Influence of sulfate-reducing bacteria on outdoor hydrogen production by photosynthetic bacterium with seawater.
The application of seawater for bacterial fermentative production is a cost-effective technology. Hydrogen production by marine photosynthetic bacterium with seawater failed to continue after more than 10 days, and was accompanied by the formation of hydrogen sulfide and a change in culture color from red to black. However, substrate consumption in the blackish culture was comparable to that in a hydrogen-producing culture. A decrease in hydrogen production occurred upon the addition of sodium sulfide at concentrations of 1.5 mM or higher. PCR analysis targeted at the 16S rDNA sequence selective for sulfate-reducing bacteria revealed the existence of sulfate-reducing bacteria in inoculation cultures of the phototrophic bacterium and medium for hydrogen production. Hence, the high sulfate concentration of seawater, the low oxidation-reduction potential under hydrogen-producing conditions, and the presence of electron donors such as acetate might promote the metabolic activities of sulfate-reducing bacteria, resulting in the deterioration of hydrogen production with seawater.
Maeda
I
I
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
Mizoguchi
T
T
Miura
Y
Y
Yagi
K
K
Shioji
N
N
Miyasaka
H
H
D019149:Bioreactors; D004275:DNA, Ribosomal / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D006859:Hydrogen / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016992:Rhodobacter / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism / Q000494:pharmacology; D016999:Sulfur-Reducing Bacteria / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D014871:Water Microbiology
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D013440:Sulfides; D006859:Hydrogen; C033479:sodium sulfide