北运河底泥中异养硝化菌的筛选及其脱氮特性

SCREENING OF HETEROTROPHIC NITRIFYING BACTERIA IN SEDIMENT OF THE BEIYUN RIVER AND ITS NITROGEN REMOVAL CHARACTERISTICS

通过富集培养、梯度稀释涂平板、平板划线分离等方法,从北运河底泥中筛选出6株具有异养硝化作用的细菌。其中,1株细菌HNM-4在初始ρ(NH3-N)为140 mg/L,丁二酸钠为碳源,C/N为6的异养硝化培养基中培养48 h时,对NH3-N去除率为75.67%。经16S rDNA测序鉴定,菌株HNM-4为假单胞菌(Pseudomonas sp.)。单因素实验表明:HNM-4发挥异养硝化作用的最适环境条件为初始ρ(NH3-N)为140 mg/L,碳源为丁二酸钠,C/N为9~18,温度为30℃,初始pH值为7~8,盐度为0~0.5%。在反硝化培养基中培养48 h时,HNM-4对NO3--N和TN去除率分别为100%和12.05%。

Six strains of heterotrophic nitrification bacteria were screened from the sediments of the Beiyun River by enrichment culture,gradient dilution coating and flat-line separation.Among them,one strain bacteria,named HNM-4 had a removal rate of 75.67%for ammonia nitrogen in the heterotrophic nitrification medium with initial ammonia nitrogen concentration of 140 mg/L,sodium succinate as carbon source and C/N of 6.HNM-4 was identified as Pseudomonas sp.by 16 S rDNA sequencing.Univariate experiments showed that the optimum environmental conditions for HNM-4 to play heterotrophic nitrification were as follows:initial ammonia nitrogen concentration of 140 mg/L,carbon source of sodium succinate,C/N of9~18,temperature of 30℃,initial pH of 7~8 and salinity of 0~0.5%.When cultured in denitrification medium for 48 h,the removal rates of nitrate nitrogen and total nitrogen by HNM-4 were 100%and 12.05%,respectively.