title: Polyamino acid display on cell surfaces enhances salt and alcohol tolerance of Escherichia coli.
abstract: Microbes employ cell membranes for reducing exogenous stresses. Polyamino acid display on microbial cell surfaces and their effects on microbial chemical stress tolerance were examined. Growth analysis revealed that displays of polyarginine, polyaspartate and polytryptophan substantially enhanced tolerance of Escherichia coli to NaCl. A titration assay indicated that polyarginine and polyaspartate altered cell surface charges, implying tolerance enhancement via ion atmosphere and/or ionic bond network formations for electrostatic ion repulsion. The enhancement by polytryptophan may have arisen from surface hydrophobicity increase for hydrophobic ion exclusion, because of a strong correlation between hydrophobic characters of amino acids and their effects on tolerance enhancement. The display also enhanced tolerance to other salts and/or alcohols in E. coli and to NaCl in Saccharomyces cerevisiae. Thus polyamino acid display has the potential as an approach for conferring chemical stress tolerance on various microbes.
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, Kobe, Hyogo, 657-8501, Japan, hirokap@xpost.plala.or.jp.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Jun
authors.initials: J
authors.lastname: Ishii
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000438:Alcohols / Q000737:chemistry / Q000494:pharmacology*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D061505:Cell Surface Display Techniques / Q000379:methods*; D004926:Escherichia coli / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000438:Alcohols; D010455:Peptides; C099320:polytryptophan; C015462:polyarginine; D012965:Sodium Chloride