3-甲基喹啉的微生物降解

从处理油制气废水的活性污泥中分离得到一株菌种Q10，经16SrDNA序列分析鉴定为睾丸酮丛毛单胞菌，该菌可以利用3-甲基喹啉作为唯一碳源和能源生长。着重研究了该菌在好氧条件下利用3-甲基喹啉作为唯一碳源和能源的降解特性．并初步分析了3-甲基喹啉的降解中间产物。实验结果表明：菌种Q10对3-甲基喹啉具有较高的降解性能．3-甲基喹啉降解的主要途径是首先生成单羟基化合物、多羟基化合物，然后主要在苯环上发生开环反应进一步降解。     

睾丸酮丛毛单胞菌对喹啉的微生物降解途径的研究

从油制气废水的活性污泥中分离得到一株可以在好氧条件下利用喹啉作为唯一碳源和能源的睾丸酮丛毛单胞菌 (Co mamonastestosteroni,编号为Q10 ) .浓度为 2 5 0mg L的喹啉可被该菌完全降解 ,TOC去除率为 70 % .实验结果表明喹啉首先降解为 1H— 2 氧喹啉 ,然后继续转化为 6 羟基— 1H— 2 氧喹啉、5 ,6 二羟基— 1H— 2 氧喹啉和 5 羟基— 6 (2 羧基乙烯基 )—1H— 2 吡啶酮 ,由此提出该菌降解喹啉的一种可能途径 .样品中还发现少量的 8 羟基— 1H— 2 氧喹啉 ,表明菌Q10 对喹啉的降解可能是通过以一种途径为主的多种途径进行的 .     

喹啉降解菌筛选及其对焦化废水强化处理

以喹啉为目标污染物,从焦化厂废水处理工段活性污泥中分离出1株能利用喹啉作为唯一碳源、氮源及能源的高效降解菌DQS-01,经16S rRNA基因分析鉴定为丛毛单胞菌科食酸菌属(Acidovorax sp.)菌株.通过考察不同培养条件下DQS-01降解菌的生物量及喹啉降解率随时间的变化,确定其最佳降解条件为接种量10%、摇瓶转速150 r·min-1、初始p H 8.0~10.0、温度35℃.应用Haldane方程对该菌在不同喹啉初始浓度下的生长动力学过程进行了模拟,拟合曲线与实验测定值相关性良好.将该菌与高效苯酚降解菌混合菌株用于焦化废水的生物强化处理,在移动床生物膜反应器(moving-bed biofilm reactor,MBBR)运行72 h后,对焦化废水COD的降解率达到87.4%.     

含氮杂环化合物在厌氧和缺氧条件下的降解研究

选取5种含氮杂环化合物吡啶，吲哚、喹啉、异喹啉，2－甲基喹啉，研究了它们在厌氧和缺氧条件下的降解情况，结果表明，上述5种化合物在厌氧条件下的降解从易到难依次为：吲哚＞异喹啉≈喹啉＞吡啶＞2－甲基喹啉，在缺氧条件下的降解从易到难依次排列为：吡啶＞吲哚＞喹啉＞2－甲基喹啉＞异喹啉。实验比较，说明5种化合物在缺氧条件下都比在厌氧条件下容易降解，特别是吡啶，其降解速率有很大提高。     

一株嗜盐菌的分离鉴定及其降解甲基绿的实验

从舟山双峰盐场的盐田中分离筛选得到一株可降解碱性染料甲基绿细菌Salinivibrio kushneri DD-1。研究了该菌株最佳的生长盐浓度以及在不同NaCl浓度、甲基绿浓度、pH值以及O_2浓度对该菌株降解甲基绿的影响,并对其降解产物进行分析。结果表明:该菌株为一株嗜盐菌,最佳生长盐浓度为50 g/L。脱色实验中,Salinivibrio kushneri DD-1在ρ(NaCl)为50 g/L时脱色率最高,达到95%;对低浓度甲基绿(25 mg/L)的脱色效果较好;脱色率随pH升高而增大,该菌株在碱性条件下对甲基绿的脱色效果更佳; Salinivibrio kushneri DD-1在厌氧条件下无法降解甲基绿,随着O_2浓度升高,脱色效果逐渐增强。甲基绿降解产物主要为4-(N,N-二甲基氨基)-4'-(N',N'-二甲基氨基)二苯甲酮、4-(N-乙基-N,N-二甲基氨基)-4'-(N',N'-二甲基氨基)二苯甲酮、[4-(N-乙基-N,N-二甲基氨基)][4'-(N',N'-二甲基氨基)][4″(N″,N″-二甲基氨基)]三苯基甲醇。     

喹啉降解菌的降解效果考察

为了探索石油污染土壤中含氮杂环化合物的降解情况,在考察石油污染土壤理化性质的基础上,选择喹啉作为目标污染物,采用选择性富集培养的方法,从45份石油污染土壤样品中,分离得到155株降解喹啉污染物的高效降解菌株,从中选择降解效率较高的2株喹啉降解菌命名为Q5和Q24,进行喹啉的降解性能研究,比较了单一优势菌株、人工复合菌群和土壤中的自然菌群对喹啉的降解情况。实验结果表明,石油污染土壤中自然菌群对喹啉的降解效果好于单一的优势菌株和人工复合菌群。     

JLNYO1菌降解地下水中阿特拉津效果的研究

从吉林市农药厂排污口采集的污泥样品，通过富集培养，从中分离筛选出一株阿特拉律（AT）高效降解菌JLNY01，该菌在10℃一定浓度的AT条件下，经过一定时间的驯化，降解率可达83．6％。在30℃下，AT能够达到完全降解。经初步鉴定该菌为假单胞菌属。     

固定化及游离态皮氏伯克霍尔德氏菌(Burkholderia pickettii)降解喹啉的试验研究

从处理焦化废水的A2/O工艺曝气池中筛选、分离得到一株能利用喹啉作为唯一碳源、氮源和能源的细菌，经鉴定为皮氏伯克霍尔德氏菌(Burkholderia pickettii)革兰氏染色阴性，杆状.采用PVA-硼酸-纱布复合载体法包埋固定了该菌，用电镜观察研究了该菌在固定化载体中的分布及形态.固定化细胞降解动力学试验表明，喹啉的降解符合零级反应.比较了固定化细胞与游离态细胞降解喹啉的特性，实验结果表明，游离态细胞利用喹啉的速率较快.     

一株降解微囊藻毒素的缺陷短波单胞菌的分离鉴定及降解特性研究

从太湖水华腐烂蓝藻中筛选出一株能够降解MC-LR的细菌,将其编号为Q3.经形态、生理生化及16S rRNA基因序列分析鉴定为缺陷短波单胞菌(Brevundimonas diminuta).研究发现,在实验条件下该菌能以MC-LR为唯一碳源和氮源生长;7 d内可将初始浓度为0.96 mg·L-1的MC-LR降解为0.37 mg·L-1,降解效率达到61.5%.同时,本研究首次发现缺陷短波单胞菌能够降解藻毒素,并且在此菌种中扩增出了降解过程的关键基因mlr A,推测该菌可能与已报道的Sphingomonas sp.ACM-3962等菌具有相同的降解机制.     

一株克雷伯氏菌的多环芳烃降解特性研究

文章通过对一株克雷伯氏菌的多环芳烃降解能力进行了相关研究,并在以萘为单一碳源的培养条件下,确定此株克雷伯氏菌降解萘的最佳温度、接种量和底物浓度,实验结果表明,该株克雷伯氏菌能够高效降解萘、荧蒽、苯并（a）蒽等多种多环芳烃,且对萘的平均降解率达62.5%。确定该菌株对萘的最佳降解条件为37℃、1 200 mg/L的底物浓度、3%的接种量,且菌株对萘的降解率受底物浓度的影响依次大于受接种量和温度的影响。     

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.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

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

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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.     

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.