Description of Galbitalea soli gen. nov., sp. nov., and Frondihabitans sucicola sp. nov.

Bacterial strains KIS82-1(T) and GRS42(T) were isolated from soil and from sap of Acer mono, respectively, in the Republic of Korea. Both strains were aerobic, Gram-stain-positive, mesophilic, rod-shaped and motile. Phylogenetically, both strains belonged to the family Microbacteriaceae of the phylum Actinobacteria. The 16S rRNA gene sequence of strain KIS82-1(T) showed the highest similarity to those of Frondihabitans peucedani RS-15(T) (97.6%), Frigoribacterium mesophilum MSL-08(T) (97.2%) and Labedella gwakjiensis KSW2-17(T) (97.0%), while strain GRS42(T) showed the highest 16S rRNA gene sequence similarity to Frondihabitans peucedani RS-15(T) (98.7%), Frondihabitans cladoniiphilus CafT13(T) (98.4%), Frondihabitans australicus E1HC-02(T) (98.2%) and Frigoribacterium faeni 801(T) (97.3%). The 16S rRNA gene sequence similarity between GRS42(T) and KIS82-1(T) was 97.0%. Phylogenetic trees indicated that strain GRS42(T) was firmly grouped into the genus Frondihabitans, while strain KIS82-1(T) did not show a clear affiliation to any genus within the family Microbacteriaceae. Strain KIS82-1(T) showed type B1β peptidoglycan with 2,4-diamino-L-butyric acid as the diamino acid. It had MK-11, MK-10 and MK-12 as respiratory quinones, anteiso-C(15 : 0), iso-C(16: 0) and iso-C(14 : 0) as major cellular fatty acids and diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid as predominant polar lipids. The peptidoglycan of strain GRS42(T) was of type B2β with D-ornithine as the diamino acid. The strain contained MK-8, MK-9 and MK-7 as respiratory quinones, summed feature 8 (C(18 : 1)ω6c and/or C(18 : 1)ω7c) as major cellular fatty acid and diphosphatidylglycerol, phosphatidylglycerol and three unknown glycolipids as predominant polar lipids. Strain GRS42(T) revealed low DNA-DNA hybridization (<50% relatedness) with closely related strains. Based on the data obtained in the present polyphasic taxonomic study, we propose that strain KIS82-1(T) represents a novel genus and species and that strain GRS42(T) represents a novel species in the family Microbacteriaceae. The genus Galbitalea gen. nov. is proposed, with strain KIS82-1(T) ( = KACC 15520(T) = NBRC 108727(T)) as the type strain of the type species, Galbitalea soli sp. nov. Strain GRS42(T) ( = KACC 15521(T) = NBRC 108728(T)) is proposed as the type strain of Frondihabitans sucicola sp. nov.