Identification and metabolic characterization of a strain with function of simultaneous desulfurization and denitrification

In order to improve the defects in traditional denitrification process that additional organic carbon increases the operational costs, a strain of facultative anaerobic bacterium, 3-1F, was isolated from soil using the method of double-layers plate and the Hungate anaerobic operation technique, for which, sulfide was adopted for its electron donor and nitrate for electron acceptor. Identification based on 16S rDNA sequence and physiological biochemical analysis indicates that the isolate has a homologous similarity of 99% with Rhodococcus erythropolis. The characterization of this strain shows that it can reach the logarithmic phase after inoculation for 24 h, and can reach a peak after inoculation for 60 h. Under these conditions, the thiosulfate and nitrate removal rates are over 94% and 75%, respectively. And the end products of this strain mainly consist of elemental sulfur and nitrogen gas, as well as small amount of sulfate. The achievement of strain 3-1F provides a useful microbiology resource for the efficiency improvement of simultaneous desulfurization and denitrification process through the way of bioaugmentation.