Probing the surface ultrastructure of Brevibacillus laterosporus using atomic force microscopy

Khalid Alzahrani; Arun Kumar Shukla; Javed Alam; Abdurahman A Niazy; Abdullah M Alsouwaileh; Mansour Alhoshan; Jamal Khalid; Hamdan S Alghamadi

doi:10.1016/j.micron.2020.102827

Probing the surface ultrastructure of Brevibacillus laterosporus using atomic force microscopy

Micron. 2020 Apr:131:102827. doi: 10.1016/j.micron.2020.102827. Epub 2020 Jan 13.

Authors

Khalid Alzahrani¹, Arun Kumar Shukla², Javed Alam³, Abdurahman A Niazy⁴, Abdullah M Alsouwaileh⁵, Mansour Alhoshan⁶, Jamal Khalid⁷, Hamdan S Alghamadi⁴

Affiliations

¹ Department of Physics and Astronomy, King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia; King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
² King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia. Electronic address: ashukla@ksu.edu.sa.
³ King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
⁴ Molecular and Cell Biology Laboratory, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
⁵ Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁶ King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia; Department of Chemical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
⁷ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

PMID: 31951938
DOI: 10.1016/j.micron.2020.102827

Abstract

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").

Keywords: Atomic force microscopy; Brevibacillus laterosporus; Cell immobilization; Imaging live bacteria; Surface ultrastructure.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brevibacillus / ultrastructure*
Microscopy, Atomic Force / methods

Supplementary concepts

Brevibacillus laterosporus