Characterization and identification of a chlorine-resistant bacterium, Sphingomonas TS001, from a model drinking water distribution system

Abstract This study describes the identification and characterization of a new chlorine resistant bacterium, Sphingomonas TS001, isolated from a model drinking water distribution system. The isolate was identified by 16s rRNA gene analysis and morphological and physiological characteristics. Phylogenetic analysis indicates that TS001 belongs to the genus Sphingomonas . The model distribution system HPC results showed that, when the chlorine residual was greater than 0.7 mg L − 1 , 100% of detected heterotrophic bacteria (HPC) was TS001. The bench-scale inactivation efficiency testing showed that this strain was very resistant to chlorine, and 4 mg L − 1 of chlorine with 240 min retention time provided only approximately 5% viability reduction of TS001. In contrast, a 3-log inactivation (99.9%) was obtained for UV fluencies of 40 mJ cm − 2 . A high chlorine-resistant and UV sensitive bacterium, Sphingomonas TS001, was documented for the first time.