Characterization of bacterial communities associated with seasonal water masses from Tongyoung in South Sea of Korea

Understanding the patterns of microbial diversity and their composition in seawater is necessary to assess the impacts of microbes on marine ecosystem. Although the potential roles of microbes in the ocean have been studied, their diversity and relationship with environmental factors remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with two different water masses from Tongyoung in the South Sea of Korea. Our results revealed highly diverse bacterial communities up to 900 Operational Taxonomic Units (OTUs) estimated from each seawater which was collected in the month of March and May, when the environmental conditions including temperature differed significantly: 7.2°C and 17.6°C in March and May, respectively. Altogether, 13 bacterial phyla were recovered from the seawater, of which Proteobacteria was the most dominant group. In addition, the value of the Shannon index, which measures the evenness of the distribution of individuals among OTUs, in May is higher than that in March, indicating that it displays a wider diversity of bacteria. Interestingly, the proportion of pathogenic bacteria was significantly increased in the month of May compared to March, suggesting that pathogenic bacteria were increasingly emerging in May. In particular, Pseudoalteromonas and Vibrio spp. were determined as major pathogenic bacteria from both water masses, of which Vibrio spp. were dominant.     

A study of crude oil‐degrading bacteria from mangrove forests in the Persian Gulf

Mangroves are coastal ecosystems, found in tropical and subtropical regions around the world. They are found in the transitional zones between land, sea, and rivers. Petroleum hydrocarbons are the most common environmental pollutants, and oil spills pose a great hazard to mangroves forests. This research was focused on the isolation and characterization of crude oil‐degrading bacteria from mangrove ecosystems at the Persian Gulf. Sixty‐one crude oil‐degrading bacteria were isolated from mangrove samples (plant, sediment, and seawater) that enriched in ONR7a medium with crude oil as only carbon source. Some screening tests such as growth at high concentration of crude oil, bioemulsifier production, and surface hydrophobicity were done to select the most efficient strains for crude oil degradation. Molecular identification of strains was carried out by amplification of the 16S rRNA gene by PCR. The results of this study were indicated that the quantity of crude oil‐degrading bacteria was higher in the root of mangrove plants compare to other mangrove samples (sediment and seawater). Also, identification results confirmed that these isolated strains belong to Vibrio sp. strain NW4, Idiomarina sp. strain BW32, Kangiella sp. strain DP40, Marinobacter sp. strain DW44, Halomonas sp. strain BS53, and Vibrio sp. strain DS35. The application of bioremediation strategies with these bacteria can reduce crude oil pollution in this important marine environment.     

近海沉积物与水体中天然大分子聚合物降解菌的原位富集与多样性分析

本研究选取5种海洋动植物大分子高聚物或其天然组织,包括虾壳、鱼鳞、海带叶片、几丁质和壳聚糖,分别在海水表层和沉积物环境中进行富集,定期取样,通过高通量测序分析菌群多样性。结果发现,不同有机物原位富集的细菌多样性存在较大的差异,而且同种底物在海水表层与沉积物中的降解菌菌群差异较大。从物种多样性看,在海水表层环境中富集的鱼鳞样品种群最丰富,而沉积物环境中富集的海带叶片样品菌群多样性最低,除其优势菌群为热袍菌门外,其他所有富集物中优势菌均为变形菌门。其中脱硫杆菌科、黄杆菌科、脱硫弧菌科和弧菌科占有较大比例,脱硫杆菌科在所有样品中优势较大,黄杆菌科在海水表层环境样品中为优势菌群,弧菌科在沉积物样品几丁质和壳聚糖样品中占比较高。本研究通过对同种海洋环境中不同富集样品之间以及同种底物不同环境中富集菌群之间的比较,分析结果得到了原位条件下参与大分子聚合物降解的菌群种类,但有待于在更多不同的海域富集物中进行验证。     

Interactions of bacteria with diatoms: influence on natural marine biofilms

Interactions between microfouling components influence the biofilm community and the cascading events, thus playing an important role in the biofouling process. Bacteria and diatoms are among the dominant forms reported in biofilms. Experiments were carried out with natural marine biofilms from a tropical monsoon‐influenced environment to evaluate the interactions between bacteria and diatoms through application of antibiotics (streptomycin and chloramphenicol). Overall, chloramphenicol inhibited diatom communities, whereas streptomycin did not. These antibiotic‐mediated changes in the fouling diatom community were consistent across the seasons. However, the rates at which the fouling communities changed depended on the initial species composition. It was also observed that elevated nutrient concentrations overrode the inhibitory effect of chloramphenicol. Maximum Vibrio enhancement was observed in the enriched conditions during the pre‐monsoon and unenriched conditions during the monsoon (with naturally elevated background nutrient concentrations), highlighting the relevance of nutrient concentrations for Vibrio spp. This has interesting implications for antibiotic‐mediated interactions between fouling diatom and bacterial communities under differing nutrient regimes. Although this study indicates the relevance of ‘cross‐talk’ at the microfouling level, understanding the effects of additional microbial products (e.g. bacteriocins and peptidoglycan) on these community‐level interactions will represent a step forward.     

厚壳贻贝(Mytilus coruscus)养殖海域与天然生长海域的微生物群落比较研究

为研究厚壳贻贝(Mytilus coruscus)生长海域微生物群落的结构与多样性特征,初步探究海域微生物群落及共生菌对贻贝生长的影响,分别采集舟山市东极镇庙子湖岛和嵊泗县枸杞岛厚壳贻贝养殖区和野生生长区海水样品,利用16SrRNA扩增子测序技术,比较分析不同海域微生物群落的组成及丰度特征以及微生物群落的差异;同时对厚...     

Microbial colonisation of artificial and deep‐sea sediments in the Arctic Ocean

Although environmental factors such as grain size and organic carbon content may influence the distribution of microbes in marine sediments, there has been little experimental study of the topic to date. To investigate how those sediment variables affect microbial colonisation under in situ conditions, deep‐sea sediments and artificial sediments (glass beads, sands) were incubated in the Arctic deep sea at 2500 m water depth with or without chitin, one of the most important carbon polymers in marine environments. Microbial abundance, biomass, chitobiase activity and changes in community structure were monitored after 7 days and 1 year. In control sediments without chitin addition, no significant changes in microbial abundance, biomass and activity were observed after 1 year. In the presence of chitin, however, considerable increases in these parameters were recorded in all three sediment types tested. Regardless of chitin addition, natural deep‐sea sediments were always associated with higher values of microbial abundance, biomass and activity compared with artificial sediments. Sediment type was always found to be the most significant factor explaining variation in enzymatic activity and bacterial community structure as compared to the effects of chitin amount, incubation time, and changes in cell number or biomass. Overall, this is the first in situ study that has addressed the effects of multiple factors and their interactions on abundance, biomass, activity and community structure of microbial communities in the deep Arctic Ocean.     

Detection of Vibrio (Listonella) Anguillarum Porin Homologue Proteins and Their Source Bacteria from Coastal Seawater

The molecular distribution of dissolved proteins in seawater from coastal marine environments in Uranouchi Bay, Kochi Prefecture, is first reported in this article. Occurrence of bacteria-derived dissolved proteins and their source bacteria were examined using a probe of the antibody (anti-Omp35La) against a porin outer membrane protein (Omp35La) of the fish pathogenic bacterium Vibrio (Listonella) anguillarum. The electrophoretograms of dissolved proteins from coastal seawater showed a large number of discrete and individual proteins overlapped each other over a wide range of molecular masses indicating active processes in coastal environments in transferring proteins from organisms to the inanimate dissolved protein pool. Among the dissolved proteins, 37 kDa- and 18 kDa-proteins reacted with the Omp35La. In order to isolate the source bacteria of such dissolved proteins, bacteria from seawater and diseased fish were screened by colony Western blotting with anti-Omp35La. The reactive strains were further examined in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting to verify the presence of Omp35La homologues among the outer membrane proteins of such strains. Outer membrane proteins reacting with anti-Omp35La were detected in only 4 strains of the 129 strains that were positive in the colony Western blotting. The level of possible source bacteria of 37 kDa- and 18 kDa-dissolved proteins was suggested to be 5–6 orders of magnitude lower than the total bacterial count. The present study leads us to hypothesize that a minor portion of the bacterial assemblage is responsible for the dissolved proteins in the coastal waters.     

利用凝胶双向扩散试验研究海洋发光细菌的分类关系

细菌分类,向以形态学和生理生化特征为主要依据。近年来,由于分子生物学的进展,提供了很多新技术,使细菌分类的研究进入分子水平。此类研究结果反映了细菌之间的亲缘关系,因而更确切地反映了细菌各属、种之间的进化联系。凝胶双向扩散试验属于免疫学方     

A study on relation between heterotrophic bacteria and shrimp disease

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海洋细菌抑菌活性菌株的筛选

从不同海区的海洋底质，生物样，水样中分离到480株海洋细菌，其中包括150株芽孢细菌和108株粪大肠杆菌，利用纸片法对其抑菌活性进行检测，结果表明：117株海洋细菌具有抑菌活性，占总分离菌株的24.4%；一般细菌，芽孢细菌，粪大肠杆菌的抑菌活性菌株分别占各供测菌株的17.1%,27.3%,35.2%；抑菌活性菌株的比例与样品来源密切相关，且各类海洋细菌的抗菌谱有很大的不同。     

Microbial status in seawater and coastal sediments during pre- and post-tsunami periods in the Bay of Bengal, India

Tsunami, the natural disaster, which occurred on December 26, 2004 in the Indian Ocean, caused severe damage to mankind in the coastal areas. Total loss of life and economic loss because of this disaster have been estimated by various agencies but its effect on microbial density has not been probed. With our previous results on microbial populations in four locations of the Chennai coast of the Bay of Bengal, India in the pre‐tsunami period, the change in microbial populations was studied after the tsunami at regular intervals in the same locations. Coastal sediment and seawater samples were collected from four different locations after 5–10 h and thereafter at intervals of every 7 days up to 28 days post‐tsunami. Bacteria, fungi and actinomycetes were isolated from the marine samples by serial dilution on respective media. Before the tsunami, the bacterial population was higher in seawater samples than the sediments, whereas fungi and actinomycetes were recorded only in the sediments. The microbial population remarkably increased 5–10 h post‐tsunami in all the marine samples irrespective of the location. However, it slowly declined in the subsequent days and became similar to that of the population recorded before the tsunami. The population of gram‐positive bacteria increased whereas the gram‐negative bacterial population decreased after the tsunami. Further, populations of pathogenic bacteria such as coliform and vibrios did not increase after the tsunami. It has been observed that the increase in populations of bacteria and actinomycetes even after 28 days of tsunami may be due to the introduction of foreign microorganisms that developed the ability to survive in the extreme environment by exhibiting special characteristics such as pigmentation and production of exopolysaccharides.     

南麂岛海洋沉积物中抗大黄鱼(Pseudosciaena crocea)致病弧菌的放线菌分离和筛选研究

采用平板涂布法从南麂岛近海海洋沉积物样品中分得86株放线菌,用琼脂块法和杯碟法结合筛选出对副溶血弧菌(Vibrio parahaemolyticus)、哈维氏弧菌(V.harveyi)两种大黄鱼病原性弧菌具有不同拮抗作用的海洋放线菌5株,其中编号NJR0956的菌株对两种致病菌的抑菌圈直径均25mm,表现出较强的抑制作用;进而测定了5株活性菌株的抗菌谱。结果表明,它们对指示菌中的副溶血弧菌、哈维氏弧菌、鳗弧菌(V.anguillarum)、溶藻弧菌(V.alginolyticus)四种病原弧菌均具有较好的拮抗作用;在对NJR0956的抑菌效果研究中发现,该菌株在牛肉膏蛋白胨液体培养基中不仅能够增殖,而且能够有效地抑制病原菌的生长。     

Degradation and utilization of protein derived from <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> by marine microbial community

Microbial degradation and utilization of proteins derived from bacterial detritus were investigated in a microcosm experiment using Pseudomonas aeruginosa detritus as a substrate. To assess the effects of natural marine microbial communities on degradation and utilization of protein derived from P. aeruginosa cells, four microcosms were prepared: natural seawater (containing the natural microbial community) with P. aeruginosa detritus (N+Pa), autoclaved seawater with P. aeruginosa detritus (A+Pa), natural seawater (N) and autoclaved seawater (A) without adding anything as a control. The numbers of total and growing bacterial cells, protease activity, and transition of P. aeruginosa proteins were monitored in the four microcosms. Changes in the numbers of total and growing bacterial cells and protease activities indicated that bacterial detritus significantly stimulated the microbial community in the microcosms. Both the surviving P. aeruginosa in A+Pa and natural microbial community in N+Pa microcosms were able to degrade and utilize P. aeruginosa detritus; however, the community in N+Pa including various microbes maintained high activity longer, indicating that diversity is an important factor in keeping the community active. Even under the very high protease activity in N+Pa, 39-kDa and 48-kDa proteins from P. aeruginosa remained in the microcosm during the entire experiment (150 days). Immunoblotting suggested the 48-kDa protein was an intact molecule of OprP, which had been detected from the dissolved fraction of natural seawater in previous studies. This result suggests that the protein molecules that had been detected from natural seawater actually had a high tolerance to microbial degradation.     

Lipid biomarker composition in surface sediments from the Carlsberg Ridge near the Tianxiu Hydrothermal Field

Hydrothermal venting has a profound effect on the chemical and biological properties of local and distal seawater and sediments. In this study, lipid biomarkers were analyzed to examine the potential influence of hydrothermal activity on the fate of organic matter(OM) in surface sediments around Tianxiu Hydrothermal Field in the Carlsberg Ridge(CR), Northwest Indian Ocean. By comparing the biomarker distributions of the samples with that of other typical hydrothermal sediments in the mid ocean ridge, it is shown that the location of the samples is not affected by the hydrothermal activity. The relatively low abundances of terrestrial n-alkyl lipids and riverine1,15-C32 diol suggested a minor contribution of terrigenous OM to the study area. The bacteria contributed predominantly to sedimentary marine OM; however, other marine source organisms, e.g., eukaryotes(i.e.,phytoplankton and fungi) could not be completely neglected. The marine-originated biomarkers showed significantly variable distributions between the two sediments, suggesting different dynamic physical and biogeochemical processes controlling the fate of marine OM. This study identified various diagnostic biomarkers(5,5-diethyl alkanes, diols and β-OH FAs), which may have significant environmental implications for future works in this region.     

Specific features of temporal and spatial distributions of light hydrocarbons in the Sea of Azov

New data from recent surveys investigating the geochemistry of light hydrocarbons over a 4-year period in the Chernomorneftegaz petroleum license area in the central Sea of Azov are presented in this paper. The distributions of light hydrocarbons in both marine sediments and seawater were studied, and stable anomalies of hydrocarbons detected. Based on complex interpretations of geochemical and geophysical data, it has been shown that migration from the deep part of the sediment cover to the surface (seabed) is the main factor which determines the spatial distribution of hydrocarbons in the modern seabed sediments and seawater. The contribution of microbial and anthropogenic processes is insignificant.     

渤海不同区域沉积物古菌的多样性分析

产甲烷古菌在滨海沉积物碳循环过程中起着重要作用。本研究以渤海不同区域沉积物为研究对象,通过T-RFLP以及室内富集培养方法,解析了渤海不同区域沉积物产甲烷菌群落结构差异,并评估其产甲烷潜力。结果表明,渤海不同区域沉积物细菌和产甲烷古菌群落结构组成存在差异,其主要优势产甲烷菌为Methanobacterium和Methanosarcina,主要优势细菌为Desulfovibrio和Thiobacillus。渤海不同区域沉积物在实验室培养条件下产甲烷量存在明显差异,表现为近岸区域沉积物产甲烷量较高。且渤海沉积物具有较高的产甲烷潜力(乙酸转换率达到46.46%),潜在甲烷排放量估计值可达1.74亿t/年。     

海水和海洋沉积物中有机磷酸酯的研究进展

有机磷酸酯(OPEs)已广泛应用于阻燃剂和增塑剂,但由于其具有较高毒性、难降解和远距离迁移等特点,从而引发的一系列海洋环境问题也逐渐受到关注。本文基于国内外海水和沉积物中OPEs的最新研究数据,分析了海水和海洋沉积物中OPEs的分析检测技术、迁移转化、分布特征和影响因素等,并针对当前研究的不足进行了讨论和展望。通过本文总结发现,海水中OPEs主要来自河流输入和大气沉降的输送,且浓度分布特征表现为表层高于底层,三种氯代有机磷酸酯[磷酸三(2-氯乙基)酯(TCEP)、磷酸三氯丙酯(TCPP)和磷酸三(1, 3-二氯-2-丙基)酯(TDCPP)]是海水中OPEs的主要组分;海洋沉积物中OPEs的含量分布表现出港湾、近岸海域和沿岸城市经济发达区域较高的趋势,其主要组分存在差异,受辛醇-水分配系数(lg Kow)和总有机碳(TOC)两个因素的影响较大。     

Evaluation of atmospheric transport as a nonpoint source of polycyclic aromatic hydrocarbons in marine sediments of the Eastern Mediterranean

Coastal marine sediment, air and seawater samples were collected at six sampling stations in the Eastern Mediterranean Sea distant from pollutant point sources. All sediment samples were analyzed to determine polycyclic aromatic hydrocarbon (PAH), black carbon (BC) and organic carbon (OC) contents. The PAH contents of gaseous and seawater samples of the study were determined in order to evaluate the role of air–sea exchange as PAH nonpoint source to the marine sediments. The average concentration of the total PAHs (∑PAHs) in the sediments varied from 2.2 to 1056.2 ng g⁻¹ dry weight. The average BC and OC contents varied from 0.3 to 5.6 and from 2.9 to 21.4 mg g⁻¹ dry weight, respectively. ∑PAH concentration in the marine atmosphere varied from 20.0 to 83.2 ng m⁻³. Air–water exchange flux (F_A–W) estimation has indicated air transport as a significant source of PAHs to pristine marine sediments of Eastern Mediterranean. In addition, the significant correlation between the PAHs and the organic and soot carbon content further suggests the importance of atmospheric input of PAHs to the sediments.     

Speed bumps and barricades in the carbon cycle: substrate structural effects on carbon cycling

The observation that a fraction of organic matter produced in marine systems evades the concerted efforts of microbial communities and is buried in sediments suggests that there are ‘speed bumps’ in carbon degradation pathways that impede microbially driven remineralization processes. The initial step in degradation of macromolecules, extracellular enzymatic hydrolysis, is often stated to be ‘the’ rate-limiting step in carbon remineralization. Experimental investigations described here, however, demonstrate that at least in certain cases, microbes produce extracellular enzymes on time scales of hours to tens of hours in response to substrate addition, and hydrolysis is extremely rapid. If enzymatic hydrolysis can be rapid, what factors slow or stop organic matter degradation? A lack of the correct inducer to initiate enzyme production, and/or a lack of the correct organism to produce the required enzyme, may result in a complete lack of hydrolysis in certain environments—a barricade, rather than a speed bump. Preliminary evidence supporting this hypothesis includes a comparison of polysaccharide hydrolysis in seawater and sediments, which demonstrates that the spectrum of enzymes active in seawater and sediments are fundamentally different. Furthermore, a survey of enzyme activities in surface waters from a range of locations suggests that pelagic microbial communities also differ widely in their abilities to express specific extracellular enzymes. Trans-membrane transport through porins is yet another potential location of structure-related selectivity.Our efforts to identify speed bumps and barricades are hampered by our inability to structurally characterize in sufficient detail the macromolecular structures present in marine systems. Furthermore, assessments of organic matter ‘quality’ from a chemical perspective do not necessarily accurately reflect the availability of organic carbon to microbial communities. For these communities, in fact, ‘quality’ may be a variable, which depends on the enzymatic and uptake capabilities of community members. To begin to assess substrate structure and quality from a microbial perspective, we will have to combine specific knowledge of macromolecular structures with detailed investigations of the enzymatic and transport capabilities of heterotrophic marine microbes.     

从养殖贝类和大菱鲆分离的海洋发光弧菌的分类地位分析

海洋发光弧菌是海水养殖中重要的条件致病菌。从福建省晋江市附近水产养殖场花蛤、牡蛎软组织及波罗地海大菱鲆肠道内含物中分离得到16 株发光细菌, 采用ARDRA（amplified ribosomal DNArestriction analysis）、16S rDNA 序列测定、Biolog 碳源代谢分析及药敏试验等方法对...