圖注：北京密云水庫(kù)趨磁細(xì)菌多樣性時(shí)空變化的主成分分析
微生物與環(huán)境具有密切關(guān)系,。已有研究表明,，微生物群落一方面受到環(huán)境中各種物理化學(xué)因素（如pH、溫度,、壓力以及營(yíng)養(yǎng)成分等）的影響,，另一方面它們本身又在自然界生物礦物形成和元素循環(huán)中發(fā)揮著重要作用。趨磁細(xì)菌能在體內(nèi)礦化形成磁鐵礦或膠黃鐵礦顆粒,，是生物礦化和生物地磁學(xué)研究的模式微生物,，具有重要的生物學(xué)和地學(xué)意義。趨磁細(xì)菌具有趨磁性（即沿著地磁場(chǎng)或外加磁場(chǎng)運(yùn)動(dòng)）的特點(diǎn),，較其它微生物易于從環(huán)境中富集,，趨磁細(xì)菌多樣性是否可作為微生物指示環(huán)境和生態(tài)變化的替代指標(biāo)鮮有研究。
近日，中科院地質(zhì)與地球物理研究所地球深部結(jié)構(gòu)與過(guò)程研究室博士研究生林巍和導(dǎo)師潘永信研究員利用實(shí)驗(yàn)室連續(xù)觀察對(duì)湖泊沉積物中趨磁細(xì)菌群落的時(shí)間和空間變化進(jìn)行了詳細(xì)研究,，運(yùn)用新的生物統(tǒng)計(jì)學(xué)手段,，揭示出趨磁細(xì)菌的環(huán)境適應(yīng)性。他們的研究結(jié)果表明,，第一,，趨磁細(xì)菌多樣性隨時(shí)間發(fā)生明顯的變化；第二,，不同采集地點(diǎn)的趨磁細(xì)菌群落具有較大差異,，說(shuō)明趨磁細(xì)菌分布可能具有地區(qū)特異性分布的特點(diǎn)；第三,，趨磁細(xì)菌的系統(tǒng)發(fā)育多樣性與其微環(huán)境中硝酸鹽的含量有密切關(guān)系,。
上述研究結(jié)果表明，趨磁細(xì)菌的群落變化與環(huán)境密切相關(guān),，因此趨磁細(xì)菌多樣性能夠作為生態(tài)環(huán)境變化以及古環(huán)境重建的潛在的重要指標(biāo),。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
