The flow cell system and confocal laser scanning microscopy were applied to investigate the characteristics of biofilm formed by the nitrogenous heterocyclic compound (NHC)-degrading bacteria under different environmental conditions. The results showed that increasing the initial inoculum density and prolonging the initial attachment time were beneficial to the adhesion and biofilm formation of the NHC-degrading bacteria on the surface of the substrate. When the flow rate of the medium was reduced, the biofilm became more homogeneous and formed more water channel structures. Moreover, the biofilm under different conditions presented a same phenomenon that the inner layer (near the surface) had a low ratio of living cells and the outer layer (distant from the surface) had a high ratio of living cells. Compared with the single-strain biofilm, the dual-strain biofilm had an advantage in thickness, surface coverage ratio and living cell ratio. The target NHC concentration also had a significant effect on the morphology and cell viability of the quinoline-degrading bacteria biofilm: at lower concentration of quinoline, the bacteria formed large and developed aggregates; while at higher concentration, the bacterial aggregates became much smaller and evenly dispersive. Besides, the ratio of living cells of the biofilm formed at lower concentration was remarkably higher than that at higher concentration.

采用流动室(Flow Cell)生物膜发生装置和激光共聚焦显微镜观察技术, 揭示不同环境条件下含氮杂环化合物(nitrogenous heterocyclic compounds, NHCs)降解菌的生物膜形成特征。结果表明, 增加初始接种菌液浓度并延长初始黏附时间, 有利于吡啶降解菌在基质表面的黏附和生物膜形成; 降低培养基流速, 细菌生物膜更加均质化且形成水通道结构; 不同条件下的生物膜都存在内层活细胞比例较低, 外层活细胞比例较高的规律。此外, 还发现相对于单一菌株, 混合菌株在生物膜厚度、基质覆盖率与活细胞比例上都更具优势。目标NHC浓度对喹啉降解菌生物膜的形态和活性也有明显的影响: 低浓度下降解菌团聚结构分布较零散, 但具有较大的体积; 高浓度下降解菌团聚结构明显变小, 在基质表面的分布则更均匀; 低浓度下生物膜的活细胞比例显著高于高浓度下的生物膜。