Low-temperature scanning electron microscope images using different magnifications.

<p>A–B. The mixed assemblages bacteria + diatom. C–D. The diatom treatment. E–F. The bacteria treatment. G–H. The control substratum. Frozen water (ice) on the surface produces a solid matrix around the glass beads in the controls. In the other treatments with microorganisms, the EPS matrix is visible, heavily covering the glass beads and permeating the intermediate pore space.