Construction of a plant-microbe phytoremediation system: combination of vetiver grass with a functional endophytic bacterium, Achromobacter xylosoxidans F3B, for aromatic pollutants removal.

The endophytic bacterial strain Achromobacter xylosoxidans F3B, which was able to utilize aromatic compounds as a sole carbon source, was inoculated into vetiver grass in this study. A real-time PCR detection method has been developed for confirming the stability of F3B in plants and DGGE profiles were conducted for examining the diversity of endophytes during the remediation process. These results showed that the endophytic bacteria strain F3B could maintain a stable population in plant roots without largely interfering with the diversity of native endophytes. Furthermore, the strain F3B could protect plants against toluene stress and maintain chlorophyll content of leaves, and a 30% reduction of evapotranspiration through vetiver leaves was observed. Our results demonstrate the potential to improve phytoremediation of aromatic pollutants by inoculating functional endophytic bacterial strains.