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

Abstract

The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S–23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genesdnaK,groELandrpoB, allocated the micro-organism to the genusGluconacetobacter, and more precisely to theGluconacetobacter xylinusgroup. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693T, a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain ofGluconacetobacter xylinus. DNA–DNA hybridizations confirmed this finding, revealing a DNA–DNA relatedness value of 81 % between strains ID13488 and LMG 1693T, and values <70 % between strain LMG 1693Tand the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693Tinto 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 1693Tcould be differentiated from closely related species of the genusGluconacetobacterby their ability to produce 2- and 5-keto-d-gluconic acid fromd-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 andd-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693Twas 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693Twas Q-10. Taken together these data indicate that strains ID13488 and LMG 1693Trepresent a novel species of the genusGluconacetobacterfor which the nameGluconacetobacter medellinensissp. nov. is proposed. The type strain is LMG 1693T( = NBRC 3288T = Kondo 51T).