给水系统附生生物膜发育的生物量和种群结构

为了满足给水管网管水质的要求,考察了不同的给水管道水力条件下聚乙烯管材上生物膜(生物量和种群结构)的发育情况。采用分子生物学与传统分离培养相结合的方法,以清华地下水为原水,在剪切力分别为0.95、0.18 Pa2种条件下,生物膜生物量和种群结构的发育呈现了同一规律,即生物膜生物量在7 d内即可发育成熟,在以后的发育中,生物膜生物量一直稳定在105CFU/cm2(CFU为菌落形成单位),但生物膜的种群结构却随着时间发生显著变化。实验中所设置2种水力条件对生物膜发育的影响差别不大;生物膜生物量的发育和种群结构的发育是2个相对独立的过程;易于分泌胞外粘液和菌体表面具有疏水性等性质可以帮助细菌更好地在生物膜中生存发展。

Biomass and community structure of biofilm development in drinking water distribution systems

The effect of hydraulic conditions on biofilm accumulation(biomass and community structure) in polyethene pipes was investigated to improve drinking water quality.The biofilm biomass and community structures for two hydraulic conditions(the shear stresses of 0.95 Pa and 0.18 Pa) have similar results with the biofilm biomass(heterotrophic plate counts,HPCS) maturing within 7 days and remaining at 105 CFU/cm2(CFU: colony-forming unit) for same time,but with the biofilm community structure continuing to change.The two hydraulic conditions did not affect effect on the biofilm development,and the biofilm community structure development was independent of that of biofilm biomass.The characteristics of the extracellular materials and the hydrophobic surfaces could help the bacteria develop in the biofilm.