不同培养条件下菌株NB5对氨氮的去除效果研究

Removal effect of strain NB5 on ammonia nitrogen under different aquaculture conditions

文章研究了从硝化菌群中分离的菌株NB5在不同培养条件下的生长情况及其对氨氮(NH4+-N)和亚硝氮(NO2−-N)的去除效果,并对菌株NB5进行了鉴定。结果发现,菌株NB5在盐度25~45、pH 6.0~9.0、15~35℃和通气量1~2 L·min^−1的条件下生长良好(P>0.05)。在盐度45、35和25条件下对NH4+-N的最大去除率分别为96.24%、88.93%和75.08%;pH 7.5和9.0条件下分别为99.53%和99.37%;温度30、25、15和35℃条件下分别为99.53%、97.22%、97.29%和71.26%;通气量为2和1 L·min^−1时分别为99.87%和99.82%。在上述培养条件下菌株NB5对NH4+-N的最大去除率均显著高于对照组和其他条件组(P<0.05)。菌株NB5在不同培养条件下对NO2−-N浓度变化无显著作用(P>0.05)。经16S rDNA序列分析,菌株NB5鉴定为海水硝酸盐还原菌(Nitratireductor aquimarinus)。研究表明,菌株NB5具有较好的环境适应性和氨氮去除效果,尤其适合中高盐度(25~45)养殖池塘环境。

We studied the growth of strain NB5 isolated from nitrifying bacteria and its removal effect on ammonia nitrogen(NH4+-N)and nitrite nitrogen(NO2−-N)under different aquaculture conditions,and identified this bacterium.The results show that strain NB5 grew well at salinity of 25−45,pH of 6.0−9.0,temperature of 15−35℃and ventilations of 1−2 L·min^−1(P>0.05).At salinities of 45,35 and 25,the maximum removal rates of NH4+-N were 96.24%,88.93%and 75.08%,respectively.At pHs of 7.5 and 9.0,they were 99.53%and 99.37%,respectively.At temperatures of 30,25,15 and 35℃,they were 99.53%,97.22%,97.29%and 71.26%,respectively.At ventilations of 2 and 1 L·min^−1,they were 99.87%and 99.82%,respectively.Under the above conditions,the maximum removal rates of NH4+-N were significantly higher than those of the control group and the other groups(P<0.05).Strain NB5 had no significant effect on NO2−-N concentration under different aquaculture conditions(P>0.05).By 16S rDNA sequence analysis,strain NB5 was identified as Nitratireductor aquimarinus.The results indicate that strain NB5 has good environmental adaptability,especially suitable for aquaculture pond environment at medium and high salinities(25−45).