title: Effects of membrane lipid composition and antibacterial drugs on the rigidity of Escherichia coli: Different contributions of various bacterial substructures.
abstract: The rigidity/stiffness is an important biomechanical property of bacteria and potentially correlated with many bacterial activities. While the rigidity or fluidity of the bacterial membrane has been extensively studied, the contributions of different bacterial substructures to the bacterial rigidity are less investigated. Here, we utilized four Escherichia coli (E. coli) strains with different membrane lipid compositions and three antibacterial drugs (EDTA, lysozyme, and streptomycin) to specifically alter bacterial substructures. By using atomic force microscopy (AFM), we found that the average height and Young's modulus of phosphatidylethanolamine (PE)-deficient E. coli strains were larger than those of PE(+) strains and that EDTA, EDTA plus lysozyme instead of lysozyme alone, and streptomycin all caused significant decreases in height and Young's modulus of the four E. coli strains. Our data imply that membrane lipid composition, the integrated outer membrane, the cell wall, and the cytoplasmic content are all responsible for bacterial rigidity but to different extents.
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, People's Republic of China.|College of Life Sciences, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, People's Republic of China.|College of Life Sciences, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Chaoye
authors.initials: C
authors.lastname: Gan
authors.affiliation: School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Shao
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, People's Republic of China.|College of Life Sciences, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Yu
authors.affiliation: Faculty of Life Sciences, Hubei University, Wuchang, Hubei, People's Republic of China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Wang
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, People's Republic of China.|College of Life Sciences, Nanchang University, Nanchang, Jiangxi, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002462:Cell Membrane / Q000737:chemistry* / Q000187:drug effects*; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000737:chemistry* / Q000166:cytology / Q000187:drug effects*; D008560:Membrane Fluidity / Q000187:drug effects*; D008563:Membrane Lipids / Q000032:analysis*; D018625:Microscopy, Atomic Force; D009113:Muramidase / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D008563:Membrane Lipids; D004492:Edetic Acid; D009113:Muramidase; D013307:Streptomycin
keywords: EDTA; atomic force microscopy (AFM); lysozyme; rigidity/stiffness; streptomycin