Optimization Study on Co-Fermentative Bio-Hydrogen Production by Enterobacter aerogenes and HAU-M1 from Corn Stover

Co-fermentative bio-hydrogen production by different hydrogen-producing bacteria is a promising way to improve substrate utilization and hydrogen production efficiency. In this study, corn stover was taken as substrate, Enterobacter aerogenes and HAU-M1 were selected as hydrogen-producing bacteria, cumulative hydrogen yield was taken as the main reference, and the single factor experiments and response surface methodology (RSM) with Box-Behnken design (BBD) were carried out to optimize the process conditions for co-fermentative hydrogen production. The results indicated initial pH and temperature were the extremely significant factors affecting co-fermentative hydrogen production. The optimal conditions with initial pH of 6.77, light intensity of 3548.28 Lux and temperature of 28.58 degrees C for co-fermentative hydrogen production by Enterobacter aerogenes and HAU-M1 were obtained. The predicted maximum cumulative hydrogen yield was 51.82 mL . (g TS)(-1) under the optimal conditions. Reliability of the obtained BBD model was verified by validation experiments, and the similar result of 50.18 mL . (g TS)(-1) was obtained. This study laid the foundation and provided references for the further research on co-fermentative hydrogen production.