Buffering action of acetate on hydrogen production by Ethanoligenens harbinense B49|
Xu, Ji-Fei; Mi, Yuan-Ting & Ren, Nan-Qi
The buffering effect of acetate on hydrogen production during glucose fermentation by Ethanoligenens harbinense
B49 was investigated compared to phosphate, a widely used fermentative hydrogen production buffer. Specific
concentrations of sodium acetate or phosphate were added to batch cultures, and the effects on hydrogen
production were comparatively analyzed using a modified Gompertz model. Adding 50 mM acetate or
phosphate suppressed the hydrogen production peak and slightly extended the lag phase. However, the
overall hydrogen yields were 113.5 and 108.5 mmol/L, respectively, and the final pH was effectively controlled.
Acetate buffered against hydrogen production more effectively than did phosphate, promoting cell growth and
preventing decreased pH. At buffer concentrations 100–250 mM, the maximum hydrogen production was
barely suppressed, and the lag phase extended past 7 h. Therefore, although acetate inhibits hydrogen
production, using acetate as a buffer (like phosphate) effectively prevented pH drops and increased substrate
consumption, enhancing hydrogen production.
Acetate; Biohydrogen; Buffering action; Ethanoligenens harbinense phosphate