초록
<P><B>Abstract</B></P> <P>Photofermentation seems to be an attractive mode of generating biohydrogen from fermentation effluent. Use of succinate fermentation effluent, however, has not been reported. <I>Rhodobacter sphaeroides</I> KKU-PS1 and <I>Rhodopseudomonas palustris</I> were acclimatised in succinate. It was determined that the KKU-PS1 was superior with respect to hydrogen productivity and was selected for further experiments. Photofermentation in succinate by the KKU-PS1 validated, generating 1217 mL H<SUB>2</SUB>/L of cumulative hydrogen at a maximum rate of 6.7 mL H<SUB>2</SUB>/L/h. Photofermentation from each single carbon sources that are components of effluent was performed and it was determined that acetate and succinate promoted the fastest growth of KKU-PS1 and hydrogen evolution, respectively. Photofermentation by the strain using mixed substrates mimicking diluted bio-succinate effluent produced yielded 1005 mL H<SUB>2</SUB>/L cumulative hydrogen at a maximum rate of 4.1 mL H<SUB>2</SUB>/L/h. The study highlighted potential of utilizing bio-succinate fermentation effluent for biohydrogen production, with further optimization required.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>R. sphaeroides</I> KKU-PS1 yielded 0.9–1.2 L H<SUB>2</SUB>/L, more than 2-fold H<SUB>2</SUB> by <I>R. palustris</I>. </LI> <LI> KKU-PS1 biomass peaked at around 1 g/L, indicating better growth than <I>R. palustris</I>. </LI> <LI> KKU-PS1 yielded 1.2 L H<SUB>2</SUB>/L from succinate, which was comparable to malate. </LI> <LI> KKU-PS1 generated 1.0 L H<SUB>2</SUB>/L from mixed substrates based on bio-succinate effluent. </LI> <LI> Sugar metabolism sustained H<SUB>2</SUB> production by KKU-PS1 during stationary growth phase. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>