Report of 21 unrecorded bacterial species in Korea belonging to the phylum Actinobacteria, discovered during the survey in 2020 Author Ham, You Ju Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea Author Jeong, Ji Won Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea Author Im, Wan-Taek Department of Biotechnology, Hankyong National University, Anseong 17579, Republic of Korea Author Kim, Won-Yong Department of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea Author Yoon, Jeong-Hun Department of Food Molecular Biotechnology, Sungkyunkwan University, Suwon 16419, Republic of Korea Author Kim, Myung Kyum Department of Bio and Environmental Technology, Seoul Woman’s University, Seoul 01797, Republic of Korea Author Seong, Chi Nam Department of Biology, Sunchon National University, Suncheon 57922, Republic of Korea Author Kim, Seung Bum Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea text Journal of Species Research 2022 11 1 1 9 journal article 10.12651/JSR.2022.11.1.001 2713-8615 8120070 Description of Streptomyces albidoflavus MA 30 Cells are Gram-stain-positive and filamentous. Colonies are filamentous, umbonate and pale yellow colored after incubation for 3 days at 30℃. Positive for nitrate reduc- tion and esculin hydrolysis; but negative for indole production, glucose fermentation, arginine dihydrolase, urease, gelatin hydrolysis, β-galactosidase and cytochrome oxidase. D-Glucose, L-arabinose, D-mannose, D-mannitol, potassium gluconate, adipic acid, malic acid, trisodium citrate and phenylacetic acid are utilized as sole carbon sources; but not N -acetyl-glucosamine, D-maltose and capric acid. Strain MA30 ( = NIBRBAC000506144) was isolated from a wetland sample from Seoul . The Gen Bank accession number for the 16S rRNA gene sequence of strain MA30 is MW164950. Description of Streptomyces avermitilis MMS 20-HV4-22 Cells are Gram-stain-positive and filamentous. Colonies are filamentous, raised, undulate and orange or brown col- ored after incubation for 3 days on ISP2 at 30℃. Positive for nitrate reduction, arginine dihydrolase, urease, esculin hydrolysis, gelatin hydrolysis and β-galactosidase; but negative for indole production, glucose fermentation and cytochrome oxidase. D-Glucose and N -acetyl-glucosamine are utilized as sole carbon sources; but not L-arabinose, D-mannose, D-mannitol, D-maltose, potassium gluconate, capric acid, adipic acid, malic acid, trisodium citrate and phenylacetic acid. Strain MMS20-HV4-22 ( = NIBRBAC000506172) was isolated from a soil sample from Okcheon-gun, Chungcheongbuk-do . The GenBank accession number for the 16S rRNA gene sequence of strain MMS20-HV4-22 is MW159351.