Fig. 3

Optimized solvents production of Clostridium beijerinckii strain BGS1 in reduced mineral salts medium containing a 60 g/L glucose with 3 g/L yeast extract, 5 g/L CaCO₃, 8 mg/L Zn²⁺ and 2 mg/L Fe²⁺, b 60 g/L sucrose with 3 g/L yeast extract, 1 g/L CaCO₃, 3 g/L sodium butyrate, and 6 mg/L Fe²⁺