This study investigated unrecorded freshwater bacterial species in Korea. Water and sediment samples were collected from the Nakdong River basin from 2020-2022. Bacterial isolates obtained through the conventional culture method with commercial media were subjected to 16S rRNA gene sequencing to identify unrecorded bacterial species. Results of 16S rRNA gene sequencing of the bacterial isolates revealed that a total of 44 bacterial isolates shared 16S rRNA gene sequence similarities of more than 98.65%, with validly published bacterial species not reported in Korea yet. These isolates were phylogenetically assigned to 4 phyla, 7 classes, 21 orders, 33 families, and 42 genera. A total of 2, 6, 12, and 24 species belonged to phyla Bacillota, Bacteroidota, Actinomycetota, and Pseudomonadota, respectively. Here, we provide details of these 44 unrecorded bacterial species, including Gram staining, colony and cellular morphologies, biochemical properties, and phylogenetic position.

1. INTRODUCTION
2. MATERIALS AND METHODS
3. RESULTS AND DISCUSSION
    3.1. Description of Cellulomonas oligotrophicaSL08-109
    3.2. Description of Blastococcus coliseiND17S-10
    3.3. Description of Phycicoccus flavusND40W-79
    3.4. Description of Klugiella xanthotipulaeND36W-16
    3.5. Description of Subtercola boreusND36S-56
    3.6. Description of Paeniglutamicibacterpsychrophenolicus 14S-24
    3.7. Description of Mycobacterium iranicum21S-146
    3.8. Description of Rhodococcus agglutinans21GGS1-73
    3.9. Description of Propioniciclava flava20HJ5-87
    3.10. Description of Raineyella antarcticaND42S-136
    3.11. Description of Nonomuraea maritima21GGS1-PS42
    3.12. Description of Actinoallomurusacanthiterrae 21GGS2-50
    3.13. Description of Brochothrixthermosphacta ND10W-13
    3.14. Description of Sporosarcinathermotolerans 21GGS2-58
    3.15. Description of Chryseobacterium bovis20HJ5-53
    3.16. Description of Flavobacterium lutiviviND42W-61
    3.17. Description of Chryseobacteriumchaponense 21W-70
    3.18. Description of Pedobacter alpinus22ND02S-062
    3.19. Description of Sphingobacterium populi21TPW-18
    3.20. Description of Sphingobacteriumendophyticum TPW-55
    3.21. Description of Aureimonasphyllosphaerae TPW-78
    3.22. Description of Methylobacteriumcerastii ND09S-20
    3.23. Description of Mesorhizobiumsediminum 22ND02W-014
    3.24. Description of Allorhizobium vitisTPS-035
    3.25. Description of Bauldia consociata21GGS1-PS26
    3.26. Description of Ciceribacter thiooxidans22M5SE1-20
    3.27. Description of Rhizobium subbaraonis14W-38
    3.28. Description of Endobacteriumyantingense MK07-66
    3.29. Description of Rhodobacter thermarum22ND02S-050
    3.30. Description of Tabrizicola aquatica01TYR-1-41
    3.31. Description of Niveispirillumcyanobacteriorum 22M6SE1-9
    3.32. Description of Novosphingobiumhassiacum 14W-109
    3.33. Description of Sphingomonasoligophenolica ND29W-66
    3.34. Description of Acidovorax caeni20HJ5-23
    3.35. Description of Massilia agri 21TPS-072
    3.36. Description of Rugamonas rivuliND10S-28
    3.37. Description of Uruburuella suis 20HJ5-7
    3.38. Description of Methyloversatilisuniversalis 22M5SE1-5
    3.39. Description of Zoogloea oryzae22ND02S-042
    3.40. Description of Pseudidiomarinagelatinasegens 20HJ-1-18
    3.41. Description of Rheinheimera nanhaiensis22ND44W-039
    3.42. Description of Pantoea cypripedii21TPW-40
    3.43. Description of Pseudomonasakapageensis ND10S-45
    3.44. Description of Stagnimonas aquatica22M6S-19
ACKNOWLEDGEMENTS

• Ju-Hyung Jeon(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Sanghwa Park(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Ja Young Cho(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Soo-Yeong Lee(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Seoni Hwang(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Jun Sung Kim(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Eui-Jin Kim(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Ji Young Jung(Microbial Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea) Corresponding author