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为探讨生防细菌应用于水产养殖动物细菌病防治的可行性,作者从厦门市海沧港口污泥中筛选到一株蜡状芽孢杆菌(Bacillus cereus)K2-1,利用琼脂扩散法发现其发酵上清对大菱鲆(Scophthalmus maximus)养殖常见致病菌——副溶血弧菌(Vibrio parahaemolyticus)、爱德华氏菌(Edwardsiella)、哈维氏弧菌(Vibrio harveyi)、嗜水气单胞菌(Aeromonas hydrophila)、溶藻弧菌(Vibrio alginolyticus))有较强拮抗作用。进一步分析抗菌物质的部分特性,结果显示,蜡状芽孢杆菌(Bacillus cereus)K2-1发酵产生的抗菌物质含有蛋白(肽)类成分,该抗菌物质具有一定的耐热性,其在温度40~70℃的条件下保持较好的抑菌效果,对酸碱度也有很强的耐受力,pH在3.0~9.0范围内,活性降低少于15%,对紫外线不敏感,对胰蛋白酶、胃蛋白酶、木瓜蛋白酶也不敏感,但对蛋白酶K敏感。从实验结果可以初步确定该菌具有较好的开发价值。 相似文献
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一株拮抗菌C-5 的分离及鉴定 总被引：1，自引：1，他引：0
针对目前海参养殖中水产微生态制剂品种单一、施用效果不稳定等现状,作者从地瓜参(Acaudina molpadioidea)肠道分离土著肠杆菌(Enterobacter),筛选到1株具有较好拮抗作用的海洋细菌C-5,该菌对副溶血弧菌(Vibrio parahaemolyticus)、溶藻弧菌(Vibrio alginolyticus)、杀鲑气单胞菌(Aeromonas salmonicida)等7种细菌有拮抗作用;通过形态观察、生理生化和16S rDNA基因序列分析鉴定为霍肠杆菌(Enterobacter hormaechei);通过卤虫(Artemia)和药敏实验检测该菌具有安全性,其对卤虫的72 h半致死浓度(LC50)为108cfu/m L,只对20种常规抗生素中的5种产生耐药性;对C-5的发酵条件进行优化,该菌优化后的发酵条件为:温度30℃,pH 7.0,盐度2%。结果表明,C-5有望作为一种益生菌应用于海水养殖病害控制。 相似文献
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为研究孕激素在大菱鲆(Scophthalmus maximus)精原细胞增殖到减数分裂过程中的作用,以6~22月龄的大菱鲆精巢为材料,通过组织学方法和定量amh、sycp3基因确定精原细胞增殖期和减数分裂期的大菱鲆精巢发育过程。通过酶联免疫吸附技术(ELISA)检测6~22月龄雄性大菱鲆血清中的孕酮(P4)和17α,20β,双羟孕酮(DHP)含量变化,利用q RT-PCR技术和原位杂交技术检测孕酮核受体(pgr)和膜受体(m PRα)在不同组织和不同发育时期的表达情况。结果表明孕激素在精原细胞增殖期高表达,开始出现初级精母细胞时降低,在精子细胞数量增加时表达量再次升高,在精子细胞变态形成精子时降低。pgr在减数分裂初期定位于精巢中的sertoli细胞,在精原细胞增殖至减数分裂期表达量逐渐增加,出现精子后显著降低;m PRα在精原细胞增殖和初级精母细胞增加时表达量都很低,在精子细胞不断增加时显著增加。推测在精原细胞增殖和减数分裂阶段孕激素可能主要通过调节pgr的表达量来促进精巢发育,而在减数分裂II期pgr和m PRα都发挥作用,在精子细胞变态成熟时,主要是m PRα发挥作用。 相似文献
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微生物聚合物聚-?-羟基丁酸酯(PHB)具有良好的生物降解性、生物相容性和热塑性,在环保、医药和农业领域具有广阔的应用前景。高PHB积累菌株的获得及其发酵条件的研究具有很好的实用价值。作者从渤海湾日晒盐场盐田卤水中分离出一株杆状细菌,经16S r DNA序列测序比对,确定为盐杆菌属(Halomonas),命名为Halomonas 100-16-2,其最适生长盐度为50~100,最适生长p H为7~8,属中度嗜盐菌。在酸水解酪蛋白(7.5 g/L)的基础培养基中分别添加0、10、20和30 g/L葡萄糖,研究盐度100条件下不同葡萄糖添加量对Halomonas 100-16-2生长和PHB含量的影响。结果表明,随着葡萄糖浓度的增加,该菌株的生长和PHB积累显著提高。葡萄糖质量浓度为30 g/L时,细胞干质量达8.60 g/L,PHB含量达到5.57 g/L(即达到细胞干质量的65%)。本研究为渤海湾盐田微生物资源的开发和利用提供了有价值的基础数据。 相似文献
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可拉酸是生物被膜上重要的胞外多糖之一,但细菌可拉酸对海洋无脊椎动物附着过程的影响还鲜少研究。本研究从自然生物被膜中分离出8株海洋细菌,对其种属进行鉴定及聚类分析,并测定其生物被膜的可拉酸含量及对稚贝附着的诱导能力。筛选所得海洋细菌形成生物被膜并测定其成膜能力及胞外产物含量,发现β-多糖的生物量与厚壳贻贝稚贝附着率呈显著正相关趋势（p <0.05）。8株海洋细菌生物被膜中可拉酸含量的定量结果显示,3株革兰氏阳性菌无法产生可拉酸,5株革兰氏阴性菌均可检测到不同含量的可拉酸,其中革兰氏阴性菌Shewanella marisflavi的可拉酸含量最高,为1 076.43μg/mL。不同可拉酸含量的海洋细菌单一生物被膜与厚壳贻贝稚贝附着率之间关系的研究结果显示,海洋细菌生物被膜对厚壳贻贝稚贝附着率的诱导效果与其可拉酸含量呈显著正相关（p <0.05）。以上结果表明,细菌生物被膜中的可拉酸能够参与诱导厚壳贻贝稚贝的附着。本研究为探究海洋细菌生物被膜的化学物质与海洋贝类附着之间的相互作用及其对贝类附着机制提出了新的见解。 相似文献
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为探讨水深对工厂化流水养殖水环境的影响,本实验将9 000尾初始体质量为141.62±24.47 g的大菱鲆(Scophthalmus maximus)按照低水深(20 cm)、中水深(40 cm)、高水深(60 cm)条件分为3个不同养殖水深组,实验周期为80 d。实验期间,跟踪检测长期和特定时期(投喂后8 h内)不同养殖水深水体中总氨氮(TAN)、亚硝酸盐(NO2--N)、固体悬浮物(SS)、化学需氧量(COD)等参数,并在实验结束时对大菱鲆成活率、体质量、饲料系数水平进行测量。研究表明,水池内水流速度与水深呈负相关,但各组间无显著性差异。高水深组的固体悬浮物含量显著(P<0.05)低于其他两组,低水深组的化学需氧量显著(P<0.05)低于其他两组,各水深组中氨氮、亚硝酸盐都在大菱鲆幼鱼安全浓度范围内,且无显著性差异。在投喂后,固体悬浮物含量在各水深组中呈先升高后降低趋势,其中低水深组波动最大。氨氮含量在投喂后3 h开始上升,其中低水深组涨幅最大。各水深组中化学需氧量随着投喂时间延长而逐渐积累,而亚硝酸盐含量基本保持不变。实验结束,低水深组中大菱鲆增质量率、特定生长率、体质量变异系数均显著(P<0.05)高于高水深组,而存活率、肥满度、饲料系数在各组之间没有显著差异。研究结果显示,增加水深有利于提高养殖水环境水质恶化的缓冲能力。在保证养殖系统水质指标安全的前提下,低水深在大菱鲆工厂化流水养殖中是一个可行的方案。 相似文献
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海洋病毒在微生物食物环中的重要作用 总被引：10，自引：0，他引：10
自从Azam(1983)等提出“微生物食物环”(Mi-crobialloop)的概念以来,微生物在海洋生态系中对物质循环和能量流动过程所起的重要作用已成为海洋生态学的研究热点。Billen,G.等(1987)认为,浮游藻类、细菌、异养鞭毛虫和小型纤毛虫在微生物食物环中扮演主要角色:浮游植物初级生产所释放的溶解有机碳(DOC)被细菌利用,而细菌又被异养鞭毛虫和小型纤毛虫所吞噬。目前,由于对病毒在海洋生态系中重要作用的新认识,这一基本物流途径的完备性已受到质疑。病毒的介入使得微生物食物环中的物质流向更为复杂化,如图1所示。许多研究表明,病毒对传统意义… 相似文献
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从胶州湾海洋异养细菌同小球藻(Chlorella vulgaris)的共存体系中,分离出6株形态特征差异较大的异养细菌,并做变性凝胶梯度电泳(Denature Gel Gradient Electrophoresis,DGGE)分析.其中一株对小球藻的生长有较大的促进作用,而其余菌株则没有明显的效果.6株细菌能在小球藻产生的胞外溶解有机物(Dissolved Organic Mate rials,DOM)溶液中生长良好,共存细菌对提高菌藻体系对无机营养盐的吸收具有较大的贡献. 相似文献
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有害赤潮对海洋生态环境和沿海经济危害巨大,如何安全、有效地治理有害赤潮非常重要。文章考察了几种常见芽孢杆菌对近海典型赤潮生物——东海原甲藻(Prorocentrum donghaiense)的去除作用,发现解淀粉芽孢杆菌(Bacillus amyloliquefaciens)对其去除作用最强。进一步考察解淀粉芽孢杆菌对不同赤潮生物的去除作用,发现该芽孢杆菌对米氏凯伦藻(Karenia mikimotoi)和赤潮异弯藻(Heterosigma akashiwo)的去除作用高于东海原甲藻。在此基础上,将解淀粉芽孢杆菌与高岭土复合,研究了微生物复合粘土对典型赤潮生物的去除效果。结果表明,解淀粉芽孢杆菌与高岭土复合后,能够有效促进该菌的生长,进而提升了其对赤潮生物的去除能力。文章对芽孢杆菌及其复合粘土去除赤潮生物的机制进行了分析和探讨,为进一步发展和优化改性粘土治理赤潮技术体系提供了重要参考。 相似文献
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To examine the possibility that outer membrane proteins (OMP) of Synechococcus sp. remain in seawater, we investigated the stability of OMPs in vitro and in situ. Some fractions prepared from Synechococcus sp. CSIRO-94 were treated with trypsin and proteinase K. Four tightly bound OMPs were separated from Synechococcus. We designated the two major OMPs of 52 kDa and 48 kDa as Omp52Sy and Omp48Sy, respectively. Degradation of the OMP in natural
seawater was monitored in microcosms to which intact Synechococcus cells and outer membrane (OM) were added. Omp52Sy and Omp48Sy were the most stable against trypsin and proteinase K among
the OMPs when they were embedded in the OM. However, in the microcosm experiment using intact cells, Omp52Sy and Omp48Sy were
detected in the particulate fraction only during the first 4 days, after which they could not longer be detected. Omp52Sy
and Omp48Sy were the most stable proteins among the Synechococcus OMPs in vitro, but they might be degraded in situ. This indicates that stability of Synechococcus porin differs depending on complex formation with other membrane molecules, which might cause different preservation of microbial
membrane proteins in the dissolved protein pool in the ocean. This study suggests that Gram negative bacterial OM with thin
peptidoglycan forms a lipid bilayer that proptects OMP, but Synechococcus OM with thick peptidoglycan cannot form a lipid bilayer. The incomplete bilayer might not be able to protect from protease
attack in the natural environment. 相似文献
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The effects of exposure to two model marine pollutants, hexachlorobenzene (HCB) and pentachlorophenol (PCP) on components of the defense system of a polychaete, Glycera dibranchiata, were determined. Although both pollutants were markedly concentrated in the tissues, the levels reached in these studies produced no mortality or morbidity. Certain parameters (in vitro phagocytosis by amebocytes, total and differential coelomocyte counts, hemolysin, hemagglutinin and bacterial agglutinin activity) were not affected by our experimental procedures. However, the activity of a bactericidal glycoprotein was consistently induced in PCP- or HCB-exposed Glycera. We suggest that the release of this factor from coelomocytes is increased by a mechanism similar to that of macrophage activation, a characteristic of the leukocytes of higher animals. Exposure to PCP caused an apparent reduction in the numbers of amebocytes capable of forming rosettes with formaldehyde-treated rabbit erythrocytes. This was interpreted as an impairment in the ability of the cells to recognize foreign material, a process required for the normal functioning of these potentially protective blood phagocytes. 相似文献
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C.H. Walker 《Marine environmental research》1985,17(2-4)
The risk of bioaccumulation of persistent liposoluble pollutants in marine food chains was highlighted by work done on organochlorine residues in marine organisms in the early 1960s. In one study, concentrations of DDE and dieldrin were determined in species from different trophic levels of the Farne Island ecosystem.1 Concentrations of pollutants were related to trophic levels, with the highest levels occurring in predators such as the cormorant (Phalacrocorax carbo) and the shag (Phalacrocorax aristotelis). This paper will consider model systems which may be used to predict bioaccumulation risks from simple in vitro data. Emphasis will be upon persistent liposoluble pollutants with relatively simple patterns of metabolism, and upon the problem of bioaccumulation by marine predators. 相似文献
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Abstract On the basis of the Atterberg indexes of various sediments collected in the Mediterranean Sea, we select two major parameters indicative of the mechanical behavior of marine soils: the sedimentary facies (i.e., mechanism of deposition expressed by silt content) and the clay mineral association characterized by smectite content in the fraction finer than 2 μm. Activity and real thixotropic ability appear to be particularly important parameters in marine engineering; better values are obtained by a double test operation in distilled and marine water. 相似文献
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The metabolism of some xenobiotics can lead to the formation of reactive intermediates with mutagenic/carcinogenic properties. With the carcinogenic PAH these have been identified as bay-region diol-epoxides.1 Phenanthrene, a non-carcinogenic, bay-region containing model PAH, is metabolised in vivo by bony fish at the proximate bay-region position, whereas mammals and other marine organisms mainly form the K-region metabolite 9,10-dihydro-9,10-dihydroxy-phenanthrene.2 We wanted to investigate this difference more closely by studying the regiospecificity of phenanthrene metabolism in vitro both with microsomes from differently pretreated cod and with isolated cytochrome P-450 isozymes from BNF-induced cod.3 Secondly, by preparing antibodies to the major isozyme isolated (called cod P-450c), we investigated the immunochemical properties of the variously treated cod liver microsomes. 相似文献
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Richard F. Lee 《Marine environmental research》1985,17(2-4)
Bis(tributyltin) oxide (TBTO) is widely used as an antifouling agent in various antifouling paints. Thus, some marinas have TBTO concentrations as high as 2 μg/liter.1 These concentrations can be toxic to zooplankton.2 The objectives of the present study were to determine the ability of a number of marine animals, including crabs, oysters and fish, to metabolize TBTO. Earlier work showed that extracts of rat liver were able to metabolize TBTO to a variety of metabolites, e.g. β-hydroxybutyldibutylin.3 The role of the cytochrome P-450 dependent mixed-function oxygenase system in oxidizing TBTO in marine animals was also of interest. Both in vivo (uptake of 14C-TBTO from food or water) and in vitro studies demonstrated that all the animals were able to metabolize TBTO. The oysters metabolized TBTO at a much slower rate than the other animals. The mixed-function oxygenase system from hepatic tissues of the various animals was able to metabolize TBTO by forming a number of hydroxylated metabolites. 相似文献
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Lipid peroxidation, which is promoted in animal tissues by a variety of toxic agents, is believed to be associated with disruption of cell membranes and loss of activity of membrane-bound enzymes. While the process of lipid peroxidation has been well studied in mammals, only a few non-mammalian species have been examined.1 In the present study, in vitro assays for lipid peroxidation were performed using microsomes prepared from the livers of rats (Rattus rattus) and a marine fish, mullet (Mugil cephalus). Although lipid peroxidation was observed in microsomes prepared from both mullet and rat tissues, and was stimulated by xenobiotics, the mechanisms of generation appeared to be different. In contrast to rats, NADH was much more effective than NADPH in stimulating lipid peroxidation in mullet liver microsomes. The results suggest that NADH-dependent, as well as NADPH-dependent, lipid peroxidation may be important in vertebrate tissues. 相似文献
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材料表面性质对微生物附着行为的影响 总被引：1，自引：0，他引：1
利用荧光显微镜计数法,研究了微生物在4种不同材料表面的初始附着行为,对微生物附着进行了定量描述,初步获得以下结果:(1)不同材料表面,细菌的附着量呈现如下差异:316L不锈钢＞PVC＞玻璃,在有机硅材料(道康宁T2)表面的附着变动性很大;(2)同种材料表面,不同细菌的附着量也不同,表现为:Shewanella oneidensis MR-1菌株和Pseudomonas aeruginosa PAO1菌株均大于Escherichia coli JM 109菌株.并由此对其附着差异和影响因素进行了讨论. 相似文献
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Centropages typicus (Crustacea,Copepoda) reacts to volatile compounds produced by planktonic algae 
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下载免费PDF全文 Chingoileima Maibam Patrick Fink Giovanna Romano Maria Cristina Buia Emanuela Butera Valerio Zupo 《Marine Ecology》2015,36(3):819-834
Volatile organic compounds (VOCs) may play the role of infochemicals and trigger chemotaxis and ecologically relevant responses in freshwater and marine invertebrates. Aquatic grazers use these signals as chemical cues to trace the presence of their food or to detect their predators. However, detailed data are still needed to fully understand the role of these relationships in marine plankton. We investigated the ability of the copepod Centropages typicus to perceive the odour of three planktonic diatoms (Skeletonema marinoi, Pseudonitzschia delicatissima and Chaetoceros affinis) and a dinoflagellate (Prorocentrum minimum). This information is ecologically relevant for orientation, habitat selection, predator avoidance and communication. In addition, as the pH of the medium influences the perception of chemical cues in aquatic environments, we tested the effect of seawater acidification resulting from increasing levels of CO2, and its influences on the olfactory reactions of copepods. For this reason, our tests were repeated in normal (pH 8.10) and acidified (pH 7.76) seawater in order to simulate future ocean acidification scenarios. Using replicated chemokinetic assays we demonstrated that VOCs produced by Ps. delicatissima and Pr. minimum attract copepods at normal pH, but this effect is lowered in acidified water. By contrast, the odour of S. marinoi mainly induces a reaction of repulsion, but in acidified water and at higher concentrations this toxic diatom becomes attractive for copepods. Our experiments demonstrate, for the first time, that copepods are sensitive to the volatile compounds contained in various microalgae; VOCs prompt chemokinesis according to algal species and odour concentrations. However, seawater acidification induces changes in copepods' perception of odours. These findings highlight the sensitivity of chemically mediated interactions to global changes 相似文献