Control strategies for hydrogen production through co-culture of Ethanoligenens harbinense B49 and immobilized Rhodopseudomonas faecalis RLD-53

This study evaluated hydrogen production by co-culture of Ethanoligenens harbinense B49 and immobilized Rhodopseudomonas faecalis RLD-53 with different control strategies. To enhance cooperation of dark and photo-fermentation bacteria during hydrogen production process, the glucose concentration, phosphate buffer concentration and initial pH were controlled at 6 g/l, 50 mmol/l and 7.5, respectively. The maximum yield and rate of hydrogen production were 3.10 mol H2/mol glucose and 17.2 mmol H2/l/h, respectively. Ethanol from E. harbinense B49 in acetate medium can enhance hydrogen production by R. faecalis RLD-53 except the ratio of ethanol to acetate (RE/A) among 0.8 to 1.0. Control of the proper phosphate buffer concentration (50 mmol/l) not only increased acetic acid production by E. harbinense B49, but also maintained stable pH of co-culture system. Therefore, the results showed that co-culture of E. harbinense B49 and immobilized R. faecalis RLD-53 was a promising way of converting glucose into hydrogen.