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1.
胞外多聚物(extracellular polymeric substance, EPS)是海洋底栖硅藻在水下表面附着时分泌的物质,环境因素对胞外多聚物的组成和分泌行为有直接影响,本文重点探讨了氧含量和附着面积对胞外多聚物的影响。采用热溶剂浸提法提取硅藻胞外多聚物,利用苯酚-硫酸法定量其中的多糖成分,利用考马斯亮蓝G-250法定量蛋白质成分,通过血球计数板法和紫外分光光度法计算细胞数量。结果表明,在氧含量高、可附着面积大的条件下,硅藻的生长繁殖速率快,且单个细胞的胞外多聚物分泌量大。氧含量对胞外多聚物主要成分中的水溶性多糖含量影响大,而对其余成分含量影响小。可附着面积对硅藻附着和生长的影响比氧含量影响小。 相似文献
2.
采用微孔板培养法,研究了爪哇曲壳藻亚缢变种胞外多聚物的分泌过程及除草剂对该过程的影响。结果表明,爪哇曲壳藻亚缢变种胞外多聚物的分泌过程分为4期即单细胞形成及重新定位期、球状体形成期、领形成和柄延伸期及细胞分裂增殖期。除草剂对胞外多聚物分泌的影响与其浓度有关当除草剂浓度为10×10-6时,除草剂对爪哇曲壳藻亚缢变种单细胞的形成和运动没有影响,但胞外多聚物柄的生产受到抑制,柄的长度也明显缩短;随着除草剂浓度的进一步增加,群体细胞不能散开形成单细胞,胞外多聚物的分泌受到完全抑制。本研究结果表明,爪哇曲壳藻亚缢变种胞外多聚物的分泌与细胞运动有关,除草剂可能影响了细胞内有机物质的合成和某些细胞器(如囊泡)的功能,从而抑制了胞外多聚物的分泌。 相似文献
3.
盐度和pH对底栖硅藻胞外多聚物的影响 总被引：11，自引：0，他引：11
研究了盐度和pH值对底栖硅藻新月筒柱藻(Cylindrotheca closterium(Ehr.)Reimannet Lewin)增殖、蛋白质含量和胞外多聚物(Extracellular Polymeric Substances,EPS)的影响.结果表明新月筒柱藻最适生长的盐度和pH值分别是15和8,属半咸水性生活.高盐度(>15)和低pH值(相似文献
4.
底栖硅藻是可见光能照射到的水下表面生物膜中的主要污损生物,胞外多聚物(Extracellular Polymeric Substances,EPS)是硅藻生物膜形成和发育过程中的关键物质,可溶性EPS和粘附性EPS的提取方法不同,对粘附性EPS的分离提取仍没有统一的方法。本研究选用了4种方法提取底栖硅藻(Amphora sp.)粘附性EPS:30℃水浴处理、70℃水浴处理、福尔马林-NaOH处理和阳离子交换树脂处理,研究了不同分离方法条件下,Amphora sp.粘附性EPS中各主要成分的提取量。结果表明,粘附性EPS中各主要成分普遍受提取方法的影响,其中DNA含量变化幅度最大,其次是蛋白质、总糖和糖醛酸含量,硫酸基含量受提取方法的影响最小。低温水浴处理提取效率低,高温水浴处理可能影响EPS的后续分析,阳离子交换树脂提取粘附性EPS的效果较好,但对细胞的破坏最严重,福尔马林-NaOH处理提取的EPS总量最高,提取总糖、糖醛酸的效果最好,而且没有造成严重的细胞破裂。因此福尔马林-Na OH处理是相对均衡和高效的提取硅藻粘附性EPS的方法。 相似文献
5.
营养盐水平对四种海洋浮游硅藻胞外多糖产量的影响 总被引：10，自引：0，他引：10
4种海洋浮游硅藻(牟勒氏角毛藻、海链藻、三角褐指藻和新月菱形藻)培养在改进的f／2培养基中，研究了不同氮、磷和硅营养水平对它们胞外多糖产量的影响．结果表明，硅藻胞外多糖的生产和释放具有种间特异性，角毛藻和海链藻胞外多糖的生产和释放主要在静止期，而三角褐指藻和新月菱形藻在指数生长期前期和静止期都能生产和分泌较高的胞外多糖；培养液中低浓度磷减少了4种硅藻在静止期胞外多糖的产量，但增加了角毛藻在生长期前期胞外多糖的产量；氮浓度的降低增加了三角褐指藻在指数生长前期胞外多糖的产量，但减少了其他3种藻类胞外多糖的产量；硅浓度的降低对4种硅藻胞外多糖的产量影响不大，在一定程度上还促进了静止期胞外多糖的生产．本研究表明，营养盐水平对硅藻胞外多糖生产的影响因种类和细胞所处生长期不同而存在着很大的差异． 相似文献
6.
盐度和营养限制对盐田底栖硅藻披针舟形藻生长及胞外多糖产率的影响 总被引：1，自引：0，他引：1
从台南盐场藻垫中分离得到底栖硅藻披针舟形藻(Navicula lanceolata),该藻生长的最适盐度是1.6% NaCl.在最适盐度之上,随着盐度增大,藻细胞生长受到轻微抑制.氮磷营养限制条件下披针舟形藻生长受到严重抑制,氮营养限制比磷营养限制对藻生长的抑制作用更显著.高盐度和氮磷营养限制条件下,披针舟形藻胞外多糖(EPS)产率都明显增加,氮营养限制比磷营养限制对EPS产率的促进作用更显著.这表明在盐田高盐和氮磷营养限制条件下披针舟形藻产生更多的EPS,有利于藻垫的形成和稳定. 相似文献
7.
透明胞外聚合颗粒物（TEP）是凝聚网的重要组成部分甚至核心，在微尺度范围上形成了水环境结构的重要梯度，对于元素地球化学生物循环、碳沉降以及食物网有着举足轻重的作用。本文研究了东海典型断面PN透明胞外聚合颗粒物的分布特征及来源。结果表明:东海典型断面PN透明胞外聚合颗粒物含量介于28~376 μg Xeq./L之间，平均值为（115±67）μg Xeq./L；呈现出明显的夏季 > 冬季 > 秋季 > 春季的季节变化特征以及近岸 > 外海和底层 > 表层的分布趋势。通过对比透明胞外聚合颗粒物分布趋势和硅藻、甲藻分布趋势以及统计分析得出，东海典型断面PN透明胞外聚合颗粒物主要来源于硅藻，甲藻贡献不大；而外海TEP的来源可能主要由超微型浮游植物贡献。 相似文献
8.
胶州湾浮游植物群落结构及其变化的初步研究 总被引：22，自引：0，他引：22
利用2003年胶州湾调查资料，分析了浮游植物群落结构及其与温度和营养盐的相关性。结果表明，胶州湾浮游植物群落主要由硅藻和甲藻组成，生态类型为近岸广布种、温带种和暖温带种以及少数暖水种。浮游植物数量一年中出现2次高峰期，主高峰出现在9月，次高峰出现在2月，低值期在7月和10月至翌年1月期间。浮游植物数量较近几年继续降低，尤其是峰值。浮游植物在春季以角毛藻、丹麦细柱藻、中肋骨条藻和冰河拟星杆藻为优势种群，夏季至秋初暖水性近岸种中华齿状藻、泰晤式旋鞘藻和广温性种星脐圆筛藻占优势地位，而秋季至冬初羽纹硅藻和派格棍形藻逐渐占优势地位，并一直持续整个冬季。溶解无机氮、硅酸盐和磷酸盐与硅藻丰度无明显相关性（R^2〈0．1）。中心硅藻丰度与溶解态无机氮呈线性负相关（R^2=0．4399），而与硅酸盐和磷酸盐无明显相关性（R^2〈0．1）。群落多样性指数与中心硅藻丰度和硅酸盐呈线性相关（R^2=0．3198和0．4443）。 相似文献
9.
双环海链藻(Thalassiosira diporocyclus Hasle)赤潮 总被引：10，自引：6，他引：10
20 0 1— 2 0 0 2年的秋冬季节 ,于中国东南沿海的南澳岛周围海域突发了双环海链藻赤潮 ,该赤潮藻及其赤潮在中国都是首次记录。该赤潮藻以实心胶质块的群体形式出现 ,其群体一般呈球形或椭球形 ,常为茶褐色 ,大小不一 ,直径多数在 2— 3mm之间 ,最小的不到 0 1mm ,最大的约有 5mm。胶质块由双环海链藻和数种羽纹硅藻组成 ,前者分布于外层 ,后者包埋其中。双环海链藻的细胞密度最大达 1 75× 10 7cells/L ,占浮游植物总细胞数的 78 8%。如把包埋其中的羽纹硅藻考虑进去 ,赤潮藻胶质块的组成细胞总密度则高达 2 2 8× 10 7cells/L以上 ,占浮游植物总细胞数的 95 9%。赤潮藻的密度由湾内向外海呈显著递减趋势 ,与营养盐的平面分布格局相反。该赤潮起源于外海 ,赤潮发生机制可能与 2 0 0 1— 2 0 0 2厄尔尼诺年导致的水温异常升高有关。 相似文献
10.
在西沙群岛潮间带底栖硅藻的研究中发现了1个新种──三波胸隔藻Mastogloiatriundulatasp.nov.和5个新记录：楔形胸隔藻Mastogloiacuneata（Meister）Simonsen，红胸隔藻椭圆变种Mastogloiaerythraeavar．ellipticaVoigt,，红胸隔藻格鲁变种MastogloiaerythraeaVar．grunowiiFoged,缢缩棒杆藻小形变种Rhopalodiaconstrictavar.minorKrammer和具盖棒杆藻伸长变种Rhopalodiaoperculatavar.productaGrunow. 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
14.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
15.
16.
《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
17.
Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
18.
Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
19.
This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
20.
Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献