PDF(Pubmed)
Abstract：
Industrial biocides aim to keep water systems microbiologically controlled and to minimize biofouling. However, the resulting dead cells are usually not removed from the water streams and can influence the growth of the remaining live cells in planktonic and sessile states. This study aims to understand the effect of dead Pseudomonas fluorescens cells killed by industrial biocides-benzalkonium chloride (BAC) and 2,2-dibromo-3-nitrilopropionamide (DBNPA)-on biofilm formation. Additionally, the effect of different dead/live cell ratios (50.00% and 99.99%) was studied. The inoculum was recirculated in a Parallel Plate Flow Cell (PPFC). The overall results indicate that dead cells greatly affect biofilm properties. Inoculum with DBNPA-dead cells led to more active (higher ATP content and metabolic activity) and thicker biofilm layers in comparison to BAC-dead cells, which seems to be linked to the mechanism of action by which the cells were killed. Furthermore, higher dead cell ratios (99.99%) in the inoculum led to more active (higher culturability, metabolic activity and ATP content) and cohesive/compact and uniformly distributed biofilms in comparison with the 50.00% dead cell ratio. The design of future disinfection strategies must consider the contribution of dead cells to the biofilm build-up, as they might negatively affect water system operations.
摘要：
工业杀菌剂旨在保持水系统的微生物控制并最大程度地减少生物污染。然而,产生的死细胞通常不会从水流中去除，并且会影响浮游和固着状态下剩余的活细胞的生长。这项研究旨在了解工业杀菌剂苯扎氯铵（BAC）和2,2-二溴-3-次氮基丙酰胺（DBNPA）杀死的死荧光假单胞菌细胞对生物膜形成的影响。此外,研究了不同死/活细胞比率（50.00％和99.99％）的影响。将接种物在平行板流动池(PPFC)中再循环。总体结果表明,死细胞极大地影响生物膜性质。与BAC死亡细胞相比，DBNPA死亡细胞接种导致更活跃（更高的ATP含量和代谢活性）和更厚的生物膜层。这似乎与杀死细胞的作用机制有关。此外，接种物中较高的死细胞比率(99.99%)导致更活跃(较高的可培养性，代谢活性和ATP含量）以及粘性/致密且均匀分布的生物膜，与50.00％的死细胞比率相比。未来消毒策略的设计必须考虑死细胞对生物膜积聚的贡献，因为它们可能会对供水系统的运行产生负面影响。
