Spectroscopic characterization of extracellular polymeric substances (EPS) extracted from Pseudomonas putidaATCC 11172 produced under different carbon concentrations

Abstract

The extracellular polymeric substances (EPS) extracted from Pseudomonas putida ATCC 11172, were used as model to quantify the effect of carbon concentration on the chemical composition of EPS.P. putida was grown using Luria broth (LB) medium with and without glucose in order to promote different EPS composition. The influence of glucose amount was studied by supplementing the LB medium with glucose at 0.5% w/v (LBG 0.5%) and 1.0% w/v (LBG 1%). The produced EPS was characterized by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). FTIR were used to describe the difference in functional groups on free and bound EPS surfaces. XPS analysis was performed to quantify the element surface composition, to evaluate the local chemical environment of carbon and oxygen at the free and bound EPS, and to calculate the overall concentration of polysaccharides, peptide and hydrocarbon compounds of free and bound EPS. The combination of XPS and FTIR spectroscopy allows a more comprehensive characterization of free and bound EPS surfaces.