[Enrichment and Characterization of A Denitrifying Bacteria Consortium from Lihe River's Sediment]

A denitrifying bacteria consortium was enriched from LiHe River's sediment, the dynamics of total nitrogen (TN), nitrate (NO3- -N), nitrite (NO2- -N), ammonium (NH4+ -N) and COD at different enrichment cultivation stages were studied, and the total volume, the releasing rates and the composition of gas released during the denitrification process were analyzed. The full-length 16S rDNA clone library was constructed, enclosing the diversity of the denitrifying bacteria consortium. The results showed, in the enrichment phase 4, under the load of TN 330 mg x L(-1), the best nitrogen removal effect was obtained, which the TN and NO3- -N removal rates reached 90.9% and 100% within 9 hours, respectively. The accumulation amounts of NO2- -N and NH4+ -N were merely 3.39 mg x L(-1) and 16.64 mg x L(-1). And the COD removal rate was 85%. The process released 260 mL of the compound gas, in which the main ingredient was N2 associated with a small quantity of CH4 and CO2. The denitrifying bacteria consortium consisted of the family Pseudomonadaceae and the family Rhodocyclaceae, belonging to Proteobacteria phylum, in which the OUT abundances were 57.8% and 31.6%, respectively. The family Pseudomonadaceae was the predominant group.