Figure F120. Photomicrographs and schematic images of epifluorescence observations of aerobic culture after 2 weeks of incubation. A-1, A-2. DAPI-stained natural seawater bacteria fluoresce blue in the suspensions of clay minerals, which fluoresce yellow-orange. B-1, C-1. The bacterial mass forms exopolymeric clusters. B-2, C-2. Within these clusters, seawater bacteria of various sizes can be distinguished.