Isolation and nitrogen removal capability of a psychrotolerant bacterium,Pseudomonas sp.strain W4
A psychrotolerant bacterium strain W4 was isolated from active sludge and its nitrogen-removal capability at 5,15,and 25 ℃ was evaluated.Results showed that W4 is affiliated to Pseudomonas,and could grow at 4 to 42℃,0 to 30 g·L-1NaCl,and pH 6 to 9.At 5 ℃,strain W4 removed 74.3％of NH4+-N(initial concentration of 76.0 mg·L-1)within 72 h,corresponding to an average nitrogen-removal rate of 0.78 mg·L-1·h-1.Under aero-bic conditions,up to 42.4％of nitrate(86.3 mg·L-1)or 38.2％of nitrite(82.2 mg·L-1)could be removed by strain W4.At 15 and 25 ℃,the nitrogen-removal efficiency was further improved,as evidenced by that more than 95％of ammonium,66％of nitrate,and 69％of nitrite were removed.Strain W4 showed the activity of heterotroph-ic nitrification and aerobic denitrification(HA-ND).No nitrite accumulation was observed during nitrification process.The HA-ND capability by strain W4 justifies the potential in the treatment of inorganic nitrogen pollution under meso-to psychrophilic conditions.Our findings help enrich psychrotolerant nitrogen-removing microbial resources,and contribute to the nitrogen pollution treatments through HA-ND process.
万方数据
维普
