Acclimation of 2-chlorophenol Biodegrading Activated Sludge and Microbial Community Analysis.

Abstract

Taking glucose as co-substrate, the activated sludge which could effectively biodegrade 2-chlorophenol (2-CP) of 40 mg/L was successfully domesticated after acclimation for 49 days in sequencing batch reactors. High-throughput sequencing (HTS) analysis revealed that the community richness initially increased for 5 days and then decreased after another 20 days with the increase of 2-CP. The original sludge obtained from water resource recovery facility had the highest diversity. At the beginning of acclimation, the community diversity decreased. With the acclimation going on, both richness and diversity of community increased, but decreased significantly when the concentration of 2-CP was increased to 40 mg/L. Saccharibacteria_norank, Bacillus, Saprospiraceae_uncultured and Lactococcus were the dominant bacteria detected in this study. Bacillus and Pseudomonas were the main chlorophenol-degrading bacteria. WCHB1-60_norank, Tetrasphaera, Comamonadaceae_unclassified and Haliangium had lower tolerance to 2-CP. Higher bacterial tolerance to CPs does not mean higher degrading capability. The degradation of CPs was not positively correlated with the abundance of known 2-CP degrading bacteria detected in this study.