低温厌氧氨氧化生物滤池细菌群落沿层分布规律

Bacterial community distribution of anaerobic ammonium oxidation biofilter at low temperature

通过扫描电镜（SEM）、变性梯度凝胶电泳技术（DGGE）和克隆测序等方法,对低温（14.9~16.2℃）稳定运行的上流式厌氧氨氧化（ANAMMOX）生物滤池内上（140~190 cm）、中（60~140 m）、下（10~60 cm）3部分细菌群落分布进行研究。研究结果表明：大部分氨氮、亚氮在反应器中部呈比例地去除,总氮去除负荷达2.4 kg/（m3.d）;类似ANAMMOX菌的球形细菌主要分布在反应器中部;生物滤柱上部细菌多样性最高,中部其次,下层细菌多样性最低,细菌群落结构沿层变化是适应生物滤柱沿层氮素变化的结果;生物滤柱不同滤层分布着同一种厌氧氨氧化菌（ANAMMOX）与好氧氨氧化菌（AOB）,克隆测序鉴定ANAMMOX菌为Candidatus Kuenenia stuttgartiensis,AOB为Nitrosomonas sp.ENI-11;AOB的存在能够消耗进水中的微量溶解氧,为反应器创造厌氧环境,有利于生物滤柱中部富集较多的ANAMMOX菌。

Techniques of scanning electron microscopy （SEM）, denaturing gradient gel electrophoresis （DGGE）, cloning and sequencing were utilized together to study bacterial community distribution of upper （140-190 cm）, middle （60-140 cm） and lower （10-60 cm） parts of an up-flow anaerobic ammonium oxidation （ANAMMOX） biofilter, which was run stably at low temperature （14.9-16.2 ~C）. The results show that a large proportion of ammonia and nitrite proportional disappears in the middle part of biofilter and a high total nitrogen removal rate of 2.4 kg/（m3＂d） is obtained. The spherical bacteria, which is similar to ANAMMOX bacteria, predominates in the middle part of biofilter. There is the highest bacterial diversity in the upper part of biofilter, followed by middle part and minimum bacterial diversity in lower part. Bacterial community structures varied in different parts ofbiofilter due to nitrogen distinction along biofilter layer. There is only one type of ANAMMOX bacterium and AOB presented in different parts of biofilter, which are identified as Candidatus Kuenenia stuttgartiensis and Nitrosomonas sp. ENI-11, respectively. AOB can consume trace dissolved oxygen existence in influent, which is beneficial to anaerobic environment formation and ANAMMOX bacteria enrichment in the middle part ofbiofilter.