title: Transcriptome profiling of Shewanella oneidensis gene expression following exposure to acidic and alkaline pH.
abstract: The molecular response of Shewanella oneidensis MR-1 to variations in extracellular pH was investigated based on genomewide gene expression profiling. Microarray analysis revealed that cells elicited both general and specific transcriptome responses when challenged with environmental acid (pH 4) or base (pH 10) conditions over a 60-min period. Global responses included the differential expression of genes functionally linked to amino acid metabolism, transcriptional regulation and signal transduction, transport, cell membrane structure, and oxidative stress protection. Response to acid stress included the elevated expression of genes encoding glycogen biosynthetic enzymes, phosphate transporters, and the RNA polymerase sigma-38 factor (rpoS), whereas the molecular response to alkaline pH was characterized by upregulation of nhaA and nhaR, which are predicted to encode an Na+/H+ antiporter and transcriptional activator, respectively, as well as sulfate transport and sulfur metabolism genes. Collectively, these results suggest that S. oneidensis modulates multiple transporters, cell envelope components, and pathways of amino acid consumption and central intermediary metabolism as part of its transcriptome response to changing external pH conditions.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, Tennessee 37831, USA.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Leaphart
authors.forename: Dorothea K
authors.initials: DK
authors.lastname: Thompson
authors.forename: Katherine
authors.initials: K
authors.lastname: Huang
authors.forename: Eric
authors.initials: E
authors.lastname: Alm
authors.forename: Xiu-Feng
authors.initials: XF
authors.lastname: Wan
authors.forename: Adam
authors.initials: A
authors.lastname: Arkin
authors.forename: Steven D
authors.initials: SD
authors.lastname: Brown
authors.forename: Liyou
authors.initials: L
authors.lastname: Wu
authors.forename: Tingfen
authors.initials: T
authors.lastname: Yan
authors.forename: Xueduan
authors.initials: X
authors.lastname: Liu
authors.forename: Gene S
authors.initials: GS
authors.lastname: Wickham
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000143:Acids; D000468:Alkalies; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D046228:Microarray Analysis; D020592:Shewanella / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D000143:Acids; D000468:Alkalies; D001426:Bacterial Proteins