Fig. 1.

Fabrication and physical properties of hydrogel-based TS. (A) Sketch of the spherification process to make the hydrogel beads. (B) TS before (Left) and after (Right) saturation with nutrient growth media [0.5× Murashige and Skoog medium (Top), lysogeny broth (Middle), and soil extract (Bottom)]. The logo behind the cuvette is not visible before saturation but becomes clearly visible upon saturation of the TS. (C) Transmittance of TS (at 1,080 nm, in 0.5× MS) as a function of the concentration of the polymer and MgCl₂ solutions used during spherification. The colormap also shows the length of the optical path that leads to 10% transmittance at 1,080 nm. (D) Collapse stress of TS (filled with 0.5× MS) as a function of the concentration of the polymer and MgCl₂ solutions used during spherification. The colormap also shows the thickness of TS that would collapse at its bottom. (E) Bead size as a function of the inner diameter of the nozzle used during spherification. (F) Total and effective porosity of TS as a function of the size of the beads. (G) Shrinkage of the beads as a function of time (with and without plants) and their recovery upon saturation with media on days 7 and 14.