Abstract：
Quorum sensing (QS) and quorum quenching (QQ) are common phenomena in microbial systems and play an important role in the nitrification process. However, rapidly start up partial nitrification regulated by N-acyl-homoserine lactones (AHLs)-mediated QS or QQ has not been reported. Hence, we chose N-butyryl homoserine lactone (C4-HSL) and N-hexanoyl homoserine lactone (C6-HSL) as the representative AHLs, and Vanillin as the representative quorum sensing inhibitor (QSI) combined intermittent aeration to investigate their effects on the start-up process of partial nitrification. The start-up speed in the group with C4-HSL or C6-HSL addition was 1.42 or 1.26 times faster than that without addition, respectively. Meanwhile, the ammonium removal efficiency with C4-HSL or C6-HSL addition was increased by 13.87 % and 17.30 % than that of the control group, respectively. And, partial nitrification could maintain for a certain period without AHLs further addition. The increase of Nitrosomonas abundance and ammonia monooxygenase (AMO) activity, and the decrease of Nitrobacter abundance and nitrite oxidoreductase (NXR) activity were the reasons for the rapid start-up of partial nitrification in the AHLs groups. Vanillin addition reduced AMO and hydroxylamine oxidoreductase (HAO) activity, and increased Nitrobacter abundance and NXR activity, thus these were not conducive to achieving partial nitrification. Denitrifying bacteria (Hydrogenophaga, Thauera and Aquimonas) abundance increased in the Vanillin group. QS-related bacteria and gene abundance were elevated in the AHLs group, and reduced in the Vanillin group. Function prediction demonstrated that AHLs promoted the nitrogen cycle while Vanillin enhanced the carbon cycle. This exploration might provide a new technical insight into the rapid start-up of partial nitrification based on QS control.
摘要：
群体感应(QS)和群体淬火(QQ)是微生物系统中常见的现象,在硝化过程中起着重要作用。然而,由N-酰基高丝氨酸内酯（AHLs）介导的QS或QQ迅速启动部分硝化尚未报道。因此，我们选择N-丁酰基高丝氨酸内酯（C4-HSL）和N-己酰基高丝氨酸内酯（C6-HSL）作为代表性的AHLs，以香兰素为代表的群体感应抑制剂（QSI）联合间歇曝气，考察其对部分硝化启动过程的影响。添加C4-HSL或C6-HSL组的启动速度比不添加组快1.42或1.26倍，分别。同时,添加C4-HSL或C6-HSL的除铵效率比对照组提高了13.87％和17.30％，分别。And,部分硝化可以维持一段时间，而无需进一步添加AHLs。亚硝基单胞菌丰度和氨单加氧酶（AMO）活性的增加，硝化细菌丰度和亚硝酸盐氧化还原酶（NXR）活性的降低是AHLs组快速启动部分硝化的原因。香兰素添加降低了AMO和羟胺氧化还原酶（HAO）活性，并增加了硝化细菌的丰度和NXR活性，因此，这些都不利于实现部分硝化。反硝化细菌（Hydrogenophaga，香兰素组的Thauera和Aquimonas）丰度增加。QS相关细菌和基因丰度在AHLs组升高,在香兰素组中减少。功能预测表明，AHLs促进了氮循环，而香兰素促进了碳循环。这一探索可能为基于QS控制的部分硝化快速启动提供新的技术见解。
