초록
<P><B>Abstract</B></P> <P>Hydrogen is a carbon-neutral energy feedstock which is produced during fermentation of various carbon sources. The genomes of clostridia encode mainly [Fe-Fe]-hydrogenases. <I>Clostridium beijerinckii</I> DSM791 performed anaerobic fermentation of glycerol in batch culture at pH 7.5 and pH 5.5 and produced H<SUB>2</SUB>. At pH 7.5, the glycerol consumption rate was 3.7 g/g cell mass/h, which was higher than that at pH 5.5. H<SUB>2</SUB> production reached 5 mmol/h/g cell mass at pH 7.5. The specific hydrogenase activity was ∼1.4 fold higher if cells were grown on glycerol compared to cells grown on glucose. Single (Fe<SUP>2+</SUP>, Fe<SUP>3+</SUP>, Ni<SUP>2+</SUP>) or mixed supply of metals (Fe<SUP>2+</SUP> and Ni<SUP>2+</SUP>) increased the specific hydrogenase activity by ∼50%. These results suggest that <I>C. beijerinckii</I> DSM791 could be used as a potential H<SUB>2</SUB> producer. It may help to further enhance H<SUB>2</SUB> production using different industrial or agricultural wastes where glycerol and other carbon sources are present.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Clostridium beijerinckii</I> DSM791 converted glycerol to H<SUB>2</SUB> at pH 7.5 and pH 5.5. </LI> <LI> At pH 7.5, the glycerol consumption rate was 3.7 g/g cell matter/h and it was higher than at pH 5.5. </LI> <LI> H<SUB>2</SUB> production reached 5 mmol/h/g cell mass at pH 7.5. </LI> <LI> Hyd activity was ∼1.4 fold higher if cells were grown on glycerol compared to cells grown on glucose. </LI> <LI> Fe<SUP>2+</SUP>, Fe<SUP>3+</SUP>, Ni<SUP>2+</SUP> or mixed supply of metals (Fe<SUP>2+</SUP> and Ni<SUP>2+</SUP>) increased the Hyd activity by ∼50%. </LI> </UL> </P>