Isolation and characterization of novel acetogenic strains of the genera and .

Due to their metabolic versatility in substrate utilization, acetogenic bacteria represent industrially significant production platforms for biotechnological applications such as syngas fermentation, microbial electrosynthesis or transformation of one-carbon substrates. However, acetogenic strains from the genera and remained poorly investigated for biotechnological applications. We report the isolation and characterization of four acetogenic strains and one strain. All isolates showed a characteristic growth pattern under a H + CO atmosphere. An initial heterotrophic growth phase was followed by a stationary growth phase, where continuous acetate production was indicative of H-dependent acetogenesis. One of the novel isolates obtained from compost (strain COM) additionally produced ethanol besides acetate in the stationary growth phase in H-supplemented cultures. Genomic and physiological characterizations showed that strain COM represented a novel species and the name is proposed (=DSM 116160 = CCOS 2104). Phylogenomic analysis of the novel isolates and reference strains implied the reclassification of the / phylogenomic cluster to the species and of the phylogenomic cluster to the species . Furthermore, we provide first insights into active prophages of acetogens from the genera and .