Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar

The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693 ^T, a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81 % between strains ID13488 and LMG 1693 ^T, and values <70 % between strain LMG 1693 ^T and the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693 ^T into a single novel species was supported by amplified fragment length polymorphism (AFLP) and (GTG)5-PCR DNA fingerprinting data, as well as by phenotypic data. Strains ID13488 and LMG 1693 ^T could be differentiated from closely related species of the genus Gluconacetobacter by their ability to produce 2- and 5-keto-D-gluconic acid from D-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3 % ethanol in the absence of acetic acid and on ethanol, D-ribose, D-xylose, sucrose, sorbitol, D-mannitol and D-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693 ^T was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693 ^T was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693 ^T represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter medellinensis sp. nov. is proposed. The type strain is LMG 1693 ^T (= NBRC 3288T = Kondo 51 ^T).