Abstract:The present study collected 8 samples from aquaculture ponds for performing enrichment, isolation, purification and identification of bacteria strain scapable of removing NO2--N, NO3--N and NH4+-N. We obtained 8, 8 and 11 bacteria strains which could remove NO2--N, NO3--N and NH4+-N, respectively. These bacteria were classified into the genera Pseudomonas, Paracoccus, Zobellella, Achromobacter, Bosea, Paenarthrobacter, Corynebacterium, Bacillus, Delftia and Gordonia. After analysis of denitrification characteristics, two heterotrophic nitrification and aerobic denitrification bacteria strains with excellent denitrification effects were obtained and identified as Pseudomonas stutzeri j-1 and Zobellella denitrificans 2G-5, respectively. After incubated in 3 nitrogen media for 18 hours, the removal rates of NO2--N, NO3--N and NH4+-N by strain j-1 and 2G-5 were ranged from 99.53% to 99.89%. When applied in non-sterile aquaculture water, strain j-1 was successfully colonized and showed efficient denitrification. Whereas, strain 2G-5 didn’t proliferate well and its denitrification effect was unremarkable. This study exploited a collection of denitrification bacteria, obtained two heterotrophic nitrification and aerobic denitrification strains with important application potential, and provided biological materials for further study on bacterial mechanisms of nitrogen circulation and metabolism, and on research and development of denitrification techniques.
