A thermotolerant acetic acid bacterium, designated strain CWBI-B418(T), isolated in Senegal from mango fruit (Mangifera indica), was characterized in detail by means of genotypic and phenotypic methods. The novel strain was strictly aerobic and exhibited optimal growth on YGM medium at 35 degrees C. Cells were Gram-negative, motile and coccoid. The strain was assigned to the genus Acetobacter on the basis of 16S rRNA gene sequence analysis. DNA-DNA hybridization experiments with its phylogenetically closest relatives showed that strain CWBI-B418(T) represented a novel Acetobacter genospecies. The DNA G+C content of strain CWBI-B418(T) was 56.0 mol%. Phenotypic characteristics enabling the differentiation of strain CWBI-B418(T) from phylogenetically related Acetobacter species were: production of 2-keto-D-gluconic acid from D-glucose, but not 5-keto-D-gluconic acid, production of catalase but not oxidase, growth on yeast extract with 30 % d-glucose, growth with ammonium as sole nitrogen source with ethanol as carbon source, utilization of glycerol and ethanol but not maltose or methanol as carbon sources, and growth in the presence of 10 % ethanol. Based on the genotypic and phenotypic data presented, strain CWBI-B418(T) clearly represents a novel Acetobacter species, for which the name Acetobacter senegalensis sp. nov. is proposed. The type strain is CWBI-B418(T) (=LMG 23690(T)=DSM 18889(T)).