One of the main obstacles to studying the surface ultrastructure of microbial cells by atomic force microscopy (AFM) is determining how to immobilize live cells on the AFM substrates. Each method has its own advantages and disadvantages. The aim of this study was to characterize a new simple and inexpensive method using two types of polyethersulfone (PES) membrane filters that differ in pore size (micropore and nanopore) to immobilize live and dead Brevibacillus laterosporus for AFM imaging. B. laterosporus was easily trapped by the microporous PES membrane, facilitating the successful AFM scanning of the bacterial surface ultrastructure. In addition, B. laterosporus strongly attached to the nanoporous membranes and withstood the pulling forces exerted by the AFM tip during scanning. These methods of immobilization did not affect the cell viability. The nanostructure and roughness of the bacterial surface were also observed for live, fixed, and air-dried cells. Live and dead bacteria displayed similar morphologies at low resolution, while at high resolution, live bacteria displayed a more convoluted surface ("brain-like structure").

通过原子力显微镜（AFM）研究微生物细胞表面超微结构的主要障碍之一是确定如何将活细胞固定在AFM基质上。每种方法都有其自身的优点和缺点。这项研究的目的是描述一种使用两种类型的孔径不同的聚醚砜（PES）膜滤器（微孔和纳米孔）来固定活的和死的枯草芽孢杆菌以进行AFM成像的简单，廉价的新方法。B.lateosporus很容易被微孔PES膜捕获，有利于细菌表面超微结构的成功AFM扫描。另外，B。Laterosporus牢固地附着在纳米多孔膜上，并抵抗了AFM尖端在扫描过程中施加的拉力。这些固定方法不影响细胞活力。还可以观察到活细胞，固定细胞和风干细胞的细菌表面的纳米结构和粗糙度。活细菌和死细菌在低分辨率下显示出相似的形态，而在高分辨率下，活细菌显示出更易卷曲的表面（“脑样结构”）。