초록
<P>This study aimed to investigate the characteristics of hydrogen production by mixed cultures using <I>Laminaria japonica</I> hydrolysates. The hydrolysates of <I>L. japonica</I> were prepared by pretreatment methods, including heat (100°C or 121°C) and acid (HCl or H<SUB>2</SUB>SO<SUB>4</SUB>) pretreatments. The mixed cultures could produce hydrogen using <I>L. japonica</I> as a substrate, with the highest cumulative hydrogen production of 825 ± 14 mL/L from HCl-pretreated <I>L. japonica</I>. High-throughput sequencing of the 16S rRNA gene revealed that the microbial community in the hydrolysate of HCl-pretreated <I>L. japonica</I> was the most diverse among all the samples, with a Shannon diversity index of 5.253. The mixed culture from HCl-pretreated <I>L. japonica</I> and those from heat-pretreated (100°C and 121°C) <I>L. japonica</I> occupied different regions in a principal component analysis (PCA) plot. The dominant population in the hydrolysate of HCl-pretreated <I>L. japonica</I> was represented by hydrogen-producing bacteria, <I>Clostridium</I> spp. and <I>Bacillus</I> spp. The results suggested that <I>L. japonica</I> was an optimal feedstock for hydrogen production. The acid (HCl) pretreatment method could effectively enhance the hydrogen production from <I>L. japonica.</I> </P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Laminaria japonica</I> was an optimal feedstock for hydrogen production. </LI> <LI> The highest hydrogen production was 825 ± 14 mL/L from HCl-pretreated <I>L. japonica.</I> </LI> <LI> High hydrogen production was attributed to the diversity of the microbial community. </LI> <LI> <I>Clostridium</I> spp. were the dominant bacteria in the hydrolysate of HCl-pretreated <I>L. japonica.</I> </LI> </UL> </P>