Bio-hydrogen Production from Volatile Fatty Acids by Rhodobactersphaeroides RV in Continuous Non-axenic Culture with Blue Light

摘要

Hydrogen can be produced from volatile fatty acids (VFAs) by the anaerobicphotosynthetic bacteria (purple nonsulfur bacteria). Most of previous study was focused onaxenic culture. It is important to evaluate the characteristics of hydrogen production incontinuous non-axenic culture because the effect of contamination is essential for a practicaluse. In this study, photoproduction of hydrogen from VFAs was investigated in a continuousnon-axenic culture by using Rhodobacter sphaeroides RV as the seed. The artificial substratewas composed of three kinds of VFAs, acetate, propionate and butyrate. The composition ofcarbon sources was investigated three cases imitated to the effluent from anaerobic hydrogenfermentation. The irradiation of blue light was selected to cut the effective irradiation foralgae growth and photosynthesis. As the result, algae and sulfate reducing bacteria, thesespecies inhibit hydrogen production and growth by purple nonsulfur bacteria, could not growin photo bioreactor and the 16S rDNA band of Rb. Sphaeroides RV was detected throughoutthe experiment. It was shown that the irradiation of blue light was suitable for continuoushydrogen production by purple nonsulfur bacteria. In case that the composition of substratewas mainly acetic acid, the substrate conversion efficiency was the highest of threecompositions of carbon sources. And in case that the composition of substrate was mainlybutyric acid, the removal of COD was the lowest. The result was shown that it was necessaryfor hydrogen production by purple nonsulfur bacteria that carbon sources were composed ofmainly acetic acid.