In-Situ Monitoring of the Biofilm Formation of Pseudomonas Putida on Hematite Using Flow-Cell ATR-FTIR Spectroscopy

In situ flow-cell ATR-FTIR using a Hematite coated germanium crystal was used to describe and monitor chemical interactions between Pseudomonas putida and Hematite in real time. ATR-FTIR spectra of bacteria growing on Hematite showed a shift in the carboxylate signal when compared to the samples obtained from the planktonic culture, suggesting the formation of a metal complex between the carboxylate groups and the iron metal on the hematite surface. Small differences in the polysaccharide and phosphoryl regions of the infrared spectra of planktonic and attached cells were also observed. This work shows how the use of in-vivo ATR-FTIR flow cell experiments, with a hematite-coated germanium crystal, allows a better description and monitoring of the chemical interactions between the bacteria and mineral surfaces in real time, as the initial step to understand the fundamental mechanisms involved in bacterial interactions to mineral surfaces.