Gluconobacter cerevisiae sp. nov., isolated from the brewery environment

Three strains, LMG 27748^T, LMG 27749 and LMG 27882 with identical MALDI-TOF mass spectra were isolated from samples taken from the brewery environment. Analysis of the 16S rRNA gene sequence of strain LMG 27748^T revealed that the taxon it represents was closely related to type strains of the species Gluconobacter albidus (100 % sequence similarity), Gluconobacter kondonii (99.9 %), Gluconobacter sphaericus (99.9 %) and Gluconobacter kanchanaburiensis (99.5 %). DNA–DNA hybridization experiments on the type strains of these species revealed moderate DNA relatedness values (39–65 %). The three strains used d-fructose, d-sorbitol, meso-erythritol, glycerol, l-sorbose, ethanol (weakly), sucrose and raffinose as a sole carbon source for growth (weak growth on the latter two carbon sources was obtained for strains LMG 27748^T and LMG 27882). The strains were unable to grow on glucose-yeast extract medium at 37 °C. They produced acid from meso-erythritol and sucrose, but not from raffinose. d-Gluconic acid, 2-keto-d-gluconic acid and 5-keto-d-gluconic acid were produced from d-glucose, but not 2,5-diketo-d-gluconic acid. These genotypic and phenotypic characteristics distinguish strains LMG 27748^T, LMG 27749 and LMG 27882 from species of the genus Gluconobacter with validly published names and, therefore, we propose classifying them formally as representatives of a novel species, Gluconobacter cerevisiae sp. nov., with LMG 27748^T ( = DSM 27644^T) as the type strain.