sp. nov., isolated from Darangshi Oreum (a volcanic cone), and the reclassification of Lu . 2003 as a later heterotypic synonym of (Shinobu 1962) Preobrazhenskaya . 1975 (Approved Lists 1980).

Two mycelium-forming actinobacterial strains, designated as DLS-47 and DLS-62, were isolated from volcanic ash collected from the surface of a rock on the peak of Darangshi Oreum (a volcanic cone) in Jeju, Republic of Korea, and their taxonomic positions were investigated by a polyphasic approach. Both of the isolates showed growth at 20-42 °C, pH 6.0-9.

sp. nov., sp. nov., and sp. nov., isolated from dried beach seaweeds.

Three actinobacterial strains, KSW2-21, KSW2-29 and KSW4-17, were isolated from dried seaweeds collected around Gwakji Beach in Jeju, Republic of Korea. Their taxonomic positions were determined based on genomic, physiological and morphological characteristics. The isolates were Gram-positive, aerobic, non-motile, rod-shaped bacteria characterized by the following chemotaxonomic features: ornithine as the cell wall diamino acid, the -glycolyl type of murein, MK-11 as the predominant menaquinone, polar lipids including diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and four unidentified phospholipids, with anteiso-C, iso-C and anteiso-C as the the major fatty acids.

Microbacterium aquilitoris sp. nov. and Microbacterium gwkjiense sp. nov., isolated from beach.

Three Gram-reaction-positive bacterial strains, designated KSW-18, KSW2-22, and KSW4-11, were isolated from seawater, and two dried seaweed samples collected at Gwakji Beach in Jeju, Republic of Korea, respectively, and their taxonomic positions were examined by a polyphasic approach. The 16S rRNA gene phylogeny showed that strain KSW4-11 was tightly associated with Microbacterium oleivorans NBRC 103075, while strains KSW-18 and KSW2-22 formed a distinctive subline at the base of a clade including the above two strains. The three isolates showed high sequence similarity with one another (99.

gen. nov. sp. nov., a novel bacterium of the order isolated from a cave and a proposal of fam. nov.

Two Gram-stain-positive, aerobic, non-spore-forming, non-motile, irregular rod-shaped actinobacteria, designated as D2-41 and D3-21, were isolated from soil samples collected in a natural cave in Jeju, Republic of Korea. Both of the isolates were shown to share 100 % 16S rRNA sequence identity. The cell wall contained -diaminopimelic acid, arabinose and galactose.

Four new species isolated from seaweeds and reclassification of five species with a proposal of gen. nov. under a genome-based framework of the genus .

The taxonomic relationships of 10 strains isolated from seaweeds collected from two beaches in Republic of Korea were studied by sequencing and analyses of 16S rRNA genes and whole genomes. For the construction of a more reliable and robust 16S rRNA gene phylogeny, the authentic and nearly complete 16S rRNA gene sequences of all the type strains were selected through pairwise comparison of the sequences contained in several public databases including the List of Prokaryotic names with Standing in Nomenclature (LPSN). The clustering of the ten study strains into five distinct groups was apparent in this single gene-based phylogenetic tree.

sp. nov., isolated from a tidal mudflat.

A Gram-reaction-negative, aerobic, motile, rod-shaped bacterium, designated GH3-8, was isolated from rhizosphere mudflats of halophytes on the seashore of Gangwha Island, Republic of Korea. Growth was observed at pH 4-10 (optimum, pH 7-8), at 4-40 °C (optimum, 37 °C) and in the presence of 0.5-20 % (w/v) NaCl (optimum, 4 %).

sp. nov. and sp. nov., isolated from larvae of L. and , respectively.

Two Gram-positive bacterial strains, designated as YMB-B2 and BWT-G7, were isolated from larvae of L. and , respectively, and their taxonomic positions examined by a polyphasic approach. Both of the isolates contained ornithine as the cell-wall diamino acid.

sp. nov. and OS3-89, isolated from rhizosphere soil of cactus.

Two mycelium-forming actinobacterial strains, designated OS3-83 and OS3-89, were isolated from rhizosphere soil of a cactus () sampled on Mara Island, Jeju, Republic of Korea. Both of the isolates were found to grow at 20-37 °C, pH 6.0-10.

sp. nov., isolated from a lava cave.

A Gram-reaction-positive, strictly aerobic, non-sporulating, non-motile, rod-shaped bacterium, designated YC3-14, was isolated from pieces of stalagmite collected in a lava cave in Jeju, Republic of Korea. Cells showed growth at 15-35 °C, pH 6.0-9.

sp. nov. and sp. nov., isolated from larvae of .

The taxonomic positions of two novel strains isolated from larvae of an insect () collected in Jeju, Republic of Korea, were determined by a polyphasic approach. Strain BWB3-3 was closely related to the type strain of , having 97.2 % 16S rRNA gene sequence similarity, whereas strain BWM-S5 formed an independent cluster within the genus in the 16S rRNA gene phylogeny and the closest relative was the type strain of (98.

gen. nov., sp. nov., isolated from larvae of mealworm L., and a proposal to transfer Liu . 2016 to a new genus as comb. nov.

Two enterobacterial strains, designated YMB-R21 and YMB-R22, were isolated from larvae of mealworm L. and examined for their taxonomic characteristics. A 16S rRNA gene-based neighbour-joining tree showed that the two isolates formed two distinct sublineages within the family and were separated from other genera of the family.

Antrihabitans stalagmiti sp. nov., isolated from a larva cave and a proposal to transfer Rhodococcus cavernicola Lee et al. 2020 to a new genus Spelaeibacter as Spelaeibacter cavernicola gen. nov. comb. nov.

An actinobacterial strain, designated YC3-6, was isolated from a larva cave in Jeju, Republic of Korea. The novel isolate was found to grow at 10-30 °C, pH 5.0-10.

sp. nov., isolated from larvae of , proposal of gen. nov., comb. nov. and emended descriptions of the genera , and .

Taxonomic positions of four Gram-negative bacterial strains, which were isolated from larvae of two insects in Jeju, Republic of Korea, were determined by a polyphasic approach. Strains CWB-B4, CWB-B41 and CWB-B43 were recovered from larvae of , whereas strain BWR-B9 was from larvae of . All the isolates grew at 10-37 °C, at pH 5.

sp. nov., isolated from a cave, and proposals that is a later synonym of , and are later synonyms of , and and are later synonyms of .

Two novel actinobacterial strains, designated C9-5 and C3-43, were isolated from soil samples of a cave in Jeju Island, Republic of Korea, and subjected to taxonomic study by a polyphasic approach. The organisms exhibited a typical rod-coccus developmental cycle during growth and grew at 10-30 °C, pH 5-9 and 0-3 % (w/v) NaCl. In 92 single-copy core gene sequence analysis, strain C9-5 was loosely associated with , albeit sharing low 16S rRNA gene sequence similarity (97.

sp. nov. and sp. nov., and emended description of the genus .

Taxonomic positions of six isolates, which were recovered from two different environments in Jeju, Republic of Korea, were examined by a polyphasic analysis. Cells of the isolates were Gram-reaction-negative, facultatively anaerobic, motile and rod-shaped and showed growth at 4-30 °C, pH 4.0-9.

Rouxiella aceris sp. nov., isolated from tree sap and the emended description of the genus Rouxiella.

Polyphasic taxonomic studies were performed for the seven strains, which were isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea. Cells of all the isolates were Gram-reaction-negative, facultatively anaerobic, short rods and contained the major isoprenoid quinone of Q-8, the predominant fatty acids of C and C cyclo and the major polar lipids including phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminophospholipid.

Duganella aceris sp. nov., isolated from tree sap and proposal to transfer of Rugamonas aquatica and Rugamonas rivuli to the genus Duganella as Duganella aquatica comb. nov., with the emended description of the genus Rugamonas.

A Gram-reaction-negative, strictly aerobic, betaproteobacterial strain, designated SAP-35, was isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea, and its taxonomic status was examined by a polyphasic approach. Cells of the organism were non-sporulating, motile rods and grew at 4-30 °C, pH 6-7 and in the absence of NaCl.

gen. nov., sp. nov., a new member of the family isolated from sap drawn from .

A Gram-negative, facultatively anaerobic bacterium, designated SAP-6, was isolated from sap extracted from in Mt. Halla in Jeju, Republic of Korea and its precise taxonomic status was determined by a polyphasic approach. Cells were non-sporulating, motile, short rods and showed growth at 4-37 °C, pH 6.

Hongsoonwoonella zoysiae gen. nov., sp. nov., a new member of the family Stappiaceae isolated from a tidal mudflat.

A Gram stain-negative bacterial strain, designated SY4-7, was isolated from rhizosphere mudflat of a halophyte (Zoysia sinica) collected around Seonyu Island, Republic of Korea. Cells of the organism were strictly aerobic, non-sporulating, non-motile rods and grew at 20-42 °C, pH 6-8 and 1-6% (w/v) NaCl. The 16S rRNA gene-based phylogenetic analyses revealed that strain SY4-7 formed an independent cluster separated from the recognized genera of the family Stappiaceae, which was also supported by phylogenomic analysis-based 92-core gene sequences.

sp. nov., isolated from a rhizosphere mudflat of a halophyte and proposal to reclassify Lee . 2019. and Yoon . 2003 as comb. nov. and comb. nov., respectively.

A marine alphaproteobacterium, designated as strain GH3-10, was isolated from the rhizosphere mud of a halophyte () collected at the seashore of Gangwha Island, Republic of Korea. The isolate was found to be Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive, non-motile, short rods and produced orange-coloured colonies. The 16S rRNA gene- and whole genome-based phylogenetic analyses exhibited that strain GH3-10 belonged to the genus and was most closely related to s21-N3 (98.

gen. nov., sp. nov., a new member of the family isolated from a cave.

Two Gram-stain-positive, strictly aerobic, non-spore-forming actinobacterial strains, designated YC2-7 and YC5-17, were isolated from the Yongcheondonggul (larva cave) in Jeju, Republic of Korea and their taxonomic ranks were examined by a polyphasic approach. The 16S rRNA gene tree showed that the novel isolates occupied an independent position separated from recognized genera of the family . In the 92 core gene-based phylogenomic analysis, strain YC2-7 was loosely associated with the type strain of with 66.

gen. nov., sp. nov., a new member of the family isolated from a tidal mudflat.

A strictly aerobic, Gram-stain-negative, non-motile, ovoid- and rod-shaped bacterium, designated strain GH1-50, was isolated from a tidal mudflat sample collected from Dongmak seashore on Gangwha Island, Republic of Korea. The organism showed growth at 20-40 °C (optimum, 30 °C), pH 7-8 (optimum, pH 7) and 2-6  % (w/v) NaCl (optimum, 5 %). The genes were present but bacteriochlorophyll a was not detected.

Rahnella aceris sp. nov., isolated from sap drawn from Acer pictum.

A Gram-reaction-negative, facultatively anaerobic bacterium, designated SAP-19, was isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea and its taxonomic statue was investigated by a polyphasic approach including genome- and 16S rRNA gene-based phylogenetic analyses. Cells were motile, short rods and showed growth at 20-30 °C, pH 4-9 and 0-6% (w/v) NaCl.