青岛太平湾潮间带趋磁细菌多样性

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 青岛太平湾潮间带趋磁细菌多样性 DOI: 10.5846/stxb201412012380 作者: 作者单位: 中国科学院海洋研究所 海洋生态与环境科学重点实验室;中国科学院大学,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室,中国科学院海洋研究所 海洋生态与环境科学重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41276170，41206150，41330962）；国际海域资源调查与开发“十二五”项目（深海（微）生物资源勘探与资源潜力评价）（任务书编号：DY125-15-R-03） Diversity of magnetotactic bacteria in the intertidal zone of Taiping Bay, Qingdao Author: Affiliation: Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences; University of Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在青岛太平湾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350个/cm3。透射电镜观察发现该区域趋磁细菌均为趋磁球菌。磁小体个体形状单一，皆是立方体状；磁小体排列方式多样，以链状排列为主，包括单链、双链与多链，也有少数成簇排列。EDS结果表明，磁小体成分为四氧化三铁。据估算，趋磁细菌的铁元素含量（干重）范围在0.40%-6.91%之间，平均为2.19%。通过16S rRNA基因文库的构建与测序得到了47个趋磁细菌序列，分属13个OTU。系统发育分析结果表明，它们都属于α-变形菌纲，其中9个OTU与已知最相似序列的相似性低于97%，有5个OTU与已知最相似序列的相似性低于93%，可能代表了趋磁细菌的9个新种、5个新属，说明该区域潜在的微生物新种质资源十分可观。 Abstract:Magnetotactic bacteria (MTB) are gram-negative motile prokaryotes that produce magnetosomes and can orient and migrate along the geomagnetic lines of force. They are ubiquitous in sediments and stratified water columns, distributed predominantly in the oxic-anoxic transition zone (OATZ). MTB comprise several morphological types, including cocci, rods, vibrios, spirilla, and multicellular magnetotactic prokaryotes. Usually, cocci are the dominant morphology. Variable phylogenetic relatedness of MTB has been confirmed on the basis of 16S rRNA genes. MTB can biomineralize iron oxide and/or iron sulfide magnetosomes. In most MTB, magnetosomes are organized in chain(s). In this study, we found a certain amount of MTB in the intertidal zone of Taiping Bay, Qingdao City, where the maximum abundance reaches up to 350 ind./cm3. Transmission electron microscopy revealed that all the MTB were magnetotactic cocci, with a size of (2.23±0.69) μm×(1.84±0.47) μm and the width/length ratio of 0.87±0.10 (n=21). Fifty-four percent of the MTB contained two chains of magnetosomes, eighteen percent with one chain, fourteen percent with more than two chains and fourteen percent with cluster. All of these magnetosomes were prismatic mineral crystals. There were 7-43 (mean=18,n=21) magnetosomes in a cell and the volume of magnetosomes varied between 2.71×105 nm3 and 1.63×106 nm3. Assuming that all the magnetosomes were magnetite, the percentage of Fe in MTB was 0.40%-6.91% (average 2.19%) and per square kilometer of intertidal zone produced 1.92 kg magnetite every year. This suggests that MTB may play an important role in the iron biogeochemical cycle in this area. Additionally, according to the statistics for each magnetotactic bacterium, we observed that the mass of magnetosome increased with the increasing mass of MTB (r=0.637,P=0.002 < 0.05). Phylogenetic analysis based on 16S rRNA gene sequences revealed that 47 sequences of MTB belonged to 13 OTUs (XCQD1-18, 1-2, 1-19, 51, 81, 6, 2-2, 4-20, 34, 2-23, 53, 130, 1-21) and affiliated to Alphaproteobacteria. OTU XCQD1-18 containing 23 sequences had the highest dominance index (48.93%). In addition, 6, 5, 2, 2, 2 sequences belonged to OTU XCQD2-2, XCQD1-21, XCQD1-2, XCQD2-23, XCQD130, respectively. The other OTUs had only one sequence. Shannon's diversity index H' of MTB in Taiping Bay was 2.64nit, and Species Evenness J' was 0.71. Nine OTUs (XCQD 1-18, 1-2, 1-19, 81, 6, 4-20, 34, 2-23, 53) shared less than 97% 16S rRNA gene sequence similarity with the nearest known sequences, in which, five OTUs (XCQD 81, 4-20, 4, 2-23, 53) shared lower than 93%. It suggested that they represented 9 new species and 5 novel genera. Our results indicate that there were substantial potential microorganism resources in Taiping Bay. Compared to the MTB community in Huiquan Bay, a bay adjacent to Taiping Bay, here were two MTB OTUs discovered both in Taiping Bay and Huiquan Bay. Two MTB OTUs were shared. Jaccard similarity coefficient was 0.1053, indicating that although the two bays were close to each other, the MTB communities showed great differences. Comparison of the features of MTB in Taiping Bay with two French Mediterranean coasts, Six-Fours-les-Plages and Gulf of Fos, revealed that environmental factors may have a great influence on the diversity of MTB. It is assumed that community succession, seasonal variation, and environmental distinction may contribute to the low similarity between the MTB communities and features of different intertidal areas. Our results imply that further investigation on MTB in terms of their diversity is required. 参考文献 相似文献 引证文献