Effect of arabinose concentration on dark fermentation hydrogen production using different mixed cultures

摘要

Dark fermentation hydrogen production from arabinose at concentrations rangingbetween 0 and 100 g/L was examined in batch assays for three different mixed anaerobiccultures, two suspended sludges (S1, S2) obtained from two different sludge digestersand one granular sludge (G) obtained from a brewery wastewater treatment plant. Afterelimination of the methanogenic activity by heat treatment, all mixed cultures producedhydrogen, and optimal hydrogen rates and yields were generally observed for concentrationsbetween 10 and 40 g/L of substrate. Higher concentrations of arabinose up to 100 g/Linhibited hydrogen production, although the effect was different from inoculum to inoculum.It was evident that the granular biomass was less affected by increased initial arabinoseconcentrations when calculating the rate of decrease in hydrogen yields versusarabinose concentrations, compared against the two suspended sludges.The largest amount of soluble microbial product produced for all three inocula was forn-butyrate. Also, valeric acid production was observed in some samples.