Effect of ferrate and monochloramine disinfection on the physiological and transcriptomic response of Escherichia coli at late stationary phase

WATER RESEARCH

卷:189

Article

Daer, Sahar^1,2  Goodwill, Joseph E.⁴  Ikuma, Kaoru^1,2,3 

[1] Iowa State Univ, Dept Civil Construct & Environm Engn, Ames, IA 50011 USA

[2] Iowa State Univ, Environm Sci Interdept Grad Program, Ames, IA 50011 USA

[3] Iowa State Univ, Interdept Microbiol Grad Program, Ames, IA 50011 USA

[4] Univ Rhode Isl, Dept Civil & Environm Engn, Kingston, RI 02881 USA

关键词: Disinfection;    Ferrate;    Monochloramine;    RNA-seq;    Transcriptomics;    VBNC;   

DOI  :  10.1016/j.watres.2020.116580

来源: Elsevier

【 摘 要 】

Biological mechanisms of disinfection not only vary by disinfectant but also remain not well understood. We investigated the physiological and transcriptomic response of Escherichia coli at late stationary phase to ferrate and monochloramine in amended lake water. Although ferrate and monochloramine treatments similarly reduced culturable cell concentrations by 3-log(10), 64% and 11% of treated cells were viable following monochloramine and ferrate treatment, respectively. This observed induction of viable but non-culturable (VBNC) state following monochloramine treatment but not ferrate is attributed to slower monochloramine disinfection kinetics (by 2.8 times) compared to ferrate. Transcriptomic analysis of E. coli at 15 min of exposure revealed that 3 times as many genes related to translation and transcription were downregulated by monochloramine compared to ferrate, suggesting that monochloramine treatment may be inducing VBNC through reduced protein synthesis and metabolism. Downregulation of universal stress response genes (rpoS, uspA) was attributed to growth-related physiological stressors during late stationary phase which may have contributed to the elevated expression levels of general stress responses pre-disinfection and, subsequently, their significant downregulation post-disinfection. Both disinfectants upregulated oxidative stress response genes (trxC, grxA, soxS), although levels of upregulation were time sensitive. This work shows that bacterial inactivation responses to disinfectants is mediated by complex molecular and growth-related responses. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

Free