FIGURE 3: Yeast microcolonies form in alginate-encapsulated beads packed in immobilized cell reactors. Immediately after gelation (A), the interior of bead consists of primarily single, unbudded cells evenly dispersed throughout alginate matrix, but by 3 days in ICR (B), cells have evenly dispersed in clonal clusters of 4 or more cells. After 14 days in ICR (C), cells are tightly packed, occupying majority of matrix material. Hollow chambers are dispersed throughout beads, presumably formed by CO₂ generation.