This study assessed the taxonomic hierarchy of the phylum Firmicutes as well as elucidated the isolation and classification states of novel Firmicutes species isolated from Korean territory. The hierarchical classification system of the phylum Firmicutes has been developed since 1872 when the genus Bacillus was first reported and has been generally adopted since 2001. However, this taxonomic hierarchy is still being modified. Until Feb. 2017, the phylum Firmicutes consisted of seven classes (Bacilli, Clostridia, Erysipelotrichia, Limnochordia, Negativicutes, Thermolithobacteria, and Tissierellia), 13 orders, 45 families, and 421 genera. Firmicutes species isolated from various environments in Korea have been reported from 2000, and 187 species have been approved as of Feb. 2017. All Firmicutes species were affiliated with three classes (Bacilli, Clostridia, and Erysipelotrichia), four orders (Bacillales, Lactobacillales, Clostridiales, and Erysipelotrichales), 17 families, and 54 genera. A total of 173 species belong to the class Bacilli, of which 151 species were affiliated with the order Bacillales and the remaining 22 species with the order Lactobacillales. Twelve species belonging to the class Clostridia were affiliated within only one order, Clostridiales. The most abundant family was Bacillaceae (67 species), followed by the family Paenibacillaceae (56 species). Thirteen novel genera were created using isolates from the Korean environment. A number of Firmicutes species were isolated from natural environments in Korean territory. In addition, a considerable number of species were isolated from artificial resources such as fermented foods. Most Firmicutes species, belonging to the families Bacillaceae, Planococcaceae, and Staphylococcaceae, isolated from Korean fermented foods and solar salterns were halophilic or halotolerant. Firmicutes species were isolated from the whole territory of Korea, especially large numbers from Provinces Gyeonggi, Chungnam, and Daejeon.

A Gram-stain-negative, non-spore-forming, rod-shaped, aerobic and diffusible yellow-coloured bacterial strain, designated strain ECD12 was isolated from a seaweed, Ecklonia cava. The isolate required sea salts for growth. Catalase-positive and oxidase-negative. A phylogenetic tree based on 16S rRNA gene sequences showed that strain ECD12 formed an evolutionary lineage within the radiation enclosing the members of genera Spongiibacterium and Flagellimonas sharing the highest similarity to Flagellimonas eckloniae DOKDO007 (96.8 % 16S rRNA gene sequence similarity) followed by Spongiibacterium pacificum SW169 (96.4 %) and Spongiibacterium flavum DSM 22638 (96.1 %). The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The new isolate contained MK-6 as the only isoprenoid quinone and phosphatidylethanolamine, two unidentified amino lipids and two unidentified lipids as the major polar lipids. The genomic DNA G+C content is 39 mol%. A number of phenotypic characteristics such as the production of diffusible pigment distinguished strain ECD12 from the related species. On the basis of the evidence presented in this study, a novel species, Flagellimonas aquimarina sp. nov., is proposed for strain ECD12 (=KCTC 52351=JCM 32292). Based on the sequence similarity, phylogenetic relationship and common morphological, physiological and chemical characters among the members of the genera Spongiibacterium and Flagellimonas, it is recommended that the two genera are combined into a single genus. Thus, transfer of S. flavumYoon and Oh 2012 and S. pacificum Gao et al. 2015 to the genus FlagellimonasBae et al. 2007 as Flagellimonas flava comb. nov. and Flagellimonas pacifica comb. nov., respectively, is also proposed.

A non-motile and yellow-pigmented bacterium, designated strain WW3T , was isolated from freshwater of Woopo wetland, Republic of Korea. Cells were Gram-reaction-negative, aerobic, catalase-positive and oxidase-negative. A maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that strain WW3 T forms an independent lineage within the genusAltererythrobacter. Strain WW3 T was related distantly to Altererythrobacter dongtanensisJM27T and Altererythrobacter troitsensisKMM 6042 T (97.1% 16S rRNA gene sequence similarity).DNA-DNA relatedness between strain WW3 T and the reference strains was low (30-41 %).The major fatty acids of strain WW3 T were C 17 : 1 !6c, C 17 : 1 !8c, C 15 : 0 2-OH and summed feature 8 comprising C 18 : 1 !6c and/or C 18 : 1 !7c. The predominant isoprenoid quinone of the isolate was ubiquinone-10. The DNA G+C content of strain WW3 T was 63 mol%. Phenotypic characteristics distinguished strain WW3 T from related species of the genus Altererythrobacter.On the basis of the evidence presented in this study,strain WW3 T represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter rigui sp. nov. is proposed. The type strain is WW3 T (=KCTC 42620 T =JCM 30975 T ).

An aerobic, gliding and yellow-pigmented bacterium, designated strain SFD31T, was isolated from brown alga collected from the South Sea, Republic of Korea. Cells were Gram-stain-negative, and catalase- and oxidase-positive. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain SFD31T forms an independent lineage within the genus Winogradskyella. Strain SFD31T was related distantly to Winogradskyella echinorum KMM 6211T (97.9 %, 16S rRNA gene sequence similarity), Winogradskyellalitoriviva KMM 6491T (97.4 %), Winogradskyellapulchriflava EM106T (97.2 %) and Winogradskyellaeckloniae EC29T (96.9 %). The major fatty acids of strain SFD31T were iso-C15 : 0, iso-C15 : 1 G, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and unknown 13.565. The only isoprenoid quinone of the isolate was menaquinone 6. The major polar lipids were phosphatidylethanolamine, four unidentified aminolipids and two unidentified lipids. The DNA G+C content of strain SFD31T was 36.0 mol%. Phenotypic characteristics distinguished strain SFD31T from the related species of the genus Winogradskyella. On the basis of the evidence presented in this study, a novel species, Winogradskyella flava sp. nov., is proposed for strain SFD31T (=KCTC 52348T=JCM 31798T).

The DDBJ/ENA/GenBank accession numbers for 16S rRNA gene and genome sequences of strain GH4-78 T are MG905440 and SMSE00000000, respectively. The version of the genome sequence described in this paper is version SMSE01000000. Three supplementary figures and three supplementary tables are available with the online version of this article.