图注：北京密云水库趋磁细菌多样性时空变化的主成分分析
微生物与环境具有密切关系。已有研究表明，微生物群落一方面受到环境中各种物理化学因素（如pH、温度、压力以及营养成分等）的影响，另一方面它们本身又在自然界生物矿物形成和元素循环中发挥着重要作用。趋磁细菌能在体内矿化形成磁铁矿或胶黄铁矿颗粒，是生物矿化和生物地磁学研究的模式微生物，具有重要的生物学和地学意义。趋磁细菌具有趋磁性（即沿着地磁场或外加磁场运动）的特点，较其它微生物易于从环境中富集，趋磁细菌多样性是否可作为微生物指示环境和生态变化的替代指标鲜有研究。
近日，中科院地质与地球物理研究所地球深部结构与过程研究室博士研究生林巍和导师潘永信研究员利用实验室连续观察对湖泊沉积物中趋磁细菌群落的时间和空间变化进行了详细研究，运用新的生物统计学手段，揭示出趋磁细菌的环境适应性。他们的研究结果表明，第一，趋磁细菌多样性随时间发生明显的变化；第二，不同采集地点的趋磁细菌群落具有较大差异，说明趋磁细菌分布可能具有地区特异性分布的特点；第三，趋磁细菌的系统发育多样性与其微环境中硝酸盐的含量有密切关系。
上述研究结果表明，趋磁细菌的群落变化与环境密切相关，因此趋磁细菌多样性能够作为生态环境变化以及古环境重建的潜在的重要指标。（生物谷Bioon.com）
生物谷推荐原始出处：
FEMS Microbiology Letters Volume 302 Issue 1, Pages 85 - 92 DOI:10.1111/j.1574-6968.2009.01838.x
Temporal variation of magnetotactic bacterial communities in two freshwater sediment microcosms
Wei Lin 1,2 & Yongxin Pan 1
1 Biogeomagnetism Group, Paleomagnetism and Geochronology Laboratory, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China ; and 2 Graduate University of Chinese Academy of Sciences, Beijing, China
Magnetotactic bacteria (MTB), which can mineralize nanosized magnetite or greigite crystals within cells, play important roles in biogeochemical processes, for example iron and sulfur cycling, and depositional remanent magnetization acquisitions. Despite decades of research, the knowledge of MTB distribution and ecology is still limited. In the present study, we investigated the temporal variation of MTB communities in freshwater sediment microcosms based on 16S rRNA genes and unifrac analyses. Two microcosms (MY8 and MY11) collected from two separate sites in Lake Miyun (Beijing, China) were analyzed. The majority of retrieved sequences belonged to alphaproteobacterial magnetotactic cocci in both microcosms (representing 64.29% of clones from MY8 and 100% of clones from MY11), whereas so-called 'Magnetobacterium bavaricum'-like MTB affiliated within Nitrospira phylum were exclusively found in microcosm MY8. Over a 3-month period, the temporal variation of MTB communities was evident in both microcosms. In addition, the phylogenetic discrepancy of MTB communities between two microcosms is more prominent than that of the same microcosm at different times, implying adaptation of MTB phylogenetic lineages to specific microenvironments. Among the physical–chemical parameters measured, a strong correlation was shown between nitrate and the main genetic variability of MTB communities, indicating that nitrate may influence the occurrence of MTB phylogenetic lineages in natural environments.
