Cacl2.2h2o

The present study employed P. aeruginosa PA01 (ATCC 15,692) to evaluate the effect of aminoglycosides in conjunction with the presence/absence of Ca²⁺ and Mg²⁺ ions. The strain was cultivated on Evan’s media consisting of: NaH₂PO₄.2H₂O (0.62 g/ l) (BDH, England), KCl (0.75 g/l) (Fluka), NaNO₃ (0.849 g/l) (Sigma-Aldrich), Na₂SO₄ (0.28 g/l) (Sigma), citric acid (0.38 g/l) 0.02% (v/v) (BDH, England), glucose (1.8 g/l) (Thermo Fisher Scientific, UK), CaCl₂.2H₂O (0.037 g/l) (BDH, England), MgCl₂ (0.11 g/l) (Amresco, United States American (USA)) and filter sterilised trace elements. The pH was adjusted to 7.2 prior to sterilisation by autoclaving. The concentrations of both Ca²⁺ and Mg²⁺ were amended to 1–5 mM when required.
Trace element solution contained ZnO (4.1 g/l), FeCl₃ (3.2 g/l) (Sigma–Aldrich), MnCl₂.4H₂O (2.0 g/l), CuCl₂ (1.4 g/l) (BDH, England), CoCl₂.6H₂O (4.8 g/l) (BDH, England), Na₂MoO₄.2H₂O (0.0048 g/l) (BDH, England), NOB₄O₇.10 H₂O (3.82 g/l) (Sigma, Japan) in 80 mL of concentrated HCl (Sigma–Aldrich, UK). Shaking flasks (250 ml) containing 50 mL of sterile Evan’s media and 50 μl of filtrated trace elements were inoculated with P. aeruginosa and incubated overnight at 30 °C, 250 rpm.

Analytical reagent grade anhydrous calcium nitrate (Ca(NO₃)₂, urea (NH₂)₂CO, sodium dihydrogen phosphate dihydrate (NaH₂PO₄.2H₂O), NaOH, NaCl, KCl, CaCl₂.2H₂O, and Na₂S.9H₂O were purchased from BDH and Scharlau. Benzoyl peroxide (C₁₄H₁₀O₄), Methyl-methacrylate-MMA (C₅H₈O₂) and polymethyl-methacrylate-PMMA (C₅H₈O₂)_n were purchased from Scharlau. All the stock solutions were filtered through a micropore membrane to remove the insoluble impurities.