Metabolic uncouplers inhibit biofilm and biofouling formation in membrane bioreactor (MBR) systems, which have been considered as a potential biofouling control alternative. To better understand the inhibitory mechanism of uncoupler on biofouling, this study investigated the impact of the uncoupler 3, 3', 4', 5-tetrachlorosalicylanilide (TCS) on biofilm formation of B. subtilis in different development stages. Significant reductions in both the initial bacterial attachment stage and the subsequent biofilm development stage were caused by TCS at 100 μg/L. The motility of B. subtilis in semisolid medium was inhibited by TCS, which explicitly explained the reduction in initial bacterial attachment. Meanwhile, a reduction of extracellular polymeric substance (EPS) secretion owing to TCS suggested why biofilm development was suppressed. In addition, the fluorescent materials in tight-bound EPS (TB-EPS) and loose-bound EPS (LB-EPS) of Bacillus subtilis cultured in different TCS concentrations were distinguished and quantified by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC). The results of this study suggested that the biofilm inhibitory mechanism of the uncoupler was both a inhibition in bacterial motor ability and a reduction in EPS secretion.

中文翻译：

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分析代谢解偶联剂对细菌初始附着和生物膜发育的抑制作用及其潜在机理。

代谢解偶联剂可抑制膜生物反应器（MBR）系统中的生物膜和生物积垢形成，这已被视为潜在的生物积垢控制替代方法。为了更好地理解解偶联剂对生物结垢的抑制机理，本研究调查了解偶联剂3、3'，4'，5-四氯水杨酰苯胺（TCS）在不同发育阶段对枯草芽孢杆菌生物膜形成的影响。最初的细菌附着阶段和随后的生物膜发育阶段的显着减少是由100μg/ L的TCS引起的。TCS抑制了枯草芽孢杆菌在半固体培养基中的运动，这清楚地解释了初始细菌附着的减少。同时，由于TCS，细胞外聚合物质（EPS）分泌减少表明了为什么生物膜发育受到抑制。此外，通过三维激发-发射矩阵（EEM）荧光鉴定和定量了在不同TCS浓度下培养的枯草芽孢杆菌的紧密结合EPS（TB-EPS）和宽松结合EPS（LB-EPS）中的荧光物质。光谱学和并行因子分析（PARAFAC）。这项研究的结果表明，解偶联剂的生物膜抑制机制既是抑制细菌运动能力，又是减少EPS分泌。