. 用电子自旋共振结合二级自由基自旋捕获技术测定了玉米根中自由基水平,发现诺氟沙星能够引起玉米根中大量羟基自由基的产生,为诺氟沙星引起玉米幼苗的氧化损伤提供了直接的证据.     

根表铁膜对凤眼莲吸收环丙沙星的影响

为探讨铁离子不同浓度处理下水生植物根表铁膜形成及其对环丙沙星(ciprofloxacin,CIP)吸收的影响,采用室内模拟试验,分析0.1 mg·L-1 CIP胁迫下不同浓度铁离子(0、10、20、50、100和150 mg·L-1)对凤眼莲根系生理生化及CIP富集量的影响.结果 表明,不同浓度铁离子对凤眼莲根系孔隙度...     

C4植物甜高梁和玉米幼苗对Zn胁迫的响应差异

实验采用营养液培养法,设置2,50,100,500和1000μmol-L-1浓度ZnSO4处理,比较C4植物甜高粱(Sorghum bicolor(L.)Moench.)和玉米(Zeamays.L)幼苗对zn胁迫的响应差异.结果表明,甜高粱对重金属zn胁迫的敏感性强于玉米,随着zn处理浓度加大,前者幼苗苗高、根长、单株干物质量、叶绿素含量和根系活力的下降幅度及丙二醛含量的上升幅度皆大于后者,玉米对Zn胁迫的耐受性强于甜高粱.在处理浓度达到500 μmol-L-1之前,甜高粱和玉米体内吸收的Zn随处理浓度加大显著递增,达500μmol-L-1之后,玉米根系积累的Zn不再明显增加.在处理浓度达到和高于100μmol·L-1时,甜高粱由根系向地上部转运的Zn显著高于玉米.甜高粱和玉米对Zn胁迫的敏感性差异可能缘于它们的吸收和转运差异.     

CoFe_2O_4增强超声/H_2O_2降解环丙沙星

实验合成磁性CoFe_2O_4,采用X射线衍射仪(XRD)、扫描电镜(SEM)和X射线能谱仪(EDS)对其进行表征,研究其催化超声/H_2O_2(US/H_2O_2)降解环丙沙星的效果和机理.实验考察了CoFe_2O_4和H_2O_2添加浓度、初始p H值、不同形态氮、氯离子等因素对环丙沙星降解效果的影响.并以大肠杆菌为指示菌种,分析了CoFe_2O_4催化US/H_2O_2降解环丙沙星过程中抑菌性的变化.结果表明,CoFe_2O_4能够有效增强US/H_2O_2降解环丙沙星,CoFe_2O_4和H_2O_2浓度分别为0.04 g·L~(-1)和1.0 mmol·L~(-1)、p H=3.0、反应60 min环丙沙星的降解率达到85.26%;与NH_4~+相比,NO_3~-促进环丙沙星的降解,NO_2~-和Cl~-不同程度抑制环丙沙星的降解.自由基抑制结果表明,CoFe_2O_4增强US/H_2O_2降解环丙沙星主要在于·OH的生成.CoFe_2O_4稳定性结果表明,5次反复实验后,环丙沙星60 min的降解率仅降低了4%左右,催化剂的重复利用性较高.琼脂扩散实验表明,CoFe_2O_4在催化US/H_2O_2降解环丙沙星的同时,CoFe_2O_4/US/H_2O_2体系能够完全去除其对大肠杆菌的抑菌性.     

接种邻苯二甲酸酯(PAEs)降解菌缓解PAEs对玉米胁迫效应和机制研究

邻苯二甲酸酯(PAEs)是一类典型的环境内分泌干扰物,国内农业土壤普遍受PAEs的污染。土壤中的PAEs可被农作物吸收累积,影响植物的生理生化特性和农产品的质量安全。探索PAEs污染土壤的生物修复技术以及高效降解菌缓解PAEs污染胁迫和降低农作物吸收累积PAEs迫在眉睫。以在土壤中的质量分数和检出频率均较高的邻苯二甲酸二(2-乙基己基)酯(DEHP)为目标化合物,采用DEHP污染土壤(18 mg·kg~(-1)和75 mg·kg~(-1))进行盆栽玉米(Zea mays)试验,研究接种PAEs高效降解菌(嗜吡啶红球菌Rhodococcus pyridinivorans XB)缓解DEHP胁迫对玉米生长、吸收积累DEHP的影响及其抗氧化酶系统的响应。结果显示,经DEHP处理的玉米丙二醛质量摩尔浓度显著增加(P0.05),尤其是高浓度处理的玉米根系丙二醛质量摩尔浓度增加464%;且高浓度处理的玉米根系过氧化氢酶和多酚氧化酶活性显著增加(P0.05),生物量显著下降(P0.05),说明DEHP严重影响玉米的生长。与不接种微生物处理相比,玉米接种菌株XB能显著提高玉米体内超氧化物歧化酶(10%~154%)、过氧化氢酶(11%~34%)及多酚氧化酶(48%~288%)活性,显著降低丙二醛质量摩尔浓度(30%~60%),提高玉米生物量(5%~85%),减少玉米对DEHP的吸收积累(4%~60%)。结果说明菌株XB能缓解土壤DEHP对玉米生长的胁迫,降低玉米吸收积累DEHP,有利于保障农产品质量安全。     

川南页岩气开发油基钻屑对玉米的生物毒性效应研究

以川南页岩气开发过程中产生的油基岩屑为研究对象,考察不同质量百分比浓度的油基岩屑胁迫对玉米生长过程中生长指标的影响,包括玉米的生物量指标(种子出苗率、地面高度、茎叶鲜质量、茎叶干质量、根长、根鲜质量、根干质量)和生理性指标(叶片叶绿素、过氧化氢(H₂O₂)、丙二醛(MDA)含量)。结果表明,当油基岩屑的质量百分比为100%时,玉米的出苗率仍在86.67%,油基岩屑对玉米种子的发芽率影响较小;不同质量百分比的油基岩屑胁迫下玉米幼苗的生长情况呈现低促进高抑制的现象,各项生长指标之间呈现显著差异(P<0.05),其中油基岩屑的质量百分比为100%时对玉米培育后期(30 d)地面高度和根的鲜质量显著影响(P<0.001);油基岩屑质量百分比≥50%时,油基岩屑对玉米叶片叶绿素质量浓度、H₂O₂与MDA的物质的量浓度影响显著(P<0.01);随着种植时间的延长和油基岩屑质量百分比的增加,玉米叶片中叶绿素质量浓度呈下降趋势,叶片中H₂O₂与MDA的物...     

锑对水稻根生长的影响及锑的吸收动力学特性

采用溶液培养法研究不同价态Sb对水稻根生长以及P和Sb交互作用对水稻根系吸收P、Sb的影响.试验结果表明,Sb(Ⅲ)和Sb(Ⅴ)对水稻根生长均有抑制作用,且随着溶液中Sb浓度的提高抑制效应越明显.水稻根系对Sb(Ⅲ)和Sb(Ⅴ)的吸收均可以用Freundich模型较好地模拟.水稻根系对不同价态Sb的吸收有明显差异.当溶液中Sb浓度为10 μmol·1-1时,水稻根系对Sb(Ⅴ)的吸收比Sb(Ⅲ)减少70.9%,而Sb浓度为100 μmol·1-1时,水稻根系对这两个价态的Sb吸收差异不大.P对水稻根系吸收Sb(Ⅲ)或Sb(Ⅴ)均没有影响.Sb(Ⅲ)可影响水稻根系对P的吸收,但是Sb(Ⅴ)对水稻根系吸收P影响不大.     

DEHP (Di(2-ethylhexyl)phthalat)

Background, Goal and Scope

The plasticiser DEHP is suspected to affect the human reproductive system as an endocrine disruptor (Latini et al. 2004). A meta-analysis was performed to compare annual production amounts and daily uptake of DEHP.

Methods

For this purpose, production data were used from annual publications of the Federal Statistical German Agency (Statistiches Bundesamt) and daily uptake values on the basis of urinary secretion of DEHP metabolites from Wittassek et al. (2007a).

Results

It is shown that the daily uptake of DEHP by German university students is strictly and almost perfectly correlated with the industrial production of DEHP in Germany (correlation coefficient >0.9).

Discussion

The annual production amounts are reflected by the daily uptake values. When the production amount is high, the uptake increases; when the production amount is low, the uptake decreases.

Conclusions

This strict correlation allows the extrapolation of daily DEHP uptake for the 1970s years. On this basis it can be assumed that, at least for a part of the German population, the TDI of 50 μg/kg BW/day was exceeded. Because of their higher susceptibility and, therefore, higher uptake rate (Becker et al. 2004), a considerable exposure for infants might have occurred in these years.     

Adsorption of vanadate(V) on Fe(III)/Cr(III) hydroxide waste

Adsorption of vanadate(V) from aqueous solution onto industrial solid ‘waste’ Fe(III)/Cr(III) hydroxide was investigated. HCl treated Fe(III)/Cr(III) hydroxide was found to be more efficient for the removal of vanadate(V) compared to untreated adsorbent. The adsorption follows second-order kinetics. Langmuir and Freundlich isotherms have been studied. The Langmuir adsorption capacity (Q ₀) of the treated and untreated adsorbents was found to be 11.43 and 4.67 mg g⁻¹, respectively. Thermodynamic parameters showed that the adsorption process was spontaneous and endothermic in the temperature range 32–60°C. Maximum adsorption was found at system pH 4.0. The adsorption mechanism was predominantly ion exchange. Effect of other anions such as phosphate, selenite, molybdate, nitrate, chloride, and sulfate on adsorption of vanadium has been examined.     

邻苯二甲酸二(2-乙基己基)酯生物降解性研究

研究了从污水处理厂的活性污泥和塑料厂排污口土壤中分离到的两株邻苯二甲酸二(2-乙基己基)酯(DE-HP)降解菌CQ0110Y和CQ0110G对DEHP的适宜降解条件以及其降解特性．结果表明，CQ0110Y和CQ0110G的适宜pH范围分别为6．0—8．0和6．0—7．5；适宜温度范围分别为20-35℃和25—35℃．当DEHP初始浓度小于1350mg／L时，它们对DEHP的降解反应符合一级动力学特征，DEHP半减期分别为：t1/2(CQ0110Y)=1.59d,t1/2(CQ0110G)=2.00d.，两株菌对DEHP均具有高效降解能力．图2表2参7     

沉水植物龙须眼子菜(Potamogeton pectinatus)对镉、铅的吸附特性

采用龙须眼子菜(Potamogeton pectinatus)干样为实验材料,研究了龙须眼子菜对溶液中镉、铅吸附的基本特征。相同浓度不同时间条件下的吸附实验结果显示,龙须眼子菜对溶液中镉、铅离子的吸附速度很快,大约20min就能达到平衡,吸附的限速过程是小孔扩散过程,随着时间的延长,吸附的动力学特征可用假二次方程描述。相同时间不同浓度条件下的吸附实验结果显示,龙须眼子菜对镉、铅的最大吸附量分别能达到32368和24776mg·kg-1,吸附的浓度动力学特征符合Langmuir曲线方程。所有结果都表明,龙须眼子菜能有效地从溶液中去除镉和铅,可以用于水体镉、铅污染的植物修复,也可把龙须眼子菜干样作为一种新的吸附剂用于去除工业废水中的镉和铅。     

Sexual reproduction in Acropora (Isopora) (Coelenterata: Scleractinia)

In contrast to the seasonal gamete and planula production of Acropora (Isopora) palifera on Heron Island reef (Lat. 23° S), populations on Lizard Island reef (Lat. 14° S), sampled in 1979, 1981 and 1983, and Salamaua and Busama reefs (Lat. 7° S), sampled from 1980 to 1983, planulated year-round. Intensive sampling of colonies at Salamaua and Busama showed that gametes ripened at two-month intervals and that up to six cycles of gametes and larvae could be produced by an individual colony. Gametes of only a portion of the population — usually close to 50% — ripened each month. The Salamaua population, on average, produced fewer and smaller planulae than the Heron Island population during each two-monthly reproductive cycle. Hypotheses correlating the annual periodicity of breeding in marine animals with latitudinal variation of temperature were tested. In general, the time of breeding in A. palifera at Heron Island reef is much more restricted than theories based on latitudinal variations of water temperature would predict. It is hypothesized that, in the near subtropical environment of Heron Island reef, this species has evolved a life-history strategy that limits the amount of energy allocated to reproduction and allocates more energy to growth.     

Impact of Ni(II), Zn(II) and Cd(II) on biogassification of potato waste

A study was conducted on anaerobic digestion of potato waste and cattle manure mixture, inoculated with 12% inoculum and diluted to 1:1 substrate water ratio at 37 +/- 1 degrees C. Initially pH of substrate was found to be 4.5 to 5.0. Lime and sodium bicarbonate solutions were employed to adjust the pH to 7.5. Biogas production continued up to 10 and 7 days, when lime and sodium bicarbonate solutions were used to adjust the pH, respectively. Biogassification potential was studied in response to different ratio of waste and cattle manure. Biogas production rate was higher when potato waste and cattle manure were used in 50:50 ratio. Effect of two different concentrations (2.5 and 5.0 ppm) of three heavy metals viz. (Ni (II), Zn (II) and Cd (II)) on anaerobic digestion of substrate (potato waste--cattle manure, 50:50) was studied. At 2.5 ppm, all the three heavy metals increased biogas production rate over the control value. The percentage increase in biogas production over the control was highest by Cd, followed by Ni and Zn. In all the treatments, methane content of biogas increased with increase in time after feeding. Various physico-chemical parameters viz. total solids, total volatile solids, total organic carbon and chemical oxygen demand considerably declined after 7 days of digestion and decline was greater in presence of heavy metals as compared to control. The physico-chemical parameters revealed maximum decrease in the presence of 2.5-ppm concentrations of heavy metals with the substrate. Among all the three heavy metals employed in the study, Cd++ at 2.5 ppm was found to produce maximum biogas production rate. The use of three heavy metals to enhance biogas production from potato and other horticultural waste is discussed.