A Gram-positive, aerobic, non-motile bacterial strain, KSL-107(T), was isolated from an alkaline soil from Korea and subjected to a polyphasic taxonomic study. Strain KSL-107(T) grew optimally at 25 degrees C and pH 7.0-7.5. Strain KSL-107(T) had a cell-wall peptidoglycan based on ll-2,6-diaminopimelic acid. It contained MK-9(H(4)) as the predominant menaquinone and C(16:0), C(16:0) 2-OH and 10-methyl C(18:0) as the major fatty acids. The DNA G+C content was 71.5 mol%. Comparative 16S rRNA gene sequence analyses showed that strain KSL-107(T) was phylogenetically affiliated to the genus Aeromicrobium of the family Nocardioidaceae. Similarity values between the 16S rRNA gene sequence of strain KSL-107(T) and those of type strains of Aeromicrobium species were in the range 97.9-98.2%. The isolate could be distinguished from other Aeromicrobium species by levels of DNA-DNA relatedness and differences in some phenotypic characteristics. On the basis of the data presented, it is suggested that strain KSL-107(T) (=KCTC 19073(T)=DSM 16824(T)) represents a novel Aeromicrobium species, for which the name Aeromicrobium alkaliterrae sp. nov. is proposed. An emended description of the genus Aeromicrobium is also proposed.