Phenotype and metabolism alterations in PCB-degrading Rhodococcus biphenylivorans TG9^(T) under acid stress  

作　　者：Aili Li Jiahui Fan Yangyang Jia Xianjin Tang Jingwen Chen Chaofeng Shen 

机构地区：[1]Department of Environmental Engineering,College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China [2]MOE Key Lab of Environmental Remediation and Ecosystem Health,College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China

出　　处：《Journal of Environmental Sciences》2023年第5期441-452,共12页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2019YFC1803700);the National Natural Science Foundation of China(Nos.21876149 and 42077125).

摘　　要：Environmental acidification impairs microorganism diversity and their functions on substance transformation.Rhodococcus is a ubiquitously distributed genus for contaminant detoxification in the environment,and it can also adapt a certain range of pH.This work interpreted the acid responses from both phenotype and metabolism in strain Rhodococcus biphenylivorans TG9^(T)(TG9)induced at pH 3.The phenotype alterations were described with the number of culturable and viable cells,intracellular ATP concentrations,cell shape and entocyte,degradation efficiency of polychlorinated biphenyl(PCB)31 and biphenyl.The number of culturable cells maintained rather stable within the first 10 days,even though the other phenotypes had noticeable alterations,indicating that TG9 possesses certain capacities to survive under acid stress.The metabolism responses were interpreted based on transcription analyses with four treatments including log phase(LP),acid-induced(PER),early recovery after removing acid(RE)and later recovery(REL).With the overview on the expression regulations among the 4 treatments,the RE sample presented more upregulated and less downregulated genes,suggesting that its metabolism was somehow more active after recovering from acid stress.In addition,the response mechanism was interpreted on 10 individual metabolism pathways mainly covering protein modification,antioxidation,antipermeability,H+consumption,neutralization and extrusion.Furthermore,the transcription variations were verified with RT-qPCR on 8 genes with 24-hr,48-hr and 72-hr acid treatment.Taken together,TG9 possesses comprehensive metabolism strategies defending against acid stress.Consequently,a model was built to provide an integrate insight to understand the acid resistance/tolerance metabolisms in microorganisms.

关 键 词：Environmental acidification Rhodococcus biphenylivorans Contaminant degradation Phenotypic response Transcription analysis Metabolism pathway Mechanism model 

分 类 号：X172[环境科学与工程—环境科学]