Morgan-Sagastume Fernando, Boon Nico, Dobbelaere Sofie, Defoirdt Tom, Verstraete Willy
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Can J Microbiol. 2005 Nov;51(11):924-33. doi: 10.1139/w05-077.
Up to now, the production and role of N-acyl homoserine lactones (AHLs) in activated sludge have been poorly understood. In this study, cross-feeding assays with the reporter strains Agrobacterium tumefaciens NTL4 and Chromobacterium violaceum CV026 were used to investigate AHL signal production by municipal activated sludge samples. AHL signal production was consistently detected from municipal activated sludge when different samples were incubated on nutrient media. From one municipal activated sludge sample, 10 strains producing AHL-like auto inducers were isolated by an overlay technique. 16S rDNA-based phylogenetic analysis showed that eight of the isolates belonged to Aeromonas spp. and two to Pseudomonas spp. Box-PCR indicated that six of these Aeromonas isolates were different strains and the two Pseudomonas strains were identical. The production of AHL or AHL-like compounds by these strains was confirmed by thin layer chromatography and biosensor overlays. The six different Aeromonas strains were found to produce the same set of AHLs, including N-hexanoyl-L-homoserine lactone. These results may indicate the possible presence of AHLs in municipal activated sludge. The potential roles of AHL in this eco system are briefly discussed.
到目前为止，人们对N-酰基高丝氨酸内酯（AHLs）在活性污泥中的产生情况及作用了解甚少。在本研究中，利用报告菌株根癌农杆菌NTL4和紫色杆菌CV026进行交叉饲喂试验，以研究城市活性污泥样品中AHL信号的产生情况。当不同样品在营养培养基上培养时，始终能检测到城市活性污泥产生AHL信号。从一份城市活性污泥样品中，通过覆盖技术分离出10株产生类AHL自诱导物的菌株。基于16S rDNA的系统发育分析表明，其中8株分离物属于气单胞菌属，2株属于假单胞菌属。盒式PCR表明，这些气单胞菌分离物中有6株是不同的菌株，而2株假单胞菌菌株是相同的。通过薄层色谱法和生物传感器覆盖法证实了这些菌株产生AHL或类AHL化合物。发现这6株不同的气单胞菌菌株产生相同的一组AHLs，包括N-己酰基-L-高丝氨酸内酯。这些结果可能表明城市活性污泥中可能存在AHLs。本文还简要讨论了AHL在这个生态系统中的潜在作用。
