Comparison of the Identation and Elasticity of E.coli and its Spheroplasts by AFM

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Ultramicroscopy

DOI:https://doi.org/10.1016/j.ultramic.2007.04.017· OSTI ID:958774

Sullivan, Claretta J ^[1]; Venkataraman, Sankar ^[1]; Retterer, Scott T ^[1]; Allison, David P ^[1]; Doktycz, Mitchel John ^[1]

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1. ORNL

Atomic force microscopy (AFM) provides a unique opportunity to study live individual bacteria at the nanometer scale. In addition to providing accurate morphological information, AFM can be exploited to investigate membrane protein localization and molecular interactions on the surface of living cells. A prerequisite for these studies is the development of robust procedures for sample preparation. While such procedures are established for intact bacteria, they are only beginning to emerge for bacterial spheroplasts. Spheroplasts are useful research models for studying mechanosensitive ion channels, membrane transport, lipopolysaccharide translocation, solute uptake, and the effects of antimicrobial agents on membranes. Furthermore, given the similarities between spheroplasts and cell wall-deficient (CWD) forms of pathogenic bacteria, spheroplast research could be relevant in biomedical research. In this paper, a new technique for immobilizing spheroplasts on mica pretreated with aminopropyltriethoxysilane (APTES) and glutaraldehyde is described. Using this mounting technique, the indentation and cell elasticity of glutaraldehyde-fixed and untreated spheroplasts of E. coli in liquid were measured. These values are compared to those of intact E. coli. Untreated spheroplasts were found to be much softer than the intact cells and the silicon nitride cantilevers used in this study.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 958774
• Journal Information: Ultramicroscopy, Vol. 107, Issue 10-11; ISSN 0304-3991
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ANTIMICROBIAL AGENTS
ATOMIC FORCE MICROSCOPY
BACTERIA
ELASTICITY
LIPOPOLYSACCHARIDES
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MEMBRANES
MICA
SAMPLE PREPARATION
SILICON NITRIDES
SOLUTES
TRANSLOCATION