- Volume 71, Issue 7, 2021

A novel actinomycete, designated strain KK5PA1T, was isolated from a soil sample collected from Kuan Kreng peat swamp forest, Nakhon Si Thammarat Province, Thailand. The morphological, chemotaxonomic and phylogenetic characteristics were consistent with its classification in the genus Streptomyces . Strain KK5PA1T was most closely related to Streptomyces bryophytorum NEAU-HZ10T (98.0 %) and Streptomyces guanduensis 701T (97.6 %). The G+C content of the genomic DNA was 72.3 mol%. Digital DNA–DNA hybridization and average nucleotide identity values between the genome sequence of strain KK5PA1T and those of S. bryophytorum DSM 42138T(25.1 and 79.1 %) and S. guanduensis DSM 41944T(25.1 and 79.7%) were below the thresholds of 70 and 96 % for prokaryotic conspecific assignation. Chemotaxonomic data revealed that strain KK5PA1T possessed MK-9(H6) and MK-9(H8) as the predominant menaquinones. It contained ll -diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, mannose and ribose as whole-cell sugars. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, two unidentified aminolipids, five unidentified phospholipids and an unidentified lipid. The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and C16 : 0. On the basis of these genotypic and phenotypic data, it is proposed that strain KK5PA1T represents a novel species of the genus Streptomyces , for which the name Streptomyces acididurans sp. nov. is proposed. The type strain is strain KK5PA1T (=TBRC 13094T=NBRC 114802T).

A Gram-stain-positive, rod-shaped, strictly aerobic bacterial strain (Y6T) was isolated from a sewage sludge sample collected from a fisheries processing factory in Zhoushan, Zhejiang Province, PR China. The growth range of NaCl concentration was 0–6.0 % (w/v), with an optimum at 3.0 % (w/v). The temperature range for growth was 10–42 °C, with an optimum at 37 °C. The pH range for growth was pH 7.0–10.0, with an optimum at pH 9.0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Y6T belonged to the genus Nocardioides and showed the highest sequence similarity of 97.8 % to Nocardioides jishulii dk3136T. The average nucleotide identity and in silico DNA–DNA hybridization values between strain Y6T and the reference strains were 76.9–81.2 % and 20.6–23.6 %, respectively. Chemotaxonomic analysis indicated that the sole respiratory quinone was MK-8(H4) and the predominant cellular fatty acids were iso-C16 : 0, 10-methyl-C17 : 0 and C18 : 1  ω9c. The polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, four unidentified phospholipids, three unidentified aminolipids and five unidentified lipids. The peptidoglycan was ll-2,6-diaminopimelic acid. On the basis of the phenotypic, genotypic, phylogenetic and chemotaxonomic features, strain Y6T is considered to represent a novel species, for which the name Nocardioides malaquae sp. nov. is proposed. The type strain is Y6T (=KCTC 49504T=MCCC 1K04765T).

An actinobacterium, strain CH5-8T, which formed spiral chains of spore arising from the aerial mycelium, was isolated from rhizosphere soil of Musa spp. The organism exhibited vivid greenish yellow substrate mycelium and easily produced the medium grey aerial spore mass on ISP2 medium. The typical chemotaxonomic properties of members of the genus Streptomyces were observed for strain CH5-8T, e.g. ll-diaminopimelic acid in cell peptidoglycan, MK-9(H8), MK-9(H6), and MK-9(H4) as major menaquinones and anteiso-C15 : 0, iso-C16 : 0, and anteiso-C17 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside were detected in the cells. A combination of morphological and chemotaxonomic data supported the assignment to the genus Streptomyces . The analysis result obtained for the 16S rRNA gene sequence confirmed the taxonomic affiliation at the genus level of this strain. The novel strain CH5-8T showed the highest 16S rRNA gene sequence values to Streptomyces echinatus NBRC 12763T (98.9 %), followed by Streptomyces actinomycinicus RCU-197T (98.9 %). The average nucleotide identity by blast (ANIb) and digital DNA–DNA hybridization values between CH5-8T and its closest relatives, S. echinatus CECT 3313T and S. actinomycinicus RCU-197T, were ≤91.6 % and ≤47.4 %, respectively. The digital DNA G+C content of genomic DNA was 72.1 mol%. On the basis of these phenotypic and genotypic data, strain CH5-8T represents a novel species, for which the name Streptomyces musisoli sp. nov. is proposed. The type strain is CH5-8T (=TBRC 9950T=NBRC 113997T).

Four aerobic, Gram-stain-positive, rod-shaped bacteria (HY60T, HY54, HY82T and HY89) were isolated from bat faeces of Hipposideros and Rousettus species collected in PR China. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the four novel strains formed two separate but adjacent subclades close to Microbacterium agarici CGMCC 1.12260T (97.6–97.7 % similarity), Microbacterium humi JCM 18706T (97.3–97.5 %) and Microbacterium lindanitolerans JCM 30493T (97.3–97.4 %). The 16S rRNA gene sequence similarity was 98.3 % between strains HY60T and HY82T, and identical within strain pairs HY60T/HY54 and HY82T/HY89. The DNA G+C contents of strains HY60T and HY82T were 61.9 and 63.3 mol%, respectively. The digital DNA–DNA hybridization and average nucleotide identity values between each novel strain and their closest relatives were all below the 70 % and 95–96 % thresholds for species delimitation, respectively. All four novel strains contained anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0 as the main fatty acids, MK-11 and MK-12 as the major respiratory quinones, and diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid as the predominant polar lipids. The cell-wall peptidoglycan was of B type and contained alanine, glutamate, glycine and ornithine. The acyl type of the muramic acid was glycolyl. The whole-cell sugars were rhamnose and ribose. Based on the foregoing polyphasic analyses, it was concluded that the four uncharacterized strains represented two novel species of the genus Microbacterium , for which the names Microbacterium chengjingii sp. nov. [type strain HY60T (=CGMCC 1.17468T=GDMCC 1.1951T=KACC 22102T)] and Microbacterium fandaimingii sp. nov. [type strain HY82T (=CGMCC 1.17469T=GDMCC 1.1949T=KACC 22101T)] are proposed, respectively.

A novel actinomycete, designated NUM-2625T, was isolated as an endophytic bacterium in aerial parts of Comarum salesowianum, an endemic species in the Altai, Himalaya mountain chain area, collected from Khasagt Khairkhan Mountain in Mongolia. The 16S rRNA gene sequence of strain NUM-2625T showed the highest similarity to Actinocatenispora thailandica TT2-10T (99.4 %), Actinocatenispora sera KV-744T (99.3 %), and Actinocatenispora rupis CS5-AC17T (97.7 %). Chemotaxonomic properties of strain NUM-2625T were essentially consistent with those of the genus Actinocatenispora, such as the presence of meso-diaminopimelic acid as the diagnostic diamino acid of the peptidoglycan, MK-9(H4) and MK-9(H6) as the major menaquinones, and iso-C16 : 0, iso-C15 : 0, iso-C14 : 0 3-OH, and anteiso-C17 : 0 as the major fatty acids. Meanwhile, digital DNA–DNA hybridization and average nucleotide identity values revealed a low relatedness between strain NUM-2625T and the other type strains of the genus Actinocatenispora . In addition, strain NUM-2625T exhibited several phenotypic properties that could be used to distinguish it from its closest relatives. Based on the results of polyphasic analyses, strain NUM-2625T represents a novel species in the genus Actinocatenispora , for which the name Actinocatenispora comari sp. nov. is proposed. The type strain is NUM-2625T (=NBRC 114660T=TBRC 13496T).

Two novel Rhodococcus strains, LHW50502T and LHW51113T, were isolated from marine sponges obtained on Xisha Island, Hainan Province, PR China. Rods and cocci, typical characteristics of the genus Rhodococcus , were observed. The strains contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall hydrolysates and galactose, arabinose, ribose and glucose as the whole-cell sugars. The major fatty acid identified was C16 : 0. MK-8(H4) was the predominat menaquinone of both strains. Stains LHW50502T and LHW51113T had almost identical (99.6 %) 16S rRNA gene sequences but shared relatively low similarities with previously characterized Rhodococcus species (well below 98.7 %). The results of phylogenetic analysis supported their closest relationship; however, the average nucleotide identity and digital DNA–DNA hybridization values between these two strains indicated that they belonged to distinct species. Taken together, the results of this study indicate that strains LHW50502T and LHW51113T represent two novel species of the genus Rhodococcus , for which the names Rhodococcus spongiicola sp. nov. (type strain LHW50502T=DSM 106291T=CCTCC AA 2018033T) and Rhodococcus xishaensis sp. nov. (type strain LHW51113T=DSM 106204T=CCTCC AA 2018034T) are proposed.

A Gram-stain-positive, aerobic, chemo-organotrophic, rod-shaped, non-spore-forming strain, which produced convex, circular, pink-pigmented colonies, designated as DY32-46T, was isolated from seawater collected from the Pacific Ocean. DY32-46T was found to grow at 20–40 °C (optimum, 30–35 °C), pH 6.0–8.0 (optimum, pH 6.5) and with 0–5 % (w/v) NaCl (optimum, 1–2 %). The results of chemotaxonomic analysis indicated that the respiratory quinone of DY32-46T was MK-9(H4), and major fatty acids (>10 %) were C17 : 1 ω8c, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and C15 : 1 ω6c. The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, one unidentified aminophospholipid, three unidentified glycolipids, three unidentified phospholipids, one unidentified phosphoglycolipid and five unidentified lipids. The DNA G+C content of DY32-46T was 70.6 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences and genomic data indicated that DY32-46T should be assigned to the genus Euzebya . ANI and in silico DNA–DNA hybridization values between strain DY32-46T and type strains of Euzebya species were 73.1–87.2 % and 20.2–32.4 %, respectively. Different phenotypic properties, together with genetic distinctiveness, demonstrated that strain DY32-46T was clearly distinct from recognized species of the genus Euzebya . Therefore, DY32-46T represents a novel species within the genus Euzebya , for which the name Euzebya pacifica sp. nov is proposed. The type strain is DY32-46T (=MCCC 1K03476T=KCTC 49091T).

Six novel strains (ZJ34T, ZJ561, ZJ750T, ZJ1629, zg-993T and zg-987) isolated from faeces and respiratory tracts of Marmota himalayana from the Qinghai–Tibet Plateau of PR China were characterized comprehensively. The results of analyses of the 16S rRNA gene and genome sequences indicated that the six strains represent three novel species of the genus Actinomyces , and are closely related to Actinomyces urogenitalis DSM 15434T (16S rRNA gene sequences similarities, 94.9–98.7 %), Actinomyces weissii CCUG 61299T (95.6–96.6 %), Actinomyces bovis CCTCC AB2010168T (95.7 %) and Actinomyces bowdenii DSM 15435T (95.2–96.4 %), with values of digital DNA–DNA hybridization less than 30.1 % when compared with their closest relatives but higher than 70 % within each pair of novel strains (ZJ34T/ZJ561, ZJ750T/ZJ1629 and zg-993T/zg-987). All the novel strains had C18 : 1 ω9c and C16 : 0 as the two most abundant major fatty acids. MK-9(H4) or MK-8(H4) was the sole or predominant respiratory quinone of strains ZJ34T, ZJ750T and zg-993T and their polar lipid profiles differed, but all had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidyl inositol mannoside as major components. ZJ750T shared identical peptidoglycan amino acid profile with ZJ34T (alanine, glutamic acid, lysine and ornithine) and the same whole-cell sugar composition with zg-993T (glucose, rhamnose and ribose). Strain zg-993T contained alanine, aspartic acid, glutamic acid, glycine and lysine in the peptidoglycan, and the only sugar in ZJ34T was ribose. The DNA G+C contents of the novel strains were within the range of 65.8–70.1 mol%. On the basis of the results from the aforementioned analyses, the six novel strains were classified as representing three novel species of genus Actinomyces , for which the names Actinomyces faecalis sp. nov. [type strain ZJ34T (=GDMCC 1.1952T=JCM 34355T)], Actinomyces respiraculi sp. nov. [type strain ZJ750T (=GDMCC 1.1950T=JCM 34356T)] and Actinomyces trachealis sp. nov. [type strain zg-993T (=GDMCC 1.1956T=JCM 34357T)] were proposed, respectively.

Two novel actinobacterial strains, designated C9-5T 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 C9-5T was loosely associated with Rhodococcus tukisamuensis , albeit sharing low 16S rRNA gene sequence similarity (97.4 %). A combination of morphological and chemotaxonomic characteristics supported assignment with the genus Rhodococcus . With respect to 16S rRNA gene sequence similarity, the novel isolates showed the highest identity to the type strain of Rhodococcus subtropicus (98.7 % sequence similarity), followed by Rhodococcus olei (98.5 %) and Rhodococcus pedocola (98.4 %).The average nucleotide identity and digital DNA–DNA hybridization values between strain C9-5T and members of the genus Rhodococcus were ≤81.5 and ≤37.1 %, respectively. A set of physiological and chemotaxonomic properties together with overall genomic relatedness differentiated the novel isolates from members of the genus Rhodococcus , for which the name Rhodococcus spelaei sp. nov. is proposed. The type strain is C9-5T (=KACC 19822T=DSM 107558T). Based on genome analysis performed here, it is also proposed that Rhodococcus biphenylivorans Su et al. 2015 is a later heterotypic synonym of Rhodococcus pyridinivorans Yoon et al. 2000, Rhodococcus qingshengii Xu et al. 2007 and Rhodococcus baikonurensis Li et al. 2004 are later heterotypic synonyms of Rhodococcus erythropolis (Gray and Thornton 1928) Goodfellow and Alderson 1979 (Approved Lists 1980), and Rhodococcus percolatus Briglia et al. 1996 and Rhodococcus imtechensis Ghosh et al. 2006 are later heterotypic synonyms of Rhodococcus opacus Klatte et al. 1995.

Four mesophilic and Gram-stain-positive strains (zg-686T/zg-691 and HY186T/HY189) isolated from Tibetan Plateau wildlife (PR China) belong to the genus Gordonia according to 16S rRNA gene and genomic sequence-based phylogenetic/genomic results. They have a DNA G+C content range of 67.4–68.3 mol% and low DNA relatedness (19.2–27.6 %) with all available genomes in the genus Gordonia . Strains zg-686T/zg-691 and HY186T/HY189 had C18 : 1ω9c, C18 : 0 10-methyl, C16 : 1 ω7c/C16 : 1ω6c and C16 : 0 as major cellular fatty acids. The polar lipids detected in strains zg-686T and HY186T included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyl inositol mannoside and phosphatidylinositol. The respiratory quinones comprised MK8(H2) (10.8 %) and MK9(H2) (89.2 %) for strain zg-686T, and MK6 (7.7 %), MK8(H2) (8.4 %), MK8(H4) (3.1 %) and MK9(H2) (80.8 %) for strain HY186T. Optimal growth conditions were pH 7.0, 35–37 °C and 0.5–1.5 % NaCl (w/v) for strains pair zg-686T/zg-691, and pH 7.0, 28 °C and 1.5 % (w/v) NaCl for strains pair HY186T/HY189. Based on these genotypic and phenotypic results, these four strains could be classified as two different novel species in the genus Gordonia , for which the names Gordonia jinghuaiqii sp. nov. and Gordonia zhaorongruii sp. nov. are proposed. The type strains are zg-686T (=GDMCC 1.1715T =JCM 33890T) and HY186T (=CGMCC 4.7607T =JCM 33466T), respectively.

Three novel actinomycete strains, designated as DR6-1T, DR6-2 and DR6-4, isolated from the roots of Dendrobium heterocarpum Lindl in Thailand were studied using a polyphasic taxonomic approach. The strains grew at 20–37 °C, at pH 5–10 and with 5 % (w/v) NaCl. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan and MK-9(H4) was a major menaquinone. Arabinose and galactose were the major sugars in the cell wall. The predominant cellular fatty acids were iso-C16 : 0 and iso-C15 : 0. The detected polar lipids were diphosphatidylglycerol, hydroxyphosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylglycerol. Strains DR6-1T, DR6-2 and DR6-4 shared 99.9–100 % 16S rRNA gene sequence similarity and were closely related to Amycolatopsis echigonensis JCM 21831T (98.7-98.8%). The approximate genome size of strain DR6-1T was 9.6 Mb with a G+C content of 69.6 mol%. The ANIb and dDDH values between genomic sequences of strain DR6-1T and Amycolatopsis echigonensis JCM21831T, Amycolatopsis rubida JCM 10871T and Amycolatopsis nivea KCTC 39515T were 90.55, 92.25, 92.60%, and 47.20, 52.10 and 52.50%, respectively. Based on the phenotypic, chemotaxonomic and genotypic characteristics, it has been concluded that strains DR6-1T, DR6-2 and DR6-4 represent a novel species of the genus Amycolatopsis for which the name Amycolatopsis dendrobii sp. nov. is proposed. The type strain is DR6-1T (=JCM 33742T=KCTC 49546T=TISTR 2840T).

A Gram-stain-positive, yellow-pigmented, non-motile actinobacterial strain, designated as BIT-GX5T, was isolated from a sesame husks compost collected in Beijing, PR China. This bacterium was found to be able to grow in the temperature range from 16 to 50 °C and had an optimal growth temperature at 45 °C. Its taxonomic position was analysed using a polyphasic approach. The 16S rRNA gene sequence (1482 bp) of strain BIT-GX5T was most similar to Cellulosimicrobium funkei ATCC BAA-886T (99.45%), Cellulosimicrobium cellulans LMG 16121T (99.17%) and Cellulosimicrobium marinum RS-7-4T (98.75%). The results of phylogenetic analyses, based on the 16S rRNA gene, concatenated sequences of five housekeeping genes (gyrB, rpoB, recA, atpD and trpB) and genome sequences, placed strain BIT-GX5T in a separate lineage among the genus Cellulosimicrobium within the family Promicromonosporaceae . The major polar lipids of strain BIT-GX5T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, aminophospholipid and aminolipid. The major isoprenoid quinone was MK-9(H4), while the cell-wall sugars were galactose, rhamnose, glucose and mannose. The peptidoglycan type was A4α l-Lys–d-Ser–d-Asp. The major fatty acids were anteiso-C15:0 and iso-C15: 0, which were similar to other members in the genus Cellulosimicrobium. Results of in silico DNA–DNA hybridization and average nucleotide identity calculations plus physiological and biochemical tests exhibited the genotypic and phenotypic differentiation of strain BIT-GX5T from the other members of the genus Cellulosimicrobium . Therefore, strain BIT-GX5T is considered to represent a novel species within the genus Cellulosimicrobium , for which the name Cellulosimicrobium composti sp. nov. is proposed. The type strain is BIT-GX5T (= CGMCC 1.17687T = KCTC 49391T).

A novel Gram-stain-positive, catalase-positive, oxidase-negative, aerobic, non-motile, rod-shaped bacterium, designated strain YIM M12148T, was isolated from a marine sediment sample collected from the Indian Ocean. The strain grew optimally at 28 °C, pH 8.0 and in the presence of 1–3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM M12148T belongs to the genus Gulosibacter , with the highest sequence similarity to Gulosibacter faecalis NBRC 15706T (96.12 %). The cell-wall sugars of strain YIM M12148T were rhamnose, ribose, glucose and mannose. The predominant isoprenoid quinones were MK-8 and MK-9. The polar lipids consisted of major amounts of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown lipid. Major fatty acids (>5 % of the total) of the novel isolate were anteiso-C15 : 0, iso-C15 : 0, iso-C13 : 0 and anteiso-C13 : 0. The genomic DNA G+C content of strain YIM M12148T was 67.15 mol%. On the basis of genotypic and phenotypic data, it is apparent that strain YIM M12148T represents a novel species of the genus Gulosibacter , for which the name Gulosibacter sediminis sp. nov. is proposed. The type strain is YIM M12148T (=KCTC 29660T=DSM 29154T).

In the present study, four bacterial strains, two (S-713T and 406) isolated from faecal samples of Tibetan antelopes and the other two (S-531T and 1598) from leaves of dandelion collected on the Qinghai–Tibet Plateau of PR China, were analysed using a polyphasic approach. All four isolates were aerobic, rod-shaped, non-motile, oxidase-negative, Gram-stain-positive and catalase-positive. According to four phylogenetic trees, strain pairs S-713T/406 and S-531T/1598 form two independent branches belonging to the genus Nocardioides , and are closest to Nocardioides lianchengensis , Nocardioides dokdonensis , Nocardioides salarius , Nocardioides marinisabuli , Nocardioides psychrotolerans and Nocardioides szechwanensis . Although sharing MK8-(H4) as their major isoprenoid quinone, strains S-713T and S-531T contained C18 : 1  ω9c (24.64 and 16.34 %) and iso-C16 : 0 (9.74 and 29.38 %), respectively, as their main fatty acids, with remarkable differences in their biochemical profiles but only slight ones in their optimal growth conditions. The chromosomes of strains S-713T and S-531T were 4 207 844 bp (G+C content, 73.0 mol%) and 4 809 817 bp (G+C content, 72.5 mol%), respectively. Collectively, the two strain pairs represent two separate novel species of the genus Nocardioides , for which the names Nocardioides dongkuii sp. nov. and Nocardioides lijunqiniae sp. nov. are proposed, with S-713T (=JCM 33698T=CGMCC 4.7660T) and S-531T (=JCM 33468T=CGMCC 4.7659T) as the respective type strains.

Two actinobacteria, designated as strain LDG1-01T and LDG1-06T, were isolated from lichen samples collected in Thailand. Results of morphological characterization, chemotaxonomic studies and 16S rRNA gene analysis indicated that both strains were members of the genus Actinoplanes . MK-9(H4) was found as the major menaquinone. The major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. Phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol were observed as the polar lipids, but differences in minor unidentified polar lipids were found between the strains. Results of comparative genome analysis based on average nucleotide identity and digital DNA–DNA hybridization calculations revealed that both strains showed values below 95 and 70 %, respectively, from each other and closely related Actinoplanes type strains. Based on data from this polyphasic study, strains LDG1-01T and LDG1-06T represent novel species of the genus Actinoplanes . The names proposed are Actinoplanes lichenicola sp. nov. (type strain, LDG1-01T (=JCM 33066T=TISTR 2982T) and Actinoplanes ovalisporus sp. nov. (type strain, LDG1-06T=JCM 33067T=TISTR 2983T).

A Gram-stain-positive, rod-shaped, aerobic, non-motile, non-sporulating bacterial strain, designated CSA1T, was isolated from chromium-containing soil sampled at a chemical plant. Growth of strain CSA1T occurred at pH 6–10 (optimum, pH 7), 15–45 °C (optimum, 30 °C) and in the presence of 0.5–6.5 % (w/v) NaCl (optimum, 2 %). The 16S rRNA gene sequence of strain CSA1T revealed the highest similarity to Leucobacter ruminantium A2T (97.5 %), Leucobacter tardus K 70/01T (97.3 %), Leucobacter humi Re6T (96.6 %), Leucobacter kyeonggiensis F3-P9T (96.2 %), Leucobacter zeae CC-MF41T (96.1 %) and Leucobacter weissii S27T (96.0 %). The draft genome of CSA1T was approximately 3 350 931 bp in size with a G+C content of 70.6 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values among strain CSA1T and the selected Leucobacter species were 74.0–79.2 % (ANIb), 84.3–87.1 % (ANIm) and 21.5–25.4 % (dDDH), which are below the recommended cutoff values for species delineation. The major fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The predominant menaquinones were MK-11, MK-8 and MK-6. The cell-wall amino acids were 2,4-diaminobutyric acid, alanine, glycine, glutamic acid and threonine. From the phenotypic, chemotaxonomic and molecular features, strain CSA1T was considered to represent a novel species of the genus Leucobacter , for which the name Leucobacter chromiisoli sp. nov. is proposed. The type strain is CSA1T (=JCM 34359T=CGMCC 1.18746T).