Biodegradation of low-density polyethylene by mixed fungi composed of Alternaria sp. and Trametes sp. isolated from landfill sites.

With the development of industry and modern manufacturing, nondegradable low-density polyethylene (LDPE) has been widely used, posing a rising environmental hazard to natural ecosystems and public health. In this study, we isolated a series of LDPE-degrading fungi from landfill sites and carried out LDPE degradation experiments by combining highly efficient degrading fungi in pairs. The results showed that the mixed microorganisms composed of Alternaria sp. CPEF-1 and Trametes sp. PE2F-4 (H-3 group) had a greater degradation effect on heat-treated LDPE (T-LDPE). After 30 days of inoculation with combination strain H-3, the weight loss rate of the T-LDPE film was approximately 154% higher than that of the untreated LDPE (U-LDPE) film, and the weight loss rate reached 0.66 ± 0.06%. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to further investigate the biodegradation impacts of T-LDPE, including the changes on the surface and depolymerization of the LDPE films during the fungal degradation process. Our findings revealed that the combined fungal treatment is more effective at degrading T-LDPE than the single strain treatment, and it is expected that properly altering the composition of the microbial community can help lessen the detrimental impact of plastics on the environment.

Lacibacter sediminis sp. nov., isolated from contaminated freshwater sediment.

Two Gram-stain-negative bacterial strains, S13-6-6 and S13-6-22T, were isolated from sediment sample collected at a water depth of 4 m from Lake Hongze, Jiangsu Province, PR China. The cells of strains S13-6-6 and S13-6-22T were non-spore-forming, aerobic, non-motile and formed orange colonies on R2A agar. Comparative 16S rRNA gene sequence studies revealed a clear affiliation of the two strains with he phylum Bacteroidota, and revealed the highest pairwise sequence similarities with Lacibacter daechungensis H32-4T (97.8 %), Lacibacter cauensis NJ-8T (97.8 %), Lacibacter luteus TTM-7T (97.4 %) and Lacibacter nakdongensis SS2-56T (97.4 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains formed a clear phylogenetic lineage with the genus Lacibacter. The major fatty acids were identified as iso-C15 : 1G, iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (>10 %), and the respiratory quinone was identified as menaquinone MK-7. The polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids, an unidentified phospholipid and six unidentified lipids. The genomic DNA G+C content was determined to be 40.2 mol% (HPLC) for strain S13-6-6 and 40.3 % (genome) for strain S13-6-22T. The combined genotypic and phenotypic data indicated that strains S13-6-6 and S13-6-22T represent a novel species of the genus Lacibacter, for which the name Lacibacter sediminis sp. nov. is proposed. The type strain is S13-6-22T (=CGMCC 1.17450T =JCM 35802T).

Description of Hymenobacter sediminicola sp. nov., isolated from contaminated sediment.

A polyphasic taxonomic study was conducted on two Gram-negative, non-sporulating, non-motile bacterial strains, S2-20-2T and S2-21-1, isolated from a contaminated freshwater sediment in China. Comparative 16S rRNA gene sequence studies revealed a clear affiliation of two strains with Bacteroidetes, which showed the highest pairwise sequence similarities with Hymenobacter duratus BT646T (99.3%), Hymenobacter psychrotolerans Tibet-IIU11T (99.3%), Hymenobacter kanuolensis T-3T (97.6%), Hymenobacter swuensis DY53T (96.9%), Hymenobacter tenuis POB6T (96.8%), Hymenobacter seoulensis 16F7GT (96.7%), and Hymenobacter rigui KCTC 12533T (96.5%). The phylogenetic analysis based on 16S rRNA gene sequences showed that two strains formed a clear phylogenetic lineage with the genus Hymenobacter. Major fatty acids were identified as iso-C15:0, anteiso-C15:0, and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c/t) and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). Major cellular polar lipids were identified as phosphatidylethanolamine, three unidentified aminolipids, an unidentified aminophosopholipid and an unidentified lipid. The respiratory quinone was detected as MK-7 and the genomic DNA G + C content was determined to be 57.9% (genome) for type strain S2-20-2T and 57.7 mol% (HPLC) for strain S2-21-1. The observed ANI and dDDH values between strain S2-20-2T and its closely related strains were 75.7-91.4% and 21.2-43.9%, respectively. Based on physiological, biochemical, genetic and genomic characteristics, we propose that strains S2-20-2T and S2-21-1 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter sediminicola sp. nov. is proposed. The type strain is S2-20-2T (= CGMCC 1.18734T = JCM 35801T).

Solihabitans fulvus gen. nov., sp. nov., a member of the family Pseudonocardiaceae isolated from soil.

A polyphasic taxonomic study was carried out on an actinobacterial strain (AN110305T) isolated from soil sampled in the Republic of Korea. Cells of the strain were Gram-stain-positive, aerobic, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of strain AN110305T with Actinomycetia, with highest pairwise sequence similarities to Goodfellowiella coeruleoviolacea DSM 43935T (97.6%), Umezawaea tangerina MK27-91F2T (97.0%), Kutzneria chonburiensis NBRC 110610T (96.9%), Kutzneria buriramensis A-T 1846T (96.8%), Umezawaea endophytica YIM 2047XT (96.8%), Kutzneria albida NRRL B-24060T (96.7%) and Saccharothrix coeruleofusca NRRL B-16115T (96.6%). Cells of strain AN110305T formed pale-yellow colonies on Reasoner's 2A agar. MK-9 (H4) (68%) and MK-10 (H4) (32%) were the predominant menaquinones. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethyl ethanolamine, hydroxy-phosphatidylethanolamine, an unidentified aminolipid and an unidentified aminophospholipid were major polar lipids. Iso-C16:0 (24.5%), anteiso-C15:0 (19.3%), anteiso-C17:0 (15.7%) and iso-C15:0 (15.2%) were the major fatty acids and meso-diaminopimelic acid was the pepdidoglycan. The cell-wall sugars were composed of galactose, glucose, mannose and ribose. The genomic DNA G+C content was 70.7 mol%. Based on genotypic and phenotypic data, strain AN110305T could be distinguished from all genera within the family Pseudonocardiaceae and represents a novel genus and species named Solihabitans fulvus gen. nov., sp nov. The type strain is AN110305T (=KCTC 39307T =DSM 103572T).

Salinarimonas soli sp. nov., isolated from soil.

A light pink coloured bacterium, designated strain BN140002T, was isolated from a soil sample collected in Goesan-gun, Chungcheongbuk-do, Republic of Korea. Cells of strain BN140002T were Gram-stain-negative, aerobic, motile and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed 94.7, 94.7, 93.9, 93.3, 93.4 and 93.0% similarities to Salinarimonas rosea KCTC 22346T, Salinarimonas ramus DSM 22962T, Saliniramus fredricksonii HL-109T, Microvirga soli R491T, Chelatococcus caeni EBR-4-1T and Chelatococcus composti PC-2T, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine. The major cellular fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 1 (C12 : 0 aldehyde and/or unknown 10.98) and the predominant ubiquinone was Q-10. The genomic DNA G+C content of strain BN140002T was 70.1 mol%. The genomic orthoANI values between strain BN140002T and Salinarimonas rosea KCTC 22346T and Salinarimonas ramus DSM 22962T were 75.0 and 74.8 %, respectively. Strain BN140002T had a class I-C type CRISPR-Cas system (CRISPR-associated helicase Cas3, CRISPR-associated protein Cas8c, CRISPR-associated protein Cas7, CRISPR-associated RecB family exonuclease Cas4, CRISPR-associated protein 1, 2). Based on phenotypic, chemotaxonomic and phylogenetic data, strain BN140002T should be assigned as a novel species of the genus Salinarimonas, for which the name Salinarimonas soli sp. nov. is proposed. The type strain is BN140002T (=KCTC 42643T=CCTCC AB 2017173T).

Nocardioides humilatus sp. nov., isolated from farmland soil in the Republic of Korea.

A Gram-stain positive, aerobic, irregularly rod-shaped, non-spore-forming bacterium, designated as BN130099T, was isolated from farmland soil sampled in Goesan-gun, Chungbuk, Republic of Korea. Phylogenetic analysis of its 16S rRNA gene sequence showed that the strain is closely related to Nocardioides pelophilus KACC 19192T with 98.11 % similarity. The DNA G+C content of strain BN130099T was 68.84 mol% (draft genome sequence). The genome sequence of BN130099T displayed key enzymes involved in bioremediation of organic pollutants and biosynthetic clusters of saquayamycin. The strain contained ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-8(H4) as the major respiratory quinone. The predominant fatty acid was iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. The results of physiological and biochemical characterization allowed the phenotypic differentiation of strain BN130099T from N. pelophilus KACC 19192T. The strain represents a novel species of the genus Nocardioides, for which we propose the name Nocardioides humilatus sp. nov. The type strain is BN130099T (=KCTC 49079T=CCTCC AB 2018135T).

Description of desferrioxamine-producing bacterium Chitinophaga agrisoli sp. nov., isolated from soil.

A Gram-stain-negative, non-motile, yellow-pigmented and non-spore forming rod-shaped bacterium, designated strain BN140078T, was isolated from farmland soil, Chungbuk, Republic of Korea. It was able to grow aerobically at 10-40 °C (optimum 28 °C), pH 5.5-7.5 (optimum pH 7.0) and with 0-2.0% (w/v) NaCl concentration (optimum 1.0%) on Reasoner's 2A (R2A) agar medium. Comparative 16S rRNA gene sequence analysis showed that the strain BN140078T had 96.9%, 96.5% and 96.1% 16S rRNA gene similarities with Chitinophaga ginsengihumi KACC 17604T, Chitinophaga rupis KACC 14521T and Chitinophaga japonensis KACC 12057T, respectively. The predominant respiratory quinone was menaquinone MK-7 and the major fatty acids (≥ 5%) were C16:1 ω5c, iso-C15:0, iso-C17:0 3-OH and Summed Feature 3 (C16:1 ω7c and/or C16:1 ω6c). The polar lipids were composed of phosphatidylethanolamine, four unidentified amino lipids and six unidentified lipids. The genomic DNA G+C content was 49.5 mol%. The genome of strain BN140078T comprises a number of biosynthetic gene clusters for secondary metabolites, in particular those for non-ribosomal peptide products. The polyphasic taxonomic study clearly distinguished this strain from its closest phylogenetic neighbors. Thus, we propose that the BN140078T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga agrisoli sp. nov. was proposed. The type strain is BN140078T (=KCTC 62555T = CCTCC AB 2018162T).

Nocardioides antri sp. nov., Isolated from Soil in a Rock Cave.

A Gram-positive, aerobic, rod-shaped, non-spore-forming bacterium, designated as BN140041T, was isolated from cave soil at Gubyeongsan Mountain, Boeun-gun, Chungbuk province in Republic of Korea. Phylogenetic analysis of the 16S rRNA gene sequence showed that the strain is closely related to Nocardioides silvaticus S-34 T, N. pelophilus THG-T63T, and N. immobilis FLL521T with 97.4%, 97.1%, and 96.8% similarity. The draft genome length was 4.27 Mb containing 424 contigs with a DNA G + C content of 70.5 mol%. The ANI value between strain BN140044T and its closely related species N. silvaticus S-34 T was 82.6%. The genome sequence of BN140041T displayed a key enzyme involved in the bioremediation of organic pollutants. The diagnostic diamino acid of peptidoglycan was LL-2,6-diaminopimelic acid. The major respiratory quinone was MK-8(H4), and the major fatty acids (> 5% of the total fatty acids) were iso-C16:0 (55.3%), C18:1ω9c (7.7%) and iso-C17:0 (5.7%). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and phosphatidylinositol. The results of genotypical, physiological, and biochemical characterization allow the phenotypic differentiation of strain BN140041T from related the Nocardioides strains. Therefore, strain BN140041T represents a novel species of the genus Nocardioides, for which we propose the name Nocardioides antri sp. nov. The type strain is BN140041T (= KCTC 49080 T = CCTCC AB 2018226 T).

Paraconexibacter algicola gen. nov., sp. nov., a novel actinobacterium isolated from a eutrophic lake during the end of cyanobacterial harmful algal blooms, and proposal of Paraconexibacteraceae fam. nov. in the order Solirubrobacterales.

A novel bacterium, strain Seoho-28T, was isolated from a shallow eutrophic lake during the end of cyanobacterial harmful algal blooms and was characterized taxonomically and phylogenetically. Strain Seoho-28T was a Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium. The strain grew optimally with 0 % NaCl and at 25-30 °C on Reasoner's 2A medium. The phylogenetic analysis based on 16S rRNA gene sequences positioned the novel strain among the order Solirubrobacterales, but sequence similarities to known species were less than 94.7 %. The genomic DNA G+C content of the strain Seoho-28T was 74.2 mol%. Genomic comparisons of strain Seoho-28T with families in the order Solirubrobacterales were made using the Genome-to-Genome Distance Calculator, average nucleotide identity and average amino acid identity analyses (values indicated ≤14.9, ≤73.5 and ≤57.8 %, respectively). Strain Seoho-28T contained C16 : 0-iso, C18 : 1 ω9c and C16 : 0 as major fatty acids and MK-7 (H4) as the major quinone. Strain Seoho-28T contained diphosphatidylglycerol, phosphatidylinositol and an unidentified phospholipid as major polar lipids. Meso- and ll-diaminopimelic acids were the diagnostic diamino acids in the cell-wall peptidoglycan. Based on the genotypic, chemotaxonomic and phenotypic results, strain Seoho-28T represents a novel genus and species, Paraconexibacter algicola gen. nov., sp. nov., which belongs to a new family Paraconexibacteraceae in the order Solirubrobacterales and the class Thermoleophilia. The type strain is Seoho-28T (=KCTC 39791T=JCM 31881T).

Tabrizicola algicola sp. nov. isolated from culture of microalga Ettlia sp.

A novel Gram-stain-negative, aerobic, non-spore-forming, non-motile, and rod-shaped bacterium, strain ETT8T was isolated from a chemostat culture of microalga Ettlia sp. YC001. Optimal growth was with 0-2% NaCl and at 25-37 °C on R2A medium. Phylogenetic analysis based on the 16S rRNA gene and genome sequence showed that strain ETT8T belongs to the genus Tabrizicola, with the close neighbours being T. sediminis DRYC-M-16T (98.1 %), T. alkalilacus DJCT (97.6 %), T. fusiformis SY72T (96.9 %), T. piscis K13M18T (96.8 %), and T. aquatica RCRI19T (96.5 %). The genomic comparison of strain ETT8T with type species in the genus Tabrizicola was analysed using the genome-to-genome distance calculator (GGDC), average nucleotide identity (ANI), and average amino acid identity (AAI) (values indicated ≤17.7, ≤75.4 and ≤71.9 %, respectively). The genomic DNA G+C content of strain ETT8T was 64.4 %, plus C18 : 1 ω6c and C18 : 0-iso were the major fatty acids and Q-10 the major respiratory quinone. Strain ETT8T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine aminolipid, and four unidentified lipids as the major polar lipids. Based on the chemotaxonomic, genotypic, and phenotype results, strain ETT8T was recognized as a novel species of the genus Tabrizicola for which the name Tabrizicola algicola sp. nov. is proposed. The type strain is ETT8T (=KCTC 72206T=JCM 31893T=MCC 4339T).

Lysobacter profundi sp. nov., isolated from freshwater sediment and reclassification of Lysobacter panaciterrae as Luteimonas panaciterrae comb. nov.

A polyphasic taxonomic study was carried out on strains CHu50b-3-2T and CHu40b-3-1 isolated from a 67 cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of the strains were Gram-stain-negative, non-spore-forming, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of two strains with γ-Proteobacteria, which showed the highest pairwise sequence similarities to Lysobacter hankyongensis KTce-2T (96.5 %), Lysobacter pocheonensis Gsoil193T (96.3 %), Lysobacter ginsengisoli Gsoil 357T (96.1 %), Lysobacter solanacearum T20R-70T (96.1 %), Lysobacter brunescens KCTC 12130T (95.4 %) and Lysobacter capsici YC5194T (95.3 %). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Lysobacter. The major fatty acids were identified as summed feature 9 (iso-C17 : 1 ω9c and/or C18 : 1 10-methyl), iso-C15 : 0, iso-C16 : 0 and iso-C17 : 0. The respiratory quinone was identified as ubiquinone Q-8. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G+C content was determined to be 66.8 mol% (genome) for strain CHu50b-3-2T and 66.4 mol% (HPLC) for strain CHu40b-3-1. Based on the combined genotypic and phenotypic data, we propose that strains CHu50b-3-2T and CHu40b-3-1 represent a novel species of the genus Lysobacter, for which the name Lysobacter profundi sp. nov. is proposed. The type strain is CHu50b-3-2T (=KCTC 72973T=CCTCC AB 2019129T). Besides Lysobacter panaciterrae Gsoil 068T formed a phylogenetic group together with strain Luteimonas aquatica RIB1-20T (EF626688) that is clearly separated from all other known Lysobacter strains. Based on the phylogenetic relationships together with fatty acid compositions, Lysobacter panaciterrae Gsoil 068T should be reclassified as a member of the genus Luteimonas: Luteimonas aquatica comb. nov. (type strain Gsoil 068T=KCTC 12601T=DSM 17927T).

Caulobacter soli sp. nov., isolated from soil sampled at Jiri Mountain, Republic of Korea.

A Gram-stain-negative, yellow-pigmented, aerobic, non-spore-forming, motile with a single polar flagellum and rod-shaped bacterium, Ji-3-8T, was isolated from a soil sample taken from Jiri Mountain, Republic of Korea. Comparative 16S rRNA gene sequence studies showed the isolate had clear affiliation with Alphaproteobacteria and the closest relatedness to Caulobacter rhizosphaerae KCTC 52515T, Caulobacter henricii ATCC 15253T, Caulobacter segnis ATCC 21756T, Caulobacter hibisci THG-AG3.4T, Caulobacter flavus RHGG3T and Caulobacter vibrioides CB51T showing 99.1, 98.9, 97.7, 97.6, 97.5 and 97.4 % 16S rRNA gene sequence similarity, respectively, and 94.7-96.5 % to the remaining species of genus Caulobacter. The predominant ubiquinone was Q-10 and the major fatty acids were C18 : 1 ω7c 11-methyl, C16 : 0, summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c) and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The major polar lipids were found to be phosphatidylglycerol, two unidentified phosphoglycolipid and two unidentified glycolipids. The G+C content of the genomic DNA of strain Ji-3-8T was 68.1 mol%. Average nucleotide identity and digital DNA-DNA hybridization values of strain Ji-3-8T with C. rhizosphaerae KCTC 52515T, C. henricii ATCC 15253T, C. segnis ATCC 21756T, C. flavus RHGG3T and C. vibrioides were 79.7-87.7% and 23.0-34.3%, respectively. Based on the polyphasic evidence, it is proposed that strain Ji-3-8T forms a novel species in the genus Caulobacter, for which the name Caulobacter soli sp. nov. is proposed. The type strain is Ji-3-8T (=CCTCC AB 2019389T=KCTC 72990T).

Genomic insights into a novel species Rhodoferax aquaticus sp. nov., isolated from freshwater.

A novel non-phototrophic member of the genus Rhodoferax was obtained from freshwater. The purpose of this study was to analyse the genome of a nonphototrophic strain and propose a new species based on its phylogenetic, genomic, physiological and chemotaxonomic characteristics. The results of phylogenetic analysis based on 16S rRNA gene sequences supports that the strain, designated Gr-4T, has a close relationship to the genus Rhodoferax. The observed average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain Gr-4T and its closest related strains were 72.3-74.6 % and 21.9-22.8 %, respectively. These values were much lower than the species separation thresholds for ANI or dDDH of 95-96 and 70 %, respectively, and in fact fall in the intergeneric range. Strain Gr-4T does not contain RuBisCO-related genes, but does contain GS/GOGAT pathway-related genes enabling nitrate ammonification. A polyphasic study and a genomic-level investigation were done to establish the taxonomic status of strain Gr-4T. Based on the phylogenetic, genomic and physiological differences, it is proposed that the isolate be classified to the genus Rhodoferax as Rhodoferax aquaticus sp. nov. with isolate Gr-4T (=KCTC 32394T=JCM 19166T) as the type strain.

Lacisediminimonas profundi gen. nov., sp. nov., a member of the family Oxalobacteraceae isolated from freshwater sediment.

A novel Gram-stain-negative bacterial strain, CHu64-6-4T, was isolated from a 67-cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of strain CHu64-6-4T were aerobic nonmotile and formed colorless colonies on R2A agar. The phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain formed a separate lineage within the family Oxalobacteraceae, exhibiting 97.2% and 97.1% 16S rRNA gene sequence similarities to Glaciimonas singularis and Paraherbaspirillum soli, respectively. Strain CHu64-6-4T showed less than 74.4% average nucleotide identity compared to the type strains of related genera within the family Oxalobacteraceae. In the UPGMA dendrogram based on the ANI values of genomic sequences, strain CHu64-6-4T formed an evolutionary lineage independent of the genera Glaciimonas and some other taxa. The chemotaxonomic results showed Q-8 as the predominant respiratory ubiquinone, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethnolamine as the major polar lipids, Summed Feature 3 (C16:1ω7c and/or iso-C15:0 2-OH), C16:0, and C18:1ω7c as the major fatty acids, and a DNA G+C content of 62.1 mol%. The combined genotypic and phenotypic data showed that strain CHu64-6-4T could be distinguished from all genera within the family Oxalobacteraceae and represents a novel genus, Lacisediminimonas profundi gen. nov., with the name Lacisediminimonas profundi sp. nov., in the family Oxalobacteraceae. The type strain is CHu64-6-4T (=KCTC 62287T=JCM 32676T).

Lacisediminihabitans profunda gen. nov., sp. nov., a member of the family Microbacteriaceae isolated from freshwater sediment.

A novel Gram-stain-positive bacterial strain, CHu50b-6-2T, was isolated from a 67-cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of strain CHu50b-6-2T were aerobic non-motile and formed yellow colonies on R2A agar. The phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain formed a separate lineage within the family Microbacteriaceae, exhibiting 98.0%, 97.7% and 97.6% 16S rRNA gene sequence similarities to Glaciihabitans tibetensis KCTC 29148T, Frigoribacterium faeni KACC 20509T and Lysinibacter cavernae DSM 27960T, respectively. The phylogenetic trees revealed that strain CHu50b-6-2T did not show a clear affiliation to any genus within the family Microbacteriaceae. The chemotaxonomic results showed B1α type peptidoglacan containg 2, 4-diaminobutyric acid (DAB) as the diagnostic diamino acid, MK-10 as the predominant respiratory menaquinone, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified glycolipid as the major polar lipids, anteiso-C15:0, iso-C16:0, and anteiso-C17:0 as the major fatty acids, and a DNA G + C content of 67.3 mol%. The combined genotypic and phenotypic data showed that strain CHu50b-6-2T could be distinguished from all genera within the family Microbacteriaceae and represents a novel genus, Lacisediminihabitans gen. nov., with the name Lacisediminihabitans profunda sp. nov., in the family Microbacteriaceae. The type strain is CHu50b-6-2T (= KCTC 49081T = JCM 32673T).

Description of novel members of the family Sphingomonadaceae: Aquisediminimonas profunda gen. nov., sp. nov., and Aquisediminimonas sediminicola sp. nov., isolated from freshwater sediment.

Two Gram-stain-negative bacterial strains, DS48-3T and CH68-4T, were isolated from freshwater sediment taken from the Daechung Reservoir, Republic of Korea. Cells of strains DS48-3T and CH68-4T were aerobic, non-motile, non-spore-forming and rod-shaped. Strain DS48-3T was isolated from a sediment surface sample at a depth of 48 m from the Daechung Reservoir and was most closely related to the genus Sphingopyxis according to 16S rRNA gene sequence analysis (94.5-95.9 % similarity). Strain CH68-4T was isolated from the very bottom of a 67-cm-long sediment core collected from Daechung Reservoir at a water depth of 17 m and was most closely related to the genus Sphingopyxis (16S rRNA gene sequence similarity of 93.7-95.0 %). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the two strains formed a separate lineage within the order Sphingomonadales showing similarity values below 95.9 % with their closest phylogenetic neighbours, and sharing 97.3 % similarity with each other. The combined genotypic and phenotypic data showed that strains DS48-3T and CH68-4T could be distinguished from all genera within the family Sphingomonadaceae and represented two distinct species of a novel genus, Aquisediminimonas profunda gen. nov., sp. nov. (type strain DS48-3T=KCTC 52068T=CCTCC AB 2018061T) and Aquisediminimonas sediminicola sp. nov. (type strain CH68-4T=KCTC 62205T=CCTCC AB 2018062T).

Flavitalea flava sp. nov., a bacterium isolated from a soil sample, and emended description of the genus Flavitalea.

A Gram-stain negative strain, designated AN120636T, was isolated from a soil sample collected from Goesan-gun, Chungbuk, South Korea. The strain was strictly aerobic, with golden yellow-pigmented colonies on R2A agar. Cells were non-motile, long or short rods and some were observed to be coccal. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain AN120636T belongs to the genus Flavitalea in the family of Chitinophagacea, with Flavitalea populi (95.4%), Pseudoflavitalea soli (95.0%), Flavitalea gansuensis (94.7%) and Pseudoflavitalea rhizosphaerae (94.7%) as its close relatives. Growth was observed at 15-32 °C, pH 5.0-7.0 and in the absence of NaCl. The strain contained iso-C17:0 3-OH, iso-C15:1 G and iso-C15:0 as its major cellular fatty acids; phosphatidylethanolamine as the major polar lipid; MK-7 as its respiratory quinone; and the polyamine was homospermidine. The genomic DNA G+C content was 44.8 mol%. On the basis of the polyphasic evidence, strain AN120636T is considered to represent a novel species, for which the name Flavitalea flava sp. nov. is proposed. The type strain is AN120636T (=KCTC 52346T=CCTCC AB 2017174T).

Aurantisolimonas haloimpatiens gen. nov., sp. nov., a bacterium isolated from soil.

A Gram-stain negative, strictly aerobic and non-motile bacterium, designated strain BN130233T, was isolated from a soil sample collected from Gyeongsangbuk-do, Republic of Korea. Colonies were orange in colour, with wet and smooth surfaces. Phylogenetic analyses based on the 16S rRNA gene sequences resulted in strain BN130233T forming a cluster with members of the family Chitinophagaceae Kämpfer et al. 2011, while sharing the highest sequence identity of 91.2 % with Chitinophaga niastensis JS16-4T. Good growth was observed at 20-28 °C, pH 7.0 and in the absence of NaCl. The major fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The respiratory quinone was MK-7. Major polar lipids contained phosphatidylethanolamine, an unidentified phospholipid, three unidentified aminolipids and eight unidentified lipids. The genomic DNA G+C content was 40.6 mol%. Phenotypic and chemotaxonomic characteristics together with 16S rRNA gene sequence analyses showed that strain BN130233T was distinct from its close phylogenetic relatives in the family ChitinophagaceaeKämpfer et al. 2011. The strain is, therefore, proposed as a representative of a new genus and new species with the name Aurantisolimonas haloimpatiens. The type strain of Aurantisolimonas haloimpatiens is BN130233T (=CCTCC AB 2017051T=KCTC 42642T).

Stackebrandtia soli sp. nov., a novel actinobacterium isolated from a soil sample.

An aerobic actinobacterium, strain AN130378T, was isolated from a soil sample collected in Korea and subjected to taxonomic investigation using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence data showed that strain AN130378T is a member of the genus Stackebrandtia, with sequence similarities of 97.3 % to Stackebrandtia albiflava YIM 45751T and 97.1 % to Stackebrandtia endophytica YIM 64602T. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, and galactose, glucose and xylose. The major menaquinones were MK-11(H4), MK-10(H4) and MK-11(H6), while the major fatty acids were identified as iso-C15 : 0, anteiso-C17 : 0, anteiso-C15 : 0, iso-C17 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, an unidentified aminophospholipid, four unidentified glycolipids, three unidentified phospholipids and two unidentified polar lipids. The G+C content of the genomic DNA was determined to be 67.7 mol%. All chemotaxonomic and genotypic data indicated that the strain belongs to the genus Stackebrandtia. On the basis of morphological, chemotaxonomic data and phylogenetic analysis, strain AN130378T is considered to represent a novel species within the genus Stackebrandtia, for which the name Stackebrandtia soli sp. nov. is proposed. The type strain is AN130378T (=DSM 103573T=KCTC 39809T).