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.

From mannan to bioethanol: cell surface co-display of β-mannanase and β-mannosidase on yeast Saccharomyces cerevisiae

“…One such cell surface-display system using Flo1p (a lectin-like cell wall protein) permits the incorporation of an anchor ranging in length from 42 a.a. (Flo42) to 1326 a.a. (Flo1326), thereby accommodating accessibility of large substrates to the target enzymes displayed on the yeast cell wall [25]. Among the anchors, Flo428 (428 a.a.) is a well-balanced anchor protein that provides both substrate accessibility and enzyme expression [25–27]. …”

Constitutive cell surface expression of ZZ domain for the easy preparation of yeast-based immunosorbents

“…The PGK1 gene encodes a 3-phosphoglycerate kinase that is a key enzyme in glycolysis, and, therefore, its promoter (P PGK1 ) could drive the constitutive ZZ protein expression. To prepare this plasmid, the gene encoding the ZZ domain was inserted into the previously constructed pFGKII426 vector [Suzuki et al, 2015]. The resulting plasmid (pFGKII426-EZZ) and other plasmids to be compared were introduced into the S. cerevisiae BY4741 strain.…”