一株施氏假单胞菌Pseudomonas stutzeriDN-LWX19的脱氮性能

Denitrification performance of Pseudomonas stutzeri DN-LWX19

从缺氧生物滤池筛选纯化得到一株具有高效反硝化能力的异养菌DN-LWX19,通过形态观察、生理生化特性及16S r DNA同源性分析,确定该菌株为施氏假单胞菌(Pseudomonas stutzeri)。脱氮性能研究结果表明,菌株DN-LWX19在NO-3-N初始浓度为120.43 mg/L的试管培养基中,60 h对NO-3-N去除率达90%,NO-2-N积累浓度仅0.05 mg/L。以添加适量乙酸钠的实际污水处理二级出水为液体培养基,研究DN-LWX19在初始NO-3-N浓度约为30.00 mg/L时的脱氮效果,当碳氮比(COD/NO-3-N)为5∶1时,菌株DN-LWX19在32 h对NO-3-N去除率为100%,但是有NO-2-N的积累(7.00 mg/L),且至72 h无明显变化;当碳氮比为9∶1时,菌株DN-LWX19在32h对NO-3-N的去除率为100%,且无NO-2-N的积累。

A heterotrophic bacteria DN-LWX19,with a highly efficient denitrification capacity,was isolated from a lab-scaled anoxic biofilter. DN-LWX19 was identified as Pseudomonas stutzeri according to its morphological,physiological and biochemical properties and phylogenetic analysis by the 16 S r DNA sequence. The results showed that,the removal efficiency of NO-3-N was 90% and the accumulation of NO-2-N was only 0. 05 mg / L after the 60 h denitrification in the vitro medium under the influent NO-3-N of 120. 43 mg / L. When the DN-LWX19 was cultivated in the synthetic wastewater secondary treated effluent adding the appropriate amount of CH3 COONa with NO-3-N concentration of 30. 00 mg / L,the removal efficiency of NO-3-N reached 100% under the 32 h denitrification at initial C / N( COD / NO-3-N) ratio of 5 ∶ 1,but the accumulation of NO-2-N was 7. 00 mg / L and without any change until 72 h cultivation. Moreover,the removal efficiency of NO-3-N reached 100% without any accumulation of NO-2-N under the 32 h denitrification at initial C / N ratio of 9 ∶ 1.