烟酰化壳寡糖季铵盐的制备及抑菌活性研究

海洋生物体内蕴含着丰富的天然活性物质,许多都具有抑菌活性,据此研制新型海洋生物源抑菌药物,是海洋生物产业中的一个新领域,也是新型抑菌药物研发的重要途径。壳聚糖是来自海洋中虾蟹等甲壳类动物外壳的甲壳素的脱乙酰产物,壳寡糖是壳聚糖的降解产物,具有比壳聚糖更好的水溶性和生物活性,在食品和生物医药等领域具有更广阔的应用前景。为了提高壳寡糖的抑菌活性,本研究以壳寡糖和烟酸为原料、N, N-羰基二咪唑为催化剂合成了壳寡糖烟酸接枝衍生物,并与不同链长的溴代烷烃亲核反应得到其阳离子化衍生物。壳寡糖及其衍生物的化学结构通过红外光谱(FTIR)和核磁共振波谱(NMR)进行分析表征,壳寡糖及其衍生物对2种海洋致病细菌和3种植物致病真菌的体外抑菌能力分别采用肉汤稀释法和菌丝生长速率法进行研究和评估。结果表明,与壳寡糖相比,合成的终产物对致病菌的抑制能力得到了极大增强,其中含有己基的烟酰化壳寡糖季铵盐表现出最强的抑制海洋致病细菌活性(MIC=0.125mg/mL、MBC=0.25mg/mL),并且该化合物表现出较强的抗真菌活性,在1.0 mg/mL时,对灰葡萄孢菌和围小丛壳的抑制率分别为65.7%和51.5%。...     

南极放线菌NJ-F2萃取物的抗菌活性初步研究

从南极第24次科学考察采集的海泥样品中分离获得放线菌NJ-F2,对NJ-F2发酵液的乙酸乙酯萃取物进行体外抗菌实验,并采用16S rDNA方法对NJ-F2进行系统发育分析.结果表明萃取物对金黄色葡萄球菌和枯草芽孢杆菌的最低抑菌浓度(MIC)、最低杀菌浓度(MBC)分别为0.25 mg/mL,5.0 mg/mL;而对大肠杆菌和产气杆菌的MIC、MBC分别为0.5 mg/mL,5.0 mg/mL,但对真菌没有抗菌作用;16SrDNA分析结果表明NJ-F2为链霉菌属(Streptomyces sp.).     

氨基酸在改性黏土上的吸附机制研究

研究了四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)化合物在改性黏土的吸附特征, 考察了改性剂PACl 添加比例、介质pH 及离子强度对吸附过程的影响, 并探讨了吸附机制。结果表明, 在一定比例的PACl 改性能促进氨基酸在高岭土上的吸附, 最佳改性比例为5%, 赖氨酸、谷氨酸、甘氨酸、组氨酸的最大吸附量分别为827、712.56、723.14、732.56 μmol/g; 氨基酸在改性黏土上的吸附动力学符合伪二阶动力学模型; 利用Weber-Morris 模型测定四种氨基酸内部粒子扩散常数, 5%改性条件下赖氨酸、谷氨酸、甘氨酸、组氨酸的内部粒子扩散常数分别为0.847、0.567、0.780、0.603。热力学研究表明, 氨基酸在改性黏土上的吸附等温线是C 型等温线, 5%改性条件下四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)的热力学自由能分别为?1.99、?2.41、?3.16、?2.94 kJ/mol, 说明氨基酸在改性黏土上的吸附是一个自发的吸附过程。介质pH 及离子强度对吸附过程具有重要影响。     

山楂提取物生物合成纳米银对四种常见水产病原菌的抑制作用

近年来,"绿色"生物合成纳米抑菌材料以其方法简单、价格低廉、环境友好的优势已成为纳米技术领域中的一项激动人心的发展策略。为了研究生物合成纳米银(Silver nanoparticles,Ag NPs)对水产病原菌的抑菌效果,本研究分别以山楂果实超纯水提取物和山楂乙醇提取物作为还原剂和稳定剂,采用生物合成法制备出两种纳米银抑菌材料W-Ag NPs和E-Ag NPs。通过紫外-可见吸收光谱(UV-vis)、透射电镜(TEM)和X射线衍射(XRD)等方法对合成产物的光学特性、形貌特征以及晶体结构等指标进行了比较,并采用琼脂扩散法初步检测了W-Ag NPs和E-Ag NPs对大肠杆菌和金黄色葡萄球菌两种典型病原菌的抑菌活性。研究结果显示,W-Ag NPs的合成效果较为理想,它的粒径较小、更加均一,并且具有较高的抑菌活性。在此基础上,我们进一步检测了W-Ag NPs对鳗弧菌、溶藻弧菌、副溶血弧菌及点状气单胞菌等4种典型的水产病原菌的抑菌圈,并测定了其抑菌动力学曲线、最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。研究结果表明,W-Ag NPs对四种供试水产病原菌均有显著的抑菌效果,10μg/m L和20μg/m L的W-Ag NPs均对鳗弧菌的生长产生明显的抑制作用,对鳗弧菌的MIC和MBC分别为6.5μg/m L和12.9μg/m L。研究表明山楂提取物制备的纳米银抑菌剂对水产病原菌有显著的抑制和杀灭效果,在水产养殖领域中有着广阔的开发和利用前景。     

14 种红树植物对动物病原菌的抑菌活性

采用带药培养基涂布法测定了14种红树植物甲醇提取物及从中分离获得的2种纯化合物对大肠杆菌(Escherichia coli)、绿脓杆菌(Pseudomonas aeruginosa)、伤寒沙门氏菌(Salmonella typhi)、痢疾志贺氏菌(Shigella dysenteriae)、普通变形杆菌(Proteus vulgaris)、金黄色葡萄球菌(Staphyloccocus aureus)、藤黄微球菌(Micrococcus luteus)、溶壁微球菌(Micrococcus lysodeikticus)和蜡样芽胞杆菌(Bacillus cer-eus)9种动物病原菌的抑菌活性。结果表明,苦郎树(Clerodendrum inerme)、海漆(Excoecaria agallocha)、白骨壤(Avicennia marina)、苦槛蓝(Myoporum bontioides)、银叶树(Heritiera littoralis)和榄李(Lumnitzeraracemosa)有比较广谱的抗菌活性。苦槛蓝和海漆的抑菌活性较高,最低抑制浓度(Minimum inhibitoryconcentration,MIC)值分别为1～4 g/L和2～6 g/L。从苦郎树中分离获得的纯化合物KLS-46对伤寒沙门氏菌、金黄色葡萄球菌、溶壁微球菌和蜡样芽胞杆菌的MIC值分别为0.1、0.05、0.1和0.05 g/L,对其余5种病原菌的MIC值均大于0.4 g/L。从病原菌对红树植物的敏感性看,藤黄微球菌和蜡样芽胞杆菌对红树植物比较敏感。     

深海贝莱斯芽孢杆菌DH82的抑菌活性物质初步分离纯化及其抑菌谱检测

贝莱斯芽孢杆菌(Bacillus velezensis) DH82发酵上清液经最佳硫酸铵饱和度(70%)沉淀、透析获得粗蛋白,粗蛋白经Sephadex G-75柱层析的色谱条件为柱1. 6 cm×50. 0 cm;上样量为5 mL;洗脱液为超纯水,流速2 mL/min;检测波长280 nm,获得两个具有抑菌活性的峰蛋白PrⅠ和PrⅡ。两个峰蛋白经抑菌谱检测,发现对常见水产指示病原细菌包括迟缓爱德华氏菌(Edwardsiella tarda)、嗜水气单胞菌(Aeromonas hydrophila)、坎氏弧菌(Vibrio campbellii)、溶藻弧菌(Vibrio alginolyticus)、哈维氏弧菌(Vibrio harveyi)、无乳链球菌(Streptococcus agalactiae)和金黄色葡萄球菌(Staphylococcus aureus)都具有较好抑菌活性,表明深海贝莱斯芽孢杆菌DH82产生的抑菌活性物质对水产病原细菌的抑菌谱较广,其中峰蛋白PrⅡ对指示植物病原真菌水贼镰刀菌(Fusarium equisetum)也具有较好抑菌作用。进一步对峰蛋白进行最小抑菌浓度(MIC)检验,发现其对迟缓爱德华氏菌和溶藻弧菌的MIC都较低(为7. 16μg/mL)。以上研究结果表明,深海贝莱斯芽孢杆菌DH82具有较宽的抑菌谱及较强的抑菌活性,预示该菌株在常见水产细菌性及个别植物真菌性病害防治上具有较好的开发利用价值。     

海洋微藻β-葡聚糖的生物活性分析

为研究微藻来源的β-葡聚糖生物活性以及是否存在种间差异,从6种海洋硅藻和定鞭藻(Haptophyte)中制备了β-葡聚糖,进行了抗肿瘤、抗氧化、抑菌活性的分析和比较。6种微藻分别为:中肋骨条藻(Skeletonema costatum)、三角褐指藻(Phaeodactylum tricornutum)、假微型海链藻(Thalassiosira pseudonana)、柔弱角刺藻(Chaetoceros debilis)、球等鞭金藻(Isochrysis galbana)、颗石藻(Pleurochrysis sp.)。研究结果显示:1.微藻β-葡聚糖对Hela肿瘤细胞有细胞毒性:浓度为50—100μg/mL时,假微型海链藻β-葡聚糖的活性最高;200μg/mL时,颗石藻的最高,但活性均未超过50%。2.以DPPH和DCFH-DA两种方法检测抗氧化活性发现,6种微藻β-葡聚糖均有浓度相关的抗氧化活性,并且对氧自由基的清除率相对较高;当β-葡聚糖浓度为400μg/mL时,其清除率可达72%—74%。3.对不同菌的作用有差异:有浓度相关的抑制大肠杆菌的作用,浓度为400μg/mL时,抑菌率可达60%;有促进金黄色葡萄球菌生长的作用,其中,仅中肋骨条藻的β-葡聚糖有浓度相关的作用。结果表明,几种硅藻和定鞭藻的β-葡聚糖生物活性功能相同,都具有抗肿瘤、抗氧化以及抑菌或促菌作用,活性大小与浓度有明显的相关性。相同浓度或作用时间下,其活性大小及活性饱和性具有微藻种间差异。这为研究和利用微藻及其天然产物提供了参考。     

仿刺参水溶性海参皂苷的分离制备及抗真菌活性的研究

利用海洋生物资源进行天然抗真菌新药的开发,从冻干海参加工废液中提取了水溶性海参皂苷,并对其抗真菌活性进行了研究。采用大孔吸附树脂法提取水溶性海参皂苷,经Libermann Burchard反应等对提取物的性质进行鉴定后,利用管碟法对所得提取物的抗菌活性进行了测定,并利用琼脂稀释法测定了所得水溶性海参皂苷对6株供试真菌的最低抑菌浓度(MIC)。提取物在Molish反应、沉淀反应和泡沫实验中均为阳性,说明提取物中确含有皂苷类成分;在Libermann Burchard反应中,液体的颜色处在红色与紫色之间,显示提取物可能是1种三萜类皂苷。水溶性海参皂苷对6株供试真菌均具有显著的抑制作用,且在浓度为0.5~4 mg/mL的范围内,其抑菌活性与所用浓度之间呈明显的正相关性;在浓度为4 mg/mL时,水溶性海参皂苷对6株供试真菌抑制活性的大小依次为裂殖酵母菌、啤酒酵母菌、白色念珠菌、葡萄炭疽病原菌、黄瓜枯萎病原菌和黑曲霉,海参皂苷对6株真菌的MIC值依次分别为0.002,0.016,0.063,0.063,0.125,0.250 mg/mL。     

壳聚糖聚乳酸羟基乙酸纳米粒子作为抗瘤药物载体的研究

研究采用乳化溶剂挥发技术和共价交联技术,合成了壳聚糖聚乳酸羟基乙酸(壳聚糖PLGA)的3种纳米载体:空白的PLGA NPs、表面修饰的C-NPs和自组装的G-NPs。利用人乳腺癌细胞MCF-7细胞作为模型细胞,抗肿瘤药物阿霉素为载药,通过荧光显微镜观察了肿瘤细胞对FITC标记的纳米载体的体外摄取情况,并进行了定量测定。用MTT法测定了包载药物阿霉素后纳米粒子对肿瘤细胞生长的抑制率,分析了不同纳米粒子作为抗肿瘤药物载体的靶向性和载药抑制性。研究结果表明,在低浓度条件下(25~400μg/mL),MCF-7细胞对C-NPs和G-NPs的吞噬具有时间依赖性和浓度依赖性。载药纳米粒子(DOX-PLGA NPs,DOX-C-NPs和DOX-G-NPs)和游离药物(DOX)对细胞生长的抑制率也具有时间依赖性和浓度依赖性,在低药物浓度下(1~4μg/mL)孵育12h后,载药纳米粒子基本呈现出高于游离药物的细胞生长抑制率,而当药物浓度从8μg/mL增加到16μg/mL后,游离阿霉素显现出更高的细胞生长抑制率,C-NPs和G-NPs均表现出高于PLGA NPs的细胞生长抑制率。壳聚糖修饰的2种纳米粒子C-NPs和G-NPs具有良好的细胞靶向性和低浓度药物抑制率,是一种良好的抗肿瘤药物载体。     

对虾病原菌抑菌药物的研究

应用药敏纸片法研究了48种化学疗剂对中国对虾红腿病病原菌(包括Vibrio alg-inolyticus,V.campbellii,V.parahaemolyticus,Proteus vulgaris及未确定的海洋弧菌)生长的抑制作用,其中氯霉素(30μg/片)、磺胶药+TMP(25μg/片)和呋喃妥因(200μg/片)抑菌力最强、抑菌谱最广;红霉素(15iu/片)、土霉素(30μg/片)无明显抑菌作用。对27种中草药水浸液以平板点种法试抑菌作用。结果表明乌梅、石榴皮、五味子的水浸液具有较强的抑菌活性,可用于配制防病药物饵料。5,7—二氯-8-羟基喹啉对多种病原菌有较强的抑菌作用,药物平板点种法最小抑菌浓度为25mg/L,药浴法有效抑菌浓度低于5mg/L。     

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.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

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。     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

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.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

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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,