Distinct microbial communities thriving in gas hydrate-associated sediments from the eastern Japan Sea     

《Journal of Asian Earth Sciences》2014

Marine gas hydrate and cold-seep systems, which maintain a large amount of methane in the seabed, may critically impact the geochemical and ecological characteristics of the deep-sea sedimentary environment. However, it remains unclear whether marine sediments associated with gas hydrate harbor novel microbial communities that are distinct from those from typical marine sediments. In this study, microbial community structures thriving in sediments associated with and without gas hydrate in the eastern Japan Sea were characterized by 16S rRNA gene-based phylogenetic analyses. Uncultivated bacterial lineages of candidate division JS1 and a novel group NT-B2 were dominant in the sediments from gas hydrate-associated sites. Whereas, microbial populations from sites not associated with gas hydrate were mainly composed of Bacteroidetes, Nitrospirales, Chlamydiales, Chlorobiales, and yet-uncultured bacterial lineages of OD1 and TM06. The good correlation between the dominance of JS1 and NT-B2 and the association of gas hydrate could be attributed to the supply of more energetically favorable energy sources in gas-rich fluids from the deep subsurface than refractory organic matter of terrigenous and diatomaceous origin.  相似文献   

坛紫菜基因表达实时荧光定量PCR分析中内参基因的筛选     

李兵  陈昌生  徐燕  纪德华  谢潮添 《海洋学报(英文版)》2014,33(9):152-159

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Characterization of calcium deposition induced by Synechocystis sp. PCC6803 in BG11 culture medium   总被引：1，自引：0，他引：1  

闫华晓  韩作振  赵辉  周仕学  迟乃杰  韩梅  寇小燕  张艳  徐琳琳  田晨晨  秦松 《中国海洋湖沼学报》2014,32(3):503-510

Calcium carbonate （CaCO3） crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 （inoculated BG11）. In this study, the features of calcium carbonate deposition were investigated. Inoculated BGll in different calcium ion concentrations was used for the experimental group, while the BGll culture medium was used for the control group. The surface morphologies of the calcium carbonate deposits in the experimental and control groups were determined by scanning and transmission electron microscopy. The deposits were analyzed by electronic probe micro-analysis, Fourier transform infrared spectrum, X-ray diffraction, thermal gravimetric analysis and differential scanning calorimetry. The results show that the surfaces of the crystals in the experimental group were hexahedral in a scaly pattern. The particle sizes were micrometer-sized and larger than those in the control group. The deposits of the control group contained calcium （Ca）, carbon （C）, oxygen （O）, phosphorus （P）, iron （Fe）, copper （Cu）, zinc （Zn）, and other elements. The deposits in the experimental group contained Ca, C, and O only. The deposits of both groups contained calcite. The thermal decomposition temperature of the deposits in the control group was lower than those in the experimental group. It showed that the CaCO3 deposits of the experimental group had higher thermal stability than those of the control group. This may be due to the secondary metabolites produced by the algae cells, which affect the carbonate crystal structure and result in a close-packed structure. The algae cells that remained after thermal weight loss were heavier in higher calcium concentrations in BGll culture media. There may be more calcium- containing crystals inside and outside of these cells. These results shall be beneficial for understanding the formation mechanism of carbonate minerals.  相似文献   

Construction of cDNA library from intestine, mesentery and coelomocyte of Apostichopus japonicus Selenka infected with Vibrio sp. and a preliminary analysis of immunity-related genes     

Hongzhan Liu  Fengrong Zheng  Xiuqin Sun  Yimei Cai 《中国海洋大学学报(英文版)》2012,11(2):187-196

The aquaculture of sea cucumber Apostichopus japonicus (Echinodermata, Holothuroidea) has grown rapidly during recent years and has become an important sector of the marine industry in Northern China. However, with the rapid growth of the industry and the use of non-standard culture techniques, epidemic diseases of A. japonicus now pose increasing problems to the industry. To screen the genes with stress response to bacterial infection in sea cucumber at a genome wide level, we constructed a cDNA library from A. japonicus Selenka (Aspidochirotida: Stichopodidae) after infecting them with Vibrio sp. for 48 h. Total RNA was extracted from the intestine, mesentery and coelomocyte of infected sea cucumber using Trizol and mRNA was isolated by Oligotex mRNA Kits. The ligated cDNAs were transformed into DH5α, and a library of 3.24×105 clones (3.24×105 cfu mL-1) was obtained with the sizes of inserted fragments ranging from 0.8 to 2.5 kb. Sequencing the cDNA clones resulted in a total of 1106 ESTs that passed the quality control. BlastX and BlastN searches have identified 168 (31.5%) ESTs sharing significant homology with known sequences in NCBI protein or nucleotide databases. Among a panel of 25 putative immunity-related genes, serum lectin isoform, complement component 3, complement component 3-like genes were further studied by real-time PCR and they all increased more than 5 fold in response to Vibrio sp. challenge. Our library provides a valuable molecular tool for future study of invertebrate immunity against bacterial infection and our gene expression data indicates the importance of the immune system in the evolution and development of sea cucumber.  相似文献   

含水非晶碳酸钙的仿生矿化研究     

官叶斌  姚奇志  周根陶 《高校地质学报》2011,17(1):46-52

生物成因矿物的形成过程通常是通过先沉积非晶前驱体,进而转变形成某一种结晶相的途径来实现的。对生物成因 碳酸钙而言,普遍认为其非晶的前驱体相是在生物有机大分子和无机离子共同作用下形成的。在阴离子柠檬酸根存在的情 况下,仿生合成了非晶碳酸钙（Amorphous calcium carbonate,ACC）,运用场发射扫描电子显微镜（FESEM）、X-射线衍射（XRD）、 傅里叶红外光谱（FTIR）和热重-差热分析（TG-DTA）等实验手段进行了分析并观测了非晶碳酸钙后续转变。结果显示, 多羧基的阴离子能够诱导形成非晶碳酸钙,并且这些非晶碳酸钙具有与生物成因非晶碳酸钙类似的组成。这可能指示与生 物矿化相关的生物大分子,特别是一些富含极性羧基大分子能够诱导碳酸钙矿物非晶态前驱体相的形成,同时也能暂时稳 定这些非晶前驱体相。  相似文献   

湖南省传统聚落景观基因的空间特征   总被引：8，自引：2，他引：6  

胡最  刘沛林  曹帅强 《地理学报》2013,68(2):219-231

湖南省有着悠久的历史文化和优越的自然地理环境,是全国传统聚落相对集中和保存较为完好的省区之一.本文以国家和湖南省政府正式公布的30 个历史文化名村名镇为研究对象,结合传统聚落景观基因理论,建立了包括建筑特征、文化特征、环境特征、聚落布局特征4 大类共14 项指标的传统聚落景观基因识别指标体系;根据要素提取法、图案分析法、结构提取法、含义提取法等景观基因提取方法,建立了湖南省传统聚落景观基因的识别流程,并进行了传统聚落景观基因的识别与提取.在此基础上,从建筑基因的特征、选址布局基因的特征、图腾文化基因的特征3 个角度分析了该省传统聚落景观基因的空间特征.本文对湖南省传统聚落的保护与合理、可持续开发利用具有参考意义,对开展全国其他省份传统聚落的相关研究同样具有借鉴意义.  相似文献   

企鹅珍珠贝矿化基因表达模式和贝壳超微结构对珍珠质层颜色影响的研究     

张佳谊  杨蕾  陈一  王爱民  战欣 《海洋与湖沼》2022,53(1):113-119

为探究企鹅珍珠贝贝壳内表面珍珠质层不同区域颜色差异形成的原因,选取9个生物矿化相关基因,利用实时荧光定量PCR扩增技术对其在外套膜不同部位的表达水平进行测定,并利用扫描电子显微镜对贝壳珍珠质层不同区域的内表面及纵断面的微观结构进行观察.结果 表明:有8个矿化基因在企鹅珍珠贝外套膜远端膜区和中央膜区的表达量具有显著差异(...  相似文献   

不同微生物诱导钙锶生物矿化的比较研究          下载免费PDF全文

黄婷  刘明学  董发勤  刘媛媛  郭玉婷 《高校地质学报》2015,21(4):584

为了研究并比较不同微生物在不同钙锶比条件下对钙锶生物矿化过程的调制作用,选取耐辐射奇球菌、酵母菌和大 肠杆菌作为模拟生物矿化的有机基质,通过SEM,FT-IR和XRD对钙锶矿物的形貌、晶型、晶粒尺寸进行表征分析。结果 表明：①当[Ca2+]/[Sr2+]=2时,不加微生物体系中形成的是文石型和柱状方解石型混合晶体,加入微生物组则形成纺锤状方 解石型晶体。此时3种微生物均能诱导锶离子进入碳酸钙晶格;②当[Ca2+]/[Sr2+]=1时,不加菌体系中形成条稀疏的纺锤状文 石型晶体。加入酵母菌和大肠杆菌的体系则形成紧密的纺锤状和簇状文石型晶体,它们能在一定程度上抑制锶离子进入碳 酸钙晶格。而加入耐辐射奇球菌体系形成菜花状方解石型晶体,其仍能诱导锶离子置换钙离子;③当[Ca2+]/[Sr2+]=1/2时,不 加菌体系中形成大小无规则聚集成团的文石型晶体。加3种微生物体系则形成纺锤状或簇状文石型晶体,它们会在一定程 度上抑制锶离子进入碳酸钙晶格。因此,在钙离子浓度较大时,更易形成方解石物相,在锶离子浓度较大时,更易形成文 石物相。  相似文献   

多鳞(Sillago sihama)高密度遗传连锁图谱构建及生长性状QTL定位分析          下载免费PDF全文

田昌绪  朱奕安  钟键  林星桦  叶明慧  黄洋  张玉蕾  朱春华  李广丽 《海洋与湖沼》2023,54(1):194-203

为构建多鳞(Sillago sihama)遗传连锁图谱并鉴定生长等重要经济性状数量性状位点(QTL),实验通过基因分型测序(GBS)技术对163个多鳞个体(2个亲本和161个全同胞家系F1代)进行测序及标记分型,并通过复合区间定位法对该物种的体重、体高、体厚、眼径、体长和背鳍前长6个生长性状进行QTL定位分析。结果显示,多鳞首张高密度遗传连锁图谱全长2 154.803 c M,标记间平均遗传距离0.455 c M,共有4 735个SNP标记分配到24个连锁群。QTL定位分析结果发现在6个生长性状中共检测到20个生长显著相关QTL位点,分布在8个连锁群上,单个QTL的LOD值范围为3.02～4.23,可解释的表型变异范围为0.14%～8.42%。其中,在连锁群LG08聚集了8个生长性状显著相关的QTL。通过对候选QTL区间内的基因进行功能注释,共筛选到了19个潜在生长调控相关基因,包含igf1、igf2、sstr5、sst1a、tgfbr2、gas1、igfals、gfg6、gfg20、bmp7、kdm5c、tti1以及rbm10等。实验获得的遗传标记及相关候选基因是多鳞生长相关性状标记...  相似文献   

醇羟基对碳酸钙矿物成核物相及界面能影响研究     

杨阳  朱辰  王洪涛  花浩  江锐捷  毛玮  赵良 《高校地质学报》2020,26(6):617-627

文章通过对醇类物质参与下的碳酸钙成核过程进行研究，探讨生物流体中常见的羟基对矿物物相以及界面能的影响。研究结果表明多羟基醇有利于亚稳定球文石的形成，醇的加入会增加方解石和球文石的界面能，醇的羟基定向吸附造成的吸附位密度降低是提升矿物界面能最可能的机制，而溶剂氢键数量决定了碳酸根的自由度，有利于对称度低且CO₃^{2 -} 不平行的球文石形成。水和乙醇—水体系氢键作用弱，界面能低的方解石物相成为热力学优势物相。研究结果凸显了生物成矿流体受羟基影响强烈，通过控制流体中羟基物质含量，生物体可以完全掌控碳酸钙物相的形成部位，加深了对生物成因碳酸钙形成过程的理解。  相似文献