Engineering Saccharomyces boulardii for cell surface display of heterologous protein

J Biotechnol. 2025 Jan:397:44-50. doi: 10.1016/j.jbiotec.2024.11.013. Epub 2024 Nov 20.

Abstract

Saccharomyces boulardii and Saccharomyces cerevisiae share over 99 % genetic similarity yet exhibit distinct metabolic traits. While the cell surface display system of S. cerevisiae is well-documented, the equivalent system in S. boulardii has yet to be fully characterized. This study investigates the cell surface display system of S. boulardii for the expression of a heterologous protein using different anchor proteins. Six strains expressing the enhanced green fluorescent protein (Egfp) and an anchor protein as a fusion protein were constructed to visualize the cell surface display system. Then a heterologous endo-inulinase protein was expressed with selected anchor proteins through fluorescence intensity comparison. Analysis by fluorescence microscopy revealed that the anchor protein Sed1 exhibited the highest fluorescence intensity. Furthermore, expressed selected anchor proteins and heterologous protein, endo-inulinase, the engineered strain could degrade and consume almost inulin in 72 h. Through endo-inulinase expression, we confirmed that not only Egfp but also heterologous protein is well expressed, and we successfully built an S. boulardii cell surface display system.

Keywords: Anchor protein; Cell surface display system; Endo-inulinase; Saccharomyces boulardii.

MeSH terms

  • Cell Surface Display Techniques / methods
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Glycoside Hydrolases* / genetics
  • Glycoside Hydrolases* / metabolism
  • Green Fluorescent Proteins* / genetics
  • Green Fluorescent Proteins* / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces boulardii* / genetics
  • Saccharomyces boulardii* / metabolism

Substances

  • Green Fluorescent Proteins
  • enhanced green fluorescent protein
  • Glycoside Hydrolases
  • inulinase
  • Recombinant Fusion Proteins
  • Fungal Proteins