Tensile properties of yeast cell-loaded Ca-alginate gel layers

The tensile properties of Ca-alginate gel strips (2.0% (w/v) alginate) containing varying amounts of yeast cells (0.1–5.0%, w/v) were investigated. The stress, strain and energy at failure of yeast-filled alginate samples showed very similar evolutions as a function of the initial cell content, i.e., they peaked at a cell content of 0.5–0.8% (w/v). By contrast, no clear effect of cell loading on Young's modulus could be highlighted at moderate yeast concentration (≤1.0%, w/v) but the elastic modulus significantly decreased at higher cell loading. These results are discussed in light of literature data on particulate–polymer composites.