拟除虫菊酯对人红细胞膜结构的影响

研究了5种拟菊酯即北京菊酯、杀灭菊酯、溴氰菊酯、氯氰菊酯和氯菊酯对人红细胞膜上DPH光谱及荧光各向异性(r)的影响,观察了胰蛋白荧光及人红细胞溶血的变化.氯菊酯以干扰膜脂排列影响r值,浓度达到50μmol/L时,r值开始明显降低;其他4种含氰基拟菊酯则以干扰膜脂排列和DPH荧光碰撞猝灭作用共同影响r值.研究结果还表明,拟菊酯同时作用于膜脂区和膜蛋白的疏水部分,降低膜脂的有序排列,这些变化与拟菊酯对红细胞的溶血作用一致.     

太湖及辽河流域表层沉积物中拟除虫菊酯的浓度水平及毒性评估

对辽河和太湖流域表层沉积物中8种常见的拟除虫菊酯:联苯菊酯、高效氯氟氰菊酯、氯菊酯、甲氰菊酯、氟氯氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯进行分析测定.结果显示,太湖流域中拟除虫菊酯含量范围为0.02～2.91ng·g-1(干重,下同),平均含量为0.63ng.g-1,处于相对较低的水平;辽河流域中的含量相对较高,其范围是0.14～19.6ng·g-1,平均含量为6.20ng·g-1.采用毒性单元TU(选用钩虾Hyallela Azteca的LC50)对拟除虫菊酯毒性风险进行估算,太湖流域∑TU值范围是0～0.40,相比之下,辽河流域的∑TU值高出很多,范围在0.10～1.73之间,其中有3个点位的∑TU值大于1,表明其具有一定的生态风险,其毒性主要来源于氯氰菊酯和氰戊菊酯.     

对氯苯乙腈在鱼体肌肉内代谢产物的研究

对氯苯乙腈是合成取代苯乙酸酯型拟除虫菊酯氰戊菊酯、戊菊酯的关键中间体,工业上已大量生产。但其对水生生物的影响,目前研究很少。作者曾研究对氯苯乙腈在正辛醇/水溶剂体系的分配系数以及在鱼体肌肉内的积累和释放行为。本文侧重研究其在金鱼肌肉内的代谢行为。     

超高压液相色谱/质谱联用法测定水中拟除虫菊酯类农药研究

建立了水中6种拟除虫菊酯类农药的超高压液相色谱/质谱联用分析方法.对液相色谱和质谱两方面条件进行优化,采用多反应监测（MRM）模式分析,各组分在0.005～0.1 mg/L范围内线性关系良好,相关系数（R）均大于0.998;6种拟除虫菊酯类农药的最低检出限为0.000 5 ～0.002 mg/L,其中,溴氰菊酯的方法检出限满足《地表水环境质量标准》限值要求;各组分的加标回收率在92.8％～103％;相对标准偏差（RSD）均小于5％（n=6）.该方法简单、快捷,可用于实际水样的直接测定.     

四种拟除虫菊酯类农药的环境雌激素活性研究

将金鱼(Carassius auratus)分别暴露于0.1mg/L甲氰菊酯、氰戊菊酯、溴氰菊酯和0.5mg/L氯氰菊酯21d后,尾静脉取血,离心分离获得血浆,利用Western-blot方法检测金鱼血浆中是否有卵黄原蛋白产生,同时测定金鱼生殖腺指数、γ-谷氨酰转移酶和乳酸脱氢酶活性.结果表明,对照组雄性金鱼血浆中未检测到卵黄原蛋白,4种拟除虫菊酯农药均能诱导雄性金鱼分泌卵黄原蛋白,而且溴氰菊酯和氯氰菊酯明显降低了雄鱼生殖腺指数,4种农药均能够明显抑制精巢γ-谷氨酰转移酶和乳酸脱氢酶活性.由此可见,4种拟除虫菊酯类农药具有潜在的环境雌激素活性和生殖毒性.     

拟菊酯杀虫剂的光敏降解研究

研究了哒嗪硫磷、多菌灵和克百威对三种菊酯杀虫剂(氯氰菊酯、溴氰菊酯、氰戊菊酯)的光敏降解效应.在0.03—2.66μg/cm~2剂量范围内,哒嗪硫磷,多菌灵对3种拟菊酯杀虫剂有极显著的光敏效应,光解速度常数分别是拟菊酯杀虫剂单独照光的1.54—1.88倍和1.41—1.72倍.克百威对氯氰菊酯和溴氰菊酯有显著的光猝灭效应.当克百威和哒嗪硫磷共存时,克百威明显减弱哒嗪硫磷对氯氰菊酯和嗅氰菊酯的光敏效应,而增强对氰戊菊酯的光敏效应.     

拟除虫菊酯类杀虫剂的酶促降解

测定了降解菌Ａｌｃａｌｉｇｅｎｅｓ ｓｐ．ＹＦ １１粗酶液对拟除虫菊酯杀虫剂的降解性能,粗酶液降解杀灭菊酯、甲氰菊酯、氯氯菊酯、溴氰菊酯氯菊酯、三氟氯氰菊酯的最适ｐＨ分别为８．０、８．５、８．０、８．０、９．０、７．５;米氏常数分别为４１．４、１３６．８、６５．４、２２２．８、５．２、８．６７ｎｍｏｌ／ｍｌ;最适温度为３２．５℃,该粗酶液在ｐＨ５．０－１０．５均具有降解活性。     

淡色库蚊二氯苯醚菊酯水解酶研究

本实验比较了对拟除虫菊酯抗性和敏感淡色库蚊幼虫的二氯苯醚菊酯水解酶的活力和性质,结果表明:(1)无论抗性和敏感品系都专一性地水解反式二氯苯醚菊酯,而对顺式异构体不降解。(2)酶活力主要集中在无细胞器结构的细胞浆内。(3)拟除虫菊酯抗性淡色库蚊的二氯苯醚菊酯水解活力比敏感品系大约一倍。(4)抗性和敏感品系二氯苯醚菊酯水解酶的米氏常数、最适反应pH、最适反应温度相近,但最大反应速度则抗性比敏感品系大2.3倍。这表明抗性的产生主要由于酶量的增加,而不是酶系发生变化。     

一株拟除虫菊酯农药降解菌的分离鉴定及其降解特性与途径

采用富集培养法,从拟除虫菊酯农药厂废水排放口的活性污泥中分离到1株菊酯农药高效降解菌P-01.经形态、生理生化特征及16S rDNA序列分析,初步鉴定其为无色杆菌属（Achromobacter sp.）.响应曲面法优化菌株P-01的降解条件,其降解最优条件为31.4℃、初始pH7.6和接种量0.4g·L-1,在此条件下...     

长江口及其邻近海域颗粒态氨基酸的分布以及对有机质降解和来源的指示

本研究于2018年3月采集长江口及其邻近海域50个站位样品，对颗粒态氨基酸（PAA）的分布与组成进行了分析。结果表明:PAA的平均浓度为（1.86 ± 1.02）μmol/L（0.76～5.55 μmol/L），其主要组分为天门冬氨酸（Asp）、谷氨酸（Gly）、丝氨酸（Ser）、丙氨酸（Ala）和甘氨酸（Glu）。颗粒有机碳（POC）和颗粒氮（PN）的平均浓度分别为（74.21 ± 37.70）μmol/L（18.06～238.66 μmol/L）和（7.52 ± 3.46）μmol/L（2.27～19.86 μmol/L）。PAA、POC与PN具有相似的分布特征，长江口内浓度低于近岸浓度，近岸浓度高于远岸浓度，垂直分布上较为均匀。研究海域中的C/N由近岸向远海逐渐降低，表明陆源输入有机质的影响逐渐降低。基于氨基酸的衍生参数Asp/Gly和Ser + Thr（苏氨酸）[mol%]表明该海域颗粒物中有机质主要源于硅质碳源，与硅藻在该海域中相对较高的生物量有关。碳、氮归一化产率[PAA-C（N）%]以及降解因子（DI）所指示的降解趋势并不完全一致，这或许与PAA-C（N）%和DI适用于不同降解阶段以及氨基酸来源与转化的多样性有关。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

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.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

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.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

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.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

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.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

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.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

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.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

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.     

Sorption of 1-naphthol by plant cuticular fractions

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.