AHLs信号分子对MBR膜生物污染的影响

针对膜生物反应器(MBR)运行过程中膜污染的变化情况,利用超高效液相色谱(UPLC-MS/MS)技术检测不同运行时期污泥和膜上滤层中N-酰基高丝氨酸内酯(AHLs)类信号分子的含量和种类变化,并结合胞外聚合物(EPS)与溶解性微生物产物(SMP)中各组分的含量变化,对污染的阶段性变化和群体感应信号分子间的相互关系进行较为全面的分析。研究发现,在MBR系统运行中,导致膜生物污染的污染物有EPS和SMP,而主要有3种群体感应信号分子能促进混合液与生物滤层中污染物的分泌。其中,C8-HSL能促进混合液SMP及EPS中多糖的产生,3-oxo-C8-HSL对混合液SMP中的蛋白质和DNA有很强的促进作用,3-oxo-C6-HSL能促进膜上EPS中蛋白质的产生,表明群体感应信号分子通过影响污染物的产生来导致膜生物污染。

Impact of N-acyl Homoserine Lactones (AHLs) Signal Molecules on Membrane Biofouling

Aiming at the change of membrane fouling during membrane bioreactor ( MBR ) operation , ultra-performance liquid chromatography linked to tandem mass spectrometry ( UPLC-MS/MS) was used to detect the content and species of AHLs type signal molecules in the activated sludge and the MBR biocake under different running time. Meanwhile, each component content of EPS and SMP in the biocake and activated sludge were detected. The relationship between the pollution and quorum-sensing signal molecules was analyzed. The results showed that, during the operation of MBR, the contaminants that cause membrane biofouling were EPS and SMP, and there were three groups of quorum-sensing signal molecules that promoted the secretion of pollutants in the mixture and biocake. Among them, C8- HSL could promote the production of polysaccharides of SMP and EPS in the activated sludge, 3-oxo-C8- HSL had a strong effect on the protein and DNA of SMP in the mixed liquor, 3-oxo-C6-HSL could promote production of protein in EPS on membrane surface. It indicated that quorum-sensing signal molecules could cause membrane biofouling by affecting the generation of contaminants.