Cyanide production from glass bead "biofilm" model. Concentration of cyanide given off by glass bead biofilm cultures over 6 hours and trapped in 1 ml 4 M NaOH. A., B. and C. cyanide concentration trapped in NaOH for P. aeruginosa PAO1, B. cenocepacia J2315 and B. cenocepacia K56-2 respectively. Solid bars: with glass beads, diagonal striped bars: without glass beads. Measurements are averages of 3 independent replicates with SE error bars.