Denitraticella aggregata gen. nov., sp. nov. a denitrifying benzoate-utilizing bacterium isolated from a terrestrial...

Microorganisms play a pivotal role in denitrification and in the degradation of aromatic compounds, processes essential for nitrogen and carbon recycling in diverse ecosystems. Mud volcanoes, with their fluctuating redox conditions and hydrocarbon emissions, represent potential natural sources of such microorganisms. A novel facultatively anaerobic, facultatively lithoautotrophic bacterium (strain SMB388^T) was isolated from terrestrial mud volcano (Krasnodar Krai, Russia). Cells of the strain were straight motile rods. Growth was observed at temperatures up to 42 °C (optimum at 30 °C), pH 6.0-10.0 (optimum at pH 8.0) and NaCl concentrations of 0-10% (w/v) (optimum at 2.0-2.5% (w/v)). The isolate grew chemolithoautotrophically with molecular hydrogen, elemental sulfur or thiosulfate as an electron donor, nitrate or oxygen as an electron acceptor and CO₂/HCO₃^- as a carbon source. It also grew with organic substrates such as carboxylic acids, benzoate, glycerol, propanol, yeast extract and peptone. The isolate did not utilize mono- or disaccharides. The total size of the genome of strain SMB388^T was 3.4 Mb, and the genomic DNA G + C content was 64.4 mol%. Phylogenomic analysis placed SMB388^T into the family Zoogloeaceae. Based on phenotypic and phylogenetic characteristics, strain SMB388^T represents a novel species of the novel genus for which we propose the name Denitraticella aggregata gen. nov., sp. nov. (the type strain is SMB388^T = KCTC 25769^T = VKM B-3859^T).