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1.
不同类型含磷营养物质对微小亚历山大藻(Alexandrium minutum)生长和毒素产生的影响 总被引：6，自引：2，他引：6
采用显微镜细胞计数和麻痹性贝毒的高效液相色谱分析方法,通过对比磷酸二氢钾、磷酸甘油和三磷酸腺苷（ATP）等含磷营养物质对微小亚历山大藻生长和毒素产生的影响,研究了微小亚历山大藻对不同类型含磷营养物质的利用情况.结果表明,在磷限制条件下,加入磷酸二氢钾、磷酸甘油和ATP均能促进微小亚历山大藻的生长,所获得的最大藻细胞密度分别为22700、28400和27800藻细胞/ml,对数期生长速率分别为0.12/d、0.14/d和0.15/d,溶解态有机磷对藻生长的促进作用稍好于溶解态无机磷.三种含磷营养物质对毒素产生的效应没有明显差别,稳定期藻细胞毒素含量分别为22.87、23.98和21.80fmol/cell.磷限制对毒素组成的影响很大,磷限制条件下膝沟藻毒素GTX1/4的含量占绝对优势,GTX2/3含量很少.在添加含磷营养物质后,GTX1/4所占比例降低,GTX2/3比例增加,说明磷限制显著改变了微小亚历山大藻的毒素组成.对藻体碱性磷酸酶活性分析的结果显示,磷限制组具有最高的碱性磷酸酶活性,添加有机磷化合物实验组的碱性磷酸酶活性显著高于添加无机磷化合物的实验组.研究结果表明,微小亚历山大藻可以利用实验中采用的无机磷化合物和有机磷化合物,但其利用溶解态有机磷化合物的机制尚不清楚,可能是通过诱导合成碱性磷酸酶来水解培养基中的溶解态含磷有机物,从而释放无机磷酸盐用于藻细胞的生长. 相似文献
2.
对 2种有毒亚历山大藻——引自台湾的微小亚历山大藻 AMTK- ( Alexandriumminutum AMTK- )和引自美国阿拉斯加的亚历山大藻 KW0 6( Alexandrium sp.KW0 6)——在不同生长阶段的产毒状况、毒素组成和毒性大小进行了研究 ,比较了两者的异同。结果显示 ,2种藻的单位细胞毒素含量与培养阶段的变化趋势是一致的 ,即在对数生长初期达最高 ,之后逐渐下降 ;微小亚历山大藻 AMTK- 主要生产 GTXs毒素 ,从对数生长后期到静止期其毒素组成比有所变化 ,GTX1 ,GTX4比例增高而 GTX2 ,GTX3降低 ,亚历山大藻KW0 6主要生产 STX毒素 ;亚历山大藻 KW0 6的毒性高于微小亚历山大藻 AMTK- 。 相似文献
3.
两种亚历山大藻产毒过程和毒素特征研究 总被引：5，自引：0，他引：5
对2种有毒亚历山大藻－引自台湾的微小亚历山大藻AMTK－1（Alexandrium minutum AMTK-1)和引自美国阿拉斯加的亚历山大藻KW06（Alexandrium sp.KW06)－在不同生长阶段的产毒状况、毒素组成和毒性大小进行了研究，比较了两者的异同。结果显示，2种藻的单位细胞毒素含量与培养阶段的变化趋势是一致的，即在对数生长初期达最高，之后逐渐下降；微小亚历山大藻AMTK－I主要生产GTXs毒素，从对数生长后期到静止期其毒素组成比有所变化，GTX1，TGX4比例增高而TX2，GTX3降低，亚历山大藻KW06主要生产STX毒素；亚历山大藻KW06的毒性高于微小亚历山大藻AMTK－1。 相似文献
4.
通过对塔玛亚历山大藻(ATHK和AT-6藻株)、链状亚历山大藻(ACDH藻株)和微小亚历山大藻(AM-1藻株)的PSP毒素含量和组成以及它们分别对轮虫、黑褐新糠虾和鲈鱼存活影响的比较研究发现:塔玛亚历山大藻AT-6藻株不产生麻痹性贝毒毒素PSP,而塔玛亚历山大藻ATHK、链状亚历山大藻ACDH和微小亚历山大藻AM-1均产生PSP毒素,其总含量分别为19.74、5.395、5.57fmol/cell(2.60、0.36、1.61pgSTXeq/cell)。塔玛亚历山大藻AT-6对轮虫、黑褐新糠虾和鲈鱼这三种生物均没有不利影响;对于轮虫,塔玛亚历山大藻ATHK和链状亚历山大藻ACDH的96hLC50分别为:200和1200cells/ml,而微小亚历山大藻AM-1无不利影响;对于糠虾,塔玛亚历山大藻ATHK、链状亚历山大藻ACDH和微小亚历山大藻AM-1的96hLC50分别为7000、11000、16000cells/ml;对于鲈鱼,这三株藻的96hLC50分别为3700、4000、20000cells/ml。四株亚历山大藻对三种生物的毒性大小与其PSP毒素含量和组成无直接的相关关系,其毒性作用可能来自其他未知毒性物质。塔玛亚历山大藻ATHK不同组分分别对三种生物的毒性比较研究表明:藻细胞重悬液和藻液对三种生物的不利影响最为显著,去藻过滤液和细胞碎片对轮虫和鲈鱼没有明显影响,但糠虾的存活率有所下降;细胞内容物对轮虫和糠虾也无影响,但对鲈鱼的存活有一定影响。以上研究表明:不同亚历山大藻的毒性大小存在差别,其对不同生物的危害机制也不相同,除PSP毒素外,亚历山大藻可能还存在其他的毒性物质。 相似文献
5.
通过实验室构建不同氮磷比条件下的酸化海水环境,培养麻痹性贝毒(paralytic shellfish toxin,PST)产毒藻微小亚历山大藻(Alexandrium minutum),采用藻细胞计数法、分光光度法、高效液相色谱-质谱法等分析方法,探讨了不同氮磷比条件下的酸化海水对微小亚历山大藻的生长、氮磷营养盐吸收、产毒等参数的影响。结果表明,在一定程度上,酸化环境对A.minutum的生长、PST的胞内累积和胞外释放有促进作用,且胞外培养液中PST含量增加的程度更高;同时,酸化海水促进胞内毒性较低的N-H类膝沟藻毒素(GTX2和GTX3)被氧化成毒性较高的N-OH类膝沟藻毒素(GTX1和GTX4),导致A.minutum的细胞毒性和培养液毒性增加。而海水中氮磷比的进一步升高,在一定程度上促进了微小亚历山大藻细胞毒素含量和毒性的增加,但并未促进其生长,且降低了藻细胞内的磷储量。 相似文献
6.
塔玛亚历山大藻对海产双壳类生命活动的影响 总被引：4，自引：1，他引：4
通过一种重要有毒赤潮藻——产麻痹性贝毒毒素PSP的塔玛亚历山大藻对几种海产双壳类主要发育阶段:受精卵、D形幼虫、眼点幼虫、稚贝、仔贝和成贝生命活动的影响研究,发现该藻对双壳类孵化率、存活率、运动能力、滤食率和生长都有影响,毒性效应与藻密度有明显的相关关系.该藻对受精卵的抑制作用在100个/cm3的密度下最显著,36h后孵化率仅为对照组的30%.进一步的逐项毒性筛选实验表明此毒性来源于藻液、藻细胞和细胞碎片,而与去藻过滤液、藻细胞内容物、标准毒素STX无关,由此可以证实塔玛亚历山大藻确能产生一类非PSP毒素,并与细胞表面的未知毒素相关. 相似文献
7.
亚历山大藻溶血毒性的初步研究 总被引：1，自引：0，他引：1
研究了11株亚历山大藻（Alexandrium spp．）的溶血毒性，其中7株亚历山大藻具有显著的溶血毒性，说明溶血毒性在亚历山大藻中具有一定的普遍性，但各亚历山大藻藻株溶血毒性的大小与其所产麻痹性贝类毒素（Paralytic Shellfish Poisoning，PSP）的能力无直接关系；针对性地研究了一株典型PSP产毒甲藻——塔玛亚历山大藻（A．tamarense，ATHK株）的溶血毒性特点，该株亚历山大藻具有较强的溶血毒性，指数期单个藻细胞的溶血毒性大小约相当于4pg皂素的溶血能力，而且其溶血毒性的大小与藻的生长阶段和细胞密度都有一定关系：指数期的溶血毒性最大；藻细胞、细胞碎片、细胞内容物都有一定的溶血毒性，其中细胞碎片的毒性最大；研究还表明一种PSP标准品STX毒素并没有溶血毒性，进一步说明亚历山大藻产生的溶血毒性是其他非PSP物质造成的，这类溶血毒素对人类健康和生态环境的影响值得关注。 相似文献
8.
采用浮游植物计数法、高效液相色谱串联质谱法、分光光度法等分析方法,探索了微小亚历山大藻(Alexandrium minutum)在批次培养过程中氮磷吸收、产毒、生物量、p H等参数的动态变化关系。结果表明,微小亚历山大藻对磷的吸收迅速,可以将磷储存于体内,待生长使用。该藻对氮的吸收相对缓慢,环境中氮缺乏时,产毒量不再增加,说明氮对产毒有着重要的调控作用。在第二对数期中出现了碳限制环境,导致叶绿素a在碳限制条件下无法表征藻的生物量,相反,叶绿素a和生物量呈负线性关系,可能是叶绿素转化成其它含碳物质,用于生长。毒素不仅存在于细胞体内,培养液中(胞外)也含有毒素,并且胞外毒素从稳定期开始逐渐升高。胞内毒素的组成中GTX1/4占据绝对优势,GTX2/3含量相对较少。生长延缓期和第一对数期,各种毒素组成比例相对稳定,而在随后的生长期内,GTX1/4在总毒素中的占比逐渐上升,GTX2/3占比逐渐下降,表明微小亚历山大藻毒素组成会随着生长周期的变化而发生变化。 相似文献
9.
在f/2全营养培养条件下,采用共培养以及滤液交叉培养的方法研究了中肋骨条藻(Skeletonema costatum)和微小亚历山大藻(Alexandrium minutum)之间的竞争作用,结果表明: 微小亚历山大藻指数生长后期的无藻细胞滤液对中肋骨条藻的生长没有抑制作用,但中肋骨条藻滤液明显抑制了微小亚历山大藻的生长,且抑制作用随着中肋骨条藻滤液比例的增大而增大,他感作用是影响这两种微藻间竞争的重要方式之一;通过向培养基中添加自他感物质标准品15S-hydroxy-5Z,8Z,11Z,13E,17Z-eicosapentaenoic acid (15(S)-HEPE)考察其对中肋骨条藻自身以及微小亚历山大藻生长的影响,发现15(S)-HEPE在中肋骨条藻滤液中并不是能够抑制微小亚历山大藻生长的他感物质,今后应进一步深入分析中肋骨条藻释放的抑制微小亚历山大藻生长的他感物质。 相似文献
10.
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
11.
不同氮源对微藻增殖的影响 总被引：12，自引：1，他引：11
采用室内实验的方式研究了无机氮和有机氮对不同微藻增殖的影响情况。比较了不同氮源(氯化铵和尿素)对纤细角毛藻(Chaetoceros gracilis)、赤潮异弯藻(Heterosigma akashiwo Hada)、亚历山大藻(Alexandrium sp．)、隐藻(Chroomonas salina f.adolenscens)4种海洋微藻生长的不同影响。结果表明,有机氮尿素对海洋微藻增殖的影响比无机氮的复杂。由微藻最适生长的氮、磷浓度得到N：P值,讨论了该值对微藻增殖的影响,以及影响N：P值的可能情形。 相似文献
12.
采用高浓度无机三态氮(铵氮4NH?-N、亚硝氮2NO?-N和硝氮3NO?-N)共存的模拟海水体系,在最适生长条件下,研究了小分子有机物(糖类、有机酸、醇、有机氮)和p H对海洋着色菌(Marichromatium gracile)YL28去除水体无机三态氮的影响。结果表明:以葡萄糖、乙酸钠和乙醇为唯一碳源时,水体中的高浓度2NO?-N和3NO?-N均能被完全去除,4NH?-N的去除率分别为93.40%、84.55%和66.63%;碳源为乙酸钠时菌体生长最好,体系中添加蛋白胨或尿素,仅4NH?-N的去除效果明显降低。p H值在6.0—9.0时,该菌株对4NH?-N、2NO?-N和3NO?-N均具有去除能力。由此可知:YL28菌株对模拟海水养殖水体中高浓度无机三态氮具有良好的去除能力,高浓度有机氮化物(蛋白胨和尿素)对4NH?-N的去除能力有明显影响,但对2NO?-N和3NO?-N仍保持高效的去除能力。本研究为不产氧光合细菌制剂在水产养殖中的合理应用提供参考。 相似文献
13.
Eight common red tide species including the Dinoflagellates Alexcandrium tamarense,Prorocentrum minimum , Prorocentrum mican , Diatoms Skeletonema costatum , Cerataulina pelag-ica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Isochrysis galbana were chosen to study the effect of four nitrogen substrates (NO_3 - N, NH_4 - N, Urea - N, Mixed - N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550 μmol,, NO_3 - N was the best nitrogen source among these four nitrogen substrates; Urea - N and Mixed - N were also good for the growth of most algae, but not as good as NO_3 - N for some species; NH_4 - N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmol experiments on the growth of I. galbana , P. minimum and L. minimus in NH_4 - N and NO_3 - N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in 相似文献
14.
--Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum , Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates ( NO3 - N, NH4 - N, Urea - N,Mixed - N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μrnol, NO3 N was the best nitrogen source among these four nitrogen substrates; Urea - N and Mixed- N were also good for the growth of most algae, but not as good as NO3 - N for some species; NH4 - N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4 - N and NO3 - N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3 - N and NH4 - N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4 - N substrate, the growth rates of P.minimum and L. minimus were slower than in same concentration of NO3 - N; At concentration of 50μrmol , the growth rate of P. minimum in NH4 - N was not significantly different from that in NO3 - N, while the growth rate of L. minimus was only about 30% of that in NO3 - N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation. 相似文献
15.
Zena G. Kaufman John S. Lively Edward J. Carpenter 《Estuarine, Coastal and Shelf Science》1983,17(5):483-493
The uptake of urea, nitrate and ammonium by phytoplankton was measured using 15N isotopes over a one-year period in Great South Bay, a shallow coastal lagoon. The bay is a unique environment for the study of nutrient uptake since ambient concentrations of and urea remain relatively high through the year, and phytoplankton are probably never nutrient limited. Urea nitrogen averaged 52% of the total assimilated, while ammonium represented 33% and nitrate 13%. High rates of ammonium uptake occurred only at low urea concentrations (ca< 1-μg-atom urea l?1). Over the sampling period urea was present in relatively high concentrations, averaging 5·35 μg-atom N l?1, while means for ammonium and nitrate averaged 1·94 and 0·65 μg-atom N l?1, respectively. Total N uptake measured with 15N averaged about 3·3 times the calculated (from elemental ratios and 14C productivity measurements) N needs of the phytoplankton population. Highest nitrogen uptake occurred in the summer and coincided with the primary production maximum. 相似文献
16.
The ability of cultured zooxanthellae to use ammonium and nitrate was tested. The zooxanthellae were initially isolated from the anemone Aiptasia pulchella. The zooxanthellae were able to grow on media supplemented with either form of dissolved inorganic nitrogen (DIN) although ammonium was inhibitory above 300 μM. In accord with the intact symbiosis and freshly isolated algae, the cultured zooxanthellae took up ammonium. In contrast, the cultured algae demonstrated nitrate uptake and utilization. This was enhanced with DIN deprivation. Nitrate reductase was found in the algae and appeared to be inducible. Within the animal host, excretory ammonium may repress this induction. 相似文献
17.
R. N. Sambrotto B. J. Mace 《Deep Sea Research Part II: Topical Studies in Oceanography》2000,47(15-16)
Oceanographic samples were collected across the Antarctic Polar Front (APF) region in the vicinity of 60°S, 170°W during the US JGOFS program from December 1997 to March 1998. This paper reports the uptake rates of new (nitrate) and regenerated (ammonium and urea) nitrogen measured by 15N tracer techniques together with the levels of ammonium, urea-N and dissolved free amino acids (DFAAs) during December and mid-February–March. The APF was an important biological boundary, and in December rates of new (nitrate) uptake were greatest south of the APF, exceeding 10 mmol m−2 d−1 near the retreating ice edge. In February, nitrate uptake rates were an order of magnitude lower. Rates of ammonium uptake in both periods were greater in the warmer water north of the front. Nitrogen f-ratios varied from 0.50 to less than 0.05, with larger values associated with the >5 μm size fraction at the ice edge and generally lower values north of the APF. Urea was an important nitrogen source north of the APF, and lowered f-ratios there by 22% on average when included as part of total nitrogen uptake. Urea uptake was less important south of the APF. Ammonium concentrations increased dramatically south of the APF later in the season, suggesting a system dominated by regeneration. Seasonal changes in the concentrations of regenerated organic compounds such as urea and DFAAs were less obvious, although DFAAs exhibited consistent maxima in the high flow regions of the APF. A mass balance based of ammonium fluxes suggests that nitrification was significant at locations south of the APF in February. In these nitrate-replete waters, light/mixing conditions in the surface water (the Sverdrup criterion) accounted for over 50% of the variance in nitrate uptake rates. The stability responsible for higher new production south of the APF is due both to the separation of this region from the maximum zonal wind field to the north as well as to melt-water contribution from the retreating ice field. Estimated new production and exportable carbon production exceeded 500 mmol nitrate m−2 yr−1 and 40 g C m−2 yr−1, respectively, south of the APF. Thus, new production in the marginal ice zone of the Southern Ocean rivals that in coastal systems and indicates that this is an important region for export production. 相似文献
18.
Dissected tissues of three shellfish species,the Chinese scallop,Chlamys farreri,Manila clam,Ruditapes philippinarum,and Razor shell,Solen strictu were evaluated for in vitro transformation of paralytic shellfish poisoning(PSP) toxins. Tissue homogenates were incubated with extraction from toxic algae Alexandrium minutum to determine toxin conversion. The effects of heating and addition of a natural reductant(glutathione) on toxin conversion were also assessed. The toxin profile was investigated through high performance liquid chromatography with fluorescence detection(HPLC-FLD) . The evident variations in the toxin content were observed only in Chinese scallop viscera homogenates. The concentration of GTX4 was reduced by 45%(approximately 0.8 μmol/dm 3 ) and 25%(approximately 1 μmol/dm 3 ) for GTX1,while GTX2 and GTX3 increased by six times(approximately 1 μmol/dm 3 ) and 3 times(approximately 0.3 μmol/dm 3 ) respectively. Simultaneously,the total toxicity decreased by 38% during the 48 h incubation period,the final toxicity was 20.4 nmol STXeq/g. Furthermore,heated Chinese scallop viscera homogenates samples were compared with non-heated samples. The concentration of the GTX4 and GTX1 was clearly 28%(approximately 0.53 μmol/dm 3 ) and 17%(approximately 0.69 μmol/dm 3 ) higher in heated samples,GTX2 and GTX3 were four times(0.66 μmol/dm 3 ) and two times(0.187 μmol/dm 3 ) lower respectively. GSH(+) Chinese scallop viscera homogenates samples were compared with GSH(-) samples,the concentration in the GTX4 and GTX1 was 9%(approximately 0.12 μmol/dm 3 ) and 11%(approximately 0.36 μmol/dm 3 ) lower respectively,GTX2 and GTX3 was 17%(approximately 0.14 μmol/dm 3 ) and 19%(approximately 0.006 μmol/dm 3 ) higher respectively. In contrast,there was a little change in the concentration of PSP toxins of Manila clam and Razor shell tissue homogenates. These observations on three shellfish tissues confirmed that there were species-specific differences in PSP toxins transformation. PSP toxins transformation was more pronounced in viscera tissue than in muscle tissue. PSP toxins was possibly interfered by some carbamoylase enzyme,and the activity in Chinese scallop viscera tissue is more remarkable than in the other two species. 相似文献
19.
Stphane L'Helguen Christian Madec Pierre Le Corre 《Estuarine, Coastal and Shelf Science》1996,42(6):803-818
Uptake rates of ammonium, nitrate, urea and nitrite were measured for 1 year (1988) at a coastal station in the well-mixed waters of the western English Channel. Ammonium was the major form of nitrogen (N) utilized (48%) by phytoplankton, followed by nitrate (32%), urea (13%) and nitrite (7%). Seasonal changes of uptake of ammonium, nitrate and urea showed a broad, intense summer maximum. Nitrite uptake was low throughout the year except for a peak value in June. Uptake rates of ammonium and nitrate were independent of substrate concentrations, whereas those of urea and nitrite were not. The summer maxima of ammonium, nitrate and total N uptake, and the significant relationships of N-uptake index to ambient light, and of chlorophyll-a-specific N uptake to surface-incident light, indicate that light is the major factor controlling N uptake in these waters. This is due to the permanent vertical mixing which reduces the mean light available for N uptake to <15% of the incident light. Mixing also injects regenerated N continuously into the euphotic zone, thus alleviating nitrogen limitation and accounting for the larger proportion of regenerated N uptake in total N uptake. 相似文献