Application of atomic force microscopy to observation of marine bacteria
Application of atomic force microscopy to observation of marine bacteria
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DOI：
10.1023/b:joce.0000038328.54339.e4
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发表时间：
2004-04-01
影响因子：
2.3
通讯作者：
Kogure, K
中科院分区：
文献类型：
--
作者：
Nishino, T;Ikemoto, E;Kogure, K
原子力显微镜（AFM）是近年来发展起来的一种台式仪器，它可以对生物样品的表面结构进行高分辨率成像，同时测量其尺寸。本文介绍了原子力显微镜在海洋细菌研究中的应用。将天然和培养的细菌保留在过滤器上或置于玻璃上，洗涤，风干并通过AFM观察。对仪器条件、滤膜的选择、固定和过滤效果、与荧光显微镜计数的比较、细菌细胞的大小和形状等进行了研究。Isopore过滤器最适合浓缩和后续观察，因为其表面平坦。横截面图像显示，杆状细胞和球状细胞都是扁平的，前者通常具有双峰形状。细菌细胞基于它们的横截面形状和大小与非生命颗粒区分开。AFM和EFM的细菌计数显示出良好的一致性。虽然尺寸测量很容易通过仪器完成，但AFM倾向于高估微球的尺寸。因此，需要在生物体的大小测量方面做更多的工作。由于原子力显微镜可以在高放大倍数下观察到自然细菌细胞的图像，因此可以作为研究海洋细菌精细结构的新工具。
The atomic force microscopy (AFM) is a recently developed, bench-top instrument that can image the surface structures of biological specimens at high resolution with simultaneous measurement of their size. This paper describes the application of AFM to marine bacteria. Both natural and cultured bacteria were retained on a filter or placed on glass, washed, air-dried and observed by AFM. The instrumental condition, the choice of suitable filter, effect of fixation and filtration, comparison wit epifluorescent microscopic (EFM) count, and the size and shape of bacterial cells were investigated. An Isopore filter was best for concentration and subsequent observation because of its surface flatness. Cross section images showed that both rod and coccoid cells were flattened, the former usually having a two-humped shape. Bacterial cells were differentiated from non-living particles based on their cross section shape and size. Bacterial counts by AFM and EFM showed good agreement. Although size measurement is easily done by the instrument, AFM tends to overestimate the size of microspheres. More work is thus needed on the size measurement of living organisms. Because AFM easily provides images of natural bacterial cells at high magnification, it can be used as a new tool to study the fine structures of marine bacteria.