Microbial ecological engineering for biohydrogen production

A large number of microbial species, originating from a variety of environments, are capable of producing biohydrogen through fermentation. The potential of mixed microbial cultures is particularly interesting given their broad metabolic flexibility, which makes it possible to consider using complex organic resources derived from biomass processing. However, the microbial diversity of mixed cultures is also a source of process instability due to the expression of multiple bacterial metabolic pathways, which can lead, in particular, to the re-consumption of the bioH₂ produced. To date, few control strategies – and these are mainly physico-chemical in nature – are available to ensure the optimisation of continuous biohydrogen production processes. The research carried out has enabled the identification and subsequent use of key species at the heart of metabolic networks as biological controllers of microbial ecosystems, thereby improving the stability and conversion yields of biohydrogen.