Probing nanostructures of bacterial extracellular polymeric substances versus culture time by Raman microspectroscopy and atomic force microscopy.
The structure of a bacterial cell wall may alter during bacterial reproduction. Moreover, these cell wall variations, on a nanoscale resolution, have not yet fully been elucidated. In this work, Raman spectroscopy and atomic force microscopy (AFM) technique are applied to evaluate the culture time-dependent cell wall structure variations of Pseudomonas putida KT2440 at a quorum and single cell level. The Raman spectra indicate that the appearance of DNA/RNA, protein, lipid, and carbohydrates occurs till 6 h of cultivation time under our experimental conditions. AFM characterization reveals the changes of the cellular surface ultrastructures over the culture time period, which is a gradual increase in surface roughness during the time between the first two and eight hours cultivation time. This work demonstrates the feasibility of utilizing a combined Raman spectroscopy and AFM technique to investigate the cultivation time dependence of bacterial cellular surface biopolymers at single cell level.
Biological Engineering Program, College of Engineering, 4105 Old Main Hill, Utah State University, Logan, UT 84322-4105, USA.
Gerald D
GD
McEwen
Yangzhe
Y
Wu
Anhong
A
Zhou
D001704:Biopolymers / Q000737:chemistry; D002473:Cell Wall / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D016958:Pseudomonas putida / Q000737:chemistry* / Q000648:ultrastructure; D013059:Spectrum Analysis, Raman
D001704:Biopolymers