초록
<P><B>Abstract</B></P> <P>Photocatalytic hydrogen production using an inorganic bio-hybrid system can contribute to the proficient utilization of light energy, but it would necessitate the development of novel approaches for preparing a new hydrogen-producing biocatalyst. In this study, we developed a hybrid system to produce hydrogen, whereby the highly efficient light-harvesting inorganic semiconductor (TiO<SUB>2</SUB>) was mixed with <I>Escherichia coli</I> to form a biocatalyst with the addition of an electron mediator (MV<SUP>2+</SUP>) under different visible light irradiation. Under this hybrid system, the hydrogen production by <I>E. coli</I> was light intensity-dependent showing maximum production at 2000 W m<SUP>−2</SUP>, with a 2-fold increase in the hydrogen production compared to that without TiO<SUB>2</SUB>. The experiments on the continued cycle of hydrogen production revealed that the production could be continued for at least 3 cycles of 5 h incubation for each. A possible pathway utilizing glucose for hydrogen production by the hybrid system was proposed based on the analysis of the levels of metabolites. A feasibility study was also conducted using natural sunlight for hydrogen production by the hybrid system. Overall results demonstrated that whole cells of <I>E. coli</I> could be employed for photocatalytic hydrogen production where the intactness of the <I>E. coli</I> was retained under experimental conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Photogenerated electron from the NPs has ability to interact with bacterial cell. </LI> <LI> The combination of photocatalyst and biocatalyst enhances hydrogen production. </LI> <LI> TiO<SUB>2</SUB>/MV<SUP>2+</SUP>/<I>E. coli</I> hybrid system produces more hydrogen compared with control. </LI> <LI> Use of natural sunlight is feasible for photocatalytic biohydrogen production. </LI> </UL> </P>