Growth and hydrogen production by Escherichia coli during utilization of sole and mixture of sugar beet, alcohol, and beer production waste

Escherichia coli anaerobically utilize various carbon sources and produce hydrogen (H-2) as fermentation end product. Twofold diluted mixture of 10% distiller's grains (DG), 4% brewer's spent grains (BSG), and 10% sugar beet molasses (SB) are favorable for enhanced H-2 production compared to the single wastes. In wild type cells, H-2 production was prolonged till similar to 120 h compared to single waste while in multiple mutant H-2 production was determined till similar to 192 h. Specific growth rate was highest in wild type cells in single but not mixed carbon sources reaching to 0.723 h(-1) with 20-fold dilution of SB utilization. Cumulative H-2 production was similar to 2.7-fold higher in multiple mutant when twofold diluted mixed waste of SB, BSG, and DG was applied compared to wild type reaching to 215 mL. The obtained data can be applied in utilization of agro-industrial waste for production of biomass and bio-H-2.

Automated summary

Escherichia coli can anaerobically utilize various carbon sources for hydrogen production. Mixed carbon sources can enhance H-2 production compared to single waste. The H-2 production and growth rate differ between wild type cells and multiple mutants in mixed waste conditions.