Foliimonas ilicis gen. nov., sp. nov., a carbon monoxide-oxidizing bacterium belonging to a novel genus of the family Phyllobacteriaceae isolated from leaves of Ilex aquifolium

TL;DR

Scientists discovered a new species of bacteria, Foliimonas ilicis, from holly leaves that can oxidize carbon monoxide and belongs to a new genus.

Contribution

The discovery of a novel genus and species of CO-oxidizing bacteria, Foliimonas ilicis, within the Phyllobacteriaceae family.

Findings

Strain SB112T is a new species of a new genus Foliimonas, distinct from known genera in the Phyllobacteriaceae family.

The genome of SB112T contains the coxL gene, suggesting the ability to oxidize carbon monoxide.

Phylogenomic and genomic analyses confirmed the novelty of the strain, with ANI and dDDH values below species delineation thresholds.

Abstract

A novel carbon monoxide (CO)-oxidizing bacterial strain designated as SB112T was enriched and isolated from Ilex aquifolium leaves from Tocil Wood Nature Reserve in Coventry, UK. The strain was Gram reaction-negative, aerobic, rod-shaped, motile with a polar flagellum and non-spore-forming. Growth of strain SB112T was observed at 10–45 °C, pH 6.0–12.0 and NaCl concentrations of 1–3%. The genomic DNA G+C content was 58.3 mol%, and the major fatty acids (>10%) of strain SB112T were C18 : 1 ω7c, C18 : 1 ω7c 11-methyl and C19 : 0 cyclo ω7c. Major polar lipids were phosphatidylcholine, diphosphatidylglycerol, phosphatidylglycerol and a phospholipid. Strain SB112ᵀ contains ubiquinone-10 as the major respiratory quinone. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SB112T formed a separate lineage within the family Phyllobacteriaceae, showing sequence identities of 97.7%, 97.6% and 97.5%, with its closest relatives Aminobacter niigataensis, Aminobacter aminovorans and Mesorhizobium plurifarium, respectively. Phylogenomic analyses using whole-genome sequences consistently placed this strain within the family Phyllobacteriaceae. However, its phylogenetic position did not correspond to any known genus within this family. The genome of strain SB112T was found to possess the form II coxL gene, which encodes the large subunit of the CO dehydrogenase and potentially enables CO oxidation. The average nucleotide identity and digital DNA–DNA hybridization with members of closely related genera yielded values below the thresholds for prokaryotic species delineation (95–96 and 70%, respectively). Based on the phenotypic, chemotaxonomic, phylogenetic, genomic and physiological properties, strain SB112T is considered to represent a novel species of a new genus Foliimonas within the family Phyllobacteriaceae for which the name Foliimonas ilicis gen. nov., sp. nov. is proposed. The type of strain is SB112T (=LMG 33802T, =NCAIM B.02691T).

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