Autotrophic and heterotrophic denitrification by a newly isolated strain Pseudomonas sp. C27

The denitrifying sulfide removal (DSR) process applied autotrophic and heterotrophic denitrification pathways to achieve simultaneous conversion of nitrate to N2, sulfide to elementary sulfur, and organic substances to CO2. The current bottlenecks impeding the development of DSR process include the need of balanced growth of both autotrophic denitrifiers and heterotrophic denitrifers in the same reactor and the capability of treating wastewaters at fix compositions. This work isolated a strain, identified as Pseudomonas sp. C27 (GenBank accession number GQ241351), which can grow on heterotrophic and mixotrophic media and can perform both autotrophic and heterotrophic denitrification in mixotrophic medium. The C27 strain can grow well on succinate, acetate, malate, priopionate and ethanol and has the optimal growth temperature at 25–30 °C and pH at 9.0. Pathways of DSR reactions by C27 were proposed. Discussion on the potential use of the isolated C27 in novel DSR process was available.