摘要
The widely distributed genus Shewanella is famous for its capacity of electron transferring and extracellular polymeric substance (EPS) production. Regarding to the EPS production by Shewanella is a critical event for its application, the aim of this study is to decipher the effect of calcium ion on a new S. xiamenensis BC01 (SXM). It grew and survived at a high concentration of 20 mM CaCl 2 in LB medium. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that calcium had an effect on cell resulted in the stimulating EPS production and changing morphology of nano-filament. Further characterization of the EPS through attenuated total reflectance of Fourier transform infrared (ATR-FTIR) spectroscopy, and protein identification of whole cell via SDS-PAGE coupled with tandem mass spectrometry implied calcium affected membrane and flagellum structure. The flagellin domain-containing protein was found to be relative with the process of flagella assembling, which enhanced EPS formation. Finally, the production of EPS increased from 0.35 g/L to 1.7 4g/L was corresponding to the increment of calcium. Thus, the decolorization rate of azo dye reactive blue by EPS was increased from 26.5 % to 49.5 % upon the addition of calcium.