초록
<P><B>Abstract</B></P> <P> <I>Rhodobacter capsulatus</I> is a photosynthetic bacterium with the ability to produce H<SUB>2</SUB> under photosynthetic condition. In this study, a new strain JL1 isolated from lake water was identified as <I>Rhodobacter capsulatus</I> by phylogenetic analysis of 16S ribosomal DNA (rDNA) sequence. Initial medium pH and <SMALL>L</SMALL>-glutamate (nitrogen source) concentration were optimized. At optimum pH 7.0 and 7 mmol/L <SMALL>L</SMALL>-glutamate, <I>R. capsulatus</I> JL1 could grow and produce hydrogen on the carbon sources of acetate, butyrate, glucose, xylose and fructose with the maximum substrate to H<SUB>2</SUB> conversion efficiencies of 67.5%, 26.6%, 46.1%, 46.2% and 46.6%, respectively. The maximum H<SUB>2</SUB> production rate, 124 ± 0.6 mL/(L·h), was obtained using 20 mmol-glucose/L as the carbon source. The addition of appropriate acetic acid to the tests with low concentration of glucose was able to improve the H<SUB>2</SUB> yield. Under the optimum operation parameters, the maximum H<SUB>2</SUB> yield and H<SUB>2</SUB> production rate of <I>R. capsulatus</I> JL1 from 16.4 g-corn straw/L-culture were 2966.5 ± 43.2 mL/L and 71.1 ± 4.5 mL/(L·h), while the chemical oxygen demand (COD) removal rate was up to 49.6%. This study indicates that <I>R. capsulatus</I> JL1 can serve as good candidate strain for H<SUB>2</SUB> production with organic waste water as well as effluent of dark-fermentation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new Photosynthetic bacteria was identified to be <I>Rhodobacter capsulatus</I> JL1. </LI> <LI> It showed lower pigment content compared with <I>R. capsulatus</I> SB1003. </LI> <LI> Mixture of acetate and glucose enhanced its hydrogen production performance. </LI> <LI> It showed high hydrogen production performance with corn straw hydrolysate. </LI> </UL> </P>