Lozada Mariana, Itria R F Raúl F, Figuerola E L M Eva L M, Babay P A Paola A, Gettar R T Raquel T, de Tullio L A Luis A, Erijman Leonardo
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina.
Water Res. 2004 Apr;38(8):2077-86. doi: 10.1016/j.watres.2004.01.032.
A molecular approach was used to evaluate the effect of nonylphenol ethoxylate surfactants on the bacterial diversity in lab-scale activated sludge reactors. Separate bench-scale units were fed synthetic wastewater with and without addition of branched nonylphenol ethoxylates (NPnEO). The performance of the reactors, in terms of carbonaceous removal was largely unaffected by the presence of NP10EO in the feeding solution. However, addition of NP10EO exerted a pronounced shift in bacterial community composition. In situ hybridization analyzing larger phylogenetic groups of bacteria with ribosomal RNA-targeted oligonucleotide probes revealed the dominance of clusters composed of Betaproteobacteria, accounting for up to one-third of 4',6-diamidino-2-phenylindol-dihydrochloride (DAPI)-stained cells in NP10EO amended reactors and only 5% of DAPI-stained cells in the controls. These shifts in populations of larger phylogenetic groups were confirmed by dot-blot analysis of rRNA. Members of gamma subclass of Proteobacteria were present in low numbers in all activated sludge samples examined, suggesting that only bacteria affiliated with the beta subclass of Proteobacteria may have a specific role in NP10EO degradation.
采用分子方法评估壬基酚聚氧乙烯醚表面活性剂对实验室规模活性污泥反应器中细菌多样性的影响。分别向小型试验装置中投喂添加和不添加支链壬基酚聚氧乙烯醚（NPnEO）的合成废水。就含碳物质的去除而言，进料溶液中NP10EO的存在对反应器性能的影响不大。然而，添加NP10EO使细菌群落组成发生了显著变化。利用核糖体RNA靶向寡核苷酸探针进行原位杂交分析较大的细菌系统发育类群，结果显示由β-变形菌组成的菌群占主导地位，在添加NP10EO的反应器中，该菌群占4',6-二脒基-2-苯基吲哚二盐酸盐（DAPI）染色细胞的比例高达三分之一，而在对照反应器中仅占DAPI染色细胞的5%。通过对rRNA的斑点印迹分析证实了较大系统发育类群中这些种群的变化。在所检测的所有活性污泥样品中，变形菌纲γ亚类的成员数量较少，这表明只有与变形菌纲β亚类相关的细菌可能在NP10EO降解中具有特定作用。
