Bombella favorum sp. nov. and Bombella mellum sp. nov., two novel species isolated from the honeycombs of Apis mellifera

As part of a study investigating the microbiome of bee hives and honey, two novel strains (TMW 2.1880 and TMW 2.1889 ) of acetic acid bacteria were isolated and subsequently taxonomically characterized by a polyphasic approach, which revealed that they cannot be assigned to known species. The isolates are Gram-stain-negative, aerobic, pellicle-forming, catalase-positive and oxidase-negative. Cells of TMW 2.1880 are non-motile, thin/short rods, and cells of TMW 2.1889 are motile and occur as rods and long filaments. Morphological, physiological and phylogenetic analyses revealed a distinct lineage within the genus . Strain TMW 2.1880 is most closely related to the type strain of with a 16S rRNA gene sequence similarity of 99.5 %, and ANIb and DDH values of 94.16 and 56.3 %, respectively. The genome of TMW 2.1880 has a size of 1.98 Mb and a G+C content of 55.3 mol%. Strain TMW 2.1889 is most closely related to the type strain of with a 16S rRNA gene sequence similarity of 99.5 %, and ANIb and DDH values of 85.12 and 29.5 %, respectively. The genome of TMW 2.1889 has a size of 2.07 Mb and a G+C content of 60.4 mol%. Ubiquinone analysis revealed that both strains contained Q-10 as the main respiratory quinone. Major fatty acids for both strains were C , C cyclo 8 and summed feature 8, respectively, and additionally C 2-OH only for TMW 2.1880 and C only for TMW 2.1889 . Based on polyphasic evidence, the two isolates from honeycombs of represent two novel species of the genus , for which the names sp. nov and sp. nov. are proposed. The designated respective type strains are TMW 2.1880 (=LMG 31882 =CECT 30114 ) and TMW 2.1889 (=LMG 31883 =CECT 30113 ).