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1.
肠道细菌对厚壳贻贝稚贝附着的作用研究 总被引：1，自引：0，他引：1
为探讨肠道细菌形成的微生物被膜对贝类附着的作用,从厚壳贻贝(Mytilus coruscus)成体肠道中分离10株肠道细菌,调查厚壳贻贝肠道细菌形成微生物被膜特性,分析微生物被膜密度、细菌种属与厚壳贻贝稚贝附着之间的相互关系。所有肠道细菌均可有效促进稚贝附着。其中,Paracoccus sp.1微生物被膜诱导的稚贝附着率最高(61%),且微生物被膜膜厚较厚,细菌分布较密集;仅5株肠道细菌Roseovarius sp.1、Winogradskyella sp.1、Tenacibaculum sp.4、Bacillus sp.5和Nonlabens sp.1的被膜密度与附着显著相关(P0.05)。系统发育分析发现肠道细菌诱导附着率与其种属无关。本研究表明源于厚壳贻贝成贝肠道细菌可以促进其稚贝的附着,说明肠道细菌对厚壳贻贝的生长发育具有一定的作用。本研究结果为深入探讨肠道细菌与厚壳贻贝相互作用和推动该种规模化养殖提供理论依据。 相似文献
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Bacteria and diatoms exist in sessile communities and develop as biofilm on all surfaces in aqueous environments. The interaction between these microorganisms in biofilm was investigated with a bacterial genus Pseudoalteromonas sp. (strain 3J6) and two benthic diatoms Amphora coffeaeformis and Cylindrotheca closterium. Each biofilm was grown for 22 days. Images from the confocal microscopy show a difference of adhesion between Pseudoalteromonas 3J6 and diatoms. Indeed, a stronger adhesion is found with C. closterium suggesting cohabitation between Pseudoalteromonas 3J6 and C. closterium compared at an adaptation for bacteria and A. coffeaeformis. The cellular attachment and the growth evolution in biofilm formation depend on each species of diatoms in the biofilm. Behaviour of microalgae in presence of bacteria demonstrates the complexity of the marine biofilm. 相似文献
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磺胺类、四环素、喹诺酮类和多粘菌素抗生素是医学与养殖业中的常用抗生素,其中多粘菌素在畜牧养殖业中常作为促长剂添加。调查分析了这4类抗生素的常见耐药基因在东海温州近海水域的分布情况。利用抗性平板筛选温州近海水域对磺胺类、四环素类及喹诺酮类抗生素耐药的可培养细菌分离株,对耐药分离株通过PCR方法进行目标耐药基因检测;对目标耐药基因阳性的耐药分离株进行多粘菌素耐药基因MCR检测以及采用微量二倍稀释法测定对上述4类抗生素的耐药性。结果表明,利用抗性平板筛选获得可培养耐药分离株1 605株,从中筛选到目标耐药基因阳性的51株,检出率为3.18%,包括含磺胺类耐药基因35株、含四环素耐药基因36株、含喹诺酮耐药基因17株、含多粘菌素耐药基因2株; 51株耐药菌归于7个菌属,其中气单胞菌属(Aeromonas sp.) 43株,占比84.31%,枸橼酸杆菌属(Citrobacter sp.)和希瓦氏菌属(Shewanella sp.)各2株,埃希氏菌属(Escherichia sp.)、类芽孢杆菌属(Paenibacillus sp.)、Thalassobius sp.及Amphritea sp.各1株;上述2株非常见分离株不统计在内,常见的49株均对四环素耐药, 41株对多粘菌素耐药,对磺胺类和喹诺酮类耐药的分离株均为34株;同时,发现23株对4类抗生素均产生耐药, 16株对多达3种抗生素耐药,多重耐药现象普遍存在。同时,鉴定出MCR-3阳性的条件致病菌维氏气单胞菌和豚鼠气单胞菌各1株。综上,温州市近海水域中含有常见耐药基因的耐药分离株检出率较低,但同一耐药基因的细菌分布多样,对磺胺类、四环素类、喹诺酮类及多粘菌素类等4类抗生素表现出较强的耐药性,多重耐药现象明显。研究结果将为评估温州近海水域的细菌耐药性风险,规范抗生素的使用提供科学依据。 相似文献
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在相同的分离培养条件下,为比较地域差别较大的福建海域海绵动物(山海绵Mycale sp.和网架海绵Stylissa sp.)和海南海域海鞘动物(皱瘤海鞘Styela plicata和乳突皮海鞘Molgula manhattensis)之间可培养放线菌多样性的差异,作者采用5种放线菌分离培养基和1种细菌通用培养基,对海绵和海鞘中的放线菌进行分离培养。采用16S rRNA 基因限制性片段长度多态性(Restriction Fragment Length Polymorphism, RFLP)分析和序列分析,揭示其多样性。共获得可培养放线菌198株,其中从海绵中分离到87株放线菌,从海鞘中分离到111株放线菌。RFLP分析表现为38种不同的图谱类型。16S rRNA基因序列分析表明,从海绵中分离到的放线菌包括6个放线菌属,其中有2株菌的16S rRNA基因序列与最相近的菌株相似性低于97%,可能是潜在的新菌株;从海鞘中分离到的放线菌包括7个放线菌属,有8株可能是潜在的新菌株。比较海绵和海鞘中可培养放线菌的多样性发现,从海绵中分离到的放线菌,除节细菌(Arthrobacter)以外,均包括在海鞘分离的放线菌属中。海鞘相关放线菌多样性水平不容忽视,是除海绵之外另一获得新型放线菌资源以及药用天然活性产物的重要来源。 相似文献
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ＴｈｅｃｈｅｍｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆａｅｒｏｓｏｌｓｉｎｔｈｅＫｕｒｏｓｈｉｏａｒｅａ－Ⅰ．Ｓｏｕｒｃｅｓａｎｄｆｌｕｘｅｓ￥ＣｈｅｎＬｉｑｉ；ＹａｎｇＸｕｌｉｎ；ＴａｎｇＲｏｎｇｋｕｎａｎｄＹｕＱｕｎ＇（ＲｅｃｅｉｖｅｄＦｅｂｒ... 相似文献
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研究了南麂列岛海洋自然保护区浮游植物物种组成、数量分布、多样性指数及其与营养盐、浮游动物的关系.经鉴定,共发现浮游植物86种,隶属于33属.网样浮游植物平均密度为194.00×104个/m3,水样浮游植物平均密度为4.98×104个/m3,优势类群有角毛藻(Chaetoceros sp.)、角藻(Ceratuym sp.)、中肋骨条藻(Skeletonema costatum)、红色裸甲藻(Akashiwo sanyuineum)等.网样浮游植物多样性平均指数为2.28,水样浮游植物多样性平均指数为2.17.根据浮游植物组成特点,将其分为两个生态类群:近岸性和广布性类群,外海性类群. 相似文献
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为了研究海洋生物污损对船体和海洋工程的影响,作者将热喷涂镀钴基、镍基及含铜氧化钛基膜的船用厚钢板试样片放置在海水中,利用振荡培养箱模拟海洋环境,进行晃片培养。分离纯化镀膜钢片表面上的细菌,研究早期污损细菌的生长规律,通过革兰氏染色、生理生化实验对细菌进行鉴定,伯杰氏系统细菌学手册查证。采用纸片法测定抑菌圈,研究铜、钴、镍3种金属离子对污损细菌的影响,观察不同离子浓度的抑菌圈。研究结果表明:早期海洋污损细菌有G~+芽孢杆菌属(Bacillus)、G~+芽孢乳杆菌属(Sporolactobacillus)、G~+无芽孢杆菌(Bacilli)、葡萄球菌属(Staphylococcus)、G~+无芽孢丝状菌、假单胞菌属(Pseudomonas)6类;其中G~+细菌首先吸附; Cu~(2+)的最佳抑制质量浓度为30 g/L, Co~(2+)的最佳抑制质量浓度为80 g/L, Ni~(2+)的最佳抑制质量浓度为110 g/L。 相似文献
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Microbial carbon fixation is a paramount process in the ocean especially below the photic zone both in water and sedimentary ecosystems. Autotrophic microbes that fix carbon dioxide are renowned. However, the question whether heterotrophs can also fix carbon is intriguing. Ten heterotrophically grown, identified bacterial isolates from the Sino-Pacific marine sediments were tested for autotrophic uptake potential with and without addition of electron donors. Nine of the ten isolates showed carbon uptake capacity without addition of any substrate at very low rates in the order of 10~(-8) to 10~(-4) fmol/(cell·h). The addition of manganese and ammonium at 1 mmol/L final concentration enhanced the uptake potential. Addition of 1 mmol/L final concentrations of reduced iron(10~(-6) to10~(-5) fmol/(cell·h) and sulfide(10~(-5) fmol/(cell·h) decreased the uptake potential significantly at p0.1. Bacterial tolerance to formaldehyde suggested propensities of anaplerotic chemical reactions that form metabolic intermediates of C-1 metabolism pathways. The isolates displayed high metabolic flexibility. With the changes in electron donors, the isolates metabolically toggled between relatively anoxic reductive iron/sulfur cycles and the oxidative cycles of manganese/ammonium and vice-versa. This property makes these microbes successful survivors in the highly dynamic Sino-Pacific sediments. 相似文献
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Antimicrobial-resistance of Streptococcus pneumoniae isolated from the Lebanese environment 总被引：4，自引：0，他引：4
The aim of this study was to isolate and molecularly characterize Streptococcus pneumoniae in samples collected from the aquatic environment in Lebanon. For this purpose, 57 samples of ground waters, sea water, sediments and crabs were collected. Biochemical tests as well as PCR were used for further identification and molecular characterization of 46 suspected isolates using specific primers for the lytA-gene and protein 2B-gene. The confirmed isolates were evaluated for their antimicrobial resistance, using the minimum inhibitory concentration method. Crab samples exhibited a high contamination level of an average count of 8.2 x 10(4)CFU/g. In water samples, the highest contamination was recorded near a coastal landfill with a bacterial count of 1.8 x 10(3)CFU/ml whereas the lowest bacterial counts (non detectable) were observed in ground water samples. Twenty out of the 46 suspected isolates came from sea water, and 17 out of those were characterized by PCR as S. pneumoniae. Testing the antimicrobial resistance of the 20 isolates to various antimicrobials showed that all sea water isolates were resistant to vancomycin, gentamicin, and oxacillin (100%), whereas 62.5% were resistant to clindamycin, and only 25% were erythromycin resistant. Resistance rates were higher in the case of fresh water samples, with 57% resistance to erythromycin, and 100% resistance to vancomycin, gentamicin, clindamycin and oxacillin. Alternatively, all tested crab isolates were susceptible to erythromycin. However, they showed a high resistance of 80% against vancomycin, gentamicin, clindamycin and 100% against oxacillin. 相似文献
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台湾海峡中北部海洋线虫群落的种类组成及分布 总被引：3，自引：0，他引：3
1998年2月对台湾海峡中北部3个断面13个取样站进行了自由生活海洋线虫调查，获得了海洋线虫100种，隶属于3目28科91属，其中密度较高的种有萨巴线虫（Sabatieria sp.1)、变异矛咽线虫（Dorylaimopsis variabilis)、Vasostoma sp．、花斑线虫（Spilophorella sp.)、吞咽线虫（Daptonema sp.)、Linhystera sp.1、吸咽线虫（Halalaimus sp.1)和（Filoncholaimus sp.)等。虽然这些海洋线虫绝大多数只鉴定江口外海降低。从优势种分布看，不同取样站其密度差异很大。海洋线虫的取食类型以选择性食沉积物者（1A）占优，有38种，但刮食性种类（2A）和非选择性食沉积物者（1B）也分别为29种和25种，表明了台湾海峡中北部海洋吸虫取食类型的复杂性。文中还探讨了海洋线虫分布与海流等环境因子的关系。 相似文献
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福建省主要河口海湾沉积物中甲藻休眠孢囊分类学初步研究 总被引：6，自引：0，他引：6
通过对福建省厦门湾、闽江口海域、三沙湾三个主要河口海湾144个站位表层沉积物样品中甲藻休眠孢囊的系统分析,根据甲藻休眠孢囊的形状、外壁结构、颜色、表面修饰物等形态特征共鉴定出9属25种及不定种,并对各孢囊属种的特征进行了分类描述,其中有毒甲藻休眠孢囊2种,即Alexandrium minutun,A. tamarense, 有害种类4 种, 即Alexandrium affine,Lingulodiniumpolyedrum,Scrippsiella trochoide.通过对比表明Alexandrium affine,A. minutum,Diplopelta cf. parva,Polykrikos cf. schwartzii,Protoceratium reticulatum,Protoperidinium minutum,P.cf. minutum,P. cf. americanum以及Alexandrium sp.,Protoperidinium sp.1,P. sp.2等11种甲藻休眠孢囊为本次在福建省海域新发现的种,这些新发现的甲藻种类可能是近年来通过国际间往来的航运船只在我国沿岸海域排放压舱水或贝类引种带来的. 相似文献
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平端深海偏顶蛤(Gigantidasplatifrons)是南海台西南冷泉区的典型优势物种,鳃丝上皮细胞内共生大量甲烷氧化菌,通过甲烷有氧氧化合成有机物为共生体系提供物质能量,是平端深海偏顶蛤赖以生存的重要能量来源器官,溶酶体在共生体系的营养互作和稳态维持中可能发挥重要作用,本研究使用电镜技术观测了常压培养过程中(0d,30d,90d)平端深海偏顶蛤共生体系中共生菌和溶酶体的动态变化,通过鳃上皮含菌细胞超显微结构的变化研究常压培养对深海共生体系的影响,并探讨溶酶体在宿主—共生菌营养传递和共生菌群稳态维持中的关键作用。研究发现,在原位状态样品中(0d)共生菌和溶酶体呈极化分布,细胞结构完整清晰;蓄养30d后,含菌细胞出现明显破碎,共生菌数量大幅降低,溶酶体数量、范围和消化程度大幅增加,对细胞顶端的甲烷氧化菌进行分解;而90d后,共生菌在溶酶体的作用下消失殆尽,鳃部有明显细胞脱落后留下的坑洞,细胞呈现空泡状,无法明确区分各种细胞组分。上述结果展示了长期常压蓄养过程中鳃上皮含菌细胞中溶酶体与甲烷氧化菌的动态变化,推测当共生菌丢失后溶酶体也同步降低活跃度,平端深海偏顶蛤在共生互作中通过溶酶体主导消化和调控共生菌。 相似文献
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Habitat modification in tidepools by bioeroding sea urchins and implications for fine‐scale community structure 
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下载免费PDF全文 By creating novel habitats, habitat‐modifying species can alter patterns of diversity and abundance in marine communities. Many sea urchins are important habitat modifiers in tropical and temperate systems. By eroding rocky substrata, urchins can create a mosaic of urchin‐sized cavities or pits separated by exposed, often flat surfaces. These microhabitats appear to harbor distinct assemblages of species. We investigated how a temperate rocky intertidal community uses three small‐scale (<100 cm2) microhabitats created by or adjacent to populations of the purple sea urchin (Strongylocentrotus purpuratus): pits occupied by urchins, unoccupied pits, and adjacent flat spaces. In tidepools, flat spaces harbored the highest percent cover of algae and sessile fauna, followed by empty pits and then occupied pits. The Shannon diversity and richness of these sessile taxa were significantly higher in flat spaces and empty pits than in occupied pits. The composition of these primary space holders in the microhabitats also varied. Unlike primary space holders, mobile fauna exhibited higher diversity and richness in empty pits than in flat spaces and occupied pits, although results were not significant. The protective empty pit microhabitat harbored the highest densities of most trophic functional groups. Herbivores, however, were densest in flat spaces, concordant with high algal coverage. These results suggest the habitats created by S. purpuratus in addition to its biological activities alter community structure at spatial scales finer than those typically considered for sea urchins. 相似文献
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海洋细菌在不同基质表面微生物粘膜中的组成 总被引：2，自引：0，他引：2
在青岛近岸海区两个不同地点 ,分别进行浸海挂片实验研究四种不同基质表面 (玻片、钢片以及涂有防污漆、防锈漆的玻片 )微生物粘膜中细菌组成。从不同基质表面微生物粘膜中共分离32 3株附着细菌 ,大多数为杆状或球杆状革兰氏阴性细菌 ,且大部分具有鞭毛。依据形态及生理生化特征将革兰氏阴性细菌鉴定到属 ,分别属于气单胞菌属 ( Aeromonas)、发光杆菌属 ( Photobacteri-um)、莫拉氏菌属 ( Moraxella)、假单胞菌属 ( Pseudomonas)、弧菌属 ( Vibrio)和产碱菌属 ( Alcali-genes)等 12个属 ,其中气单胞菌属是优势菌属。不同基质表面 ,微生物粘膜细菌组成不同 相似文献
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广西钦州湾外湾表层沉积硅藻分布特征 总被引：2，自引：1，他引：1
本文对钦州湾外湾54个表层沉积物中硅藻进行分析,鉴定出硅藻153种,分属50属。其中Thalassionema nitzschioides是本区域内最为丰富的硅藻种类。对应分析结果表明,钦州湾表层沉积硅藻分布主要受到海水盐度的影响,其中淡水硅藻Achnanthes delicatula、A.hauckiana、A.levanderi和Cocconeis disculus可以作为低盐度海水环境的指示种,半咸水种Cyclotella striata/C.stylorum、Paralia sulcata与海洋中硅藻Thalassionema frauenfeldii、T.nitzschioides则可以很好的指示高盐度环境。钦州湾外湾54个表层沉积站位可划分为3个硅藻分布区,分别对应高低不同的海水盐度,与实际站位地理分布基本一致。 相似文献
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Spatial and temporal variation in fish assemblage structure of Koycegiz Lagoon–Estuarine System (KLES), located on the northwestern Turkish coast of Mediterranean, was investigated along an estuarine gradient where salinity ranged from 5 in upper reaches to 40 in lower reaches during October 1993–September 1994. Throughout the study, 42 species, consisting of marine (25), marine–estuarine-dependent (12), freshwater (3), catadromous (1), and estuarine resident (1) forms, were collected in trammel nets. Although species richness of marine species was greater than that of other groups, numerical contribution by marine species to the total catch was only 16%. Tilapia spp., the most abundant species mostly during summer and early spring at upper reaches, contributed 17% of the total samples. Among the seven species of Mugilidae, which contributed 42% of the total catch, Mugil cephalus, Liza aurata, and Liza salines contributed 10, 13, and 10% of the total catch, respectively. Consistent with findings from other studies, species richness and abundance were highest during late spring and summer and the lowest during winter and early spring. Samples from sites at or near the sea had more marine species. Samples from upper reaches had more freshwater and marine–estuarine-dependent species. Canonical correspondence analysis (CCA) indicated that salinity and turbidity were the most important environmental parameters affecting fishes. Sites near the sea were associated with high salinity and low turbidity, and sites in upper reaches had low salinity and high turbidity. Thus, the pattern observed in fish assemblage structure appears to be strongly influenced by species' responses to dominant salinity and turbidity gradients. 相似文献
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The physiological costs of living in seawater likely influenced the secondary evolutionary transitions to marine life in tetrapods. However, these costs are alleviated for species that commute between the land and the sea, because terrestrial habitats can provide frequent access to fresh water. Here, we investigate how differences in the ecology and physiology of three sea krait species (Laticauda spp.) interact to determine their environmental tolerances and geographic distributions. These three species vary in their relative use of terrestrial versus marine environments, and they display concomitant adaptations to life on land versus at sea. A species with relatively high dehydration rates in seawater (Laticauda colubrina) occupied oceanic areas with low mean salinities, whereas a species with comparatively high rates of transcutaneous evaporative water loss on land (Laticauda semifasciata) occupied regions with low mean temperatures. A third taxon (Laticauda laticaudata) was intermediate in both of these traits, and yet occupied the broadest geographic range. Our results suggest that the abilities of sea kraits to acquire fresh water on land and tolerate dehydration at sea determine their environmental tolerances and geographic distributions. This finding supports the notion that speciation patterns within sea kraits have been driven by interspecific variation in the degree of reliance upon terrestrial versus marine habitats. Future studies could usefully examine the effects of osmotic challenges on diversification rates in other secondarily marine tetrapod species. 相似文献