Characteristics of Autotrophic and Heterotrophic Denitrification by the Strain Pseudomonas sp. H117

Strain H117 was isolated from the Tang Yu reservoir. Based on the phylogenetic characteristics, strain H117, which was identified as Pseudomonas sp. strain H117, had the capability to utilize bicarbonate and sodium acetate as a carbon source under anaerobic conditions. Furthermore, the strain could grow on both autotrophic and heterotrophic media, and could perform both autotrophic and heterotrophic denitrification in the medium. Response surface methodology analysis demonstrated that the maximum degradation ratio of nitrate-occurred under the following conditions in the autotrophic medium: initial pH of 6.00, C/N ratio of 4.68 and temperature of 31.33 degrees C. The maximum degradation ratio of nitrate occurred under the following conditions in the heterotrophic medium: initial pH of 6.16, C/N ratio of 8.23 and temperature of 28.48 degrees C. Finally, the denitrification performance of strain H117 was evaluated under the optimum conditions. These results suggest that strain H117 has potential applications for the bioremediation of polluted groundwater.