不同营养条件下水动力扰动对细菌附着行为的影响

为探究水体的营养条件和水动力扰动对细菌附着行为的影响，文章以给水管网中常见的铜绿假单胞菌(Pseudomonas aeruginosa)野生株及其藻酸盐分泌过量的突变株为研究对象，借助于死活染色生物量测定方法，分析其在不同水动力和营养水平下的附着行为。结果表明：在充足营养水平(1:1 LB培养基)下，水动力扰动未对野生株的表面覆盖率(6h)产生显著影响$(P > 0.05)$ ；而在低营养水平(1:50 LB培养基)下，培养 $6\mathrm{h}$ ，转速从 $0\mathrm{r / min}$ 增至 $120\mathrm{r / min}$ 时，野生株覆盖率较静置时增加4.60倍 $(P < 0.001)$ 。不同环境条件下，突变株的覆盖率均高于野生株，证明胞外聚合物(extracellular polymeric substances, EPS)对细菌附着行为具有重要影响。研究结果可为饮用水系统和其他水环境的微生物污染控制提供理论指导。

To investigate the effects of nutritional conditions and hydrodynamic disturbances on bacterial attachment behavior in water bodies, this paper focused on the common Pseudomonas aeruginosa (wild-type and alginate secreting mutant strains) in water supply networks. The attachment behavior of Pseudomonas aeruginosa under different hydrodynamic and nutritional levels was analyzed via the dead and live staining biomass measurement. The results showed that hydrodynamic disturbance did not have a significant effect on the surface attachment(6 h) of wild-type strains$(P > 0.05)$ at the sufficient nutritional level(1:1 LB medium). In contrast, the attachment amount of wild-type strains increased by 4.60 times $(P < 0.001)$ following decreased nutritional level(1:50 LB medium) and increased hydrodynamic disturbance with the rotation speed rising from $0\mathrm{r / min}$ to $120\mathrm{r / min}$ . Under different environmental conditions, the attachment amount of mutant strains was higher than that of wild-type strains, which proved the importance of extracellular polymeric substances(EPS) on bacterial attachment behavior. This study can provide theoretical guidance for the control of microbial contamination in drinking water systems and other aqueous environments.