Journal: Biofilm

Article Title: Inactivation of Cysteine Synthase CysK-A enhances flocculation, biofilm formation, and sensitivity to oxidative stress in Azospirillum brasilense Sp7

doi: 10.1016/j.bioflm.2025.100335

Figure Lengend Snippet: Colony and biofilm calcofluor staining assays. Production of exopolysaccharide (EPS) by the wild-type ( A. brasilense Sp7), the cysK-A mutant ( A. brasilense AR), and the complemented ( A . brasilense AR-pAB- cysK ) strains were visualized by staining with calcofluor, which binds to β-linked polysaccharides. ( A ) Colonies were grown for 5 days at 30 °C on solid LB medium (lacking NaCl) supplemented with Calcofluor (200 μg/mL). Images were captured under UV illumination to visualize fluorescence. Scale bar = 10 mm. ( B ) Confocal micrographs of biofilms grown for 5 days at 30 °C on agar-solidified Nfb∗ medium containing Calcofluor (85 μM). The biofilms were observed with a Nikon Eclipse Ti-E C2+ microscope. Scale bar = 20 μm.

Article Snippet: After five days of static incubation at 30 °C, three-dimensional biofilm structures were observed using an Eclipse Ti-E C2+ confocal laser scanning microscope (Nikon) equipped with CFI Plan Apo VC 20x/1.2 and CFI Plan Apo VC 60x/1.2 WI objective lenses.

Techniques: Staining, Mutagenesis, Fluorescence, Microscopy