悬浮载体生物膜内硝化菌群空间分布规律

Spatial Distribution of Nitrifying Bacteria Communities in Suspended Carrier Biofilm

利用16SrRNA寡核苷酸探针荧光原位杂交和共聚焦激光扫描显微镜联用技术，对悬浮载体生物膜内硝化菌群的空间分布规律进行了分析．试验采用3组结构完全相同的悬浮载体生物膜反应器，每个反应器的曝气区为6L，沉淀区为2L，水力停留时间为1．0h，3个反应器的进水COD／NH4^＋—N分别为15、10和5，从反应器中取出载体颗粒表面的生物膜进行分析，研究各反应器中生物膜的微生物群落结构的变化规律。结果表明，SCBR内载体表面生物膜的总体厚度在80～120μm左右，氨氧化菌和亚硝酸盐氧化菌主要分布在生物膜表面的20～30μm左右范围内，随着进水中COD／NV4^＋-N的增加，氨氧化菌和亚硝酸盐氧化菌在整个生物膜中所占的比例逐步下降。

Spatial distributions of ammonia oxidizing bacteria （AOB） and nitrobacteria in a renovated suspended carrier biofilm reactor （SCBR） were investigated by using fluorescence in situ hybridization （FISH） with 16S rRNA oligonucleotide probes in combination with confocal laser scanning microscopy （CLSM）. Three bench-scale structurally identical SCBR reactors were operated under different ratios of COD to NH4^＋-N in Influents, 5, 10 and 15, respectively. Each SCBR reactor was consisted of a 6 L of aeration basin and a 2L of clarifier, with the hydraulic retention time （HRT） of 1.0h. The monitoring results showed that the thickness of biofilm in the SCBR was about 80 to 120 micron. Both the total amount of AOB and nitrohacteria decreased with depth in biofilm, most of the nitrification bacteria communities lied in the upper layer of biofilm, about 20 to 30 micron. The proportion of AOB to all bacteria in biofilm decreased when the ratio of COD to NH4^＋ -N increased.