FTIR Spectrum and Detoxication of Extracellular Polymeric Substances Secreted by Microorganism

In order to explore the effect of extracelluar polymeric substances (EPS) on resistance and removal of heavy metals, the production of EPS, secreted by cadmium-resistant strain (SCSE425-7) and cadmium-removal strain (SCSE709-6) was investigated combined with Fourier transform infrared spectroscopy (FTIR). The results showed that the high resistance to cadmium of strain SCSE425-7 was related to the high production of soluble EPS, whereas SCSE709-6 secreted more insoluble EPS resulting in better cadmium removal performance. It was indicated that soluble extracellular carbohydrates may help the bacteria to enhance resistance to Cd2+, and insoluble EPS could contribute to Cd2+ removal effectively. The FTIR spectra showed that the peaks of amide and carboxyl were main functional groups for Cd2+ adsorption.