Autotrophic denitrification with anaerobic Fe²⁺ oxidation by a novel Pseudomonas sp. W1 Available to Purchase

In the present study, a novel Pseudomonas sp. W1 was characterized in terms of its ability to perform nitrate removal coupled with anaerobic Fe²⁺ oxidation under autotrophic growth condition. The effects of operating parameters with respect to the initial solution pH, temperature and initial Fe²⁺ concentration on nitrate removal were investigated by central composite design. Based on the results of response surface methodology, the maximal nitrate removal efficiency was achieved under the following conditions: pH 7.0, temperature 30 °C and initial Fe²⁺ concentration 1,100 mg L⁻¹. Under this optimal condition and with an initial NO₃⁻-N concentration of 55 mg L⁻¹, this strain could remove NO₃⁻-N with 90% reduction of NO₃⁻-N, corresponding to oxidizing Fe²⁺ with 71% oxidation of Fe²⁺ after 7 days of incubation. The result of kinetic evaluation indicated that this bacterium showed significant substrate affinity to both NO₃⁻-N and Fe²⁺.