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浮游植物间的交互化感作用被认为是自然水体中浮游生物群落演替及优势种转换的主要因素之一.铜绿微囊藻(Microcystis aeruginosa)是富营养化湖泊中的常见蓝藻,其产毒品系相较非产毒品系具有较高的竞争优势,其产生的主要次生代谢产物微囊藻毒素-LR(MC-LR)通常被认为是重要的化感物质.但是到目前为止其在水生生态系中的生物学功能尚不明确.为探究并区分MC-LR及其他次生代谢产物对浮游植物的化感效应,本文研究了MC-LR与高浓度普通小球藻(Chlorella vulgaris)生长及有效量子产率的剂量—效应关系;比较了能够产生显著抑制效应的MC-LR、能够产生同等浓度MC-LR的产毒品系铜绿微囊藻滤液以及细胞粗提液对小球藻生长及有效量子产率的抑制效应.结果显示,MC-LR能够对小球藻生长及有效量子产率产生抑制作用,并且抑制率随着MC-LR浓度的增加而增大.在用200μg/L及以上浓度的MC-LR感染24 h后,叶绿素a浓度为1500μg/L的小球藻的生长与有效量子产率均比对照组显著降低.能够产生相同浓度MC-LR的产毒品系铜绿微囊藻细胞滤液对其没有产生显著影响,而其细胞粗提液却能够产生更强的抑制效应.与MCLR处理组相比,粗提液处理组小球藻的生长及有效量子产率分别降低了14%和3%.以上结果表明,MC-LR对普通小球藻的化感作用具有剂量依赖性;MC-LR之外的其他次生代谢物也能够产生抑制效应. 相似文献
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为探究太湖梅梁湾水体及沉积物中微囊藻毒素（MC-LR、MC-RR、MC-YR）含量的垂向分布特征，于2018年5月采集梅梁湾6个点位表层水、上覆水、混合水、间隙水以及柱状沉积物样品，并采用超高效液相色谱-串联质谱法分析样品中微囊藻毒素的含量.分析结果表明：水体中（表层水、上覆水、混合水以及间隙水）MC-LR、MC-RR、MC-YR的浓度范围分别为11.80~1297.14、2.50~818.40、1.80~176.00 ng/L，表层水、上覆水以及混合水中MC-LR的浓度高于MC-RR和MC-YR，MC-RR和MC-YR之间差别较小，而间隙水中MCs三种异构体浓度大小顺序为：MC-LR > MC-RR > MC-YR；垂向分布上，间隙水中MCs异构体（MC-LR、MC-RR、MC-YR）浓度均远高于表层水、上覆水以及混合水，表层水MCs异构体浓度略高于上覆水，混合水MCs异构体浓度介于表层水和上覆水之间.对沉积物的研究发现，1~10 cm表层沉积物中MC-LR、MC-RR、MC-YR含量范围分别为0.60~26.95、0~0.90、0~8.10 ng/g，且1~10 cm层中MCs三种异构体平均含量大小顺序为：MC-LR > MC-YR > MC-RR，其中MC-LR、MC-RR、MC-YR的检出率分别为100%、70%、92%；垂向分布上，MC-RR含量较低且变化不大，而MC-YR和MC-LR含量均随沉积物深度的增加先升高后降低.相关性分析结果表明，表层水和混合水中MCs与总磷浓度呈显著正相关，而与总氮浓度无显著相关性；上覆水、间隙水以及沉积物中MCs与总氮、总磷浓度均呈显著正相关. 相似文献
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Laboratory experiments were used to study the sensitivity of both male and female Daphnia magna to a toxic cyanobacterium, Microcystis aeruginosa. Male and female D. magna were fed with M. aeruginosa and a green alga (Scenedesmus obliquus) in different mixtures that included 0%, 25%, 50%, 75% and 100% Microcystis. Growth of both males and females declined with increasing proportion of Microcystis in the diet. Males were slightly less sensitive to Microcystis than females with EC50 for growth inhibition at 72% and 63% Microcystis in the diet, respectively. On monospecific Microcystis diet, mortality rates for males (0.16 d–1) and females (0.17 d–1) were similar. The reproductive rate of females was the most sensitive endpoint with an EC50 of 42% Microcystis in the diet, whereas population growth rates were the least sensitive (EC50 of 74% Microcystis). Microcystis in the diet severely depressed growth and reproduction in Daphnia and poses a severe threat to its survival in which only a switch in reproductive strategy might provide Daphnia a refuge to a Microcystis environment that gradually becomes uninhabitable. 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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Isolates of Microcystis blooms collected from Dianchi Lake of South-western China in different seasons were tested by mouse bioassays. The LD50 of the vcdcrocystis isolates corre-sponding M. wesenbergii, M.viridis and M. aeruginosa were 221 mg · kg -1, 188 mg · kg -1, and 198 mg · kg -1 respectively. The cells of the three samples contained hepatotoxins or microcystins. The HPLC (high performance liquid chromatography) analysis showed that all the three Microcystis species contained microcystin LR. In addition, M. wesenbergii contained microcystin RR, M. viridis contained microcystinYR, M. aeruginosa contained both microcystin RR and YR. The results suggested that in different seasons the toxins which were produced by the dominating Microcystis species were fluctuent with regard to the composition and content of the toxins and consen-quently were obvious factors that aroused the water quality to decrease and change. 相似文献
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2011年我国实施了新的生活饮用水卫生标准,卫生指标扩展至106项,并配套了相关的检测方法,其中微囊藻毒素、莠去津采用液相色谱紫外检测器的检测方法;丙烯酰胺、灭草松、2,4-D采用气相色谱-电子捕获检测器的检测方法;呋喃丹、草甘膦采用液相色谱荧光检测器的检测方法。这些检测方法均有前处理程序繁琐、工作量大、可操作性差的缺点,在实际工作中应用较为困难。本文采用超高效液相色谱-串联质谱技术（UPLC-MS/MS）,建立了水样过0.22 μm滤膜,直接进样测定自来水、地下水及地表水中8种有机污染物（草甘膦、呋喃丹、灭草松、莠去津、2,4-滴、丙烯酰胺、微囊藻毒素-RR和微囊藻毒素-LR）的分析方法。8种化合物在各自的线性范围内线性关系良好,相关系数均不低于0.993,定量下限为0.07~5 μg/L,低、中、高三个加标水平的回收率为94.2%~103.7%,相对标准偏差为1.1%~7.8%。本文建立的方法操作简便,可以实现在6 min内一次性分析8种目标化合物,与国家标准方法相比,显著提高了分析效率;与文献报道的均是单一类化合物检测方法相比,本检测方法具有相似的灵敏度和检测限,但是目标化合物覆盖更全面,分析时间更短。 相似文献
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鄱阳湖不同湖区营养盐状态及藻类种群对比 总被引：4，自引：1，他引：3
在平水期、丰水期和枯水期对鄱阳湖典型天然碟形湖、人控湖汊和主湖区进行了水质、藻类和蓝藻毒素等对比调查,结果表明鄱阳湖各个湖区的水质与藻类种群等差异较大,蓝藻毒素浓度和底泥中铁含量的分布具有一定关联性.在各水文季节蓝藻均为人控湖汊藻类的主要优势种之一.平水期鄱阳湖藻类生物量(叶绿素a浓度)与水体的pH呈正相关关系,与采样点的水深呈负相关关系,碟形湖区水体营养盐浓度和藻类细胞密度均较其他湖区水体低.丰水期各湖区的水质差异相对较小,碟形湖藻类细胞密度仍低于其他湖区,但蓝藻已成为各湖区的优势种,该时期藻类生物量与水体总磷浓度及浊度呈正相关关系.枯水季鄱阳湖各水体藻类生物量与水体总氮浓度、铵态氮浓度及电导率呈正相关关系,碟形湖与主湖区发生了完全分离,水体流动性差,暴发蓝藻水华的风险较高.高温丰枯季节鄱阳湖水体蓝藻毒素浓度与底泥铁含量呈现一定的相关分布关系,底泥铁含量高的地方,其水体蓝藻毒素浓度通常比较高,应警惕鄱阳湖流域富铁红壤流失带来的湖区蓝藻水华风险加剧后果.上述研究结果将为鄱阳湖水环境的预警和污染控制提供科学指导. 相似文献
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Study on Algae Removal by Immobilized Biosystem on Sponge 总被引：2，自引：0，他引：2
PEI Haiyan HU Wenrong 《中国海洋大学学报(英文版)》2006,5(4):327-332
In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake＇s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time （HRT） was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preyingby microcreatures were the two main modes of algal removal, which occurred in two steps： first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures. 相似文献