Zn^2＋对球等鞭金藻生长及生化成分的影响

探讨了不同浓度Zn2 对球等鞭金藻细胞生长及细胞内多糖、叶绿素、蛋白质等生化成分含量的影响.研究表明,浓度低于4.0 mg/L的Zn2 对球等鞭金藻的生长无明显抑制作用.当Zn2 浓度高于10.0mg/L时,则对球等鞭金藻的生长产生明显的抑制作用,随着Zn2 浓度的升高,球等鞭金藻胞内叶绿素和多糖含量降低,而蛋白质含量则明显升高.     

四溴双酚A(TBBPA)对叉鞭金藻的毒性效应研究

以叉鞭金藻(Dicrateria inornata)为研究对象,分析了不同质量浓度四溴双酚A(TBBPA)污染下微藻光合色素含量、可溶性蛋白含量、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,以及细胞形态和细胞内部结构的变化。研究结果显示:在TBBPA较低质量浓度(0.5和2.0mg/L)污染条件下,叉鞭金藻的叶绿素a(Chl-a)、叶绿素c(Chl-c)和类胡萝卜素(Car)含量显著高于对照组,其含量第24小时达最大值;较高质量浓度(4.0和8.0mg/L)污染条件下,3种色素含量则显著低于对照组,其含量在第24小时达最小值。实验期间各实验组叉鞭金藻的可溶性蛋白含量、SOD活性和MDA含量主要被诱导;4.0mg/L的TBBPA作用叉鞭金藻96h后,藻细胞表面形态和内部亚显微结构均发生变化,与光合色素含量降低、MDA含量增加相一致。     

IAA对球等鞭金藻和棕鞭藻生长及总脂含量的影响

本文研究了0.1~5mg/L的3-吲哚乙酸(IAA)对球等鞭金藻(Isochrysis galbana)和0.1~3mg/L的IAA对棕鞭藻(Ochromonas neopolitana)的叶绿素荧光参数(PSII最大光能转化效率Fv/Fm、相对电子传递速率rETR、光化学淬灭qP)、细胞密度、叶绿素含量、总脂含量及脂肪酸组成的影响。研究表明,球等鞭金藻和棕鞭藻进行光合作用和生长的最适IAA浓度分别为0.1和0.25mg/L。此条件下,2株藻的Fv/Fm、rETR、qP、细胞密度和叶绿素含量均显著高于对照组和其它处理组。其中,球等鞭金藻的细胞密度和叶绿素含量分别比对照组增加了32.6%和37.1%,总脂含量显著高于其它处理组,但与对照组差异不显著(P0.05);棕鞭藻的细胞密度和叶绿素含量在IAA浓度为0.25mg/L时分别比对照组增加了48.7%和34.4%,总脂含量在IAA浓度为0.5mg/L时显著高于对照组和其它处理组,但与0.25mg/L处理组差异不显著(P0.05)。0.1mg/L的IAA浓度对球等鞭金藻DHA(二十二碳六烯酸)的合成有促进作用,但对其它各脂肪酸(14:0、16:0、16:1n-7和18:1n-9)含量均无显著影响;0.25mg/L的IAA浓度促进了棕鞭藻DHA和多不饱和脂肪酸的合成。研究结果表明,球等鞭金藻和棕鞭藻进行生长和油脂积累的最适IAA浓度分别为0.1和0.25mg/L,此结果为2株藻的大规模培养提供了理论依据。     

有机磷农药对海洋微藻致毒性的生物学研究

本文以叉鞭金藻和三角褐指藻为材料，采用室内一次性培养的方法研究久效磷对光合色素（叶素α和类胡萝卜素）含量的影响。结果显示，低浓度的久效磷短时间处理对微藻细胞的光合色素含量影响轻微，有时甚至可使光合色素含量升高；随着久效磷浓度的提高和处理时间的延长，微藻的光合色素含量明显降低，说明久效磷对光合色素有严重的破坏作用。久效磷对叉鞭金藻叶绿素α的７２ｈＥＣ５０为６．８ｍｇ／Ｌ，４８ｈＥＣ５０为１０．６ｍｇ     

稀土对球等鞭金藻生长的影响

于１９９５年８－１２月,利用单因子实验法,首次研究了混合稀土对球等鞭金藻（Ｉｓｏｃｈｒｙｓｉｓｇａｌｂａｎａ）生长繁殖的影响,结果表明,海水中稀土最佳浓度范围为１．６６－６．６０ｍｇ／Ｌ,细胞浓度和叶绿素含量分别提高１１．６％－２３．２％和１９．９％－４５．２％混合稀土加入浓度高于９．９ｍｇ／Ｌ对球等鞭金藻的生产产生抑制作用,稀土对球等鞭金藻生长的促进作用与其他营养盐类浓度有关,当细胞处于指数生长     

UV-B辐射对叉鞭金藻和三角褐指藻光合色素的影响

以叉鞭金藻和三角褐指藻为材料，采用室内一次性培养的方法研究了UV－B辐射对光合色素（叶绿素a和类胡萝卜素）含量的影响，结果显示，低剂量的UV－B辐射处理对叉鞭金藻的光合色素含量影响不明显，甚至可使光合色素的含量升高；而高剂量的UV－B辐射处理引起叉鞭金藻光合色素含量降低，三角褐指藻的叶绿素a和类胡萝卜素含量随着UV－B辐射的增强表现出逐渐降低的趋势，说明UV－B辐射增强对海洋微藻光合色素有严重的破坏作用。     

油菜素内酯对两种单细胞藻生长和某些生理活性的影响

研究于１９９１年３月－１９９２年７月在大连进行，实验藻取自大连凌水养殖二场饵料室。分别用浓度为５，１０，５０μｇ／Ｌ和１，５，１０μｇ／Ｌ的油菜素内酯处理亚心形扁藻及球等鞭金藻，研究其对单细胞藻生长的结果表明，两种藻的各处理组的瞎缓期均缩短，细胞生长加快。促进生长最佳浓度。亚心形扁藻的１０μｇ／Ｌ，球等鞭金藻的５μｇ／Ｌ；油菜素内酯可提高实验藻的叶绿素含量并促进其光合作用；在处理组的亚心形扁藻和球     

烯效唑对铜藻(Sargassum horneri)生长及抗氧化系统的影响

本文研究了不同浓度(0,0.1,1.0,4.0和8.0mg/L)的植物生长调节剂烯效唑处理20天内对铜藻(Sargassum horneri)的生长及抗氧化系统的影响。结果表明,烯效唑显著抑制了铜藻的生长,各处理组藻体的长度和比生长速率(SGR)均显著低于对照组,且烯效唑处理浓度越高,抑制作用越明显。0.1和1.0mg/L烯效唑处理组的叶绿素a、类胡萝卜素和可溶性蛋白的含量均显著提高,可溶性糖的含量在前5天内有短暂的促进,而4.0和8.0mg/L处理组的叶绿素a、类胡萝卜素和可溶性蛋白的含量显著下降,而可溶性糖的含量显著升高。抗氧化防御指标的变化也呈现差异性,各处理组的超氧化物歧化酶(SOD)活性在5d时均显著提高,而随着处理时间的延长,低浓度(≤1.0mg/L)处理组SOD活性恢复到对照组水平,高浓度(≥4.0mg/L)处理组SOD活性仍保持在较高水平,显著高于对照组。0.1mg/L处理组的过氧化氢酶(CAT)活性在实验10d时才显著升高,表现为逐渐诱导的现象,丙二醛(MDA)含量在20d时略低于对照组;而其他三个高浓度处理组的CAT活性在实验期间,均显著升高,MDA含量20d时也显著高于对照。以上研究结果丰富了植物生长调节剂对藻类生长影响的研究体系,为烯效唑在大型藻类中的合理应用提供了理论依据。     

盐藻生长过程中氮磷利用与色素积累

考察了盐藻在氮浓度3mmol/L和0.59mmol/L两种条件下的生长、氮磷的利用以及色素积累的情况。结果表明氮浓度3mmol/L培养基有利于藻细胞的增值，最终藻体浓度大，稳定期可维持数日；0．59mmol/L培养基有利于细胞胡萝卜素积累，单位细胞胡萝卜素与叶绿素的比值达到12．3，是氮浓度3mmol/L培养基的两倍左右。盐藻细胞在生长初期快速利用氮源，之后即使培养基中仍有较高浓度的氮源，藻细胞也不再利用。两种条件下藻细胞对磷的利用情况相同。两种培养基中盐藻单位细胞叶绿素含量均先增加后减少，胡萝卜素含量均先降低后增加。     

金属离子对中肋骨条藻的胁迫效应及叶绿素a 合成的影响

研究中肋骨条藻(Skeletonema costatum)生长对不同质量浓度的5种金属离子胁迫的响应,探讨5种金属离子对中肋骨条藻叶绿素a合成的影响.结果显示:生长方面,中肋骨条藻对Cd2+和Ba2+的响应较明显,培养至第10天,Cd2+质量浓度为1、10 mg/L组生长量仅有对照组的59％及43.6％; Ba2+质量浓度为2 mg/L组到第10天是对照组的69.4％,而0.5 mg/L组超过对照组38.9％;中肋骨条藻对其他金属离子的胁迫响应不明显;叶绿素合成方面,Cd2+质量浓度为1 mg/L时,叶绿素a合成量达最高,高于对照组157％;而Ba2+质量浓度为0.5、1 mg/L时,超出对照组的116％和483％;其他金属离子对中肋骨条藻叶绿素a合成均起抑制作用,各个质量浓度组均低于对照组,其中pb2+质量浓度为0.3 mg/L、Mn2+质量浓度为1 mg/L及Li+质量浓度为0.1 mg/L时,叶绿素a含量达最低值,仅为对照组的34.1％、37.5％和17.6％;结论是质量浓度为0.5 mg/L的Ba2+可促进中肋骨条藻的生长及叶绿素的合成,对其产业化规模培养具有重要意义.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

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.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

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.     

INFORMATION FOR AUTHORS

<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,     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Net Sand Transport Direction in a Tidal Inlet, using Foraminiferal Tests as Natural Tracers

The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.