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五株微囊藻毒素降解菌的分离与鉴定 总被引：9，自引：0，他引：9
有毒蓝藻产生的蓝藻毒素导致地表水的污染已是全球普遍的现象,最常见的毒素是能导致肝癌的肝毒素微囊藻毒素(MC),迄今为止尚无适用的MC驱除技术,微生物降解MC可能是一条有效的途径．本研究以铜绿微囊藻(Microcystis aeruginosa PCC 7806)所产生的MC为底物,从多个形成微囊藻水华的水体中分离获得能显著降解MC的细菌18株,相对降解能力从18．4％到48．2％．对其中5株MC相对降解能力较强的菌,通过形态特征和生理生化特征分析,鉴定出5株菌分别为:不动细菌属(Acinetobacter)、肠杆菌属(Enterobacter)、微杆菌属(Microbacterium)、芽孢杆菌属(Bacillus)和弗拉特氏菌属(Frateuria),均不同于已报道的属种． 相似文献
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2013年洱海水华期间微囊藻毒素和浮游植物动态变化 总被引：2，自引：1，他引：1
2013年秋季,洱海再次出现大规模水华,周边几十万居民的饮用水安全引起当地政府的极大关注.为了解水华发生期间洱海水体微囊藻毒素的含量和浮游植物的种类及丰度,分别在2013年9月和10月两次在洱海采集水样,测定其中两种主要微囊藻毒素MC-LR和MC-RR含量,探讨微囊藻毒素含量对洱海周边水源地的安全影响.同时也对水华期间的浮游植物特别是蓝藻进行研究,从而分析微囊藻毒素与浮游植物种类和丰度的关系.结果表明,洱海水体中微囊藻毒素含量偏低,暂不会对人类健康产生威胁,但在洱海的水鸟体内仍然检测到微囊藻毒素的富集,显示洱海蓝藻水华对水生生物的潜在危害不容忽视.浮游植物的研究发现,洱海水华的优势种属为微囊藻(Microcystis)和暗丝藻(Psephonema aenigmaticus).9月份暗丝藻更占优势,10月份则是微囊藻更占优势.研究结果显示处于富营养化初期的洱海水体中湖湾微囊藻毒素的含量与浮游植物中产毒蓝藻的种类和丰度密切相关. 相似文献
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我国淡水水体蓝藻水华的频繁发生已成为我国目前和今后长时期内面临的重大水环境问题.微囊藻(Microcystis)因其产生对人类健康具有危害的微囊藻毒素而尤其受到重视.研究者对构成蓝藻水华的主要种类、微囊藻毒素的毒性、毒理等方面的认识逐渐明晰,但对微囊藻毒素生物学功能的了解还相对较少.本文对微囊藻毒素的产生,尤其是近年来随着技术的发展在微囊藻毒素生物学功能方面的研究开展讨论:总结了微囊藻毒素可能作为化感物质、参与光合作用、在微囊藻的越冬或复苏中可能发挥的作用以及可能参与微囊藻群体形成及维持等4个方面的生物学功能;分析了微囊藻毒素作为信号分子的研究现状;探讨了全球气候变化及实验室模拟条件下微囊藻毒素产毒与无毒株的竞争,并对微囊藻毒素未来的研究热点及组学技术可能在其研究中的应用进行了展望. 相似文献
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滇池水体中微囊藻毒素含量变化与环境因子的相关性研究 总被引：23，自引：1，他引：23
本文对2003年4-12月滇池马村湾、海东湾微囊藻毒素和总磷、总氮、溶解氧、透明度、光照强度、叶绿素a、pH值、水温及微囊藻种群优势度进行了分析,讨论了以上指标在滇池马村湾和海东湾的分布和月变化情况以及与微囊藻毒素含量之间的关系．相关性分析表明马村湾、海东湾微囊藻毒素在水体中分布与总氮和氮磷比之间呈现非常显著的负相关性(P<0．01);与透明度、光照强度和微囊藻种群优势度存在显著的正相关性(P<0．05)．在影响微囊藻毒素的各因素中,运用多因素逐步回归分析得知马村湾、海东湾微囊藻毒素浓度主要南水体的总氮、总磷、叶绿素a和溶解氧以及透明度决定(R2=0．560,P<0．017)． 相似文献
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随着蓝藻水华环境问题的日益严重,微囊藻毒素(MCs)的污染问题也越来越受到重视.一些藻毒素污染严重的湖泊、水库等周边区域的土壤也受到了影响.用含有藻毒素的地表水及地下水进行灌溉、将蓝藻作为有机肥等措施都会将MCs带入土壤.一旦MCs进入到土壤,它将会随着降水从地表迁移到土壤深层.这将会对作物的生长以及土壤生态系统造成影响,而且会对人类身体健康造成威胁.本文介绍了土壤中不同种类的MCs对一些粮食作物和蔬菜作物生长的影响、在作物体内的积累情况,以及对地下水的污染情况,概述了MCs的致毒机理,分析了其对土壤生物造成影响的可能性,并对今后的研究方向进行了展望. 相似文献
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微囊藻毒素粗提物对水环境中温和气单胞菌活的非可培养状态的影响 总被引：2，自引：0，他引：2
细菌VBNC状态(Viable but non-culturable state),又称"活的非可培养状态",是自然水体中广泛存在的细菌的一种特殊存活状态,复杂的环境因子变化是VBNC状态转换的可能原因.本研究利用接种温和气单胞菌的无菌湖水,研究铜绿微囊藻(Microcystis aeruginosa)培养液和微囊藻毒素粗提液对水环境中温和气单胞菌VBNC状态转换的影响,结果发现,温和气单胞菌在无菌湖水中同时存在VBNC状态和可培养状态;产毒微囊藻培养液和微囊藻毒素粗提液均能促进温和气单胞菌中VBNC细菌与可培养细菌之间的状态转换,说明微囊藻毒素可能是水环境中影响细菌VBNC状态转换的重要环境因素,其进一步的分子机制研究正在进行中. 相似文献
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微囊藻(Microcystis)产生大量胞外多糖(EPS),包括包裹在细胞外的胶鞘多糖(CPS)和释放到周围环境中的水溶性多糖(RPS).为探究EPS在蓝藻水华发生中的生理生态学意义,迫切需要了解微囊藻EPS的化学特性.本文从太湖分离群体微囊藻,经过大约18个月实验室培养后,其中一些藻株转变为单细胞形态.选择5株群体藻和4株单细胞藻,比较分析这些藻株EPS的化学特性发现:(1)所有9株藻的EPS均为含有脱氧己糖的酸性杂多糖;(2)所有9株藻的CPS的糖醛酸含量(1.2%~2.1%)均低于RPS的糖醛酸含量(2.4%~6.2%);(3)所有9株藻的EPS均含有乙酰基和硫酸基,其中,每一株藻CPS的乙酰基含量均高于RPS的乙酰基含量,所有群体藻CPS的乙酰基含量(4.1%~6.6%)高于所有单细胞藻CPS的乙酰基含量(2.0%~3.2%).本文进而讨论了EPS化学特性对EPS水溶性和微囊藻群体形成的影响,以及对其生态学作用的影响.在这些化学特性中,乙酰取代基团被认为可能是影响微囊藻EPS生理生态学作用的重要因素. 相似文献
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Development of a Capillary Zone Electrophoretic Method for the Rapid Separation and Detection of Hepatotoxic Microcystins 总被引：5，自引：0，他引：5
Analysis of trace amounts of various hepatotoxic microcystins in marine and freshwater samples is very important since these toxins, especially microcystin-LR, have been demonstrated to have tumour-promoting activity. In this study, instead of measuring the total amount of microcystins, we developed a capillary zone electrophoretic method for the separation and detection of individual toxin standards. No additives were used for enhancement of resolution. This technique is characterized by a high separation efficiency, short analysis time and small sample volume. In order to improve the detection sensitivity, a laser-induced fluorescence detector was used, and the labelling of microcystins was accomplished through a two-step procedure. First, the microcystin standards were converted into cysteine conjugates, followed by derivatization with Fluorescein 5-Isothiocyanate (FITC). After derivatization, the FITC-labelled microcystins were directly injected, separated and detected in 8 min. This method was shown to be a promising technique for sensitive and rapid analysis of individual microcystin toxins. 相似文献
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Vera Pavlova Pavel Babica Detelina Todorova Zlatka Bratanova Blahoslav Mar&#x;lek 《洁净——土壤、空气、水》2006,34(5):437-441
This paper presents the results from analyses of water samples from 15 Bulgarian reservoirs and lakes for detection of microcystins presence by high‐performance liquid chromatography (HPLC) coupled to a ultraviolet (UV) and photo diode array (PDA) detector. In 3 of the studied drinking water reservoirs cyanobacterial blooms were not detected. Cyanobacterial blooms were observed in 6 of 12 investigated water bodies used for fishing and water sports. Microcystis was the dominant cyanobacterial genus. The concentration of total microcystins in the biomasses ranged from 8 to 1070 μg g–1 (d.w.). Microcystin‐LR and microcystin‐RR were the predominant microcystins, followed by microcystin‐YR. Presence of dissolved microcystins was obtained in one water sample with concentration of total microcystins 1.64 μg L–1. Presence of microcystin‐LF and ‐LW or unknown peaks possessing characteristic microcystin‐like UV‐spectra were not detected. Those first results for occurrence of microcystins in some Bulgarian reservoirs and lakes are a contribution to the knowledge on their distribution. 相似文献
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On the diet of Nile tilapia in two eutrophic tropical lakes containing toxin producing cyanobacteria
Ronald Semyalo Thomas RohrlackDuncan Kayiira Yusuf S. Kizito Stephen ByarujaliGeorge Nyakairu Petter Larsson 《Limnologica》2011,41(1):30-36
Due to the production of toxins, cyanobacteria may adversely affect economically important fish such as Nile tilapia Oreochromis niloticus in tropical lakes. We studied the diet composition and factors affecting the diet of Nile tilapia in two tropical lakes where cyanotoxins were present. Particle-bound microcystins were present in all analysed water samples, ranging in concentration from 0.00012 to 1.11 and from 0.006 to 0.254 μg L−1 in Murchison Bay in Lake Victoria and Lake Mburo, respectively. Detritus and phytoplankton were the main dietary components of the Nile tilapia, with phytoplankton contributing to over 30% by volume of stomach contents. The cyanobacteria Microcystis spp., which are also the most likely source of microcystins in the lakes, accounted for more than 80% of ingested phytoplankton. Microcystis spp. were also the most abundant cyanobacteria in both lakes (>60%). We found no significant relationship between the contribution of phytoplankton in Nile tilapia diet and the concentration of microcystins in the water but we found a close association between water transparency and the contribution of insects to Nile tilapia diets in Murchison Bay. Our results further show that none of the other measured environmental variables was a good predictor of diet items in Nile tilapia. Adult Nile tilapia in our study lakes, rely heavily on filter feeding, particularly under conditions of low water transparency, trapping detritus and phytoplankton cells especially colonies. They can ingest more mobile prey like insects and insect larvae when the water transparency and visibility increases. 相似文献
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H. Ait Hammou D. Latour S. Samoudi K. Mouhri M. Douma J. Robin M. Loudiki 《Water Resources》2018,45(3):409-417
In order to understand initial conditions that promote the first occurrence of a Microcystis aeruginosa bloom and to evaluate its toxic potential, we studied spatio-temporal dynamics of phytoplankton, including Microcystis, microcystins concentrations, the relative proportion of potentially microcystin producing cells and physicochemical parameters in the recently setup Moroccan reservoir “Yaacoub Al Mansour.” High summer temperatures, thermal stability, hydrological stability of the water column and the decrease of nutrient contributions seem to be the major environmental factors responsible of this first bloom occurrence. Despite the low cellular abundance, high microcystins concentrations, associated with low percentage of toxic strains, were measured. Thus, microcystins analysis and associated management of the reservoir are necessary from the beginning of the setup and can help managers to find the better environmental strategy against early cyanobacteria proliferations. 相似文献
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Lucie Bláhová Pavel Babica Eliška Maršálková Blahoslav Maršálek Ludek Bláha 《洁净——土壤、空气、水》2007,35(4):348-354
The first outcomes of the national monitoring program on cyanobacteria and their toxins in the Czech Republic are reported. The concentrations of extracellular microcystins (MCs, analyzed by ELISA) in 206 water samples collected from 94 localities have been investigated. Observed MC concentrations were relatively high in comparison with the literature data, although weather conditions during the covered season (year 2004) were less favorable for the cyanobacterial water blooms. Detectable MCs (>0.125 μg/L) were found in 145 waters (70% of all samples) with a median concentration of 0.67 μg/L. The total median, including samples with no detectable MCs, was 0.26 μg/L. The seasonal trend showed an increase from July to September at most localities (maximum concentrations of about 8 μg/L and extremes up to 37 μg/L). However, a peak at the beginning of the season or continuously elevated MC concentrations were also observed at some localities. Positive correlations between increasing concentrations of MCs and the dominancy of Microcystis spp. have been observed. The survey provides the first large-scale study of the occurrence and seasonal variability of extracellular microcystins that are of particular interest for drinking water management. 相似文献
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Water Resources - For the first time, data are given on cyanobacterial toxins entering tap water, supplied to the population of some cities in Yaroslavl oblast. The detection of microcystins with... 相似文献
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Cyanobacterial toxins in Italian freshwaters 总被引：1，自引：0，他引：1
Valentina Messineo Serena Melchiorre Antonella Lugliè Maria Antonietta Mariani Antonio Di Corcia Ermanno Carloni 《Limnologica》2009,39(2):95-106
This study focuses on the occurrence and distribution of cyanobacterial toxins from 1989 to 2006 in several Italian lakes of different characteristics and human uses, the latter including drinking water abstraction and recreation. Phytoplankton and LC/MS/MS toxin analyses were performed on surface water samples collected from 28 lakes. The most widespread species associated with toxin production belonged to the genera Microcystis, Planktothrix and Anabaena. Extracellular concentrations varied from non-detectable values up to 226.16 ng/mL for microcystins (sum of all variants), to 126 ng/mL for total cylindrospermopsin, and to 100 μg/g (dry weight) for anatoxin-a.The toxin concentrations in the lake waters did not always correlate with the cyanobacteria cell densities. This implies a need for control studies including toxin detection in water together with microscopic cell evaluations, in order to avoid possible toxin underestimates. 相似文献
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The present study was undertaken to investigate the accumulation of microcystins (MCYST) in the various tissues of an endemic and protected fish species (Rutilus panosi). We also tried to identify any differences in sensitivity and accumulation of MCYST, for various specimens of the same fish species related to body length. MCYST concentrations in lake water and fish tissues were determined by a commercial Microcystin ELISA kit. Results showed that considerable amount of toxins were found to be accumulated in tissues of R. panosi throughout the year. Among them, liver had the highest MCYST concentrations (407.97 ± 32.43 ng/g). This study confirmed the accumulation of high MCYST concentrations in fish brain (308.75 ± 26.49 ng/g). Our results suggest, that MCYST accumulation in R. panosi tissues is size depended. High MCYST concentration in the muscle of the fish increases the risk of unsafe consumption, thus threatening human health. 相似文献