FIG. 5.

Elemental analysis. LIBS was used to analyze the elemental composition of (A) liquid LB medium alone (background sample), (B) 0.2 ml of liquid (cell free) from an inoculated 50 mM SrCl₂ culture, and (C) 0.2 ml of precipitate material from an inoculated 50 mM SrCl₂ culture. Prior to elemental analysis, the precipitate (C) was washed twice in 50 mM Tris-Cl buffer (pH 7.0). Duplicate samples were analyzed by use of the LIBS technique in triplicate. Representative spectra are presented with the same vertical full scale.