Effects of sonication on bacteria viability in wastewater treatment plants evaluated by flow cytometry - Fecal indicators, wastewater and activated sludge
Effects of sonication on bacteria viability in wastewater treatment plants evaluated by flow cytometry - Fecal indicators, wastewater and activated sludge
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DOI：
10.1016/j.watres.2006.08.021
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发表时间：
2007-01-01
期刊：
影响因子：
12.8
通讯作者：
Giuliano, Ziglio
中科院分区：
文献类型：
--
作者：
Foladori, Paola;Laura, Bruni;Giuliano, Ziglio
超声波对废水或污泥的应用有助于聚集体的分散，颗粒物质的增溶性及其生物降解性的增加，由于细胞膜完整性的丧失而对微生物的损害。本研究旨在调查20 kHz频率超声处理对城市污水处理厂原废水和活性污泥中存在的微生物活力的影响，以及大肠杆菌和粪肠杆菌的纯菌株。细胞核酸荧光染色后，用流式细胞术对散装液中游离的活菌和死菌进行鉴定和定量。结果表明：(1)即使在较低的超声比能（E-s）下，大肠杆菌细胞对超声也有较高的敏感性，且有大量细胞解体；（ii）相反，即使施用了高水平的大肠杆菌，粪肠杆菌也比大肠杆菌更具耐药性；（iii）原始废水中的细菌表现出与大肠杆菌相似的活菌和死菌动态；（iv）在活性污泥样品中，低水平的e会导致絮凝体普遍解体，释放出散装液体中的单个细胞，而只有非常高水平的e才会引起细菌的破坏。(c) 2006 Elsevier Ltd.版权所有。
The application of sonication to wastewater or sludge contributes to the dispersion of aggregates, the solubilisation of particulate matter with an increase in its biodegradability, the damage of microorganisms due to the loss of cellular membrane integrity. This research is aimed at investigating the effects of sonication at 20 kHz frequency on viability of microorganisms present in raw wastewater and activated sludge taken from a municipal wastewater treatment plant, as well as pure strains of Escherichia coli and E. faecalis. Flow cytometry was applied for the identification and quantification of viable and dead bacteria free in the bulk liquid, after the fluorescent staining of cellular nucleic acids. The main results showed that: (i) cells of E. coli were highly sensitive to sonication, even at low specific ultrasonic energy (E-s), and disintegration of a large amount of cells was observed; (ii) on the contrary E. faecalis were more resistant than E. coli, even if high levels of E, were applied; (iii) bacteria in raw wastewater exhibited a dynamic of viable and dead bacteria similar to E. coli; (iv) in activated sludge samples, low levels of E. produced a prevalent disaggregation of flocs releasing single cells in the bulk liquid, while disruption of bacteria was induced only by very high levels of Es. (c) 2006 Elsevier Ltd. All rights reserved.