Neurotoxins from Marine Dinoflagellates: A Brief Review

Dinoflagellates are not only important marine primary producers and grazers, but also the major causative agents of harmful algal blooms. It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Consumption of seafood contaminated by algal toxins results in various seafood poisoning syndromes: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP) and azaspiracid shellfish poisoning (ASP). Most of these poisonings are caused by neurotoxins which present themselves with highly specific effects on the nervous system of animals, including humans, by interfering with nerve impulse transmission. Neurotoxins are a varied group of compounds, both chemically and pharmacologically. They vary in both chemical structure and mechanism of action, and produce very distinct biological effects, which provides a potential application of these toxins in pharmacology and toxicology. This review summarizes the origin, structure and clinical symptoms of PSP, NSP, CFP, AZP, yessotoxin and palytoxin produced by marine dinoflagellates, as well as their molecular mechanisms of action on voltage-gated ion channels

Response of phytoplankton to nutrients addition in the upwelling regions of the Taiwan Strait

2006年6月在台湾海峡近岸上升流区通过表层水体营养盐添加的现场培养实验,研究该海区营养盐限制情况及其浮游植物水华产生的主要影响因素。对营养盐,叶绿素a浓度和浮游植物细胞丰度进行了测定,结果表明,实验中不存在明显的硅限制;氮磷营养盐均存在明显的限制,且氮限制情况更为严重。营养盐添加后,冰河拟星杆藻(Asterionellopsis glacialis)等硅藻迅速生长成为优势藻种,其对氮磷的利用机制有所不同。对氮营养盐采取吸收后迅速同化利用,相较于硝酸盐的补充,氨氮补充条件下优势硅藻更易迅速生长并迅速死亡;对磷营养盐的利用则由于体内磷库的存在,采用迅速吸收后贮存在体内慢慢消耗的利用机制。氮营养盐的补充是上升流期间浮游植物水华产生的主要因素。 【英文摘要】 In situ incubation experiments of nutrients addition to surface water from the upwelling region in the Taiwan Strait were conducted to investigate nutrient limitation of this area and the main factors that caused the phytoplankton bloom in June,2006.Variation of nutrients,Chl-a concentration and phytoplankton species density were analyzed.The results showed no clear limitation by silicon,however clear nitrogen and phosphate limitations were found,and nitrogen limitation was more serious than phosphate limit...国家自然科学重点基金资助项目(40331004)~

Effects of Two Antibiotics on Growth and Toxin Production of A. Tamarense CI01

论文以中国南海筛选的一株塔玛亚历山大藻AlEXAndrIuM TAMArEnSE CI01为研究对象,研究了两种抗生素,氨苄青霉素(AMPICIllIn,AMP)和新霉素(nEOMyCIn,nM)对A.TAMArEnSE CI01细胞生长、形态以及毒素含量的影响。结果表明:和空白对照组相比,经1 500μg/Ml nM处理过的藻细胞密度增长速度比较慢;经2 000μg/Ml AMP处理过的藻细胞虽然会发生质壁分离现象,但藻细胞密度增长速度比较快;通过高效液相(HPlC)分析藻细胞的毒素含量发现两种抗生素均明显降低了A.TAMArEnSE CI01细胞中毒素的含量。同时监测加入抗生素后A.TAMArEnSE CI01藻培养液中细菌数量和磷酸盐浓度的变化,揭示1 500μg/Ml nM和2 000μg/Ml AMP加入A.TAMArEnSE CI01后,抑制或杀死了能产毒或有利于产毒的细菌,或者是影响了细胞内参与毒素合成的酶从而干扰了毒素的正常合成,而导致藻细胞毒素合成能力降低。Two antibiotics,viz.ampicillin(Amp) and neomycin(Nm) were investigated regarding their effects on a toxic dinoflagellate,A.tamarense C101,which was isolated from the South China Sea.The study found that Nm concentration of 1 500 μg/mL retarded the growth rate of the algal cell,while 2 000 μg/mL of Amp stimulated the cells growth though resulting in sloughing-off of part of the cell walls.Analysis of the toxin content of A.tamarense C101 by HPLC indicated that both of the antibiotics decreased the toxin of the algae through inhibition of the activity of toxin-producing or toxin-benefiting bacteria.Otherwise the antibiotics might influenced some enzymes involved in toxin biosynthesis,leading to the decreased toxin producing capacity of A.tamarense C101.福建省科技计划项目资助(200610025

EFFECT OF ALEXANDRIUM TAMARENSE ON POPULATION DYNAMICS OF BRACHIONUS PLICATILIS

采用单个体培养方法研究有毒赤潮藻塔玛亚历山大藻(Alexandriumtamarense)的细胞再悬浮液、细胞破碎液及其与亚心形扁藻(Platymonassubcordiformis)的混合藻液对褶皱臂尾轮虫(Brachionusplicatilis)实验种群动态的影响.结果表明,塔玛亚历山大藻及其细胞破碎液延缓了褶皱臂尾轮虫的生长发育,使轮虫的生殖前期延长,生殖期及寿命缩短,特定年龄出生率降低,产卵量减少,从而导致轮虫生殖力下降,种群增长受阻.其中以塔玛亚历山大藻细胞再悬浮液对轮虫的影响最为显著,rm仅为0.1832d-1.图1表2参18The effect of a toxic dinoflagellate, Alexandrium tamarense (strain ATHK) on the experimental population dynamics of the individual cultured rotifer, Brachionus plicatilis was studied. The experiment is divided into four treatments by culturing the rotifer in sand-filtered seawater with Platymonas subcordiformis as control;in sand-filtered seawater with A. tamarense cells as re-suspended treatment; in sand-filtered seawater with P. subcordiformis and broken A. tamarense as broken cells treatment; and in sand-filtered seawater with P. subcordiformis and A. tamarense as mixed cells treatment. The results showed that A. tamarense and its broken cells retarded the growth and development of B. plicatilis by prolonging its reproductive prophase, shortening its reproduction and life expectancy, reducing its natality in certain ages and decreasing the amount of spawned eggs. In all cases, the re-suspended A. tamarense cells produced the most significant adverse effect on the rotifer with the least r_ m (0.183 2 d -1 ). Fig 1, Tab 2, Ref 18教育部骨干教师基金项目;; 集美大学基金项目(C50209)资助~

米氏凯伦藻细胞表面膜蛋白质组及其对温度变化的响应研究

米氏凯伦藻(Karenia mikimotoi)近年在我国福建、浙江和广东沿海经常形成赤潮,其赤潮不仅影响到海洋生态系统的稳定,也严重威胁到水产养殖以及人类生命健康安全。本论文以米氏凯伦藻为研究对..

Effects of nutrient limitation on cell cycle,toxin content and composition of Alexandrium tamarense CI01

优化了塔玛亚历山大藻AlEXAndrIuM TAMArEnSE CI01细胞同步化方法,研究了n、P限制对A.TAMArEnSE CI01细胞周期及毒素含量和组成变化的影响。结果表明,采用前期驯化、细胞沉降分离和光限制诱导相结合的同步化方法,细胞同步率提高了约14%。n、P限制条件下,细胞分裂受抑制,分别停滞于g2/M期和g1期。营养盐对毒素合成及组成影响比较明显:n限制下单细胞毒素含量降低,P限制下单细胞毒素含量升高。在正常营养和P限制条件下,C1,2占毒素总量的98%以上,gTX2,3占总毒素量的2%左右;n限制条件下,C1,2所占比例下降到90%左右,而gTX2,3比例增长到约10%。根据C1,2和gTX2,3在一个细胞周期内的变化规律推测,毒素的合成受光诱导并在细胞周期g1期的特定时间内合成,细胞可能先合成gTX2,3毒素,后被转化为C1,2毒素。This study optimized the cell synchronized method of Alexandrium tamarense CI01 and investigated the effects of nutrient limitation on cell cycle,toxin content and composition of A.tamarense CI01.The result showed that the synchronization ratio of A.tamarense CI01 cells increased 14% compared to the traditional darkness induced method.Under nutrient limitation conditions,nitrate-limited cells were arrested at G2/M phase while phosphate-limited cells were arrested at G1 phase.Toxin content and composition of A.tamarense CI01 varied significantly at the different cell cycle phases.Nitrate-limitation decreased toxin content while phosphate-limitation increased toxin content compared to the nutrient replete condition.Compared to nutrient replete and phosphate-limitation conditions,the ratio of C1,2 declined from 98% to 90%,and the ratio of GTX2,3 increased from 2% to 10% under nitrate-limitation.Toxin biosynthesis was induced by light and always occurred during a defined time frame within the G1 phase of the cell cycle.Analyzing toxin biosynthesis time and ratios of C1,2 and GTX2,3 toxins in cells,we postulate that GTX2,3 is synthesized firstly and then is transferred to C1,2 in A.tamarense CI01.国家自然科学基金(40776068;40876059

SnO2-Pt/γ-Al2O3催化葡萄糖制备乳酸甲酯的研究

以γ-Al2O3为载体,采用浸渍法制备了SnO2-Pt/γ-Al2O3催化剂,探讨工艺参数（反应温度、反应时间、催化剂用量）对葡萄糖催化转化制备乳酸甲酯的影响,并对催化剂的重复使用性能以及放大实验进行探索。同时采用扫描电子显微镜（SEM）、X光射线电子能谱（XPS）、X射线衍射（XRD）、氮气吸附-脱附、NH3程序升温脱附（NH3-TPD）等对SnO2-Pt/γ-Al2O3催化剂进行了表征。结果表明:金属Pt和SnO2均匀地分散到γ-Al2O3载体上,催化剂体系同时具有B酸和L酸的分布,比表面积为117.08 m2/g,孔容为0.23 cm3/g,平均孔径为6.54 nm,催化活性明显。当葡萄糖为1 g、催化剂用量（以葡萄糖质量计）为10%、葡萄糖与甲醇料液比为1∶10（g∶mL）、反应温度220℃、反应10 h的条件下,SnO2-Pt/γ-Al2O3表现出较高催化活性,葡萄糖转化率为92.63%,乳酸甲酯选择性高达20.08%,且催化剂表现出良好的重复使用性能和放大稳定性,重复使用3次时,葡萄糖转化率仍达88.43%,乳酸甲酯选择性达19.27%;物料投加量放大10倍时,葡萄糖转化率仍达86.27%,乳酸甲酯选择性达18.71%。国家自然科学基金资助项目(31670599);;\n云南省可再生能源发展专项资金项目(云财产业[2015]86号);;\n云南省教育厅研究生科技创新项目(No.2018Y130

Accumulation,transformation and depuration of parlytic shellfish toxins by the scallop Patinopecten yessoensis

以我国麻痹性贝毒高发区的虾夷扇贝为研究对象,研究了麻痹性贝毒在扇贝各组织内的累积、转化和排出过程。实验分为洁净海区吊养排毒和室内投喂有毒藻累毒两部分。排毒实验表明,内脏团和鳃排毒率最快,为3.27%/d,外套膜为2.71%/d,证明虾夷扇贝属慢性排毒者。累毒过程中扇贝无不良反应,累毒实验第2 d(A2)扇贝总毒性即达到19.41μgSTXEQ/g(干质量),说明虾夷扇贝对麻痹性毒素敏感性低、累积快、累积量大,不同组织对毒素的累积速率差异不大,在4.80%~4.98%/d之间。内脏团及外套膜始终是毒素最主要的分布组织,占总毒素95%以上,闭壳肌最少。扇贝各组织中毒素组分的复杂性与其毒性正相关,且毒素间有转化现象,内脏团和外套膜是最主要的转化组织。主要转化类型有:gTX1,4被还原成gTX2,3;gTX2,3转化为STX;STX转化为dCSTX以及α、β异构体的相互转化。This study investigated the accumulation,transformation and depuration of paralytic shellfish toxin(PST) in the scallop Patinopecten yessoensi collected from the PST-contaminated area.Two experiments were conducted:in situ depuration of PST in non-PST contaminated sea area and accumulation of PST in laboratory.In the depuration experiment,the visceral mass and gill presented the faster detoxification rate than the mantle,and the average toxin depuration rate reached 3.27% and 2.71% per day,respectively,indicating P.yessoensis was belong to the slow detoxification bivalve.In the accumulation experiment,the total toxicity of the scallop reached 19.41 μg STXeq/g(dry weight)at day two(A2) and no adverse effects were observed during the accumulation experiment,suggesting P.yessoensis has low sensitivity,high tolerance ability to PST with a fast accumulation rate.There was no obvious discrepancy(4.80%~4.98%/day) in accumulation rate between different tissues of P.yessoensis.Toxin content presented the positively correlation ship with the toxin profiles,the visceral mass and mantle contained the higher toxin content and more toxin profiles,while the adductor muscle contained the least.Toxin biotransformation in P.yessoensis was tissues-specific.Transformation in visceral mass and mantle was more significant and the main toxin biotransformation forms occurred as the followings:N-OH toxin GTX1,4 was converted into N-H toxins GTX2,3,GTX2,3 was converted into dcSTX,STX was converted into dcSTX,as well as the reciprocal transformation between isomeric compounds

Sn O2-Pt/γ-Al2O3催化葡萄糖制备乳酸甲酯的研究

以γ-Al2O3为载体，采用浸渍法制备了SnO2-Pt/γ-Al2O3催化剂，探讨工艺参数（反应温度、反应时间、催化剂用量）对葡萄糖催化转化制备乳酸甲酯的影响，并对催化剂的重复使用性能以及放大实验..