排序方式： 共有15条查询结果，搜索用时 0 毫秒
1.
荣成月湖是一个典型天然潟湖,潮间带沉积物中存在多种形态趋磁细菌。通过Roche454高通量测序平台,对沉积物样品(B_S)和磁收样品(B_M)进行16SrRNA基因高通量测序,认识荣成潮间带沉积物的细菌群落结构,并了解趋磁细菌多样性及系统进化地位。研究结果表明沉积物样品中主要的细菌类群为δ-变形菌纲,占总细菌数的26.4%,其次是γ-变形菌纲和α-变形菌纲;而磁收样品中细菌多样性和种类明显降低,以α-变形菌纲占绝对优势,相对比例达72.6%。在磁收样品和沉积物样品分别发现了1 612条和186条reads与趋磁细菌相关,分别占细菌总数的5.76%和0.85%,磁收样品中趋磁细菌数是沉积物样品的6.8倍。对两个样品中获得的趋磁细菌序列进行系统进化分析,发现这些序列多数属于变形菌门的α-变形菌纲,以趋磁球菌占绝对优势,少数属于δ-变形菌纲,与多细胞趋磁原核生物亲缘关系最近。海洋趋磁螺菌属仅在B_M样品中检出,趋磁弧菌属在B_M样品优势度高于B_S样品,而多细胞趋磁原核生物和趋磁螺菌属在B_S样品中优势度更高。通过分析样品间的差异OTUs,认为荣成潮间带沉积物中可能存在大量未知的趋磁细菌新类群。研究结果为下一步培养和开发趋磁细菌这一功能菌群,发现趋磁细菌新类群及趋磁细菌生态功能提供了基础资料。 相似文献
2.
3.
4.
日前，武汉大学和黑龙江测绘局联合组建的极地测绘科学国家测绘局重点实验室在武汉大学揭牌。武汉大学和黑龙江测绘局都是多年从事极地科学考察的测绘部门，极地测绘科学国家测绘局重点实验室的组建能够通过优势互补、强强联合，实现全面提高我国极地测绘科学领域的研究能力和学术水平，推动中国极地测绘科学事业的发展， 相似文献
5.
Bacterial diversity and community structure in the East China Sea by 454 sequencing of the 16S rRNA gene 总被引：1，自引：0，他引：1
The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater samples and five sediment samples sourced in May 2011. A total of 22 phyla, 34 classes, 74 orders, 146 families, and 333 genera were identified in this study. Some of them were detected for the first time from the East China Sea. The estimated richness and diversity indices were both higher in the sediment samples compared with in the seawater samples. All the samples were divided by their diversity indices into four regions. Similarity analysis showed that the seawater samples could be classified into six groups. The groups differed from each other and had unique community structure characteristics. It was found that different water masses in the sampling areas may have had some influence on the bacterial community structure. A canonical correspondence analysis revealed that seawater samples in different areas and at different depths were affected by different environmental parameters. This study will lay the foundation for future research on microbiology in the East China Sea. 相似文献
6.
在三亚天涯海角潮间带沉积物中发现了一定量的海洋趋磁细菌,最大丰度可达100个/cm3。透射电子显微镜(TEM)观察发现该区域趋磁细菌绝大多数为趋磁球菌。磁小体形状单一,皆为棱柱形;磁小体排列方式多样,以链状排列为主,包括单链、双链,也有少数成簇排列。高分辨率透射电子显微镜(HRTEM)与X-射线能谱仪(EDXS)结果表明,磁小体成分为Fe3O4。趋磁细菌的铁含量平均为2.05%(0.70%~7.53%)。通过16S r RNA基因文库的构建与测序,在78个阳性克隆中得到了16个趋磁细菌序列,分属9个OTU。系统发育分析结果表明,其中8个OTU属于α-变形菌纲,1个OTU属于γ-变形菌纲。在全部9个OTU中,有8个OTU与已知趋磁细菌序列的相似性低于97%,有5个OTU与已知趋磁细菌序列的相似性低于93%,说明该区域存在可观的趋磁细菌资源。 相似文献
7.
在高空气象观测工作中,经常遇到特殊记录。造成这些特殊记录的原因,有上空仪器故障,有人为的错误,还有天气实况的真实反应。如何正确处理这些特殊记录,对于天气预报,科学实验,资料保存都是很有价值的。本文利用温度随高度变化的规律,谈谈分析处理特殊记录的一些体会。 一、复杂天气情况下, 特殊记录的分析处理 在对流层,一般情况下,温度随高度的 相似文献
8.
Magnetotactic bacteria are a group of Gram-negative bacteria that synthesize magnetic crystals, enabling them to navigate in relation to magnetic field lines. Morphologies of magnetotactic bacteria include spirillum, coccoid, rod, vibrio, and multicellular morphotypes. The coccid shape is generally the most abundant morphotype among magnetotactic bacteria. Here we describe a species of giant rod-shaped magnetotactic bacteria(designated QR-1) collected from sediment in the low tide zone of Huiquan Bay(Yellow Sea, China). This morphotype accounted for 90% of the magnetotactic bacteria collected, and the only taxonomic group which was detected in the sampling site. Microscopy analysis revealed that QR-1 cells averaged(6.71±1.03)×(1.54±0.20) m m in size, and contained in each cell 42–146 magnetosomes that are arranged in a bundle formed one to four chains along the long axis of the cell. The QR-1 cells displayed axial magnetotaxis with an average velocity of 70±28 mm/s. Transmission electron microscopy based analysis showed that QR-1 cells had two tufts of fl agella at each end. Phylogenetic analysis of the 16 S r RNA genes revealed that QR-1 together with three other rod-shaped uncultivated magnetotactic bacteria are clustered into a deep branch of A lphaproteobacteria. 相似文献
9.
10.
趋磁细菌是一类能够沿着磁力线运动的革兰氏阴性细菌, 主要生活在淡水和海洋的有氧-无氧过渡区。本调查通过对青岛汇泉湾潮间带沉积物柱状样分层样品中趋磁细菌的计数和沉积物理化因子的分析, 研究了趋磁细菌的垂直分布特征及其与环境因子的关系。结果显示趋磁细菌以趋北型的趋磁球菌占优势, 主要分布环境的氧化还原电位为179.7～-107.0 mV, 为弱还原-还原性质, 最大丰度(94～169个/cm3)出现在氧化还原跃层(表层下5～9cm黄-黑沙界面处), 暗示有氧-无氧过渡区; 趋磁细菌的垂直变化趋势与粒径、含水率、硫酸盐的变化趋势基本一致。 相似文献