酰基高丝氨酸内酯延缓好氧颗粒污泥解体的研究

Study on Acyl Homoserine Lactones delaying the disintegration of aerobic granular sludge

为探究外源信号分子对好氧颗粒污泥(AGS)稳定性的影响,在SBAR系统中分别投加不同类型的酰基高丝氨酸内酯(AHLs),并分析AGS胞外聚合物(EPS)相对含量变化,采用液相色谱-质谱技术(LC-MS)分析系统中信号分子的分布,基于BugBase物种表型预测微生物种群变化.结果表明,投加C12-HSL对微生物分泌EPS有明显促进作用,EPS含量达120.78 mg·g^(-1),系统运行90 d未出现颗粒解体现象,可维持AGS稳定状态;信号分子投加后C10-HSL主要分布于水相,而C12-HSL和C14-HSL更容易进入泥相;信号分子投加后种群结构变化显著,革兰氏阴性菌属丰度都有不同提升,在投加C12-HSL之后优势菌属为可塑菌属(Plasticicumulans)丰度显著增加(可达18.14%)、黄杆菌属(Flavobacterium)、梭菌属(Clostridium_sensu_stricto_1).C12-HSL通过提高革兰氏阴性厌氧菌属,并促进内源C14-HSL分泌,进而使EPS相对含量增加的方式延缓好氧颗粒污泥解体.

To investigate the effect of exogenous signal molecules on the stability of aerobic granular sludge,different types of acyl homoserine lactones(AHLs)were dosed in the SBAR system and their relative content changes in the extracellular polymeric substances(EPS)of AGS were analyzed.The distribution of signal molecules in the system was analyzed by liquid chromatography-mass spectrometry(LC-MS).Changes in microbial populations were predicted based on BugBase species phenotypes.The results showed that C12-HSL had a significant promotion effect on EPS secretion.The EPS content reached 120.78 mg·g^(-1),and the system was operated 90 d,maintaining the steady state of AGS without disintegration.The added signal molecules C10-HSL was mainly distributed in the aqueous phase,while C12-HSL and C14-HSL were more in biomass phase.The abundance of Gramnegative genera increased,and the dominant genera were Plasticicumulans(up to 18.14%),Flavobacterium and Clostridium after the injection of C12-HSL.C12-HSL retarded AGS disintegration by enhancing Gram-negative anaerobic genera and promoting endogenous C14-HSL secretion,which in turn increased the relative content of EPS.