초록
<P><B>Abstract</B></P> <P>Hydrogen (H<SUB>2</SUB>) gas production in batch cultures was studied upon utilization of the mixture of glucose, glycerol and formic acid by <I>Escherichia coli</I> BW25113 wild type (wt) at pH of 5.5–7.5. At pH 7.5H<SUB>2</SUB> was continuously produced during 240 h but at pH 6.5 and 5.5 it was detected till 168 h and 120 h, respectively. Specific growth rate (μ) of wt was the highest (1.05 h<SUP>−1</SUP>) at pH 6.5. Moreover, at pH 5.5 in <I>hycE</I> μ decreased by ∼4.14 fold compared to wt, suggesting major role of Hyd-3 in cell growth. H<SUB>2</SUB> yield (8.8 mmol H<SUB>2</SUB> L<SUP>−1</SUP>) was the highest at pH 7.5. In <I>hybC</I> H<SUB>2</SUB> yield was increased ∼1.62 fold than in wt. These data might be applied for biomass and biohydrogen production from various organic wastes where mixtures of carbon sources are present.</P> <P><B>Highlights</B></P> <P> <UL> <LI> At pH 7.5 <I>E. coli</I> produced H<SUB>2</SUB> continuously during 240 h. </LI> <LI> During growth on mixed carbon sources μ of wild type was the highest at pH 6.5 </LI> <LI> In <I>hybC</I> mutant H<SUB>2</SUB> yield was increased by 1.6 fold, compared to wild type. </LI> <LI> In <I>hycE</I> at pH 7.5 the pH decrease was more by 0.6 units compared to wild type. </LI> </UL> </P>