Bosea minatitlanensis sp. nov., a strictly aerobic bacterium isolated from an anaerobic digester.

A strictly aerobic, mesophilic bacterium, strain AMX 51(T), 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 51(T) was a member of the alpha-Proteobacteria, most closely related to Bosea thiooxidans DSM 9653(T) (similarity of 98.88 %). Methylobacterium organophilum JCM 2833(T), Methylobacterium mesophilicum JCM 2829(T), Afipia clevelandensis DSM 7315(T), Afipia felis DSM 7326(T), Afipia broomeae DSM 7327(T), Blastobacter denitrificans LMG 8443(T) and Bradyrhizobium japonicum DSM 30131(T) showed significant 16S rRNA gene sequence similarities to strain AMX 51(T). The DNA G+C composition of strain AMX 51(T) was 68.5 mol%. DNA-DNA hybridization analysis revealed 44.2 and 15.1 % relatedness between strain AMX 51(T) and the respective type strains of Bosea thiooxidans and A. felis. Overall results suggest that strain AMX 51(T) (=DSM 13099(T)=ATCC 700918(T)=CIP 106457(T)) represents a novel species of the genus Bosea; the name Bosea minatitlanensis sp. nov. is proposed.