Electronic Supplementary Material (ESI) for RSC Advances. This journal is © The Royal Society of Chemistry 2020

Electronic Supplementary Material (ESI) for RSC Advances. Biofilm formation potential and chlorine resistance of typical

isolated from drinking water distribution systems Zebing Zhu,ab Lili Shan,*a Fengping Hu,*a Zehua Li,a Dan Zhong,b Yixing Yuan b and Jie Zhang b

a. School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, China. E-mail: [email protected]; [email protected] b. State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China

Table S1 Basic information of tested bacteria strains.

GeneBank Cell morphology Identified bacteria Accession Colony morphology Gra Biochemical （similarity） Shape NO. m reaction

Round, uaquaversal Sphingomonas sp. upwarping, smooth, Short rod oxidase positive, MT279969 （DQ840049， Alphaproteobacteria G- yellowish brown/bright (oval) catalase positive 99%） yellow defluvii Convex surface，smooth, oxidase egative, MT279968 （NR026506， Straight rod G- beige/light yellow catalase positive 99%） Round, convex surface, Acinetobacter sp. Short rod oxidase egative, MT279971 Gammaproteobacteria smooth, slightly opaque, G- （FR677019，99%） (round) catalase positive light yellow Bacillus cereus Round, not smooth, oxidase egative, MT279970 （GQ462533， Firmicutes，Bacilli Rod G+ irregular edge, milky catalase positive 99%） Microbacterium Fine, long and Actinobacteria， Round, slight bulge, oxidase egative, MT279967 laevaniformans irregular rod G+ Actinobacteridae rough, opaque yellow catalase positive （JQ229810，99%） (V shape)

Note: G+: Gram-positive bacteria, G-: Gram-negative bacteria. Fig. S1 SEM images of tested bacteria strains (40 000× or 20 000×). Fig. S2 Biofilm activity of single-species biofilm at different incubation times. The average error bar percentages are 48.04% for Acidovorax defluvii, 17.30% for Acinetobacter sp., 33.58% for Bacillus cereus, 27.03% for Microbacterium laevaniformans, and 34.90% for Sphingomonas sp..