초록
<P><B>Abstract</B></P> <P>Brewery spent grains (BSG), one of the by-products of brewery production, were used for <I>Escherichia coli</I> growth and hydrogen (H<SUB>2</SUB>) production. The dilute acid and alkali pretreatment methods were used to hydrolyze the rough lignocellulose structure, and optimal conditions for the BSG hydrolysate (BSGH) preparation were developed. <I>E. coli</I> BW25113 wild type strain and hydrogenase (Hyd)-negative mutants with deletions of genes encoding key subunits of Hyd 1–4 (Δ<I>hyaB,</I> Δ<I>hybC,</I> Δ<I>hycE,</I> Δ<I>hyfG</I>), as well as for a Δ<I>hyaB</I> Δ<I>hybC</I> double mutant were investigated with regards to growth, acidification of the medium, redox potential kinetics and H<SUB>2</SUB> production when using BSGH. Readings of redox Pt electrode dropped to −400 ± 10 mV, with H<SUB>2</SUB> yield of ∼0.75 mmol H<SUB>2</SUB> L<SUP>−1</SUP> at the 3rd h wild type strain growth. Changes in redox Ti-Si electrode readings were negligible. H<SUB>2</SUB> production was not observed with defective Hyd-3 and Hyd-4; therefore, Hyd-3 and Hyd-4 are responsible for H<SUB>2</SUB> production using BSGH, whereas defective Hyd-1 and Hyd-2 led to a ∼2-fold stimulation of H<SUB>2</SUB> yield. The data were confirmed by determining cumulative H<SUB>2</SUB> yield. These findings are useful for development of renewable energy, especially H<SUB>2</SUB> production biotechnology, using different organic wastes as sustainable energy feedstocks.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Brewery spent grains (BSG) dilute acid pretreatment was developed. </LI> <LI> Optimization of conditions for <I>E. coli</I> growth on BSG hydrolysate and H<SUB>2</SUB> production was improved. </LI> <LI> Hydrogenase (Hyd)-3 and Hyd-4 are responsible for H<SUB>2</SUB> production. </LI> <LI> Mutations in the genes for Hyd-1 and Hyd-2 led to enhanced H<SUB>2</SUB> production; cumulative H<SUB>2</SUB> yield was determined. </LI> </UL> </P>