Growing interest in hydrogen as an energy carrier of the future
is in contrast to the fact that at present, most of hydrogen produced
worldwide comes from thermo-chemical conversion of fossil fuels
(Wukovits et al., 2012). As a result of numerous studies on alternative
production systems, it is now widely recognized that similar
to bioethanol or biomethane, hydrogen can be sustainably produced
by biological conversion of carbohydrate-containing biomass
(Azbar and Levin, 2012). Among promising methods of biomass
conversion to hydrogen, two-stage bacterial fermentation, that is,
dark fermentation followed by photofermentation has attracted
much attention (Claassen et al., 2009).