The effect of butyrate concentration on photo-hydrogen production from acetate by Rhodopseudomonas faecalis RLD-53

Abstract

The effect of butyrate addition on H 2 production from acetate by purple non-sulphur photosynthetic bacteria Rhodopseudomonas faecalis RLD-53 was studied in this work. Experimental results showed that butyrate was not used as carbon source for H 2 production, but different concentration (12.5–100 mmol/l) of butyrate added in acetate medium has obviously affected H 2 yield and maximum H 2 production rate. H 2 yield and maximum H 2 production rate increased with the increasing of butyrate concentration when butyrate concentrations at 12.5–25 mmol/l and then gradually decreased when the butyrate concentration by further increase to 100 mmol/l; this indicated that the increase of butyrate would lead to the inhibition of H 2 production. H 2 yield (3.43 mol-H 2/mol-acetate) and maximum H 2 production rate (32.54 ml/l/h) were the highest when acetate was at 25 mmol/l and butyrate at 25 mmol/l. These are higher than most reported values in the literature.