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1.
1,4-二氯苯对蛋白核小球藻的毒性效应   总被引:3,自引:1,他引:2  
研究不同质量浓度的1,4-二氯苯(1,4-DCB)对蛋白核小球藻(Chlorella pyrenoidosa)的生长状况、蛋白质含量、叶绿素含量、超氧化物歧化酶活性(SOD酶活性)和脂质过氧化丙二醛(MDA)含量的影响,检测1,4-DCB对海洋微藻的毒性效应及其毒性机理.结果表明:1,4-DCB对蛋白核小球藻的生长有一定的抑制作用,该效应表现出一定的浓度和时间依赖性;1,4-DCB处理4 d后,蛋白核小球藻细胞蛋白质含量和叶绿素含量下降,SOD酶活性降低,MDA含量升高,这表明1,4-DCB通过产生活性氧自由基引起脂质及其他生物大分子的氧化损伤可能是1,4-DCB对蛋白核小球藻产生毒害效应的主要机制,受有机物污染后藻类作为饵料的价值降低.   相似文献   

2.
陆长梅  吴国荣 《云南环境科学》2000,19(A08):22-25,39
本文研究了Hg^2+对普通小球藻的致毒效应与银杏叶提取物的保护作用。试验显示:普通小球藻的生理代谢活动对Hg^2+敏感,单Hg^2+浓度提高,普通小球藻生长量降低;可溶性蛋白含量、SOD活性、总抗氛能为等在Hg^2+0~3mg.L^-1范围内应激升高,4~5mg.L^-1时升高幅度下降;而O2^-、MDA、脂质氢过氧化物含量均在供处理Hg^2+浓度 持续上升,表现出Hg^2+促进O2^-、MDA与  相似文献   

3.
为了探究镉对背角无齿蚌(A.woodiana woodiana)外套膜和鳃抗氧化酶活性及脂质过氧化的影响,按照96 h的LC50为134.9 mg·L-1,分别于镉(Cd2+)浓度为4.22、8.43、16.82、33.7和67.45 mg·L-1,染毒24、48、72和96 h后测定背角无齿蚌外套膜和鳃中抗氧化酶包括超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPX)和过氧化氢酶(CAT)活性及脂质过氧化产物丙二醛(MDA)的含量.结果表明,背角无齿蚌在不同浓度镉(Cd2+)溶液中经急性毒性处理24、48、72和96 h后,外套膜抗氧化酶活性呈现“抑制-诱导-抑制”的规律性变化,鳃抗氧化酶活性呈现“诱导-抑制”的规律性变化.镉处理后的背角无齿蚌外套膜和鳃SOD、GPX和CAT活性,表现出明显的组织差异性,且鳃诱导SOD、GPX和CAT活性较外套膜早.经镉处理以后,外套膜和鳃中MDA含量呈现升高趋势,高浓度镉处理组较对照组脂质过氧化损伤出现显著差异(**p<0.01),具有剂量-效应和时间-效应.  相似文献   

4.
为探究壳聚糖(CTS)缓解小麦幼苗镉(Cd)毒害的机制,通过水培试验,以百农207小麦为试验材料,研究外源壳聚糖对Cd胁迫下小麦幼苗的生理特性、抗氧化能力和Cd积累的影响,并利用偏最小二乘(PLS)回归模型定量分析幼苗各理化指标与镉积累量间的关系.结果表明,相较于CK,10 μmol·L-1和25 μmol·L-1 Cd胁迫显著抑制了小麦幼苗的叶绿素含量(叶绿素a、叶绿素b、类胡萝卜素和总叶绿素)、光合作用和生物量的积累,使得幼苗根系变短变粗且侧根减少,同时改变了超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,增加了H2 O2 和丙二醛(MDA)的积累.镉胁迫下,外源壳聚糖使小麦幼苗茎叶和根系镉含量分别降低13.22 %~21.63 %和7.92 %~28.32 %,镉积累量分别降低5.37 %~6.71 %和1.91 %~4.09 %.不同镉水平下,外源壳聚糖使小麦根系和茎叶中H2 O2 含量显著降低了38.21 %~47.46 %和45.81 %~55.73 %,MDA 含量显著降低了37.65 %~48.12 %和29.87 %~32.51 %;根系中SOD和POD 含量分别提高2.78 %~5.61 %和13.81 %~18.33 %.外源壳聚糖可通过提高Cd胁迫下小麦幼苗的光合特征和抗氧化酶活性的方式,降低小麦地上部和根部的Cd含量与积累量,减轻细胞膜脂质的过氧化程度,进而缓解Cd胁迫对小麦幼苗生长的毒害作用.  相似文献   

5.
研究了氯氰菊酯对蛋白核小球藻(Chlorella pyrenoidosa)生长、细胞内含物(可溶性蛋白、可溶性糖)及抗氧化酶类(超氧化物歧化酶,SOD)、膜脂氧化产物(丙二醛,MDA)的影响.结果表明,在氯氰菊酯暴露下,藻细胞的生长受到不同程度的抑制,且抑制程度随氯氰菊酯浓度的增大而增大,氯氰菊酯对蛋白核小球藻生长的72h半效应浓度(EC50)为4.89mg·L-1.藻细胞所有生理生化指标对氯氰菊酯响应迅速,在暴露初期较为敏感,24h后趋于平稳.其中,可溶性糖和可溶性蛋白含量上升,中等浓度组(3.2,5.6mg·L-1)上升趋势最为显著.SOD活性则呈现出低浓度(1.0,1.8mg·L-1)促进、高浓度(>3.2mg·L-1)抑制效应.氯氰菊酯可使藻体内丙二醛(MDA)含量升高,氯氰菊酯浓度越高,藻体内MDA含量越高.研究结果表明,对藻细胞SOD活性的抑制及膜脂过氧化可能是氯氰菊酯对蛋白核小球藻产生毒害作用的重要原因.  相似文献   

6.
纳米氧化镍对3种绿藻的毒性效应   总被引:2,自引:0,他引:2       下载免费PDF全文
雷静静  冯佳  谢树莲 《中国环境科学》2013,33(10):1842-1849
通过配制不同浓度(0,60,120,180,240,300mg/L)纳米氧化镍(nNiO)悬浊液,对四尾栅藻(Scenedesmus quadricauda)、普通小球藻(Chlorella vulgaris)和羊角月牙藻(Selenastrum capricornutum)进行连续胁迫10d的毒性试验,测定nNiO对3种绿藻生长状况、叶绿素a、蛋白质、脂质过氧化物丙二醛(MDA)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的影响.结果表明,nNiO胁迫对四尾栅藻、普通小球藻和羊角月牙藻的生长均有一定抑制作用,在同一时间段内,总体呈明显剂量效应;nNiO低浓度(60~120mg/L)胁迫对供试藻的影响表现为“抑制—促进—抑制”,在一定时间内对供试藻有促进生长的作用;nNiO胁迫对四尾栅藻、普通小球藻和羊角月牙藻的毒性效应表现为叶绿素a和蛋白质含量减少,MDA含量升高,抗氧化活性降低;羊角月牙藻对nNiO的耐受性较强,四尾栅藻和普通小球藻较敏感.  相似文献   

7.
为研究水生生物对水体中重金属和有机磷农药毒性的生理响应,以锯齿新米虾为试验生物,采用半静止毒性试验方法,分别研究了Cu2+和毒死蜱5 d暴露时间对锯齿新米虾肌肉组织生理指标的影响.结果表明,锯齿新米虾暴露在不同浓度Cu2+和毒死蜱溶液下,随着暴露时间的延长,肌肉组织蛋白浓度均有不同程度的降低.Cu2+溶液较低浓度组(0.086 mg·L-1和0.172 mg·L-1)和毒死蜱较高浓度组(0.006 0μg·L-1和0.012 0μg·L-1)中,总SOD活性表现抑制效应;Cu2+溶液较高浓度组(0.344 mg·L-1和0.688 mg·L-1)表现为"抑制-诱导-抑制"的变化趋势,而毒死蜱较低浓度组(0.001 5μg·L-1和0.003 0μg·L-1)表现为"抑制-诱导"的变化趋势;暴露在Cu2+和毒死蜱溶液下,MDA含量变化相似,且在一定浓度范围内,随着Cu2+和毒死蜱浓度增加,MDA含量呈逐渐上升的趋势,说明Cu2+和毒死蜱加快了锯齿新米虾肌肉组织脂质过氧化作用;ACh E活性在Cu2+和毒死蜱溶液中表现为抑制效应,且在Cu2+和毒死蜱溶液的较高浓度组中,其活性随浓度的增加而呈逐渐降低的趋势,说明Cu2+和毒死蜱对锯齿新米虾肌肉组织的正常生理功能产生了影响,其浓度越高,产生的损伤效应越大.研究表明,鉴于不同浓度的Cu2+和毒死蜱溶液对锯齿新米虾肌肉组织的损伤程度不同,总SOD、MDA和ACh E可以作为评价重金属和有机磷农药对锯齿新米虾急性毒性效应的生理指标.  相似文献   

8.
为探究稀土元素铈(Ce)对锌(Zn)胁迫下小麦幼苗生长的缓解效应,通过水培试验,以百农307为试验材料,研究外源Ce对500 μmol·L-1 Zn胁迫下小麦幼苗生长、Zn积累和生理特性的影响.结果表明,500 μmol·L-1 Zn胁迫显著抑制了小麦幼苗叶绿素含量(叶绿素a、叶绿素b和总叶绿素)、光合作用和生物量的积累,使得幼苗根系变短变粗、侧根减少,同时降低了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性和可溶性蛋白含量,增加了丙二醛(MDA)的积累.外源Ce降低了根系对Zn的吸收和转运,缓解了Zn胁迫对小麦幼苗的毒害效应,具体表现为叶绿素含量和光合作用参数的升高;提高了抗氧化酶活性和可溶性蛋白含量并降低MDA质量摩尔浓度;降低脂质过氧化对细胞膜的损伤,最终表现为小麦幼苗根系和茎叶干物质量的增加.外源Ce可通过提高Zn胁迫下小麦幼苗的光合特征、抗氧化酶活性和渗透调节物质的方式,降低细胞膜脂质的过氧化程度,缓解Zn胁迫对小麦幼苗生长的毒害作用.  相似文献   

9.
汞对水花生愈伤组织生理及超微结构的毒性效应   总被引:1,自引:0,他引:1  
研究了Hg胁迫对水花生致密型愈伤组织叶绿素含量、可溶性蛋白含量、活性氧水平、抗氧化酶活性及细胞超微结构的影响.结果表明,随着Hg施加浓度的增加,总叶绿素、叶绿素a、叶绿素b、可溶性蛋白含量呈先升后降趋势,叶绿素a/叶绿素b逐渐下降;超氧化物歧化酶(SOD)、过氧化物酶(POD)活性先升后降,而过氧化氢酶(CAT)活性呈逐渐下降趋势;同时,超氧阴离子(O2-·)产生速率、丙二醛(MDA)和过氧化氢(H2O2)含量均呈逐渐上升趋势.电镜扫描结果发现,Hg胁迫破坏了细胞膜系统,特别是对线粒体、叶绿体、细胞核造成了较为严重的不可逆的损伤,所观察到的核膜破裂方式主要是超量分泌膜泡.Hg对水花生愈伤组织的致死浓度范围为20~40μmol·L-1.  相似文献   

10.
石油烃、Cu2+对沙蚕的毒性效应及对其抗氧化酶系统的影响   总被引:11,自引:4,他引:7  
在实验室模拟条件下,研究了石油烃和不同浓度的Cu2 对沙蚕(Nereis diversicolor)种群的毒性效应及对其抗氧化酶系统活性的影响.结果表明:石油烃和Cu2 对沙蚕均表现出较强的毒性,暴露3d后,其LD50值分别为117.5μL·L-1和864.0μg·L-1.Cu2 单因子污染暴露5d后,沙蚕体内过氧化物酶(POD)的活性受到显著影响,表现出先受到抑制后缓慢增加的趋势,超氧化物歧化酶(SOD)的活性也发生显著变化,其变化趋势为先被诱导而后抑制.石油烃以其约为半致死剂量水平单因子暴露5d后,POD的活性并未被显著诱导,SOD的活性则低于对照组.在石油烃与Cu2 复合污染的条件下,暴露5d后沙蚕体内POD和SOD活性表现出相同的变化趋势,即先下降后上升.通过比较,还发现沙蚕体内SOD的活性变化更能灵敏地反映出污染物对沙蚕的毒性作用.  相似文献   

11.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

12.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

13.
Several main metabolites of benzo[a]pyrene (BaP) formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone (BP 1,6- quinone), trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-diol), 3-hydroxybenzo[a]pyrene (3-OHBP), were identified by high-performance liquid chromatography (HPLC). The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that (1) the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; (2) the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; (3) the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% (w/v), concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.  相似文献   

14.
Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.  相似文献   

15.
In this study an effort has been made to use plant polyphenol oxidases; potato (Solanum tuberosum) and brinjal (Solanum melongena), for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.  相似文献   

16.
RemovalofheavymetalsfromsewagesludgebylowcostingchemicalmethodandrecyclinginagricultureWuQitang,NyirandegePascasie,MoCehuiF...  相似文献   

17.
Single and joint effects of pesticides and mercury on soil urease   总被引:6,自引:3,他引:3  
The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase (up to 13%-21%) in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship (P〈0.05) between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose (ED50) values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.  相似文献   

18.
A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several (halo)aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no (chloro)catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.  相似文献   

19.
A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field > tree land > fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT >1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.  相似文献   

20.
The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.  相似文献   

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