Effectiveness of Hydrogen Production by Bacteroides vulgatus in Psychrophilic Fermentation of Cattle Slurry

H-2 is a low-impact energy carrier, which the EU hydrogen strategy has positioned as a major component of energy policy. Dark fermentation by psychrophilic bacteria is a promising avenue of H-2 production, though one that requires further study. The aim of this study was to determine the H-2 production performance of a Bacteroides vulgatus strain during fermentation of psychrophilic cattle slurry. The test strain was isolated from an inland water body at a depth of 40 +/- 5 m. The experimental fermentation process was run at 15 +/- 1 degrees C and yielded 265.5 +/- 31.2 cm(3) biogas/g COD removed, including 46.9 +/- 2.6 cm(3) H-2/g COD removed. CO2 was the main constituent of the resultant biogas, at 79.8 +/- 1.9%. The gas also contained 17.6 +/- 1.4% H-2 and 2.3 +/- 0.2% CH4. Organic matter removal and nutrient take-up from the feedstock were low. Our findings show that practical applicability of this process is hampered by multiple operational hurdles and its relatively poor performance.

Automated summary

This study investigates the H-2 production performance of a Bacteroides vulgatus strain during fermentation of psychrophilic cattle slurry, revealing multiple operational hurdles and relatively poor performance.