Aquariibacter albus gen. nov., sp. nov., a new member of the order Burkholderiales, isolated from a freshwater aquarium.

A novel bacterium, strain SJAQ100T, was isolated from a freshwater aquarium and was characterized taxonomically and phylogenetically. Strain SJAQ100T was a Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium. The strain grew optimally with 0 % NaCl and at 25-37 °C on Reasoner's 2A agar. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strain SJAQ100T clustered with members of Burkholderiales incertae sedis in the order Burkholderiales, but sequence similarities to known species were less than 96.5 %. The genomic DNA G+C content of strain SJAQ100T was 71.2 mol%. Genomic comparisons of strain SJAQ100T with species in the order Burkholderiales were made using the Genome-to-Genome Distance Calculator, average nucleotide identity and average amino acid identity analyses (values indicated ≤22.1, ≤78.1, and ≤68.1 % respectively). Strain SJAQ100T contained C16 : 0 and C16 : 1 ω7c/C16 : 1 ω6c as major fatty acids and Q-8 as the major quinone. The major polyamines were putrescine and cadaverine. Strain SJAQ100T contained phosphatidylethanolamine and diphosphatidylglycerol as major polar lipids. Based on the genotypic, chemotaxonomic and phenotypic results, strain SJAQ100T represents a novel genus and species, Aquariibacter albus gen. nov., sp. nov., which belongs to order Burkholderiales and the class Betaproteobacteria. The type strain is SJAQ100T (=KCTC 72203T=CGMCC 1.18869T=MCC 4385T).

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).

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).

Nevskia lacus sp. nov., a gammaproteobacterium isolated from a eutrophic lake.

A novel Gram-stain negative, rod-shaped and motile bacterial strain, designated strain Seoho-38T, was isolated from a eutrophic lake in South Korea. Polyphasic taxonomic studies were performed to investigate the taxonomic position of the new isolate. The phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain Seoho-38T formed a distinct cluster with Nevskia ramosa Soe1T, Nevskia persephonica G6M-30T, Nevskia soli GR15-1T, Nevskia terrae KIS13-15T and Nevskia aquatilis F2-63T with bootstrap resampling value of 100%. Of those Nevskia strains, the new isolate shows high sequence similarity with N. ramosa Soe1T (98.7%) and N. persephonica G6M-30T (97.2%), and values lower than 96.5% with the other type strains. The new isolate was observed to grow aerobically in 0-1.5% (w/v) NaCl (optimum 0%), at pH 7.0-9.0 (optimum pH 7.0) and temperature 15-36 °C (optimum 20-30 °C) on R2A medium. DNA-DNA relatedness values between strain Seoho-38T and the type strains of reference species in the genus Nevskia were < 24%. The genomic DNA G + C content was determined to be 67.4 mol%. Ubiquinone-8 (Q-8) (95%) and ubiquinone-7 (Q-7) (5%) were identified as the respiratory quinones. The cellular polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a phosphoaminolipid, two glycolipids, an aminolipid and four unidentified lipids. The major fatty acid components were found to include summed feature 3 (C16:1ω7c and/or C16:1ω6c), summed feature 8 (C18:0ω7c and/or C18:0ω6c), C16:0 and C14:0. Based on the above polyphasic evidence, strain Seoho-38T (= KCTC 52221T = JCM 31888T) represents a new species of the genus Nevskia, for which the name Nevskia lacus sp. nov. is proposed.

Silanimonas algicola sp. nov., isolated from laboratory culture of a bloom-forming cyanobacterium, Microcystis.

A Gram-stain-negative, aerobic, rod-shaped and motile bacterium, designated M23T, was isolated from a laboratory culture of a bloom-forming cyanobacterium, Microcystis, which was isolated from a eutrophic lake in Korea. The strain grew optimally without NaCl and at 25-30 °C on R2A agar medium. Phylogenetic analysis based on 16S rRNA gene sequences positioned the novel strain among the genus Silanimonas, with the highest similarity to Silanimonas lenta DSM 16282T (98.5 %). DNA-DNA relatedness between strain M23T and the closely related species in the genus Silanimonas was <30 %. Strain M23T contained iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C16 : 0 as major fatty acids and ubiquinone-8 (Q-8) as the major quinone. Strain M23T contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylmethylethanolamine as major polar lipids. The DNA G+C content of strain M23T was 69.6 mol%. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain M23T represents a novel species in the genus Silanimonas, for which the name Silanimonas algicola sp. nov. is proposed. The type strain is M23T (=KCTC 52219T=JCM 31889T).

Reyranella aquatilis sp. nov., an alphaproteobacterium isolated from a eutrophic lake.

A novel Gram-stain-negative, rod-shaped and non-motile bacterial strain, designated strain Seoho-37T, was isolated from a eutrophic lake in South Korea. Polyphasic studies were performed to investigate the taxonomic position of the new isolate. The isolate grew aerobically with 0-1.0 % (w/v) NaCl (optimum 0 %), at pH 6.0-10.0 (optimum pH 7.0-9.0) and at temperatures of 15-36 °C (optimum 25-30 °C) on R2A medium. In the phylogenetic analysis of 16S rRNA gene sequences, strain Seoho-37T formed a clear cluster with the strains of Reyranella graminifolii, Reyranella massiliensis and Reyranella soli with a bootstrap resampling value of 100 %. DNA-DNA relatedness between strain Seoho-37T and the type strains of each species in the genus Reyranella was <20 %. The genomic DNA G+C content of strain Seoho-37T was 66.5 mol%. Ubiquinone-10 (Q-10) and ubiquinone-9 (Q-9) were found as the respiratory quinones. The cellular polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol and phosphatidylmethylethanolamine. The major fatty acid components included C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C18 : 1 2-OH. Based on the above evidence from a polyphasic study, strain Seaho-37T represents a novel species of the genus Reyranella, for which the name Reyranella aquatilis sp. nov. is proposed. The type strain is Seoho-37T (=KCTC 52223T=JCM 31892T).

Acidovorax lacteus sp. nov., isolated from a culture of a bloom-forming cyanobacterium (Microcystis sp.).

A novel Gram-negative, rod-shaped and motile bacterial strain, designated strain M36T, was isolated from a culture of a bloom-forming cyanobacterium, Microcystis sp., collected from a eutrophic lake in Korea. Its taxonomic position was investigated by using a polyphasic taxonomic approach. The isolate was found to grow aerobically at 15-42 °C (optimum 25 °C), pH 7.0-11.0 (optimum pH 8.0) and in the presence of 0-1.0% (w/v) NaCl (optimum 0% NaCl) on R2A medium. The phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain M36T is closely related to Acidovorax anthurii DSM 16745T (98.1%), Acidovorax konjaci DSM 7481T (97.7%) and Acidovorax avenae DSM 7227T (97.0%) and also formed a clear phylogenetic lineage with other Acidovorax species. DNA-DNA relatedness between strain M36T and the closely related species of the genus Acidovorax was <30%. The major fatty acid components identified included summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0 and summed feature 8 (C18:0 ω7c and/or C18:0 ω6c). The DNA G+C content of strain M36T was determined to be 66.8 mol%. Based on above polyphasic evidence, strain M36T is concluded to represent a new species of genus Acidovorax, for which the name Acidovorax lacteus sp. nov. is proposed. The type strain is M36T (=KCTC 52220T = JCM 31890T).

Pusillimonas caeni sp. nov., isolated from a sludge sample of a biofilm reactor.

A polyphasic taxonomic study was carried out on strain EBR-8-1T isolated from a biofilm reactor in Korea. The cells of the strain were Gram-stain negative, non-spore-forming, non-motile, and short rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of this strain with Betaproteobacteria, which showed high pairwise sequence similarities with Pusillimonas noertemannii BN9T (99.1 %), Pusillimonas soli MJ07T (97.3 %), Pusillimonas ginsengisoli DCY25T (97.2 %), and Pusillimonas harenae B201T (96.8 %). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a clear phylogenetic lineage within the genus Pusillimonas. The major fatty acids were identified as C16:0, C17:0 cyclo and C19:0 cyclo ω8c. The major cellular polar lipids were identified as phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified aminolipid. The respiratory quinone was identified as Q-8 and the genomic DNA G+C content was determined to be 63.3 mol%. On the basis of polyphasic evidence, it is proposed that strain EBR-8-1T should be placed in a new species, Pusillimonas caeni sp. nov. The type stain is EBR-8-1T (=KCTC 42353T = JCM 30463T).

Abundance and distribution of dimethylsulfoniopropionate degradation genes and the corresponding bacterial community structure at dimethyl sulfide hot spots in the tropical and subtropical pacific ocean.

Dimethylsulfoniopropionate (DMSP) is mainly produced by marine phytoplankton but is released into the microbial food web and degraded by marine bacteria to dimethyl sulfide (DMS) and other products. To reveal the abundance and distribution of bacterial DMSP degradation genes and the corresponding bacterial communities in relation to DMS and DMSP concentrations in seawater, we collected surface seawater samples from DMS hot spot sites during a cruise across the Pacific Ocean. We analyzed the genes encoding DMSP lyase (dddP) and DMSP demethylase (dmdA), which are responsible for the transformation of DMSP to DMS and DMSP assimilation, respectively. The averaged abundance (±standard deviation) of these DMSP degradation genes relative to that of the 16S rRNA genes was 33% ± 12%. The abundances of these genes showed large spatial variations. dddP genes showed more variation in abundances than dmdA genes. Multidimensional analysis based on the abundances of DMSP degradation genes and environmental factors revealed that the distribution pattern of these genes was influenced by chlorophyll a concentrations and temperatures. dddP genes, dmdA subclade C/2 genes, and dmdA subclade D genes exhibited significant correlations with the marine Roseobacter clade, SAR11 subgroup Ib, and SAR11 subgroup Ia, respectively. SAR11 subgroups Ia and Ib, which possessed dmdA genes, were suggested to be the main potential DMSP consumers. The Roseobacter clade members possessing dddP genes in oligotrophic subtropical regions were possible DMS producers. These results suggest that DMSP degradation genes are abundant and widely distributed in the surface seawater and that the marine bacteria possessing these genes influence the degradation of DMSP and regulate the emissions of DMS in subtropical gyres of the Pacific Ocean.

Brevibacterium daeguense sp. nov., a nitrate-reducing bacterium isolated from a 4-chlorophenol enrichment culture.

A Gram-reaction-positive, non-spore-forming, aerobic actinobacterial strain (2C6-41(T)) was isolated from the activated sludge from an industrial wastewater treatment plant in Daegu, South Korea. Its taxonomic position was investigated by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity, closest phylogenetic relatives to strain 2C6-41(T) were Brevibacterium pityocampae DSM 21720(T) (97.2 %), Brevibacterium salitolerans KCTC 19616(T) (96.7 %), Brevibacterium album KCTC 19173(T) (96.2 %) and Brevibacterium samyangense KCCM 42316(T) (96.2 %). The DNA G+C content of strain 2C6-41(T) was 66.4 mol%. Chemotaxonomic data, which included MK-8(H(2)) as the major menaquinone; meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; ribose, mannose and glucose as major cell-wall sugars; and anteiso-C(15 : 0), anteiso-C(17 : 0), C(16 : 0) and iso-C(15 : 0) as major fatty acids, supported the affiliation of strain 2C6-41(T) to the genus Brevibacterium. The aromatic ring cleavage enzyme catechol 1,2-dioxygenase was not detected in strain 2C6-41(T), but catechol 2,3-dioxygenase was detected. The results of physiological and biochemical tests, and the low level of DNA-DNA relatedness to the closest phylogenetic relative enabled strain 2C6-41(T) to be differentiated genotypically and phenotypically from recognized species of the genus Brevibacterium. The isolate is therefore considered to represent a novel species in the genus Brevibacterium, for which the name Brevibacterium daeguense sp. nov. is proposed. The type strain is 2C6-41(T) (=KCTC 19800(T) = JCM 17458(T)).

Nocardioides daeguensis sp. nov., a nitrate-reducing bacterium isolated from activated sludge of an industrial wastewater treatment plant.

A Gram-reaction-positive, rod-shaped, non-spore-forming bacterium (strain 2C1-5(T)) was isolated from activated sludge of an industrial wastewater treatment plant in Daegu, South Korea. Its taxonomic position was investigated by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity, the closest phylogenetic relatives were the type strains of Nocardioides nitrophenolicus (98.6 % similarity), N. kongjuensis (98.5 %), N. caeni (98.4 %), N. simplex (98.3 %), N. aromaticivorans (98.1 %) and N. ginsengisoli (97.5 %); the phylogenetic distance from other species with validly published names within the genus Nocardioides was greater than 3 %. Strain 2C1-5(T) was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H4) as the predominant menaquinone and iso-C16 : 0, C16 : 0 and C17 : 1ω6c as the major fatty acids. The G+C content of the genomic DNA was 74.9 mol%. These chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain 2C1-5(T) to the genus Nocardioides. The results of physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain 2C1-5(T) from existing species with validly published names. Therefore, strain 2C1-5(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides daeguensis sp. nov. is proposed, with the type strain 2C1-5(T) ( = JCM 17460(T) = KCTC 19799(T)).

Microbiome dataset of bacterial and fungal communities in anthosphere of twelve different wild plants in South Korea.

This dataset provides detailed profiles of bacterial and fungal communities associated with flowers (anthosphere) of 12 different plant species collected from remote and secluded locations characterized by a flourishing and diverse plant ecosystem. In total, 144 flower samples were collected from 12 different wild plants. Bacterial 16S rRNA and fungal ITS genes obtained using the Illumina Miseq approach were used to describe the anthosphere. Metadata and raw sequences obtained in this study are available from the National Center for Biotechnology Information (BioProject ID: PRJNA983070). Amplicon Sequence Variants (ASVs) of bacteria and fungi were analyzed using the DADA2 pipeline. After quality filtering, trimming, and removing the chimeric sequences, 2076 bacterial and 2152 fungal ASVs were identified in the anthosphere. Burkholderiales and Enterobacterales in bacteria, and Pleosporales in fungi were the predominant groups in the anthosphere regardless of the plant species. Among the twelve different plant species, Forsythia koreana exhibited the highest abundance of both bacterial and fungal groups. This dataset represents a detailed exploration of the anthosphere in the most abundant and commonly observed plant species in South Korea, and provides new insights into the microbial communities and interactions of the anthosphere.

Vegetation as a key driver of the distribution of microbial generalists that in turn shapes the overall microbial community structure in the low Arctic tundra.

Understanding the variability of microbial niches and their interaction with abiotic and biotic factors in the Arctic can provide valuable insights into microbial adaptations to extreme environments. This study investigates the structure and diversity of soil bacterial communities obtained from sites with varying vegetation coverage and soil biogeochemical properties in the low Arctic tundra and explores how bacteria interact under different environmental parameters. Our findings reveal differences in bacterial composition and abundance among three bacterial niche breadths (specialists, common taxa, and generalists). Co-occurrence network analysis revealed Rhizobiales and Ktedonobacterales as keystone taxa that connect and support other microbes in the habitat. Low-elevation indicators, such as vascular plants and moisture content, were correlated with two out of three generalist modular hubs and were linked to a large proportion of generalists' distribution (18%). Structural equation modeling revealed that generalists' distribution, which influenced the remaining microbial communities, was mainly regulated by vegetation coverage as well as other abiotic and biotic factors. These results suggest that elevation-dependent environmental factors directly influence microbial community structure and module formation through the regulation of generalists' distribution. Furthermore, the distribution of generalists was mainly affected by macroenvironment filtering, whereas the distribution of specialists was mainly affected by microenvironment filtering (species-engineered microbial niche construction). In summary, our findings highlight the strong top-down control exerted by vegetation on generalists' distribution, which in turn shapes the overall microbial community structure in the low Arctic tundra.

Paenibacillus sediminis sp. nov., a xylanolytic bacterium isolated from a tidal flat.

A Gram-positive, rod-shaped, xylanolytic, spore-forming bacterium, strain GTH-3(T), was isolated from a tidal flat adjacent to Ganghwa Island, Republic of Korea, and was characterized to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain GTH-3(T) was shown to belong to the family Paenibacillaceae, being most closely related to the type strains of Paenibacillus ginsengisoli (94.9 %), Paenibacillus anaericanus (94.8 %), Paenibacillus urinalis (94.4 %), Paenibacillus cookii (94.2 %), Paenibacillus alvei (94.1 %) and Paenibacillus chibensis (94.0 %). The G+C content of the genomic DNA of strain GTH-3(T) was 45.9±0.2 mol% (mean±sd). The major menaquinone was MK-7. The major fatty acids were anteiso-C(15:0) and iso-C(16:0). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phenotypic and chemotaxonomic data supported the affiliation of strain GTH-3(T) to the genus Paenibacillus. The results of physiological and biochemical tests allowed strain GTH-3(T) to be distinguished genotypically and phenotypically from recognized species of the genus Paenibacillus. Strain GTH-3(T) is therefore considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus sediminis sp. nov. is proposed. The type strain is GTH-3(T) ( = DSM 23491(T) = LMG 25635(T)).

Streptomyces panacagri sp. nov., isolated from soil of a ginseng field.

A Gram-positive, spore-forming, aerobic actinomycete, strain Gsoil 519T, was isolated from soil of a ginseng field of Pocheon province in South Korea. The closest phylogenetic relatives were Streptomyces marinus Sp080513GE-26T (97.94 % 16S rRNA gene sequence similarity), Streptomyces albiaxialis NRRL B-24327T (97.84 %), Streptomyces albus subsp. albus DSM 40313T (97.84 %), Streptomyces almquistii NBRC 13015T (97.81 %), Streptomyces gibsonii NBRC 15415T (97.81 %), Streptomyces rangoonensis NBRC 13078T (97.81 %), Streptomyces sodiiphilus YIM 80305T (97.77 %) and Streptomyces flocculus NBRC 13041T (97.67 %). The G+C content of the genomic DNA was 71.8 mol%. The chemotaxonomic data [MK-9(H6) and MK-9(H8) as the major menaquinones; ll-diaminopimelic acid as a component of the cell-wall peptidoglycan; ribose, xylose, mannose and glucose as the major cell-wall sugars; and anteiso-C15:0, iso-C15:0, iso-C17:0, anteiso-C17:0 and C16:0 as the major fatty acids] supported the affiliation of strain Gsoil 519T to the genus Streptomyces. The physiological and biochemical characteristics and the low level of DNA-DNA relatedness differentiated the isolate genotypically and phenotypically from recognized members of the genus Streptomyces. The isolate, therefore, represents a novel species, for which the name Streptomyces panacagri sp. nov. is proposed, with Gsoil 519T (=KCTC 19139T=DSM 41871T) as the type strain.

Georgenia daeguensis sp. nov., isolated from 4-chlorophenol enrichment culture.

During screening for 4-chlorophenol-degrading micro-organisms in activated sludge from industrial wastewater treatment, a Gram-positive, rod-shaped, aerobic bacterial strain, designated 2C6-43(T), was isolated and characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2C6-43(T) belongs to the family Bogoriellaceae, class Actinobacteria, and is related most closely to Georgenia soli CC-NMPT-T3(T) (98.8% sequence similarity), Georgenia muralis 1A-C(T) (97.6%), Georgenia thermotolerans TT02-04(T) (96.8%), Georgenia ruanii YIM 004(T) (96.6%) and Georgenia halophila YIM 93316(T) (96.0%). The G+C content of the genomic DNA of strain 2C6-43(T) was 66.2 mol%. Sugars from whole-cell hydrolysates found in strain 2C6-43(T) were rhamnose, ribose and galactose. The menaquinone MK-8(H(4)) was detected as the predominant quinone. Polar lipid analysis of 2C6-43(T) revealed diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol and phosphatidylglycerol. An aromatic compound ring cleavage enzyme of catechol 1,2-dioxygenase was detected but catechol 2,3-dioxygenase was not detected in 2C6-43(T). A fatty acid profile with anteiso-C(15:0), iso-C(15:0) and C(16:0) as the major components supported the affiliation of strain 2C6-43(T) to the genus Georgenia. However, the DNA-DNA relatedness between strain 2C6-43(T) and the type strains of five species of the genus Georgenia ranged from 17 to 40%, clearly showing that the isolate constitutes a new genospecies. Strain 2C6-43(T) could be clearly differentiated from its phylogenetic neighbours on the basis of some phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2C6-43(T) is considered to represent a novel species of the genus Georgenia, for which the name Georgenia daeguensis sp. nov. is proposed; the type strain is 2C6-43(T) (=KCTC 19801(T)=JCM 17459(T)).

Organic Connection of Holobiont Components and the Essential Roles of Core Microbes in the Holobiont Formation of Feral Brassica napus.

Brassica napus (Rapeseed) is an econfomically important oil-producing crop. The microbial interactions in the plant holobiont are fundamental to the understanding of plant growth and health. To investigate the microbial dynamics in the holobiont of feral B. napus, a total of 215 holobiont samples, comprised of bulk soil, primary root, lateral root, dead leaf, caulosphere, basal leaf, apical leaf, carposphere, and anthosphere, were collected from five different grassland sites in South Korea. The soil properties differed in different sampling sites, but prokaryotic communities were segregated according to plant holobiont components. The structures of the site-specific SparCC networks were similar across the regions. Recurrent patterns were found in the plant holobionts in the recurrent network. Ralstonia sp., Massilia sp., and Rhizobium clusters were observed consistently and were identified as core taxa in the phyllosphere, dead leaf microbiome, and rhizosphere, respectively. Arthropod-related microbes, such as Wolbachia sp., Gilliamella sp., and Corynebacteriales amplicon sequence variants, were found in the anthosphere. PICRUSt2 analysis revealed that microbes also possessed specific functions related to holobiont components, such as functions related to degradation pathways in the dead leaf microbiome. Structural equation modeling analysis showed the organic connections among holobiont components and the essential roles of the core microbes in the holobiont formations in natural ecosystem. Microbes coexisting in a specific plant showed relatively stable community structures, even though the regions and soil characteristics were different. Microbes in each plant component were organically connected to form their own plant holobiont. In addition, plant-related microbes, especially core microbes in each holobiont, showed recurrent interaction patterns that are essential to an understanding of the survival and coexistence of plant microbes in natural ecosystems.

Tumebacillus ginsengisoli sp. nov., isolated from soil of a ginseng field.

A gram-reaction-positive, rod-shaped, spore-forming bacterium, designated Gsoil 1105(T), was isolated from soil of a ginseng field in Pocheon Province in South Korea and characterized in order to determine its taxonomic position. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the order Bacillales, showing the highest level of sequence similarity with respect to Tumebacillus permanentifrigoris Eur1 9.5(T) (94.6 %). The phylogenetic distances from other described species with validly published names within the order Bacillales were greater than 9.0 %. Strain Gsoil 1105(T) had a genomic DNA G+C content of 55.6 mol% and menaquinone 7 (MK-7) as the major respiratory quinone. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 0). On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 1105(T) represents a novel species of the genus Tumebacillus, for which the name Tumebacillus ginsengisoli sp. nov. is proposed. The type strain is Gsoil 1105(T) ( = KCTC 13942(T)  = DSM 18389(T)).

Vagococcus acidifermentans sp. nov., isolated from an acidogenic fermentation bioreactor.

A Gram-staining-positive, coccus-shaped, non-spore-forming, facultatively anaerobic bacterium, designated AC-1(T), was isolated from an acidogenic fermentation bioreactor treating food wastewater. On the basis of 16S rRNA gene sequence analysis, strain AC-1(T) was shown to belong to the genus Vagococcus. The closest phylogenetic relatives were Vagococcus elongatus PPC9(T) (97.4 % 16S rRNA gene sequence similarity), Vagococcus penaei CD276(T) (96.7 %) and Vagococcus carniphilus ATCC BAA-640(T) (96.6 %). The major fatty acids were C(18 : 1)ω9c (24.8 %) and C(16 : 0) (19.5 %) and the G+C content of genomic DNA was 44.2 mol%, which supported the affiliation of strain AC-1(T) to the genus Vagococcus. Strain AC-1(T) and V. elongatus DSM 21480(T) exhibited 11 % DNA-DNA relatedness. Physiological and biochemical tests differentiated strain AC-1(T) from the type strains of recognized species of the genus Vagococcus. Therefore, strain AC-1(T) is considered to represent a novel species, for which the name Vagococcus acidifermentans sp. nov. is proposed. The type strain is AC-1(T) ( = KCTC 13418(T)  = LMG 24798(T)).

Ecological network analysis reveals distinctive microbial modules associated with heavy metal contamination of abandoned mine soils in Korea.

Heavy metal pollution in soil around abandoned mine sites is one of the most critical environmental issues worldwide. Soil microbes form complex communities and perform ecological functions individually or in cooperation with other organisms to adapt to harsh environments. In this study, we investigated the distribution patterns of bacterial and fungal communities in non-contaminated and heavy metal-contaminated soil of the abandoned Samkwang mine in Korea to explore microbial interaction mechanisms and their modular structures. As expected, the bacterial and fungal community structures showed large differences depending on the degree of heavy metal contamination. The microbial network was divided into three modules based on the levels of heavy metal pollution: heavy metal-tolerant (HM-Tol), heavy metal-mid-tolerant (HM-mTol), and heavy metal-sensitive (HM-Sens) modules. Taxonomically, microbes assigned to Vicinamibacterales, Pedosphaeraceae, Nitrosomonadaceae, and Gemmatimonadales were the major groups constituting the HM-Tol module. Among the detected heavy metals (As, Pb, Cd, Cu, and Zn), copper concentrations played a key role in the formation of the HM-Tol module. In addition, filamentous fungi (Fusarium and Mortierella) showed potential interactions with bacteria (Nitrosomonadaceae) that could contribute to module stability in heavy metal-contaminated areas. Overall, heavy metal contamination was accompanied by distinct microbial communities, which could participate in the bioremediation of heavy metals. Analysis of the microbial interactions among bacteria and fungi in the presence of heavy metals could provide fundamental information for developing bioremediation mechanisms for the recovery of heavy metal-contaminated soil.