A strictly aerobic, mesophilic bacterium, strain AMX 51T, was isolated from anaerobic digester sludge. Cells were Gram-negative, motile, non-sporulating, straight to curved rods with one polar flagellum. The isolate had phenotypic traits of the genus Bosea, including cellular fatty acid and substrate utilization profiles. Physiological characteristics and antibiotic susceptibility were determined. Phylogenetic analysis revealed that strain AMX 51T was a member of the
a-Proteobacteria, most closely related to Bosea thiooxidans DSM 9653T (similarity of 98?88 %). Methylobacterium organophilum JCM 2833T, Methylobacterium mesophilicum JCM 2829T, Afipia clevelandensis DSM 7315T, Afipia felis DSM 7326T, Afipia broomeae DSM 7327T, Blastobacter denitrificans LMG 8443T and Bradyrhizobium japonicum DSM 30131T showed significant 16S rRNA gene sequence similarities to strain AMX 51T. The DNA G+C composition of strain AMX 51T was 68?5 mol%. DNA–DNA hybridization analysis revealed 44?2 and 15?1% relatedness between strain AMX 51T and the respective type strains of Bosea thiooxidans and A. felis. Overall results suggest that strain AMX 51T (=DSM 13099T=ATCC 700918T=CIP 106457T) represents a novel species of the genus Bosea; the name Bosea minatitlanensis sp. nov. is proposed.

Bosea minatitlanensis sp. nov., strictly aerobic bacterium, anaerobic digester, cellular fatty acids, Mexico