Statistical optimization of fermentative hydrogen production from xylose by newly isolated Enterobacter sp. CN1

Statistical experimental designs were applied for the optimization of medium constituents for hydrogen production from xylose by newly isolated Enterobacter sp. CN1. Using Plackett–Burman design, xylose, FeSO₄ and peptone were identified as significant variables which highly influenced hydrogen production. The path of steepest ascent was undertaken to approach the optimal region of the three significant factors. These variables were subsequently optimized using Box–Behnken design of response surface methodology (RSM). The optimum conditions were found to be xylose 16.15 g/L, FeSO₄ 250.17 mg/L, peptone 2.54 g/L. Hydrogen production at these optimum conditions was 1149.9 ± 65 ml H₂/L medium. Under different carbon sources condition, the cumulative hydrogen volume were 1217 ml H₂/L xylose medium, 1102 ml H₂/L glucose medium and 977 ml H₂/L sucrose medium; the maximum hydrogen yield were 2.0 ± 0.05 mol H₂/mol xylose, 0.64 mol H₂/mol glucose. Fermentative hydrogen production from xylose by Enterobacter sp. CN1 was superior to glucose and sucrose.