外源自诱导物对厌氧氨氧化的影响

Effect of the exogenous autoinducers on the anaerobic ammonium oxidation(anammox)

厌氧氨氧化作为污水生物脱氮新工艺,存在着菌群倍增时间长,一旦随水流失,脱氮性能会急剧下降的问题.N-酰基高丝氨酸内酯(AHLs)作为一类典型的诱发群体感应效应的自诱导物,可能会激活部分基因的表达.有研究表明两种常见的AHLs:C6-HSL和C8-HSL对厌氧氨氧化菌群的成膜机制有促进作用.本试验通过外添加C6-HSL和C8-HSL两种自诱导物,深入探究其对厌氧氨氧化菌群的影响.结果表明浓度为0.5g/L的AHLs会抑制厌氧氨氧化菌群的生长,但能提高其脱氮性能,并显著促进联氨合成酶(hydrazine synthase subunit A,hzs A)基因的表达,但两种AHLs的促进作用有所差别,相同浓度的C8-HSL较C6-HSL对hzs A基因表达的促进作用更为明显.

Nowadays, the anaerobic ammonium oxidation（anammox） process becomes a promising new way of removing nitrogen from wastewater. However, the performance of nitrogen removal is easy to be affected by sludge washout due to the extremely long doubling time of anammox bacteria（An AOB）. As a representative autoinducer of quorum sensing（QS） system, N-acyl-homoserine lactones（AHLs） may regulate the expression of certain genes involved in anammox reaction. Previous researches have indicated that C6-HSL and C8-HSL（two types of AHLs） could stimulate biofilm formation. Therefore, this study mainly focuses on the effect of the exogenous autoinducers（C6-HSL and C8-HSL） on anammox performance. The results showed that the growth of An AOB was inhibited at AHLs concentration of 0.5 g/L, however, the nitrogen removal rate could be enhanced by inducing hzs A gene expression in the presence of both C6-HSL and C8-HSL. Moreover, higher expression level of hzs A gene in An AOB was induced by the amendment of C8-HSL than C6-HSL at the same concentration level.