Arsenic interception by cell wall of bacteria observed with surface-enhanced Raman scattering

The purpose of this study was to determine the interactions between arsenic (As) resistant bacteria and As, using surface-enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopy. According to our 16S rDNA results, eight bacteria isolated from the environment can be identified to four genera (Arthrobacter, Pseudomonas, Sphingomonas, and Acinetobacter). The bacteria were separated into cell wall and protoplast in the study to assess the As(V) attack. The As(V) stress on bacteria could be identified with SERS, but not with FTIR. The bacteria in our study primarily resist As(V) through sequestration of As(V) by the cell wall. The change in SERS peaks and their relationships with cell wall suggested that As(V) mainly interacts with functional groups on the cell wall including polysaccharides and flavin derivates.

► As resistant bacteria from As-laden and As-free environments were cultured.
► The As(V) stress on bacteria could be identified with SERS, but not with FTIR.
► Cell wall and protoplast were separated in the SERS analysis.
► The bacteria resist As(V) through sequestration of As(V) by the cell wall.
► As(V) mainly interacts with polysaccharides and flavin derivates on the cell wall.