title: Identification of Escherichia coli biomarkers responsive to various lignin-hydrolysate compounds.
abstract: Aberrations in the growth and transcriptome of Escherichia coli str. BL21(DE3) were determined when exposed to varying concentrations of ferulic acid (0.25-1 g/L), an aromatic carboxylic acid identified within lignin-cellulose hydrolysate samples. The expression of several individual genes (aaeA, aaeB, inaA and marA) was significantly induced, i.e., more than 4-fold, and thus these genes and the heat shock response gene htpG were selected as biomarkers to monitor E. coli's responses to five additional hydrolysate-related compounds, including vanillic acid, coumaric acid, 4-hydroxybenzoic acid, ferulaldehyde and furfural. While all of the biomarkers showed dose-dependent responses to most of the compounds, expression of aaeA and aaeB showed the greatest induction (5-30-fold) for all compounds tested except furfural. Lastly, the marA, inaA and htpG genes all showed higher expression levels when the culture was exposed to spruce hydrolysate samples, demonstrating the potential use of these genes as biomarkers.
authors.affiliation: School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, 100 Banyeon-ri, Eonyang-eup, Ulsan 689-805, Republic of Korea.
authors.forename: Siseon
authors.initials: S
authors.lastname: Lee
authors.forename: Dougu
authors.initials: D
authors.lastname: Nam
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Min-Kyu
authors.initials: MK
authors.lastname: Oh
authors.forename: Byoung-In
authors.initials: BI
authors.lastname: Sang
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Mitchell
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D029968:Escherichia coli Proteins / Q000032:analysis* / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects* / Q000235:genetics; D018869:Heat-Shock Response / Q000187:drug effects* / Q000502:physiology; D006868:Hydrolysis; D008031:Lignin / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D029968:Escherichia coli Proteins; D008031:Lignin