Inoculum of C. curvatus (ATCC 20509) was grown in a liq- uid medium containing 2% peptone, 1% yeast extract, and 2% of glucose at room temperature on a rotary shaker set at 150 rpm. A minimal medium that was used in this study contained (per liter): 2.7 g KH2 PO4 ; 0.95 g Na2 HPO4 ; 0.2 g MgSO4 ·7H2 O; 0.1 g yeast extract; and 0.1 g EDTA. After the pH was adjusted to 5.5 by adding concentrated HCl, the medium was supplemented with a 100× spores stock solution consisting of (per liter): 4 g CaCl2 ·2H2 O; 0.55 g FeSO4 ·7H2 O; 0.52 g citric acid; 0.10 g ZnSO4·7H2 O; 0.076 g MnSO4 ·H2 O; and 100 18 M H2 SO4 [25]. The medium was autoclaved at 121◦ C for 30 min before use. All chemicals for making medium and those used in the following procedures were purchased from either Fisher Scientific (Pittsburgh, PA, USA) or Sigma Aldrich (St. Louis, MO, USA) with the highest grade possible.