BioChem - DOS

Sodium (Na+) concentration effects on metabolic pathway and estimation of ATP use in dark fermentation hydrogen production through stoichiometric analysis

Journal of environmental management

Lee, M.J.; Kim, T.H.; Min, B.; Hwang, S.J.

Batch experiments were conducted to investigate the effects of Na<SUP>+</SUP> concentration on hydrogen production with dark fermentation. The Na<SUP>+</SUP> concentration was varied from 0 to 8 g/L in the mixed culture using an anaerobic sludge treated by acid. The maximum hydrogen production was achieved with 1 g-Na<SUP>+</SUP>/L, whereas the hydrogen production was decreased over 2 g-Na<SUP>+</SUP>/L due to the inhibitory of Na<SUP>+</SUP>. The mechanisms of Na<SUP>+</SUP> inhibition to the hydrogen production are studied using pure culture of Clostridium butyricum by calculating the energy balance. At a high sodium concentration, C. butyricum used a greater proportion of the ATP generated via fermentation for cell maintenance rather than for cell synthesis. Additionally, higher Na<SUP>+</SUP> concentrations shifted the fermentation process toward the acetate synthesis pathway instead of the butyrate pathway, and the value of Y<SUB>X/ATP</SUB> decreased. With high Na<SUP>+</SUP> concentrations, a greater ratio of hydrogen was produced via the oxidation of NADH. Excess hydrogen production decreased as the Na<SUP>+</SUP> concentration increased.

2012

Academic Press

0301-4797

1095-8630

108

pp.22-26

10.1016/j.jenvman.2012.04.027

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART63447079

Biohydrogen; Sodium inhibition; Metabolic pathway; ATP; Dark fermentation