title: Characterization of thermophilic bacteria using surface-enhanced Raman scattering.
abstract: Surface-enhanced Raman scattering (SERS) can provide molecular-level information about the molecules and molecular structures in the vicinity of nanostructured noble metal surfaces such as gold and silver. The three thermophilic bacteria Bacillus licheniformis, Geobacillus stearothermophilus, and Geobacillus pallidus, a Gram-negative bacterium E. coli, and a Gram-positive bacterium B. megaterium are comparatively characterized using SERS. The SERS spectra of thermophilic bacteria are similar, while they show significant differences compared to E. coli and B. megaterium. The findings indicate that a higher number of thiol residues and possible S-S bridges are present in the cell wall structure of thermophilic bacteria, providing their stability at elevated temperatures. Incubating the thermophilic bacteria with colloidal silver suspension at longer times improved the bacteria-silver nanoparticle interaction kinetics, while increased temperature does not have a pronounced effect on spectral features. A tentative assignment of the SERS bands was attempted for thermophilic bacteria. The results indicate that SERS can be a useful tool to study bacterial cell wall molecular differences.
authors.affiliation: Yeditepe University, Faculty of Engineering and Architecture, Genetics and Bioengineering Department, Kayisdagi, 34755, Istanbul, Turkey. mculha@yeditepe.edu.tr
authors.forename: Mustafa
authors.initials: M
authors.lastname: Culha
authors.forename: Ahmet
authors.initials: A
authors.lastname: Adigüzel
authors.forename: M Müge
authors.initials: MM
authors.lastname: Yazici
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kahraman
authors.forename: Fikrettin
authors.initials: F
authors.lastname: Sahin
authors.forename: Medine
authors.initials: M
authors.lastname: Güllüce
mesh_terms: D001406:Bacillaceae / Q000737:chemistry* / Q000648:ultrastructure; D001410:Bacillus megaterium / Q000737:chemistry* / Q000648:ultrastructure; D002473:Cell Wall / Q000737:chemistry; D003102:Colloids; D004926:Escherichia coli / Q000737:chemistry* / Q000648:ultrastructure; D001411:Geobacillus stearothermophilus / Q000737:chemistry* / Q000648:ultrastructure; D006046:Gold / Q000737:chemistry; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D013696:Temperature
chemical_list: D003102:Colloids; D012834:Silver; D006046:Gold