title: Unique stress response to the lactoperoxidase-thiocyanate enzyme system in Escherichia coli.
abstract: Using a differential fluorescence induction approach, we screened a promoter trap library constructed in a vector with a promoterless gfp gene for Escherichia coli MG1655 promoters that are induced upon challenge with the antimicrobial lactoperoxidase-thiocyanate enzyme system. None of the thirteen identified lactoperoxidase-inducible open reading frames was inducible by H(2)O(2) or by the superoxide generator plumbagin. However, analysis of specific promoters of known stress genes showed some of these, including recA, dnaK and sodA, to be inducible by the lactoperoxidase-thiocyanate enzyme system. The results show that the lactoperoxidase-thiocyanate enzyme system elicits a distinct stress response different from but partly overlapping other oxidative stress responses. Several of the induced genes or pathways may be involved in bacterial defense against the toxic effects of the lactoperoxidase-thiocyanate enzyme system.
authors.affiliation: Laboratory of Food Microbiology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, 3001 Leuven (Heverlee), Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Sermon
authors.forename: Kristof
authors.initials: K
authors.lastname: Vanoirbeek
authors.forename: Philipp
authors.initials: P
authors.lastname: De Spiegeleer
authors.forename: Rob
authors.initials: R
authors.lastname: Van Houdt
authors.forename: Abram
authors.initials: A
authors.lastname: Aertsen
authors.forename: Chris W
authors.initials: CW
authors.lastname: Michiels
mesh_terms: D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005453:Fluorescence; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007784:Lactoperoxidase / Q000378:metabolism*; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D013481:Superoxides / Q000494:pharmacology; D013861:Thiocyanates / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D013861:Thiocyanates; D013481:Superoxides; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase; C031760:thiocyanate