Fig. 3

Polyvinyl alcohol (PVA) formed a thin film on the calcium alginate beads with embedded blastopores. Light microscopic images of an uncoated (a) and with PVA 4-88/PEG/Lec coated starch bead (b, c). Grey arrows indicate the film layer on the bead with a thickness of 22.4 ± 7.3 µm (n = 20). SEM images (d) of a calcium alginate/starch bead (CaAlg/starch, left column), coated with PVA 4-88/polyethylene glycol/lecithin (PVA/PEG/Lec, middle column) or coated with blastospores in PVA/PEG/Lec (right column) in three different magnifications (rows). The white arrow presumably indicates a single, germinated blastospore adhering to the coating film. Most of the blastospores must be embedded in or under the coating layer, as 110 blastospores would be expected in the image section shown (bottom rightmost). Beads were sputtered with gold prior to SEM