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1.
从患有红体病的养殖大菱鲆(Scophthalmus maximus)的肌肉中分离得到一株优势菌并记为H1.经人工注射感染证实H1即为引起养殖大菱鲆红体病的病原菌,其半致死量LD50为2.82×105CFU/mL,而低浓度(1.41×103 CFU/mL)没有造成死亡,但注射部位有脓肿现象,注射相同体积1.5%无菌生理盐水的对照组没有明显的症状,注射部位也无异常.革兰氏染色显示该菌为革兰氏阴性,菌体呈杆状,周生鞭毛.综合该菌的形态、常规生理生化特征和API32E鉴定结果,发现H1与迟钝爱德华氏菌的表性特征非常相似,相似率迭到99.9%.在分子水平上对其16SRNA基因序列的测定,同源性分析,结果表明H1与迟钝爱德华氏菌的亲缘关系最近,相似度达到99%.综合上述研究结果,将该菌株初步鉴定为迟钝爱德华氏茵(Edwardsiella tarda). 相似文献
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报道1999~2002年对南海珠江口(21°50'~22°50'N,113°20'~114°50'E)26个站点的动态监测结果:(1)TCBS类群包括37%Ⅰ类(假单胞菌属、气单胞菌属),5%Ⅱ类(副溶血弧菌)和58%Ⅲ类(霍乱弧菌、霍乱弧菌埃尔托型,溶藻弧菌);EMB类群包括14%Ⅳ类(变形菌属、沙门氏菌属或志贺氏菌属),50%Ⅴ类(肠杆菌属、克雷伯氏菌属、哈夫尼氏菌属、沙雷氏菌属)和36%Ⅵ类(大肠杆菌);(2)26个站点之间的年平均CFU值差异显著.各站点的TCBS类群数量多而EMB类群数量少,表明TCBS类群为土著优势,而EMB类群主要来自陆源性污染;(3)26个站点被聚类为四大类别,不完全吻合其实际地理位置邻近关系,提示人为干扰活动影响超越自然地理隔离效应.站点G(万山群岛)和H(担杆岛)同属最靠近外海的孤立站点,却被划分为不同类别.H站点TCBS类群数量最高(3.7±2.6×104CFU/cm3),G站点是天然养殖区,EMB类群数量最高(9.5±6.6×103CFU/cm3),表明养殖区域陆源性EMB类群污染突出;(4)TCBS与EMB类群的月平均CFU值变化趋势相似,呈现年度周期性和季节周期性波动;(5)珠江口可以分为南、北部区域.南部区域的陆源性EMB类群污染严重,综合反映了来自珠江口水网系的高通量排放污染,养殖区域的自身污染,及其养殖活动对陆源性污染菌群的规模化“原位扩增”效应. 相似文献
3.
对虾池悬浮颗粒附着细菌的研究 总被引：4，自引：0，他引：4
用5个实验围隔研究了对虾池悬浮颗粒上的附着细菌,结果表明:附着细菌数量波动在0.65×104～23.49×104个/cm3之间,平均为(4.57±3.64)×104个/cm3,占水体细菌总数的1.47%×1.41%(0.28%～8.73%).附着细菌数为1、2、3、4个的附菌颗粒占总附菌颗粒的比数分别为40%、27%、15%及11%,多于4个附着细菌的附菌颗粒数仅占总附菌颗粒数的7%;总悬浮颗粒中的附菌颗粒所占比例为52%;附着细菌数与水体总悬浮颗粒数关系最为密切,与水温及总细菌数也具有显著相关性,但与水层POC及DOC含量却未呈现显著的相关性. 相似文献
4.
欧洲鳗鲡肝肾病病原菌的分离与鉴定 总被引：1，自引：0，他引：1
患肝肾病的养殖欧洲鳗鲡(Anguilla anguilla)出现肝、肾肿大,且肝脏具白色溃疡灶的症状。从肝脏中分离、纯化到优势细菌,定名AL60306NA1。人工感染试验证实:向欧洲鳗鲡腹腔内注射1.0×108cfu/mL菌株悬液,实验鱼死亡率达100.0%;注射1.0×107cfu/mL,死亡率为60.0%;形态学观察、API20E细菌鉴定试剂盒鉴定实验证明菌株AL60306NA1有动力、拥有革兰氏反应阴性、氧化酶阴性、H2O2酶阳性、兼性厌氧、发酵葡萄糖产酸产气、不发酵蔗糖和蜜二糖及L一阿拉伯糖、赖氨酸脱羧酶阳性、柠檬酸盐弱阳性、产生硫化氢和吲哚、MR阳性和典型的β-溶血等特征;16S rRNA特异性基因分析鉴定实验说明克隆的AL60306NA1 16S rRNA基因部份序列为1507bp、与迟缓爱德华氏菌(AB050829.1)的同源性达99.7%。综合上述结果,确定该菌株为养殖欧洲鳗鲡肝肾病的病原菌,并鉴定为迟缓爱德华氏菌(Edwardsiella tarda)野生型。用菌株AL60306NA1感染小白鼠实验测定该菌对小白鼠的LD50为7.1×105cfu/mL,同时自该菌株PCR扩增到长度约1000bp的溶血素基因特异性片段,结果表明菌株AL60306NA1有一定的致病力。 相似文献
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本研究从自然发病的养殖大黄鱼(Pseudosciaena crocea)肝脏处分离得到1株优势菌9L2,经形态学观察和传统生理生化鉴定,显示该菌为发酵型革兰氏阴性短杆菌,有动力,氧化酶阳性,水解赖氨酸及色氨酸等。利用Biolog细菌鉴定方法进行种属鉴定,确定9L2为维氏气单胞菌(Aeromonas veronii),相似性达100%。同时对其16S rDNA基因进行PCR扩增、测序和系统发育分析,结果表明该菌与气单胞菌属的菌株亲缘关系最近,与维氏气单胞菌(登录号为LMG13695)的16S rRNA基因序列相似性达99.79%。经人工腹腔注射感染吉富罗非鱼(Oreochromis niloticus)的试验结果表明,9L2对罗非鱼的半数致死剂量LD_(50)为1.08×10~3CFU/g。24种抗生素药敏试验结果表明,该菌株对诺氟沙星、新生霉素、呋喃妥因、头孢曲松等13种药物高度敏感,对洛美沙星、卡那霉素等5种药物中度敏感,对利福平、青霉素等6种药物产生耐药性。20种中药体外抑菌试验结果表明,其中11种对致病菌体外抑菌效果较好,平均抑菌浓度范围为0.11—7.20mg/mL。 相似文献
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5-羟色胺刺激长牡蛎排放精卵在四倍体诱导中的应用 总被引：4，自引：0，他引：4
本文报道了用 5 羟色胺催产出的长牡蛎精、卵 ,人工授精后诱导四倍体的实验结果 .结果表明 :在 2 6℃水温条件下 ,受精后 7min ,用 0 .5mg/dm3细胞松弛素B处理2 5min ,获得长牡蛎的胚胎四倍体 ,其诱导率为 1 6.7%,D形幼虫孵化率为 2 7.0 %;诱导效果优于采用常规解剖法 .注射 5 羟色胺刺激长牡蛎亲贝排放精、卵的有效浓度分别为 1× 1 0 -6 ～ 1× 1 0 -2 mol/dm3和 1× 1 0 -5 ～ 1× 1 0 -3mol/dm3. 相似文献
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从湖南常德某养殖场死亡的斑点叉尾（Ictalunes punctatus）肝脏、肾脏、腹水及血水中分离到一株致病性菌株zy02。对该菌进行了形态特征观察、理化特性测定及分子生物学方法鉴定,用PCR方法同时扩增其16S rDNA和gyrB基因,分析了16S rDNA和gyrB两种基因序列的同源性,并构建了系统发生树。经生理生化测定和16S rDNA与gyrB基因序列分析,zy02株为中间气单胞菌。人工感染该菌后发病鱼表现为与自然发病类似症状,且从组织中再分离的细菌特性与原感染菌相同。腹腔注射后该菌株对斑点叉尾的半致死浓度为3.89×106CFU/mL。菌株zy02对多西环素、庆大霉素及左氧氟沙星等高度敏感;对红霉素中度敏感;对阿莫西林、磺胺异噁唑、克林霉素及利福平等5种药物耐药。本研究为斑点叉尾该病防控提供了理论依据。 相似文献
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海水养殖斜带石斑鱼溃疡病病原菌(溶藻弧菌)的初步研究 总被引：15，自引：1，他引：15
从患溃疡病的斜带石斑鱼肝脏分离到 1株细菌EpGS0 2 10 0 1,人工感染试验结果证明该菌是斜带石斑鱼的病原菌 ,对斜带石斑鱼的半致死剂量为 2 .0× 10 5CFU·g-1。对EpGS0 2 10 0 1进行了生理生化特性指标测定、API细菌鉴定系统和 16SrRNA基因序列比较鉴定。结果表明 ,该菌为溶藻弧菌。药敏试验结果表明 :头孢曲松、环丙沙星、依诺沙星、氧氟沙星、复方新诺明及阿米卡星对该菌有明显的抑制作用。 相似文献
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在威海泊于、崮山及荣成 3家海带育苗场 ,采用回染实验方法对采集的海带藻体表面褐藻酸降解菌数量分布及特点进行了初步研究。结果表明 ,采自荣成的病烂海带幼苗上 ,其总异养细菌数量 ( 1 2 2× 1 0 8cfu/g)比威海两家育苗场的正常海带幼苗上总异养细菌数量 (崮山 :1 1 5× 1 0 6cfu/g及泊于 :1 1 1× 1 0 6cfu/g)高 1 0 0多倍 ,其褐藻酸降解菌的数量 ( 4 88× 1 0 7cfu/g)比后两家 (崮山 :8 0× 1 0 4 cfu/g及泊于 :4 3× 1 0 5cfu/g)的高 1 0 0— 5 0 0倍。与正常海带幼苗相比 ,烂苗脱落后的总异养细菌数量较高 ( 2 42× 1 0 7∶1 1 1× 1 0 6) ,而褐藻酸降解菌的数量相对更高 ( 1 5 0× 1 0 7∶4 3× 1 0 5) ;其中 ,脱落烂苗上的褐藻酸降解菌数量约占其总异养细菌数量的61 98%。将分离、纯化的部分褐藻酸降解菌对海带孢子体组织块进行回染实验 ,能引起海带组织产生绿烂现象 ,证明褐藻酸降解菌是海带烂苗的条件致病菌。 相似文献
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从发病的斑点叉尾肝脏和肾脏均分离到一高致病性的菌株(FF003),感染该菌后斑点叉尾表现为体表多处点状出血,特别是在下颌、腹壁、体侧处,各内脏器官不同程度出血,尤其是腹内膜和鳔内膜斑块状出血。该菌为非发酵型需氧,革兰氏阴性杆菌,对除麦芽糖、甘露糖、果糖、海藻糖、D-甘露醇以外的多种糖类不利用产酸,氧化酶阴性,精氨酸双水解酶、鸟氨酸脱羧酶、赖氨酸脱羧酶阳性,MR阳性。在以该菌16S rDNA序列(GenBank登录号为FJ908709)和GenBank数据库内同源性较高的细菌16SrDNA序列构建的系统发育树中,分离菌FF003株与鲁氏耶尔森氏菌(Yersinia ruckeri)聚为一个分支,结合形态和生理生化特点将其鉴定为鲁氏耶尔森氏菌。药敏实验结果表明氟哌酸、环丙沙星、强力霉素、氯霉素对其高度敏感,头孢拉定、克拉霉素、磺胺甲基异唑、庆大霉素、麦迪霉素等药物不敏感。 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
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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。 相似文献
13.
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
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
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. 相似文献
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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
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《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
20.
Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges. 相似文献