Diverting Electron Fluxes to Hydrogen in Mixed Anaerobic Communities Fed with Glucose and Unsaturated C18 Long Chain Fatty Acids

Statistical optimization of factors affecting biohydrogen production from xylose fermentation using inhibited mixed anaerobic cultures

“…Many reports have provided evidence showing the influence of glucose, pH and temperature on H 2 yields [14,18,19,23,29]. However, only very few studies have reported evidence using xylose as substrate with mixed anaerobic cultures [7,8,10,11,37].…”

“…According to these researchers, different organisms were likely involved in the degradation of hexose and pentose sugars. Evidence describing the effects of OA has been reported to affect H 2 consumers during glucose degradation [18]; however, its effect on xylose fermentation has not been reported.…”

“…Hydrogen consuming organisms such as hydrogenotrophic methanogens and acetate degraders such as aceticlastic methanogens are affected by threshold LCFA levels [19,22,23]. In particular, oleic acid (OA), an LCFA bearing 18 carbons and one carbonecarbon double bond, has been reported to inhibit H 2 consuming organisms during glucose fermentation [18,24]. LCFAs such as linoleic acid (LA) have been shown to also impair the performance of H 2 consumers during glucose degradation [19].…”

Assessing the impact of palmitic, myristic and lauric acids on hydrogen production from glucose fermentation by mixed anaerobic granular cultures

“…The ability of long to medium chain LCFAs to direct the flow of electrons towards H 2 production instead of methane during glucose fermentation is unknown and additional work is required to demonstrate their effects on uncoupling syntrophic interactions. Many studies have shown that LA can retain its inhibitory characteristics on a variety of anaerobic microbial populations [4,6,7]. However, the impact of LA degradation by-products (PA, MA and LUA) on H 2 producing and H 2 consuming microbial populations have not been reported.…”

Using a Statistical Model to Examine the Effect of COD: SO42− Ratio, HRT and LA Concentration on Sulfate Reduction in an Anaerobic Sequencing Batch Reactor

“…Evidence by Erdirencelebi et al [10] also support the argument that at higher COD/SO4 2− ratios, SRBs are unable to compete with MPBs for electrons derived from substrate oxidation. by Zhou et al [39]. These authors reported decreasing SO4 2− removal efficiencies from 89% to 82% as the HRT was decreased from 24 h to 12 h at a constant COD/SO4 2− ratio of 4.…”