[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.