Diaminobutyricibacter tongyongensis gen. nov., sp. nov. and Homoserinibacter gongjuensis gen. nov., sp. nov. belong to the family Microbacteriaceae.

Two bacterial strains, KIS66-7(T) and 5GH26-15(T), were isolated from soil samples collected in the South Korean cities of Tongyong and Gongju, respectively. Both strains were aerobic, Gram-stain-positive, mesophilic, flagellated, and rodshaped. A phylogenetic analysis revealed that both strains belonged to the family Microbacteriaceae of the phylum Actinobacteria. The 16S rRNA gene sequence of strain KIS66-7(T) had the highest similarities with those of Labedella gwakjiensis KSW2-17(T) (97.3%), Cryobacterium psychrophilum DSM 4854T (97.2%), Leifsonia lichenia 2Sb(T) (97.2%), Leifsonia naganoensis JCM 10592(T) (97.0%), and Cryobacterium mesophilum MSL-15(T) (97.0%). Strain 5GH26-15(T) showed the highest sequence similarities with Leifsonia psychrotolerans LI1T (97.4%) and Schumannella luteola KHIAT (97.1%). The 16S rRNA gene sequence from KIS66-7(T) exhibited 96.4% similarity with that from 5GH26-15(T). Strain KIS66-7(T) contained a B2γ type peptidoglycan structure with D-DAB as the diamino acid; MK-13, MK-12, and MK-14 as the respiratory quinones; ai-C15:0, ai-C17:0, and i-C16:0 as the major cellular fatty acids; and diphosphatidylglycerol, phatidylglycerol, and glycolipids as the predominant polar lipids. Strain 5GH26-15T had a B2β type peptidoglycan structure with D-DAB as the diamino acid; MK-14 and MK-13 as the respiratory quinones; ai-C15:0, i-C16:0, and ai-C{vn17:0} as the major cellular fatty acids; and diphosphatidylglycerol, phatidylglycerol, and glycolipids as the predominant polar lipids. Both strains had low DNA-DNA hybridization values (<40%) with closely related taxa. Based on our polyphasic taxonomic characterization, we propose that strains KIS66-7(T) and 5GH26-15(T) represent novel genera and species, for which we propose the names Diaminobutyricibacter tongyongensis gen. nov., sp. nov. (type strain KIS66-7(T)=KACC 15515(T)=NBRC 108724(T)) and Homoserinibacter gongjuensis gen. nov., sp. nov. (type strain 5GH26-15(T)=KACC 15524(T)=NBRC 108755(T)) within the family Microbacteriaceae.