Duganella Callida Sp. Nov., A Novel Addition To The Duganella Genus, Isolated From The Soil Of A Cultivated Maize Field

A Gram-negative, rod-shaped bacterium, strain Duganella callida DN04(T), 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-22(T), D. ginsengi-soli DCY83(T), and D. radicis Sac-41(T) with a 97.8, 97.6, or 96.9 % sequence similarity, respectively. We compared the biochemical phenotype of DN04(T) to D. sacchari Sac-22(T) and D. zoogloeoides 115(T) and other reference strains from different genera within the Oxalobacteraceae and while the biochemical profile of DN04(T) is most similar to D. sacchari Sac-22(T) and other Duganella and Massilia strains, there are also distinct differences. DN04T can for example utilize turanose, N-acetyl-o-glucosamine, inosine, and l-pyroglutamic acid. The four fatty acids found in the highest percentages were C-15:0 iso (24.6 %), C-15:1 isoG (19.4 %), C-17:0 iso3-OH (16.8 %), and summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 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 CP038026(T)), and the most similar ANI (average nucleotide identity) score was 84.8 % (D. radicis KCTC 22382(T)), which indicates that DN04(T) is a novel species. The genome-to-genome-distance calculation (GGDC) revealed a DDH of 28.3 % to D. radicis KCTC 22382(T), 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 DN04(T)=NRRL B-65552(T)=LMG 31736(T)).