This study was devoted for H2 production from rotten fruits of date palm (Phoenix dactylifera
L.) by three fermentation stages. A facultative anaerobe, Escherichia coli EGY was used in
first stage to consume O2 and maintain strict anaerobic conditions for a second stage dark
fermentative H2 production by the strictly anaerobic Clostridium acetobutylicum ATCC 824.
Subsequently, a third stage photofermentation using Rhodobacter capsulatus DSM 1710 has
been conducted for the H2 production. The maximum total H2 yield of the three stages
(7.8 mol H2 mol
1 sucrose) was obtained when 5 g L
1 of sucrose was supplemented to
fermentor as rotten date fruits. A maximum estimated cumulative H2 yield of the three
stages (162 LH2 kg
1 fresh rotten dates) was estimated at the (5 g L
1) sucrose concentration.
These results suggest that rotten dates can be efficiently used for commercial H2
production. The described protocol did not require addition of a reducing agent or flashing
with argon which both are expensive.