초록
<P><B>Abstract</B></P> <P>Growth properties, oxidation-reduction potential kinetics and hydrogen production of <I>Escherichia coli</I> BW25113 parental strain (PS) and hydrogenase (Hyd)-negative mutants were investigated after fermentative growth using office paper waste and cardboard (PW) hydrolysate (PWH). PWH was obtained by using dilute acid method in a steam sterilizer for 1 h, 121 °C. Optimal conditions for bacterial growth and H<SUB>2</SUB> production were identified (PWH concentrations, pH 7.5). Recording of redox potential using a platinum electrode revealed a drop to −500 ± 10 mV, with a H<SUB>2</SUB> yield of ~1.45 mmol H<SUB>2</SUB> L<SUP>−1</SUP> after 4 h of growth using PWH resulted in the formation of 0.20 ± 0.02 g bacterial cell dry weight L<SUP>−1</SUP>. Bacterial biomass formation was stimulated ~3-fold upon addition of 0.5% yeast extract, and H<SUB>2</SUB> production started early - at the beginning of the exponential phase. Moreover, mutants lacking Hyd-1 and Hyd-2 significantly enhanced H<SUB>2</SUB> production. The findings would be beneficial for the development of H<SUB>2</SUB> production biotechnology using cheap solid waste materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Office waste paper and cardboard hydrolisate (PWH) was upcycled for biomass and biohydrogen. </LI> <LI> Dilute acid method in a steam sterilizer, pH adjustment to 7.5 were used for pretreatment. </LI> <LI> <I>E. coli</I> wild type yielded H<SUB>2</SUB> of ~240 mL H<SUB>2</SUB> (g sugar)<SUP>−1</SUP> at the 4<SUP>th</SUP> h of growth. </LI> <LI> H<SUB>2</SUB> production was observed earlier upon 0.5% yeast extract added. </LI> <LI> Mutations of hydrogenases Hyd-1 and Hyd-2 enhanced H<SUB>2</SUB> production. </LI> </UL> </P>