AUTHOR=Böer Tim , Schüler Miriam Antonia , Lüschen Alina , Eysell Lena , Dröge Jannina , Heinemann Melanie , Engelhardt Lisa , Basen Mirko , Daniel Rolf , Poehlein Anja 

TITLE=Isolation and characterization of novel acetogenic strains of the genera Terrisporobacter and Acetoanaerobium

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1426882

DOI=10.3389/fmicb.2024.1426882

ISSN=1664-302X

ABSTRACT=<p>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 <italic>Terrisporobacter</italic> and <italic>Acetoanaerobium</italic> remained poorly investigated for biotechnological applications. We report the isolation and characterization of four acetogenic <italic>Terrisporobacter</italic> strains and one <italic>Acetoanaerobium</italic> strain. All <italic>Terrisporobacter</italic> isolates showed a characteristic growth pattern under a H<sub>2</sub> + CO<sub>2</sub> atmosphere. An initial heterotrophic growth phase was followed by a stationary growth phase, where continuous acetate production was indicative of H<sub>2</sub>-dependent acetogenesis. One of the novel <italic>Terrisporobacter</italic> isolates obtained from compost (strain COM<sup>T</sup>) additionally produced ethanol besides acetate in the stationary growth phase in H<sub>2</sub>-supplemented cultures. Genomic and physiological characterizations showed that strain COM<sup>T</sup> represented a novel <italic>Terrisporobacter</italic> species and the name <italic>Terrisporobacter vanillatitrophus</italic> is proposed (=DSM 116160<sup>T</sup> = CCOS 2104<sup>T</sup>). Phylogenomic analysis of the novel isolates and reference strains implied the reclassification of the <italic>T. petrolearius</italic>/<italic>T. hibernicus</italic> phylogenomic cluster to the species <italic>T. petrolearius</italic> and of the <italic>A. noterae/A. sticklandii</italic> phylogenomic cluster to the species <italic>A. sticklandii</italic>. Furthermore, we provide first insights into active prophages of acetogens from the genera <italic>Terrisporobacter</italic> and <italic>Acetoanaerobium</italic>.</p>