Abstract
Two biosafety strains, identified as Pseudomonas mendocina S16 and Enterobacter cloacae DS'5, were isolated from freshwater aquaculture ponds and showed significant heterotrophic nitrification-aerobic denitrification abilities. Within 48 h, the inorganic nitrogen removal efficiencies in the two strains were 66.59 %–97.97 % (S16) and 72.27 %–96.44 % (DS'5). The optimal conditions for organic nitrogen removal of the two strains were temperature 20–35 °C and carbon/nitrogen (C/N) ratio 10–20 while using sodium citrate as the carbon source. Sequence amplification demonstrated the presence of the denitrification genes in both the two strains, and quantitative real-time PCR results showed that the coupled expression of nap + nar would improve the nitrate removal rate in S16. The nitrogen removal efficiencies of the two strains in immobilization culture systems were 79.80 %–98.58 % (S16) and 60.80 %–98.40 % (DS'5). This study indicated the great potential application of the two strains in aquaculture tail water treatment.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have