Knowing the enemy: homoacetogens in hydrogen production reactors.

One of the bottlenecks of the hydrogen production by dark fermentation is the low yields obtained because of the homoacetogenesis persistence, a metabolic pathway where H and CO are consumed to produce acetate. The central reactions of H production and homoacetogenesis are catalyzed by enzyme hydrogenase and the formyltetrahydrofolate synthetase, respectively. In this work, genes encoding for the formyltetrahydrofolate synthetase (fthfs) and hydrogenase (hydA) were used to investigate the diversity of homoacetogens as well as their phylogenetic relationships through quantitative PCR (qPCR) and next-generation amplicon sequencing.