Fig. 1.

Polyphosphate inclusions within the marine Beggiatoa strain 35Flor after 7 days of growth. a Bright field image of a toluidine blue-stained Beggiatoa filament. Due to metachromasy polyphosphate inclusions of different sizes appear violet. b–d CLSM images of a DAPI-stained Beggiatoa filament. b Staining with DAPI reveals polyphosphate inclusions of different sizes by a yellow fluorescence signal. c In the transmission mode of the CLSM, many spherical cell compartments of different sizes are visible. d The overlay of (b) and (c) reveals congruence of polyphosphate inclusions with the large and with some of the smaller cell compartments. Small dark spots probably represent sulfur granules. Scale bars represent 5 μm