Ultrasound Treatment Reducing the Production of VBNC Bacteria in the Process of Chlorine Disinfection:Efficiency and Mechanisms  

作　　者：QI Zheng LIU Chunguang 

机构地区：[1]School of Environmental Science and Engineering,Shandong Key Laboratory of Environmental Processes and Health,Shandong University,Qingdao,Qingdao,266237,P.R.China [2]Qingdao Key Laboratory of Marine Pollutant Prevention,Shandong University,Qingdao,Qingdao,266237,P.R.China

出　　处：《Chemical Research in Chinese Universities》2023年第3期425-433,共9页高等学校化学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.42077391);the Guangdong Foundation for Program of Science and Technology Research,China(No.2020B1212060053).

摘　　要：The production and reactivation of viable but nonculturable(VBNC)bacteria by chlorine disinfection leads to an overestimation of the disinfection effect and brings health risks.Therefore,this study is to evaluate the disinfection efficiency of combined ultrasound(US)and chlorine in inhibiting the production and reactivation of VBNC bacteria and to clarify the mechanisms.The number of culturable cells was effectively reduced by 99.97%after US/chlorine treatments.The number of VBNC bacteria introduced by US treatment and chlorine treatment was 10^(3.6)CFU/mL and 10^(5.2)CFU/mL,respectively.However,US/chlorine disinfection produces fewer VBNC bacteria(101.3 CFU/mL),and the dark reactivation of the VBNC bacteria was effectively inhibited.Ultrasound and chlorine have synergistic effects in disinfection-ultrasound further enhancing bacterial membrane permeability and chlorine-induced oxidative stress,causing the bacterial antioxidant system to collapse.In addition,single cell Raman spectroscopy and gas chromatography-tandem mass spectrometry(GC-MS/MS)analysis revealed that US/chlorine treatment inhibits more strongly or even destroys the metabolism of bacteria.The significantly perturbed metabolic pathways mainly involved the amino acid,carbohydrate and lipid metabolisms.Thus,the combined US/chlorine treatment is a promising cleaner and a more efficient disinfection technology to remove VBNC bacteria in the field of water purification.

关 键 词：Ultrasonic disinfection Oxidative stress Viable but nonculturable(VBNC)bacterium Untargeted metabolomics 

分 类 号：O6[理学—化学]