title: Sensing of plant hydrolysate-related phenolics with an aaeXAB::luxCDABE bioreporter strain of Escherichia coli.
abstract: A bioluminescent Escherichia coli bioreporter strain to detect hydrolysate related phenolics was developed by cloning the aaeXAB promoter from E. coli upstream of the luxCDABE genes. E. coli str. DH5α carrying this plasmid (pDMA3) was responsive to sub-inhibitory concentrations of plant hydrolysate-related phenolics, such as ferulic and vanillic acids, responding to these compounds at concentrations as low as 9.8 and 4.9 mg/L, respectively. Experiments with a mixture of the compounds showed similar responses as with single compound tests, with a minimum detectable concentration of 19.5mg/L. Finally, tests using rice straw hydrolysates were conducted, with E. coli str. DH5α/pDMA3 showing a maximum induction of 33-fold and a minimum detectable phenolic concentration of 9.3mg/L, based upon Folin-Ciocalteu's reagent. These results demonstrate that this bioreporter maintains its sensitivity even with hydrolysate samples and that it can be potentially applied within biofuel industries to detect phenolics present within plant hydrolysates.
authors.affiliation: Dept of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
authors.forename: Ajay Kalanjana
authors.initials: AK
authors.lastname: Monnappa
authors.forename: Siseon
authors.initials: S
authors.lastname: Lee
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Mitchell
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D056804:Biofuels; D003001:Cloning, Molecular; D003373:Coumaric Acids / Q000378:metabolism* / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D008163:Luminescent Measurements; D008982:Molybdenum; D010944:Plants / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D059467:Transcriptome; D017973:Tungsten Compounds; D014641:Vanillic Acid / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D056804:Biofuels; D003373:Coumaric Acids; D017931:DNA Primers; C029556:Folin's phenol reagent; D017973:Tungsten Compounds; D008982:Molybdenum; C004999:ferulic acid; D014641:Vanillic Acid