Cultural optimization and metal effects of Shewanella xiamenensis BC01 growth and swarming motility

Background: Shewanella species belonging to dissimilatory metal bacteria were found to decolorize most textile dyes and had also attracted great interests in regard to bioremediation. However, studies have rarely been reported on Shewanella xiamenensis BC01, which was isolated as a biodecolorization and bioelectricity strain recently. In this study, the effect of cultivation conditions on S. xiamenensis BC01 was studied to explore how environmental conditions may influence S. xiamenensis growth and swarming motility. Results: Shewanella xiamenensis BC01 grew over a wide range of pH (5.0–9.0) and mild temperatures (25–42 °C). The optimal conditions for cell growth were using Luria-Bertani (LB) as medium with shaking at 150 rpm, 37 °C, and pH 8.0 which had been confirmed by shift pH and temperature. S. xiamenensis BC01 was able to resist 1 mM concentrations of various metal ions, i.e., Ca, Mg, Cu, Zn, Mn, Fe, and Al, respectively. As shown in scanning electron microscopy (SEM) analyses, cell morphologies were slightly changed under metal stress. Swarming motility showed that the velocity ranking at 80 μM and 1 mM of metal was Al > Cr > LB > Zn > Fe > Cu and Mg >Mn> Ca, respectively. Conclusions: This study evaluates the impact of cultivation methods and metal ions on the activity of S. xiamenensis BC01 and provides an alternative to bioremediation of heavy metal-containing wastewaters by utilizing this strain.