Fig 7.

Extracellular polysaccharides in strain FQ163-C3. (Top panels) Sample colonies of strains FQ163 and FQ163-C3 (from BG11-agar plates containing 30 μg Nm ml⁻¹ without and with 5 μg Em ml⁻¹, respectively) were supplemented with a solution of 1% alcian blue 8GX (Sigma) and visualized by light microscopy. (Middle panels) Filaments from spots atop BG11-agar plates (with antibiotics as described above) were suspended in 150 μl of BG11 medium, supplemented with 10 μl of 1% alcian blue 8GX, and visualized by light microscopy. (Bottom panels) Biomass from the surface of BG11-agar plates (with antibiotics as described above) was harvested and suspended in 9 ml of BG11₀ medium. These filament suspensions were supplemented with 1 ml of 0.02% alcian blue–0.06% acetic acid and, after 5 min at room temperature, harvested by centrifugation (4,000 × g, 5 min). Samples from the sediment were visualized by light microscopy.