摘要
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 rRNA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。
A quantity of magnetotactic bacteria （MTB） were found in the intertidal zone of Tianyahaijiao, Sanya, China, where the maximum abundance can reach up to 100 ind./cm3. Transmission electron microscopy （TEM） re-vealed that most of the MTB were magnetotactic cocci, containing magnetosomes, which were prismatic mineral crystals, mostly organized in chain（s） （one or two chains）, while some were in cluster. High-resolution Transmission Electron Microscopy （HRTEM） and Energy Dispersive X-ray Spectroscopy （EDXA） showed that the magnetosomes contained magnetite. It was estimated that the percentage of Fe found in the MTB was 0.70%-7.53% （average 2.05%）. Phylogenetic analyses, based on 16S rRNA gene sequences, revealed that 16 sequences of MTB belonged to 9 operational taxonomic units （OTUs） and were affiliated to the class Alphaproteobacteria, except that one OTU was affiliated to the classGammaproteobacteria. Eight OTUs shared ＆lt; 97% 16S rRNA gene sequence similarity with the nearest known sequences, in which 5 OTUs shared lower than 93% similarity. These results indicate that the MTB resources in Tianyahaijiao were considerable.
出处
《海洋科学》
CAS
CSCD
北大核心
2016年第7期8-16,共9页
Marine Sciences
基金
国家自然科学基金项目(41276170
41206150
41330962)
三亚市院地科技合作项目(2014YD02)
国家基金委-山东省联合基金项目"海洋生态与环境科学"(U1406403)~~
