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1.
A number of marine microalgae are known to produce toxins that can accumulate in shellfish and when eaten, lead to toxic and potentially fatal reactions in humans. This paper reports on the occurrence and seasonal variations of algal toxins in the waters, phytoplankton and shellfish of Southeast Queensland, Australia. These algal toxins include okadaic acid (OA), domoic acid (DA), gymnodimine (GD), pectenotoxin-2 (PTX-2) and pectenotoxin-2-seco acid (PTX-2-SA), which were detected in the sampled shellfish and phytoplankton, via HPLC-MS/MS. Dissolved OA, PTX-2 and GD were also detected in the samples collected from the water column. This was the first occasion that DA and GD have been reported in shellfish, phytoplankton and the water column in Queensland waters. Phytoplankton tows contained both the toxic Dinophysis and Pseudo-nitzschia algae species, and are suspected of being the most likely producers of the OA, PTX-2s and DA found in shellfish of this area. The number of cells, however, did not correlate with the amount of toxins present in either shellfish or phytoplankton. This indicates that toxin production by algae varies with time and the species present and that number of cells alone cannot be used as an indicator for the presence of toxins. The presence of OA and PTX-2s were more frequently seen in the summer, while DA and GD were detected throughout the year and without any obvious seasonal patterns.  相似文献   

2.
选取具有显著产毒差异的利玛原甲藻(Prorocentrum lima) SHG株与2XS株为研究对象,以2-13C-甘氨酸为示踪原料结合高分辨质谱方法,为腹泻性贝类毒素及其酯化态毒素合成与代谢途径的研究提供新方法和思路。结果表明,两株藻共发现16种腹泻性贝毒及其酯化态毒素成分。对照培养条件下SHG株(大田软海绵酸毒素含量为7.88 pg/cell,鳍藻毒素1含量为4.35 pg/cell)的产毒能力高于2XS株(大田软海绵酸毒素5.70pg/cell),而甘氨酸作为氮源培养条件可显著提高两株藻的产毒总量(P<0.05)。13C-甘氨酸标记组与甘氨酸培养组单细胞产毒量无显著变化(P>0.05)。腹泻性贝毒被标记后其同位素异构体丰度发生变化,其中酯化态受13C标记的影响程度更高,二级质谱图清晰表示出其碎片离子及脱水峰的标记情况。该方法直观阐明了甘氨酸可作为P. lima标记原料的产毒供体,并使用稳定同位素标记方法首次实现了酯化态的同步标记,有助于腹泻性贝毒生成机制的进一步研究。  相似文献   

3.
The Benguela upwelling system is subjected to blooms of harmful and toxic algae, the incidence and consequences of which are documented here. Red tides are common and usually attributed to members of the Dinophyceae, most of which are non-toxic. The incidence of these blooms varies spatially, with most blooms confined to the area west of Cape Agulhas. Cape Point forms the natural divide for species that dominate blooms of the west coast of South Africa as opposed to those that dominate the South Coast. Blooms occur most commonly from January to May, during the latter half of the upwelling season. Each red tide is associated with synoptic weather patterns, which dictate the onshore and offshore movement of dinoflagellate-dominated frontal blooms. There is also interannual variation, thought to be related to weather pattern changes. The harmful effects of high-biomass, non-toxic blooms include die-offs resulting from anoxia or hypoxia. Other effects of high biomass blooms include those that may cause mechanical or physical damage or those that may alter the foodweb. Recently, a bloom of the very small pelagophyte, Aureococcus anophagefferens, referred to as brown tide, in Saldanha Bay and Langebaan Lagoon resulted in growth arrest in both oysters and mussels. Toxic species cause mass mortalities of fish, shellfish, marine mammals, seabirds and other animals. Human illness is caused by contaminated seafood when toxic phytoplankton are filtered from the water by shellfish that accumulate toxins to levels that are potentially lethal to humans and other consumers. Of these shellfish poisoning syndromes, Paralytic (PSP) and Diarrhetic Shellfish Poisoning (DSP) are common in the Benguela. Confirmed cases of PSP have been attributed to the dinoflagellate Alexandrium Catenella. Although shellfish are usually only marginally affected, in extreme cases of poisoning, mussel mortalities have been observed, and in most instances these have been attributed to blooms of A. Catenella. Sardine Sardinops sagax mortalities in St Helena Bay have also been attributed to the ingestion of this PSP-producing dinoflagellate. Monitoring has revealed the presence of Dinophysis acuminata, D. fortii, D. hastata, D. tripos and D. rotundata, all of which have been reported to cause DSP. The dinoflagellate Gymnodiniun cf. mikimotoi, has been implicated in a type of Neurotoxic Shellfish Poisoning and human skin and respiratory irritations have been attributed to aerosol toxins produced by this species.  相似文献   

4.
A laboratory experiment was performed with the clam Ruditapes decussatus, fed with the toxic dinoflagellate Gymnodinium catenatum and the non-toxic algae Isochrysis galbana (14 days) and subsequently only with I. galbana (15 days). Individual paralytic shellfish toxins were determined by LC-FLD in G. catenatum cells, whole clam tissues, and particulate organic matter (POM) produced by clams. The toxins dcSTX and dcGTX2 + 3 in the algae were less abundant than C1 + 2 and B1, but were predominant in clams during both the exposure and depuration phases. The toxin dcNEO was only detected in clams during a short period, indicating conversion from other compounds. The toxin composition of the POM indicated the export of dcSTX as faeces or pseudo-faeces along the entire experiment (2.5–14 nmol mg−1), B1 was present in a short period of the exposure and C1 + 2 and dcGTX2 + 3 absent. A mass balance calculation indicated that approximately 95% of C1 + 2 and 85% of B1 supplied to the clams were converted into other toxins or lost in solution. Conversely, the net gain of 512, 61 and 31 nmol for dcSTX, dcGTX2 + 3 and dcNEO, respectively, suggests the conversion from other assimilated compounds by clams during exposure and depuration phases.  相似文献   

5.
改性粘土法是一种高效、环保的有害藻华应急处置技术,可通过絮凝作用有效去除水体中藻华生物。但利用改性粘土絮凝产毒藻后,水体中胞内外藻毒素的变化情况目前尚不清楚。文章考察了I型改性粘土(MCI)絮凝典型产毒甲藻——太平洋亚历山大藻(Alexandriumpacificum)后,水体中残留藻细胞内和胞外麻痹性贝类毒素(paralytic shellfish toxins, PSTs)含量、组分的变化情况。实验结果表明, MC I对密度为6.11×10~3 cells/mL的A. pacificum 3小时去除率达62%,水体中残留藻细胞单细胞毒素含量和PSTs组分与对照组无显著差异,但水体中总PSTs含量大大降低,其中由絮凝沉降导致的胞内PSTs被去除量占水体中PSTs总减少量的90%以上。另外,针对MC I对胞外PSTs吸附效果的研究发现,低于0.5 g/L的MC I对胞外PSTs无明显吸附效果,而在利用0.2 g/L MC I絮凝去除大部分亚历山大藻后,水体中胞外PSTs含量无明显变化。由此可以推测该用量下的MC I未造成大量藻细胞破裂向水体中释放毒素。该研究结果将为改性粘土治理有毒甲藻藻华的现场应用提供科学依据。  相似文献   

6.
中国近海藻毒素及有毒微藻产毒原因种调查研究进展   总被引：2，自引：0，他引：2  
麻痹性贝类毒素在我国近海污染问题已十分突出,基本呈现逐年加剧的趋势。20世纪90年代,南海麻痹性贝类毒素污染较重; 21世纪初,北黄海麻痹性贝类毒素污染较重;近几年,渤海和福建近海麻痹性贝类毒素污染较重;可产生麻痹性贝类毒素的微藻有亚历山大藻和裸甲藻等。采用小鼠生物法检测我国近海腹泻性贝类毒素超标率32%左右,采用液相色谱/质谱法检测,仅有3起超标的研究报道;现行小鼠生物法检测腹泻性贝类毒素假阳性问题十分突出,应尽快废除;腹泻性贝类毒素均是脂溶性的,脂溶性海洋生物毒素在我国近海常年可检出,偶有虾夷扇贝毒素和鳍藻毒素超标现象。可产生脂溶性毒素微藻有鳍藻和原甲藻及网状原角藻等。失忆性贝类毒素在我国近海常有检出,但无超标现象;产毒微藻有拟菱形藻等。西加鱼毒素在我国南海污染较重,但毒素标准物质的匮乏,限制了西加鱼毒素的调查研究;至今尚未确定产生西加鱼毒素的微藻。酶联免疫吸附法和液相色谱串联质谱法相结合已成为藻毒素快速准确检测成熟的技术,逐渐代替小鼠生物法和液相色谱法。  相似文献   

7.
腹泻性贝毒的高效液相色谱法测定条件改进及其运用   总被引：6，自引：0，他引：6  
对腹泻性贝毒的高效液相色谱测定方法的条件进行改变，使原来对实验条件要求苛刻的方法更适宜于一般的实验室使用，使其有可能替代国内目前常用的小鼠生物方法。井成功地运用于冬季大连海域贝类腹泻性贝毒的检测，首次报道了大连地区海域贝类腹泻性贝毒的主要成分大田软海绵酸的含量，其结果是2000年1—3月大连地区海域贝类腹泻性贝毒除个别海区外一般都末检出。  相似文献   

8.
麻痹性贝毒能够在贝类体内累积,威胁海产品消费者健康。在以往调查中,多次在毛蚶(Scapharca subcrenata)体内发现高含量的麻痹性贝毒,但对于毛蚶体内麻痹性贝毒的转化过程及其食品安全风险还缺乏认识。通过室内模拟实验,选择太平洋亚历山大藻(Alexandrium pacificum)和链状裸甲藻(Gymnodinium catenatum)作为产毒藻种,研究了两种有毒藻种所产麻痹性贝毒在毛蚶体内的转化过程。结果表明,毛蚶体内主要出现了三种麻痹性贝毒转化过程,一是R1位羟基的还原反应,二是N-磺酰氨甲酰基类毒素R4位磺酸基团的水解反应,三是含羟基苯甲酸(hydroxybenzoate)基团的链状裸甲藻毒素在R4位的水解反应。毛蚶体内麻痹性贝毒的生物转化过程复杂,对毛蚶毒性的影响具有一定的不确定性,未来仍需要进一步深化毛蚶体内毒素累积、代谢、转化过程的研究,同时加强对毛蚶体内毒素含量的全面监测,防范毛蚶可能导致的麻痹性贝毒中毒风险。  相似文献   

9.
孢囊是甲藻生活史中特殊的休眠阶段,被认为是赤潮发生的种源。于2018年4月采集了福建福宁湾海域表层沉积物,对沉积物中甲藻孢囊的分布规律进行了研究,重点揭示有毒有害甲藻孢囊的分布;同时测定了沉积物中生源要素含量,以揭示孢囊分布与生源要素的关系。共鉴定甲藻孢囊25种,其中别什藻(Biecheleria tirezensis)孢囊占据优势。孢囊的种类多样性指数(H'')偏低,为2.06~2.34;均匀度指数(J)为0.71~0.81。孢囊密度介于178.6~386.3 cysts/g (以干重计,下同),平均为286.0cysts/g。孢囊密度高值区位于水深较深、沉积物颗粒较细的长表岛外海域,而低值区则位于长表岛至海尾角的近岸海域。值得注意的是,研究分析鉴定出9种有毒有害甲藻的孢囊,包括麻痹性贝类毒素(paralytic shellfish poisoning,PSP)原因种奥氏亚历山大藻(Alexandrium ostenfeldii)和链状/塔玛亚历山大藻(Alexandrium catenella/tamarense)孢囊复合体、goniodomine A原因种平野亚历山大藻(Alexandrium hiranoi)、虾夷扇贝毒素(yessotoxin,YTX)原因种具刺膝沟藻(Gonyaulax spinifera)和网状原角藻(Protoceratium reticulatum)、产生鱼毒素的哈曼褐多沟藻(Pheopolykrikos hartmannii)以及赤潮藻类Barrufeta bravensis、锥状斯氏藻(Scrippsiella acuminata)和垂裂莱万藻(Levanderina fissa),其中Barrufeta bravensis、Gonyaulax spinifera和Scrippsiella acuminata的孢囊分布广泛且密度较高,需引起关注。  相似文献   

10.
采用高效液相色谱-串联质谱方法对我国近海贝类中腹泻性贝毒成分进行研究,结果发现采自北黄海大连附近海域的海湾扇贝和虾夷扇贝含有25~41μg/kg的虾夷扇贝毒素(yessotoxin,YTX),在虾夷扇贝体内还含有37.2μg/kg的45-OH-YTX,并在5种贝中发现微量的Homo-YTX毒素组分,这是首次报道在我国贝中检出此类毒素。虾夷扇贝毒素YTXs是一类含有2个磺酰基的脂溶性多环聚醚类化合物,对小鼠的腹腔注射急性致死毒性很高,毒理作用机制尚不清楚。本研究的结果说明我国贝类体内生物毒素成分复杂,亟需进行毒素成分结构、来源生物、生态毒理效应、分布规律及安全限定标准的研究。  相似文献   

11.
麻痹性贝类毒素(paralytic shellfish toxins,PSTs)是由某些甲藻产生的一种高毒性神经毒素,在海洋环境中分布广、危害大,可对水产养殖和人类健康造成重大危害;PSTs毒素的毒性大小随种类和结构的不同有较大差异。迄今,国内外学者针对PSTs的来源分布、迁移转化、生物合成及其影响因素等开展了大量的调查研究,但目前对于藻细胞产毒的生物合成途径、遗传学特征及其环境调控机理等研究仍处于起步阶段。PSTs的生物合成过程不仅与藻细胞自身生长阶段有关,还会受到光照、温度、营养盐等多种环境因素的影响,环境条件的改变会引起藻细胞毒素组成和含量发生不同程度的变化。近年来,研究人员应用基因组学和蛋白质组学技术,发现了产生PSTs的典型甲藻——亚历山大藻(Alexandrium)细胞内与PSTs毒素生物合成相关的某些基因或蛋白质,对我们更清晰地了解亚历山大藻产生PSTs毒素的机制具有重要意义。本文综合以往的研究报道,对亚历山大藻中PSTs的生物合成与转化及其主要影响因素进行了总结,以期为产毒有害藻华的防治提供科学依据。  相似文献   

12.
Isolates of the dinoflagellate Gonyaulax tamarensis were established from benthic cysts or motile cells collected along the north-western Atlantic coast from the Bay of Fundy to Long Island. All clones were grown under the same conditions and assayed in a blind test for toxin content and composition. Differences in toxin content (μmouse unit per cell) spanning two orders of magnitude were found, with decreasing toxicity from north to south. Some isolates had undetectable toxin levels. The low toxicity of southern strains of G. tamarensis may explain the historical absence of paralytic shellfish poisoning (PSP) in areas where cysts and motile cells have been reported. The cause of the observed geographic pattern is unknown, but is does suggest that there may be an environmentally-determined southern limit to the regional PSP problem.Qualitative data on the toxin composition of some clones indicate that saxitoxin, neosaxitoxin and gonyautoxins -II, -III and -IV are generally present. A more quantitative approach (i.e. one which examines each isolate for all of the 12 Gonyaulax toxins) is needed to fully utilize the potential of toxin composition in discriminating between strains.  相似文献   

13.
New Zealand's reputation as a supplier of high quality food products is vital to the national economy; international consumers are acutely aware of food safety issues and markets are increasingly demanding higher standards. Filter feeding bivalves are particularly sensitive to the nature of the environment in which they are grown, and quality assurance is a major preoccupation of the shellfish aquaculture industry. With the exception of a couple of incidents, most notably the Gymnodinium catenatum blooms in 2000–2003, paralytic shellfish toxin (PST) contamination has, to date, not had an important effect on the economics and sustainability of the industry. However, the dinoflagellate species responsible for producing these toxins are not uncommon in New Zealand coastal phytoplankton communities, and it is important that awareness of the potential risk is maintained. This review summarises what we know about the causes and incidence of PST contamination from research and monitoring over the last 20 years, since it was first identified in New Zealand. It describes the dynamics of major events and their consequences, and evaluates what is likely to happen in the future as aquaculture expands into new areas with known histories of this problem.  相似文献   

14.
The possibility and effectiveness of microencapsulation of okadaic acid (OA) in gelatin-acacia microcapsules has been studied. The encapsulation efficiency was higher than 33%. The microcapsules were shown to be very stable, not leaching more than 9% of the encapsulated OA in a 20-h period. OA from the microcapsules was absorbed by the mussels very efficiently, accumulating--after 3 days of feeding and one of depuration--65% of the OA in microcapsules and 22% of the total OA used at the beginning of the microencapsulation process. These efficiencies and the possibility of encapsulating single DSP toxins and derivatives constitute a valuable tool for the study of the accumulation and biotransformation of DSP toxins in bivalves.  相似文献   

15.
米氏凯伦藻(Kareniamikimotoi)隶属于裸甲藻目(Gymnodiniales)凯伦藻科(Kareniaceae)。该藻广泛分布于全球海域,是海洋中的主要有毒有害赤潮藻,也是我国第二大灾害性赤潮肇事种。米氏凯伦藻可产生半乳糖脂、溶血毒素、鱼毒素和部分细胞毒素,当其大规模暴发时会造成严重的生态灾害和经济损失,并危及海产品安全和人类健康。该藻为广温广盐种,光照耐受阈宽,多以光合作用营自养生长,主要繁殖方式为无性繁殖;另外,米氏凯伦藻能吸收利用不同形态的磷盐,并可进行吞噬营养。这些生态学特性使其具有环境适应优势,在适宜条件下过度繁殖引发藻华。  相似文献   

16.
《Oceanologica Acta》2002,25(3-4):159-170
A red tide of Lingulodinium polyedrum occured along the moroccan atlantic coast in july 1999. Observed in the beginning of the month in the Kenitra area, it spreads with the coastal drift as far as the south of safi, passing on its way upon a sanitary monitored area. This area which is submitted to an all year round bimonthly monitoring analysis of phytoplankton, contains significant natural beds of oysters, clams and mussels, as well as shellfish farms in Oualidia and Sidi Moussa lagoons. However, during this period of bloom, there was weekly monitoring of hydrologic and climatic data associated with phytoplankton analysis to identifiy the causes of this bloom.This bloom occured in 17–18°C surface waters, temperatures which are favourable to dinoflagellate encystment and development. The observation of two to three colored strips parallel to the coast suggests phytoplankton aggregation generated by internal waves created by moderate winds blowing constantly in the same direction and at constant speed at the time of the bloom. A change of climatic conditions might also be the cause of the dispersal of the phenomenon. We remark that this exceptional bloom has never reached the coastal shellfish sites, nor the monitored lagoons. The maximum Lingulodinium concentration observed was 79.103 cell l–1 at Sidi Moussa lagoon and minimum concentrations ranged from 1,6.103 cell l–1 to 18.103 cell l–1 at coastal stations. The diarrheic toxicity found in the shellfish (mussels, oysters) cannot be imputed to L. polyedrum but to associated species such as Dinophysis acuminata and D. acuta which were present, though in low density in these waters.However, taking into account the controversy on the L. polyedrum toxicity and its frequent involvement in red tides, it is necessary to include it among the potentially harmful species that should be monitored along Moroccan coasts.  相似文献   

17.
浙江近岸海域贝类中重金属和贝毒污染状况研究   总被引：4，自引：0，他引：4  
在浙江近岸海域采集了青蛤(Cyclina sinensis)、毛蚶(Scapharca subcrenata)、厚壳贻贝(Mytilus coruscus)、缢蛏(Sinonovacula constricta)、泥螺(Bullacta exarata)、菲律宾蛤仔(Ruditapes philippi-narum)、文蛤(Meretrix meretrix)、僧帽牡蛎(Ostrea cucullata)和栉孔扇贝(Chlamys farreri)共9种贝类计29份样品,检测其中重金属汞、砷、铜、铅、锌、镉以及麻痹性贝毒和腹泻性贝毒.结果表明,瑞安毛蚶、瑞安栉孔扇贝中有麻痹性贝类毒素检出,嵊泗文蛤、毛蚶和乐清牡蛎中存在重金属超标的情况;牡蛎对汞、铜、锌、镉有较强的富集能力.  相似文献   

18.
渤海裸甲藻和链状亚历山大藻的麻痹性贝毒毒素分析   总被引：1，自引：0，他引：1  
目的:分析渤海裸甲藻(Gymnodinium sp.)和链状亚历山大藻(Alexandrium catenella)的麻痹性贝毒毒素,为渤海天津海域的赤潮研究积累基础数据。方法:通过实验室培养裸甲藻和链状亚历山大藻,选取对数生长期、平台生长期的裸甲藻以及平台生长期的链状亚历山大藻,利用高效液相色谱法(HPLC)对这两种微藻进行麻痹性贝毒(PSP)毒素分析。结果:裸甲藻细胞内不含有麻痹性贝毒(PSP);链状亚历山大藻细胞内含有C毒素和GTX1-4毒素,该微藻每个细胞毒素含量约为10.81 fmol/cell。结论:裸甲藻细胞内虽不含有麻痹性贝毒(PSP),但不能排除其含有其它毒素的可能。链状亚历山大藻细胞内含有麻痹性贝毒(PSP),属于有毒微藻,需要对其进行密切监测。  相似文献   

19.
Abstract

Greenshell? mussels (Perna canaliculus Gmelin), scallops (Pecten novaezealandiae Reeve), and Pacific oysters (Crassostrea gigas Thunberg) were fed with a New Zealand strain of mass cultured Ostreopsis siamensis Schmidt (for 27 and 84 h and with 1.5 × 106 or 8.6 × 106 cells, respectively) under laboratory conditions. The microalgal cells contained 0.3 pg palytoxin equivalents cell–1 (as determined by the haemolysis neutralisation assay (HNA) of Bignami (1993)) and extracts of these cells were toxic to mice after intraperitoneal injection. No palytoxin‐like material was detected either in the hepatopancreas or the muscle and roe of mussels fed O. siamensis. Oysters contained detectable amounts of toxin in hepatopancreas muscle, and roe while higher concentrations were present in the hepatopancreas of scallops. Extracts of control shellfish (tested biotoxin free and not fed O. siamensis) were toxic to mice, and there was no definitive evidence that feeding shellfish with O. siamensis at the levels employed in the present experiment increased the toxicity of shellfish tissue extracts to mice.  相似文献   

20.
Individuals of Mytilus galloprovincialis, contaminated with Diarrheic Shellfish Poisoning (DSP) toxins, were studied with the aim to correlate the okadaic acid (OA) body burden and the percentage of damaged haemocytes by quantifying annexin V positive cells by flow cytometry. Results showed less percentage of damaged haemocytes in high OA contaminated samples. These data were compared with results of in vitro assays of mussel haemocytes exposed to increased concentrations of OA. Similarly, haemocytes exposed to the most concentrated OA solution were less damaged.  相似文献   

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