Impact of organic matter on biofilm growth and microbial community diversity

摘要

Biofilm in secondary water supply system (SWSS) may affect tap water biological stability. The growth of biofilm and the diversity of biofilm microbial community are partly influenced by organic matter content. In this paper, the impact of organic matter content on biofilm bacteria growth and biofilm density was studied. The diversity and variation process of biofilm microbial community were also analyzed by Metagenomic sequencing. Biofilm bacteria growth and compactness were positive correlate with organic matter content. Biofilm grew with tap water of low organic matter content (permanganate oxygen consumption, viz., CODMn <3 mg/L) was of higher diversity level than that in the condition of CODMn >3 mg/L. It may because of the proportion of Proteobacteria, Firmicutes and Bacteroidetes changed in low CODMn concentration condition in comparison to that in high CODMn concentration condition. Proteobacteria and Firmicutes were dominant at phylum level in biofilm in different organic matter content in this experiment. Pathogenic bacteria including Pseudomonas, Acinetobacter, Ledionella and Flavobacterium could grow with tap water that met the Chinese drinking water standards (CODMn <3 mg/L).