166 JOURNAL OF SPECIES RESEARCH Vol. 5, No. 1 INTRODUCTION Firmicutes includes industrially important groups as well as causative agents of various diseases. Lactic acid bacteria are the representative probiotic bacteria, and thus one of the most industrially important bacterial groups (Tannock, 2005). In contrast, some species of Bacillus (anthrax, food poisoning), Clostridium (tetanus, food poisoning, gas gangrene), Enterococcus (urinary tract infection), Streptococcus (pneumonia, meningitis, dental caries) and Staphylococcus (scalded skin syndrome) are some examples of medically significant bacteria of Fir- micutes (Dworkin et al., 2006). The phylum Firmicutes encompasses broad bacterial taxa that have Gram positive cell walls and low DNA G + C contents (Dworkin et al. , 2006; De Vos et al. , 2009). The phylum currently contains three classes, namely Bacilli, Clostridia and Erysipelotrichia (De Vos et al., 2009). The class Bacilli includes endospore-form- ing groups and lactic acid producing groups, Clostridia includes endospore forming or non-forming anaerobic groups and anoxygenic phototrophic groups, and Erysip- elotrichia includes non-motile, non-spore-forming and aerobic groups. The phylum Bacteroidetes is a very diverse bacterial phylum, the name of which changed several times over the past years. It is also known as the Cytophaga-Flex- ibacter-Bacteroides (CFB) group, an appellation that reflects the diversity of organisms found in this phyloge- netic group (Woese, 1987; Woese et al., 1990). Among this phylum, members of the genus Bacteroides are the Journal of Species Research 5(1):166-178, 2016 A report of 26 unrecorded bacterial species in Korea, belonging to the Bacteroidetes and Firmicutes Haneul Kim 1 , Jung-Hoon Yoon 2 , Chang-Jun Cha 3 , Chi Nam Seong 4 , Wan-Taek Im 5 , Kwang Yeop Jahng 6 , Che Ok Jeon 7 , Seung Bum Kim 8 and Kiseong Joh 1, * 1 Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Gyeonggi 17035, Korea 2 Department of Food Science and Biotechnology, Sungkyunkwan University, Suwon 16419, Korea 3 Department of Biotechnology, Chung-Ang University, Anseong 17546, Korea 4 Department of Biology, Sunchon National University, Suncheon 57922, Korea 5 Department of Biotechnology, Hankyong National University, Anseong 17579, Korea 6 Department of Life Sciences, Chonbuk National University, Jeonju 54896, Korea 7 Department of Life Science, Chung-Ang University, Seoul 06974, Korea 8 Department of Microbiology, Chungnam National University, Daejeon 34134, Korea *Correspondent: ksjoh@hufs.ac.kr An outcome of the study to discover indigenous prokaryotic species in Korea, a total of 26 bacterial species assigned to the classes Bacteroidetes and Firmicutes were isolated from diverse environmental samples collected from soil, tidal flat, freshwater, seawater, wetland, plant roots, and fermented foods. From the high 16S rRNA gene sequence similarity (>99.0%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to each independent and predefined bacterial species. There is no official report that these 26 species have been described in Korea; therefore 14 strains for the order Flavobacteriales and two strains for the order Cytophagales were assigned to the class Bacteroidetes, and 8 strains for the order Bacillales and 4 strains for the order Lactobacillales were assigned to the class Firmicutes are reported for new bacterial species found in Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section. Keywords: 16S rRNA, bacterial diversity, Bacteroidetes, Firmicutes, unrecorded species Ⓒ 2016 National Institute of Biological Resources DOI:10.12651/JSR.2016.5.1.166