黄土剖面中趋磁细菌及其磁小体的初步研究

从中国西安市附近段家坡黄土剖面分离到微好氧性的趋磁细菌，经透射电子显微镜Ｈ－７０００ＦＡ和Ｈ－６００ＳＥＭ／ＥＤＡＸ－ＰＶ９１００型分析，黄土层（Ｌ１）中仅发现弧形菌，数量少，每个菌体含２个磁小体；古土壤层（Ｓ０和Ｓｉ）含有大量杆状菌，每个菌体有１５个以上的磁小体，沿细菌长轴呈两排链状排列，且具有向南磁极游动的习性，Ｘ射线能谱分析表明，磁小体中具有高丰度的Ｆｅ和Ｃｏ。趋磁细菌中磁小体的数量在古土壤

PRELIMINARY STUDY ON MAGNETOTACTIC BACTERIA AND THEIR MAGNETOSOMES FROM LOESS SECTION

Some microaerophilic, magnetotactic bacteria were isolated from Duanjiapo loess section (S0 -L1), near Xi'an City, Shanxi Province, and analysed using H-7000 FA and H-600 SEM / EDAX-PV 9100 transmission electron microscope. A limited number of bow-shapped magnetotactic bacteria were formed in loess layers. Each cell contained two magnetosomes. In S1 layers, there were a large number of rod-shaped bacteria which have a habit of moving towards the South. Each cell contained more than 15 magnetosomes arranging in two rows. Energy dispersion X-ray analysis indicated that Fe and Co were the most abundant elements in magnetosome. Magnetotactic bacteria contained more magnetosomes in paleosol than in loess. This seems to be consistent with the fact that magnetic susceptibility is higher in paleosol layers than in loess layers in the loess section.