Duganella callida sp. nov., a novel addition to the Duganella genus, isolated from the soil of a cultivated maize field.

ABSTRACT

A Gram-negative, rod-shaped bacterium, strain Duganella callida DN04T, was isolated from the soil of a maize field in North Carolina, USA. Based on the 16S rRNA gene sequence, the most similar Duganella species are D. sacchari Sac-22T, D. ginsengisoli DCY83T, and D. radicis Sac-41T with a 97.8, 97.6, or 96.9 % sequence similarity, respectively. We compared the biochemical phenotype of DN04T to D. sacchari Sac-22T and D. zoogloeoides 115T and other reference strains from different genera within the Oxalobacteraceae and while the biochemical profile of DN04T is most similar to D. sacchari Sac-22T and other Duganella and Massilia strains, there are also distinct differences. DN04T can for example utilize turanose, N-acetyl-d-glucosamine, inosine, and l-pyroglutamic acid. The four fatty acids found in the highest percentages were C15  0 iso (24.6 %), C15  1 isoG (19.4 %), C17  0 iso3-OH (16.8 %), and summed feature 3 (C161 ⍵7c and/or C161 ⍵6c) (12.5 %). We also applied whole genome sequencing to determine if DN04T is a novel species. The most similar AAI (average amino acid identity) score was 70.8 % (Massilia plicata NZ CP038026T), and the most similar ANI (average nucleotide identity) score was 84.8 % (D. radicis KCTC 22382T), which indicates that DN04T is a novel species. The genome-to-genome-distance calculation (GGDC) revealed a DDH of 28.3 % to D. radicis KCTC 22382T, which is much lower than the new species threshold. Based on the morphological, phenotypic, and genomic differences, we propose Duganella callida sp. nov. as a novel species within the Duganella genus (type strain DN04T=NRRL B-65552T=LMG 31736T).