Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, H-12 Sector, Islamabad, Pakistan; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Chemosphere. 2017 Sep;182:40-47. doi: 10.1016/j.chemosphere.2017.04.151. Epub 2017 May 3.
A quorum quenching (QQ) consortium comprised of both acyl homoserine lactones (AHLs)- and autoinducer-2 (AI-2)-degrading bacteria, either immobilized in polymer-coated alginate beads or in liquid suspension, was examined for fouling control in lab-scale MBRs under both steady and changing organic loading rates (OLRs). Under steady conditions the QQ consortium retarded biofouling by a factor of 3. However, a continuous increase in OLR vastly reduced the effectiveness of QQ bacteria; the biofouling was retarded only by factors of 1.4-1.8. A significant increase in extracellular polymeric substance (EPS), especially loosely-bound EPS in mixed liquor together with an increase in polysaccharide content up to 4 times in EPS resulted from the increase in OLR, was attributed to the impaired QQ efficacy. In control MBRs, cake layer resistance was the major factor (>60%) contributing to the increased trans-membrane pressure, as compared with pore blockage resistance and intrinsic membrane resistance. In contrast, the pore blockage resistance became dominant in QQ MBRs (>40%).
采用由酰基高丝氨酸内酯（AHLs）和自动诱导物-2（AI-2）双降解细菌组成的噬菌斑淬灭（QQ）联合体，通过将其固定在聚合物涂覆的藻酸盐珠或液体悬浮液中，考察了其在实验室规模的膜生物反应器（MBR）中在稳定和变化的有机负荷率（OLR）下的防污控制效果。在稳定条件下，QQ 联合体将生物污垢的生长抑制了 3 倍。然而，OLR 的持续增加大大降低了 QQ 细菌的有效性；生物污垢的抑制因子仅为 1.4-1.8。由于 OLR 的增加，胞外聚合物（EPS）显著增加，尤其是混合液中的松散结合 EPS，EPS 中的多糖含量增加了 4 倍，这归因于 QQ 功效的受损。在对照 MBR 中，与孔阻塞阻力和固有膜阻力相比，滤饼阻力是导致跨膜压力增加的主要因素（>60%）。相比之下，在 QQ MBR 中，孔阻塞阻力占主导地位（>40%）。
