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 center dot h coupling with iron cycle under the anaerobic conditions. The presence of the nirS gene and meteorological chromatography analysis suggest that N-2 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 degrees 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 center dot h from iron cycle is achieved with immobilization of strain CC76 in the groundwater. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.