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探究了南大西洋深海沉积物中可培养放线菌的多样性,筛选药源活性次级代谢产物产生菌,为后续资源开发奠定基础.采用3种预处理方法及8种选择性培养基对南大西洋3个深海沉积物样品中的放线菌菌株进行选择性分离鉴定;利用兼并引物扩增法,选取代表菌株进行聚酮合酶（PKSⅠ、PKSⅡ）基因和非核糖体多肽合成酶（NRPS）基因的检测;以4株细菌为指示菌检测代表菌株的抑菌活性.共分离得到132株放线菌纯菌株,分布于放线菌亚纲的6个目、13个科、19个属中,其中有5个属为较新或较稀有种属,有2株为潜在新种.34株化合物合成基因检测菌中PKSⅠ基因、PKSⅡ基因呈阳性的比率均为17.64%,NRPS基因呈阳性的则为52.94%.抗枯草芽孢杆菌（Bacillus subtilis）和抗副溶血性弧菌（Vibrio parahaemolyticus）的菌株分别有47.06%和7.82%.南大西洋深海沉积物中放线菌资源丰富,存在较多潜在新分类单元,筛选到的活性菌株可用于后续药源活性次级代谢产物的分离. 相似文献
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培养基对海藻真菌PT2菌株的生长及活性代谢产物合成的影响 总被引：3，自引：0，他引：3
本文采用PD、GPY、YES、SYE、GPM5种不同培养基培养海藻真菌菌株PT2，并对其在不同培养基中的生长情况、代谢产物的形成及抗肿瘤活性进行分析，旨在了解不同培养基对菌株生长和活性物质合成的影响．结果显示，PT2菌株在不同培养基上的培养特征及生长速率有所不同，液体培养基发酵液抽提物的抗肿瘤活性也有较大差别，其中SYE发酵液抽提物活性最强，对KB、Raji和Hela 3种肿瘤细胞的IC50分别为7．6μg／cm^3、2．4μg／cm^3和3．3μg／cm^3．采用HPLC法对不同抽提物进行分析，发现它们之间的组成成分有显著差异．本文的实验结果表明，不同培养基对该菌株的生长及活性代谢产物的合成具有显著的影响。 相似文献
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为了从海绵共附生微生物中寻找天然高效抗污损活性物质,本文针对前期研究获取的4株具有显著抗硅藻附着的活性菌株进行活性验证和比较,选出其中最优菌株进行菌种鉴定及发酵条件优化.比较了活性菌株对小新月菱形藻(Nitzschia closterium)、咖啡双眉藻(Amphora coffeaeformis)、碎片菱形藻(Nitzschia frustulum)附着的抑制活性,确定菌株UST050418-715为最优菌株;通过16S r DNA的测序分析,结合平板的菌落形态和扫描电镜下菌体特征,鉴定活性菌株UST050418-715为短小芽孢杆菌(Bacillus pumilus).为优化该菌株的培养条件,选择了酵母粉、蛋白胨、Na Cl、p H值进行四因素三水平的正交实验,对菌株培养条件进行优化.发现选择的4个因素对应的菌株发酵产物对硅藻附着的抑制活性大小不同,影响显著性顺序是酵母粉蛋白胨Na Clp H值,综合菌株发酵产物活性、粗提物产量和菌株生长情况进行分析,确定菌株UST050418-715基于海洋2216E培养基的最佳发酵条件为:蛋白胨含量7.5 g/dm3,酵母粉含量3 g/dm3,Na Cl含量10.45 g/dm3,p H值9.5. 相似文献
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海洋链霉菌由于其独特的生理和代谢功能,成为海洋微生物活性物质的主要来源。对2010-2013年初的海洋放线菌天然产物的统计表明,研究最多的是链霉菌放线菌,占海洋放线菌新天然产物的60%。本文综述了自1976年第一个海洋链霉菌天然产物到2016年6月的40年间报道的547个海洋链霉菌天然产物的结构、生物活性及其微生物来源。其结构包括含氮化合物（如生物碱）、聚酮、萜类、甾体等,其中含氮化合物是主要类型, 占海洋链霉菌天然产物总数的61%;而67%的海洋链霉菌天然产物表现出细胞毒、抑菌、抗疟和抗寄生虫等生物活性。 相似文献
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大叶藻是一种水生单子叶植物,是构成海草床的主要藻类之一。对大叶藻内生放线菌及其活性物质的研究是发现海洋微生物资源和新天然产物的有利途径。通过纯培养的方法,使用2216E等7种培养基,从山东省威海市荣成天鹅湖采集的大叶藻样品中分离出62株内生放线菌,并利用纸片法对金黄色葡萄球菌、白色念珠菌和副溶血性弧菌等7种指示菌进行了抗菌活性筛选,其中RO培养基分离出放线菌的种类和数量都较为丰富。抗菌活性筛选结果表明,48株内生放线菌(占77.42%)至少对1种指示菌表现出一定的抑制作用,36株内生放线菌(占58.06%)抑制2种及2种以上指示菌;并且内生放线菌对革兰氏阳性指示菌(金黄色葡萄球菌和枯草芽孢杆菌)的抗菌效果明显优于革兰氏阴性指示菌。研究结果表明,大叶藻的内生放线菌具有较好的抗菌活性,可以为海洋来源抗生素的研究提供新资源。 相似文献
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海洋链霉菌M506 的鉴定及代谢产物抑菌活性初步研究 总被引：1，自引：0，他引：1
自胶州湾沉积物中分离出海洋链霉菌M506,根据其形态特征观察、生理生化特征试验及基于16S rDNA序列系统进化分析,初步鉴定该菌为灰略红链霉菌.采用不同培养条件对其进行小规模发酵,利用金黄色葡萄球菌(Staphylococcus aureus),大肠杆菌(Escherichia coli),枯草芽孢杆菌(Bacillus subtilis)和苏云金芽孢杆菌(Bacillus thuringiensis)四株细菌作为指示菌,检测其抑菌活性.结果表明,该菌株代谢产物粗提物对于金黄色葡萄球菌、枯草芽孢杆菌和大肠杆菌等具有显著抑制活性. 相似文献
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从无活性海洋来源放线菌M15的3株抗生素抗性抗肿瘤活性突变株发酵物中分离鉴定了9个原始菌M15发酵物中没有的代谢产物,其化学结构分别鉴定为1,9-二甲酯-吩嗪(1)、过氧化麦角甾醇(2)、对-甲胺基苯甲酸(3)、染料木素(4)、大豆黄素(5)、N-(2-羟基苯基)-乙酰胺(6)、邻二羟基苯甲酸(7)、尿嘧啶(8)和2-吡咯酸(9)。在初步预试活性测试中,化合物1,2,4,5,7,8对K562细胞示有一定抑制作用,相关活性有待进一步详细测评。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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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
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Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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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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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
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Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献