Characterization of coupling autotrophic denitrification with iron cycle bacterium Enterobacter sp. CC76 and its application of groundwater

Coupled autotrophic denitrification with iron cycle is an important but poorly understood process. A newly bacterium Enterobacter sp. CC76 exhibits an efficient autotrophic denitrification ability with a maximum nitrate removal rate of 0.24 mg/L•h coupling with iron cycle under the anaerobic conditions. The presence of the nirS gene and meteorological chromatography analysis suggest that N2 is produced as an end product by sequence amplification identified. Meanwhile, response surface methodology (RSM) experiments show that the maximum removal ratio of nitrate can reach to approximately 100% under the following conditions: pH of 5.58, temperature of 28.69 °C, C/N ratio of 5.09, Fe (III) concentration of 28.05 mg/L. And, a potential pathway of nitrate removal with iron cycle for strain CC76 is proposed. Moreover, a nitrate removal rate of 0.96 mg/L•h from iron cycle is achieved with immobilization of strain CC76 in the groundwater.