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Three bacterial strains, H21R-40T and H21R-36 from garlic (Allium sativum) and H25R-14T from onion (Allium cepa), were isolated from plant rhizospheres sampled in the Republic of Korea. Results of 16S rRNA gene sequence analysis revealed the highest sequence similarity of strain H21R-40T to Leucobacter celer subsp. astrifaciens CBX151T (97.3 %) and Leucobacter triazinivorans JW-1T (97.2 %), and strain H25R-14T to Leucobacter insecticola HDW9BT (98.8 %) and Leucobacter humi Re6T (98.4 %), while the sequence similarity between strains H21R-40T and H21R-36 was 99.8 %. According to the phylogenomic tree, strains H21R-40T with H21R-36 formed an independent clade separable from other Leucobacter species within the genus Leucobacter and strain H25R-14T clustered with Leucobacter insecticola HDW9BT, Leucobacter coleopterorum HDW9AT and Leucobacter viscericola HDW9CT. Strains H21R-40T and H21R-36 had orthologous average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) values (98.1 % and 86.9 %, respectively) higher than the threshold ranges for species delineation (95–96 % and 70 %, respectively). The OrthoANI and dDDH values between two strains (H21R-40T and H25R-14T) and the type strains of species of the genus Leucobacter were lower than 81 and 24 %, respectively. The peptidoglycan type of three strains was type B1. The major menaquinones and major polar lipids of the strains were MK-11 and MK-10, and diphosphatidylglycerol, phatidylglycerol and an unidentified glycolipid, respectively. The major fatty acids (more than 10 % of the total fatty acids) of strains H21R-40T and H21R-36 were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0, and those of strain H25R-14T were anteiso-C15 : 0 and iso-C16 : 0. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that the strains represent two novel species of the genus Leucobacter , named Leucobacter allii sp. nov. (H21R-40T and H21R-36) and Leucobacter rhizosphaerae sp. nov. (H25R-14T). The respective type strains are H21R-40T (=DSM 114348T=JCM 35241T=KACC 21839T=NBRC 115481T) and H25R-14T (=DSM 114346T=JCM 35239T=KACC 21837T=NBRC 115479T).

Strain RHs26T is an aerobic, Gram-stain-negative, non-flagellated and rod- or filamentous-shaped (1.0–1.1×2.3–50 µm) bacterium that was isolated from dried rice husk. It was positive for oxidase and catalase, hydrolysed starch and Tween 80, and weakly hydrolysed CM-cellulose. The strain grew at temperatures between 10 and 37 °C (optimum, 28 °C), in 0–1 % NaCl (optimum, 0 %) and at pH 6.0–9.0 (optimum, pH 7.0–8.0). The predominant membrane fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 1 ω5c, iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and two unidentified lipids. The predominant quinone was menaquinone MK-7. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHs26T belongs to the genus Spirosoma , presenting the highest sequence similarity to Spirosoma agri S7-3-3T (95.8 %). The genomic DNA G+C content of strain RHs26T was 49.5 %. Strain RHs26T showed the highest orthologous average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) values of 76.4 % and 20.0 % with S. agri KCTC 52727T while sharing OrthoANI and dDDH values of 74.6 % and 19.2 % with Spirosoma terrae KCTC 52035T, the closest relative in the phylogenomic tree. Based on the results of a polyphasic taxonomic study, strain RHs26T represents a novel species in the genus Spirosoma , for which the name Spirosoma oryzicola sp. nov. is proposed. The type strain is RHs26T (=JCM 35224T=KACC 17318T).

Two bacterial strains, designated 5GH9-11T and 5GH9-34T, were isolated from greenhouse soil sampled in Wanju-gun, Jeollabuk-do, Republic of Korea. Both strains formed yellow colonies and were aerobic, rod-shaped and flagellated. The 16S rRNA gene sequence similarity between 5GH9-11T and 5GH9-34T was 98.6 %. Strain 5GH9-11T showed the highest sequence similarities to Dyella thiooxydans ATSB10T (98.1 %) and Frateuria aurantia DSM 6220T (97.7 %) while strain 5GH9-34T revealed the highest sequence similarity to F. aurantia DSM 6220T (98.3 %) and D. thiooxydans ATSB10T (98.3 %). Phylogenetic analysis on the basis of the 16S rRNA gene sequence showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with Frateuria flava MAH-13T and Frateuria terrea NBRC 104236T. The phylogenomic tree also showed that strains 5GH9-11T and 5GH9-34T formed a robust cluster with F. terrea DSM 26515T and F. flava MAH-13T. Strain 5GH9-11T showed the highest orthologous average nucleotide identity (OrthoANI; 88.5 %) and digital DNA–DNA hybridization (dDDH) values (35.5 %) with F. flava MAH-13T, and strain 5GH9-34T revealed highest OrthoANI (88.1 %) and dDDH (34.2 %) values with F. flava MAH-13T. The orthoANI and dDDH values between strain 5GH9-11T and 5GH9-34T were 87.7 and 33.9 %, respectively. Their major respiratory quinone was ubiquinone 8, and the major cellular fatty acids were iso-C16 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl) and iso-C15 : 0. The major polar lipids of both strains were composed of large or moderate amounts of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminolipid and an unidentified aminophospholipid. Based on these data, strains 5GH9-11T and 5GH9-34T should represent two independent novel species of Frateuria , for which the names Frateuria soli sp. nov. (type strain 5GH9-11T=KACC 16943T=JCM 35197T) and Frateuria edaphi sp. nov. (type strain 5GH9-34T=KACC 16945T=JCM 35198T) are proposed.

Two bacterial strains, designated KIS38-8T and F39-2T, were isolated from a mountain soil sample and a black locust flower (Robinia pseudoacacia) in Republic of Korea, respectively. The phylogenetic tree based on 16S rRNA gene sequences showed that strain KIS38-8T was classified into the genus Ferruginibacter with the highest sequence similarity to Ferruginibacter lapsinanis HU1-HG42T (96.6 %), and strain F39-2T was grouped into the genus Mucilaginibacter with the highest sequence similarity to Mucilaginibacter daejeonensis Jip 10T (97.6 %). Orthologous average nucleotide identity and digital DNA–DNA hybridization values between strain KIS38-8T and closely related Ferruginibacter strains were less than 72 and 19 %, respectively, while those values between strain F39-2T and closely related Mucilaginibacter strains were less than 73 and 21 %, respectively. The DNA G+C contents of strain KIS38-8T and F39-2T were 36.4 and 41.4 mol%, respectively. On the basis of the phenotypic and genotypic evidence, strains KIS38-8T and F39-2T are considered to represent novel species of the genus Ferruginibacter and Mucilaginibacter , respectively, for which the names Ferruginibacter albus sp. nov. (type strain KIS38-8T=KACC 17328T=NBRC 113101T) and Mucilaginibacter robiniae sp. nov. (type strain F39-2T=KACC 19733T=JCM 33062T) have been proposed.

Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of

A Gram-stain-negative, aerobic, non-motile, rod-shaped or occasionally filamentous-shaped bacterial strain, designated 5GH13-10T, was isolated from greenhouse soil sampled in Yeoju-si, Republic of Korea. Colonies were milky-coloured, round and convex, and catalase- and oxidase-positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 5GH13-10T was related to the genus Arachidicoccus and had highest 16S rRNA gene sequence identity with Arachidicoccus rhizosphaerae Vu-144T (98.4 %). The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The predominant quinone was menaquinone MK-7, and the polar lipids were composed of phosphatidylethanolamine, one unidentified aminolipid, three unidentified aminophospholipids, one unidentified phospholipid and five unidentified lipids. The genomic DNA G+C content of strain 5GH13-10T was 43.8 mol%. The average nucleotide identity values between strain 5GH13-10T and the closely related species Arachidicoccus ginsenosidivorans Gsoil 809T, Arachidicoccus rhizosphaerae Vu-144T and Archidicoccus soli KIS59-12T were 74.86, 74.74 and 69.52 %, and the digital DNA-DNA hybridization values were 20.0, 19.8 and 18.6 %, respectively. Combined phenotypic, phylogenetic and genomic data demonstrated that strain 5GH13-10T is representative of a novel species of the genus Arachidicoccus , for which we propose the name Arachidicoccus terrestris sp. nov. (type strain 5GH13-10T=KACC 18014T=NBRC 113162T).

Biogeographic patterns in soil bacterial communities and their responses to environmental variables are well established, yet little is known about how different types of agricultural land use affect bacterial communities at large spatial scales. We report the variation in bacterial community structures in greenhouse, orchard, paddy, and upland soils collected from 853 sites across the Republic of Korea using 16S rRNA gene pyrosequencing analysis. Bacterial diversities and community structures were significantly differentiated by agricultural land-use types. Paddy soils, which are intentionally flooded for several months during rice cultivation, had the highest bacterial richness and diversity, with low community variation. Soil chemical properties were dependent on agricultural management practices and correlated with variation in bacterial communities in different types of agricultural land use, while the effects of spatial components were little. Firmicutes, Chloroflexi, and Acidobacteria were enriched in greenhouse, paddy, and orchard soils, respectively. Members of these bacterial phyla are indicator taxa that are relatively abundant in specific agricultural land-use types. A relatively large number of taxa were associated with the microbial network of paddy soils with multiple modules, while the microbial network of orchard and upland soils had fewer taxa with close mutual interactions. These results suggest that anthropogenic agricultural management can create soil disturbances that determine bacterial community structures, specific bacterial taxa, and their relationships with soil chemical parameters. These quantitative changes can be used as potential biological indicators for monitoring the impact of agricultural management on the soil environment.

Two Gram-stain-positive, rod-shaped, endospore-forming bacteria, designated 12200R-189T and 14171R-81T were isolated from the rhizosphere of tomato plants. The 16S rRNA gene sequence similarity between strains 12200R-189T and 14171R-81T were 97.2%. Both strains showed the highest 16S rRNA gene sequence similarities to Paenibacillus sacheonensis SY01T (96.3% and 98.0%, respectively). The genome of strain 12200R-189T was approximately 6.7 Mb in size with 5,750 protein-coding genes (CDSs) and the G + C content was 58.1 mol%, whereas that of strain 14171R-81T comprised one chromosome of 7.0 Mb and two plasmids (0.2 Mb each) with 6,595 CDSs and the G + C content was 54.5 mol%. Comparative genome analysis revealed that average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values among 12200R-189T, 14171R-81T, and other closely related species were below the cut-off levels 95% and 70%, respectively. Strain 12200R-189T grew at a temperature range of 15-40°C, pH 6.0-9.0, and 0-3% NaCl (w/v), whereas strain 14171R-81T grew at a temperature range of 10-37°C, pH 6.0-8.0, and 0-1% NaCl (w/v). Menaquinone-7 (MK-7) was the only isoprenoid quinone detected in both strains. The predominant cellular fatty acids (> 10%) were iso-C15:0, anteiso-C15:0, and iso-C16:0. The polar lipids of strain 12200R-189T were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), aminophospholipid (APL), phospholipid (PL), phosphatidylglycolipid (PGL), and four aminophosphoglycolipids (APGLs) and those of strain 14171R-81T were DPG, PG, PE, APL, three PLs, two PGLs, and three APGLs. Based on phylogenetic, genomic, phenotypic, and chemotaxonomic analyses, strains 12200R-189T and 14171R-81T represent two novel species of the genus Paenibacillus, for which the names Paenibacillus lycopersici sp. nov. and Paenibacillus rhizovicinus sp. nov. are proposed. The type strains are 12200R-189T (= KACC 19916T = CCTCC AB 2020027T) and 14171R-81T (= KACC 19915T = CCTCC AB 2020026T).

A Gram-stain-negative, aerobic, rod-shaped, leaf-associated bacterium, designated JS23T, was isolated from surface-sterilized leaf tissue of an oil palm grown in Singapore and was investigated by polyphasic taxonomy. Phylogenetic analyses based on 16S rRNA gene sequences and 180 conserved genes in the genome of several members of Burkholderiaceae revealed that strain JS23T formed a distinct evolutionary lineage independent of other taxa within the family Burkholderiaceae . The predominant ubiquinone was Q-8. The primary polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unidentified aminophospholipid. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c /C16 : 1 ω6c) and summed feature 8 (C18 : 1 ω7c /C18 : 1 ω6c). The size of the genome is 5.36 Mbp with a DNA G+C content of 66.2 mol%. Genomic relatedness measurements such as average nucleotide identity, genome-to-genome distance and digital DNA–DNA hybridization clearly distinguished strain JS23T from the closely related genera Burkholderia , Caballeronia , Mycetohabitans , Mycoavidus , Pandoraea , Paraburkholderia , Robbsia and Trinickia . Furthermore, average amino acid identity values and the percentages of conserved proteins, 56.0–68.4 and 28.2–45.5, respectively, were well below threshold values for genus delineation and supported the assignment of JS23T to a novel genus. On the basis of the phylogenetic, biochemical, chemotaxonomic and phylogenomic evidence, strain JS23T is proposed to represent a novel species of a new genus within the family Burkholderiaceae , for which the name Chitinasiproducens palmae gen. nov., sp. nov., is proposed with the type strain of JS23T (= DSM 27307T=KACC 17592T).

Drought stress is considered as one of major abiotic stresses; it leads to reduce plant growth and crop productivity. In this study, we selected bacterial strains for alleviating drought stress in chili pepper plants. As drought-tolerant bacteria, 28 among 447 strains were pre-selected by in vitro assays including growth in drought condition with polyethylene glycol and plant growth-promoting traits including production of 1-aminocyclopropane-1-carboxylate deaminase, indole-3-acetic acid and exopolysaccharide. Sequentially, 7 among pre-selected 28 strains were screened based on relative water content (RWC); GLC02 and KJ40, among seven strains were finally selected by RWC and malondialdehyde (MDA) in planta trials under an artificial drought condition by polyethylene glycol solution. Two strains GLC02 and KJ40 reduced drought stress in a natural drought condition as well as an artificial condition. Strains GLC02 or KJ40 increased shoot fresh weight, chlorophyll and stomatal conductance while they decreased MDA in chili pepper plants under a natural drought condition. However, two strains did not show biocontrol activity against diseases caused by Phytophthora capsici and Xanthomonas campestris pv. vesicatoria in chili pepper plants. Taken together, strains GLC02 or KJ40 can be used as bio-fertilizer for alleviation of drought stress in chili pepper plants.

Salinity is one of the major abiotic stresses that cause reduction of plant growth and crop productivity. It has been reported that plant growth-promoting bacteria (PGPB) could confer abiotic stress tolerance to plants. In a previous study, we screened bacterial strains capable of enhancing plant health under abiotic stresses and identified these strains based on 16s rRNA sequencing analysis. In this study, we investigated the effects of two selected strains, Bacillus aryabhattai H19-1 and B. mesonae H20-5, on responses of tomato plants against salinity stress. As a result, they alleviated decrease in plant growth and chlorophyll content; only strain H19-1 increased carotenoid content compared to that in untreated plants under salinity stress. Strains H19-1 and H20-5 significantly decreased electrolyte leakage, whereas they increased Ca2+ content compared to that in the untreated control. Our results also indicated that H20-5-treated plants accumulated significantly higher levels of proline, abscisic acid (ABA), and antioxidant enzyme activities compared to untreated and H19-1-treated plants during salinity stress. Moreover, strain H20-5 upregulated 9-cisepoxycarotenoid dioxygenase 1 (NCED1) and abscisic acid-response element-binding proteins 1 (AREB1) genes, otherwise strain H19-1 downregulated AREB1 in tomato plants after the salinity challenge. These findings demonstrated that strains H19-1 and H20-5 induced ABA-independent and -dependent salinity tolerance, respectively, in tomato plants, therefore these strains can be used as effective bio-fertilizers for sustainable agriculture.

A variety of microorganisms in rhizosphere affect plant health by plant growth promotion, mitigation of abiotic stresses as well as protection from pathogen attacks. In our previous study, we selected a bacterium, Bacillus mesonae H20-5, for alleviation of salinity stress in tomato plants. In this study, we verified the effect of a liquid formulation of B. mesonae H20-5 (TP-H20-5) on fruit production and phytochemical accumulation including lycopene and polyphenol in cherry tomato and strawberry fruits in on-farm tests of protected cultivation under salinity stress. When vegetables including tomato, cherry tomato, strawberry, and cucumber were treated with TP-H20-5 by irrigated systems, final marketable yields were increased by 21.4% (cherry tomato), 9.3% (ripen tomato), 120.6% (strawberry), and 14.5% (cucumber) compared to untreated control. Moreover, treatment of TP-H20-5 was showed increase of phytochemicals such as lycopene and total polyphenol compared to untreated control in cherry tomato and strawberry. Therefore, these results indicated that a formulant of B. mesonae H20-5 can be used as a potential biofertilizer for increasing fruit production and quality.

Plants are exposed to biotic stresses caused by pathogen attack and complex abiotic stresses including heat and drought by dynamic climate changes. To alleviate these stresses, we investigated two bacterial stains, H26-2 and H30-3 in two cultivars ('Ryeokkwang' and 'Buram-3-ho') of Chinese cabbage in plastic pots in a greenhouse. We evaluated effects of bacterial strains on plant growth-promotion and mitigation of heat and drought stresses; the role of exopolysaccharides as one of bacterial determinants on alleviating stresses; biocontrol activity against soft rot caused by Pectobacterium carotovorum subsp. carotovorum PCC21. Strains H26-2 and H30-3 significantly increased fresh weights compared to a MgSO4 solution; reduced leaf wilting and promoted recovery after re-watering under heat and drought stresses. Chinese cabbages treated with H26-2 and H30-3 increased leaf abscisic acid (ABA) content and reduced stomatal opening after stresses treatments, in addition, these strains stably colonized and maintained their populations in rhizosphere during heat and drought stresses. As well as tested bacterial cells, exopolysaccharides (EPS) of H30-3 could be one of bacterial determinants for alleviation of tested stresses in Chinese cabbages, however, the effects were different to cultivars of Chinese cabbages. In addition to bacterial activity to abiotic stresses, H30-3 could suppress incidence (%) of soft rot in 'Buram-3-ho'. The tested strains were identified as Bacillus aryabhattai H26-2 and B. siamensis H30-3 based on 16S rRNA gene sequence analysis. Taken together, H26-2 and H30-3 could be candidates for both plant growth promotion and mitigation of heat and drought stresses in Chinese cabbage.

Two bacterial strains, FWR-8T and CFWR-9T, were isolated from the gut of larvae of Protaetia brevitarsis seulensis that were raised at the National Institute of Agricultural Sciences, Wanju-gun, Republic of Korea. Both strains were strictly aerobic, Gram-stain-positive and non-motile. Strain FWR-8T possessed the highest sequence similarity (98.7 %) to that of Protaetiibacter intestinalis 2DFWR-13T and the phylogenetic tree revealed that strain FWR-8T formed a cluster with Ptb. intestinalis 2DFWR-13T. Pseudolysinimonas kribbensis MSL-13T and Lysinimonas yzui N7XX-4T shared a high 16S rRNA gene sequence similarity (97.8 %) and formed a cluster adjacent to the cluster that included Ptb. intestinalis 2DFWR-13T. The 16S rRNA gene sequence of strain CFWR-9T exhibited the highest similarity (97.7 %) to that of Agromyces binzhouensis OAct353T and the phylogenetic tree indicated that strain CFWR-9T formed one independent cluster with A. binzhouensis OAct353T that was within the radius of the genus Agromyces . The peptidoglycan type, major fatty acids, major menaquinones and total polar lipids of strain FWR-8T were characterized as type B1, iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0, MK-15, MK-16 and MK-14, and diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and one unidentified lipid, respectively. Those from strain CFWR-9T were type B1, iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0, MK-11, MK-12 and MK-10, and diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and one unidentified lipid, respectively. Based on the phenotypic and genotypic data, strains FWR-8T and CFWR-9T each represent a novel species within the genera Protaetiibacter and Agromyces , respectively. For these species, the names Protaetiibacter larvae sp. nov. and Agromyces intestinalis sp. nov. have been proposed, with the type strains FWR-8T (=KACC 19322T=NBRC 113051T) and CFWR-9T (=KACC 19306T=NBRC 113046T), respectively. Our results also justify a reclassification of Lysinimonas yzui as Pseudolysinimonas yzui comb. nov. and an emended description of the genus Pseudolysinimonas isprovided.

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated KIS59-12T, was isolated from a soil sample collected on Hodo island, Boryeong, Republic of Korea. The strain grew at 10–33 °C, pH 6.0–7.5 and with 0–4 % NaCl (w/v). Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain KIS59-12T was in the same clade as Arachidicoccus rhizosphaerae Vu-144T and Arachidicoccus ginsenosidivorans Gsoil809T with 97.5 and 97.2 % sequence similarity, respectively. Comparative genome analysis between strain KIS59-12T and A. rhizosphaerae Vu-144T showed that average nucleotide identity value was 69.4 % and the digital DNA–DNA hybridization value was 19.1 %. The major respiratory quinone was menaquinone-7. The major polar lipids were phosphatidylethanolamine and an unknown polar lipid. The predominant cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH, which supported the affiliation of strain KIS59-12T with the genus Arachidicoccus . The major polyamines were homospermidine and putrescine. The genomic DNA G+C content was 36.4 mol%. On the basis of phylogenetic, physiological and chemotaxonomic characteristics, strain KIS59-12T represents a novel species of the genus Arachidicoccus , for which the name Arachidicoccus soli sp. nov. is proposed. The type strain of Arachidicoccus soli is KIS59-12T (=KACC 17340T=NBRC 113161T).

A Gram-negative, aerobic, and long rod-shaped bacterium, designated as H33E-04T, was isolated from the soil of reclaimed land, Republic of Korea. The strain grew at a temperature range of 15–40 °C, pH 5.0–10.0, and 0–2% NaCl (w/v). The phylogenetic analysis based on 16S rRNA gene sequences showed that strain H33E-04T was in the same clade with Chitinophaga pinensis DSM 2588T, Chitinophaga filiformis IFO 15056T, and Chitinophaga ginsengisoli Gsoil 052T with 98.4%, 97.9%, and 97.8% sequence similarities, respectively. The de novo genome assembly revealed that the DNA G + C content of the strain was 46.2 mol%. Comparative genome analysis between strain H33E-04T and C. pinensis DSM 2588 T showed that the average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values were 79.9% and 23.4%, respectively. The major respiratory quinone was menaquinone-7 (MK-7) and the predominant cellular fatty acids were iso-C15:0 (31.7%), C16:1 ω5c (31.2%), and iso-C17:0 3-OH (11.8%), supporting the affiliation of strain H33E-04T with the genus Chitinophaga. Based on phylogenetic, physiological, and chemotaxonomic characteristics, strain H33E-04T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga agri sp. nov. is proposed. The type strain of Chitinophaga agri is H33E-04T (= KACC 21303T = NBRC114512T).

A bacterial strain, designated CJ1-R5T, was isolated from the flower of the royal azalea plant (Rhododendron schlippenbachii) collected in Jeju Island, Republic of Korea. The strain was a Gram-negative, strictly aerobic, motile, rod-shaped bacterium, growing at a temperature range of 4–33 °C (optimum 28–30 °C), pH 5.0–9.0 (optimum pH 7.0–8.0), and 0–1% NaCl (optimum 0%). The 16S rRNA sequence analysis of strain CJ1-R5T revealed the highest sequence similarity (97.9%) with Xylophilus ampelinus ATCC 33914T, and sequence similarities of less than 97.2% with other validly named species. Phylogenetic tree analysis based on the 16S rRNA gene sequences showed that strain CJ1-R5T clustered with Xylophilus ampelinus ATCC 33914T and two uncultured bacterial clones. The only quinone observed in strain CJ1-R5T was ubiquinone-8. The polar lipids observed were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid and two unidentified lipids. The major fatty acids were C16:0, C17:0 cyclo, and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The genome size of strain CJ1-R5T was 5.85 Mbp. The genomic G + C content was 68.4 mol%. ANI and dDDH values between strain CJ1-R5T and Xylophilus ampelinus ATCC 33914T were 79.0% and 22.5%, respectively. Based on the polyphasic taxonomic data, strain CJ1-R5T is considered to represent a novel species, for which the name Xylophilus rhododendri sp. nov. is proposed. The type strain is CJ1-R5T (= KACC 21265T = CCTCC AB2020030T)

In this study, two endophytic bacterial strains designated JS21-1T and S6-262T isolated from leaves of Elaeis guineensis and stem tissues of Jatropha curcas respectively, were subjected for polyphasic taxonomic approach. On R2A medium, colonies of strains JS21-1T and S6-262T are orange and yellow, respectively. Phylogenetic analyses using 16S rRNA gene sequencing and whole-genome sequences placed the strains in distinct clades but within the genus Sphingomonas. The DNA G + C content of JS21-1T and S6-262T were 67.31 and 66.95%, respectively. Furthermore, the average nucleotide identity and digital DNA-DNA hybridization values of strains JS21-1T and S6-262T with phylogenetically related Sphingomonas species were lower than 95% and 70% respectively. The chemotaxonomic studies indicated that the major cellular fatty acids of the strain JS21-1T were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C16:0, and C14:0 2OH; strain S6-262T possessed summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) and summed feature 8 (C18:1 ω6c and/or C18:1 ω7c). The major quinone was Q10, and the unique polyamine observed was homospermidine. The polar lipid profile comprised of mixture of sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and certain uncharacterised phospholipids and lipids. Based on this polyphasic evidence, strains JS21-1T and S6-262T represent two novel species of the genus Sphingomonas, for which the names Sphingomonas palmae sp. nov. and Sphingomonas gellani sp. nov. are proposed, respectively. The type strain of Sphingomonas palmae sp. nov. is JS21-1T (= DSM 27348T = KACC 17591T) and the type strain of Sphingomonas gellani sp. nov. is S6-262T (= DSM 27346T = KACC 17594T).

Rhizobacteria play important roles in plant growth and health enhancement and render them resistant to not only biotic stresses but also abiotic stresses, such as low/high temperature, drought, and salinity. This study aimed to select plant growth promoting rhizobacteria (PGPR) with the capability to mitigate biotic and abiotic stress effects on tomato plants. We isolated a novel PGPR strain, Variovorax sp. PMC12 from tomato rhizosphere. An in vitro assay indicated that strain PMC12 produced ammonia, indole-3-acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which are well-known traits of PGPR. The aboveground fresh weight was significantly higher in tomato plants treated with strain PMC12 than in non-treated tomato plants under various abiotic stress conditions including salinity, low temperature, and drought. Furthermore, strain PMC12 also enhanced the resistance to bacterial wilt disease caused by Ralstonia solanacearum. Taken together, these results indicated that strain PMC12 is a promising biocontrol agent and a biostimulant to reduce the susceptibility of plants to both abiotic and biotic stresses.

A novel bacterial strain, S-12T, of a member of the genus Phreatobacter was isolated from a cathode of a microbial fuel cell from Suwon City, South Korea. Cells were Gram-staining-negative, aerobic, non-sporulating rods, motile by means of a polar flagellum, and formed white round colonies. The strain grew at the range of 10–40 °C (optimum, 28–30 °C), pH 6.0–10.0 (optimum 7.0–8.0) and 0–1 % NaCl. The 16S rRNA gene sequence analysis showed the relatedness of S-12T to Phreatobacter stygius YC6-17T (98.2 %) and Phreatobacter oligotrophus PI_21T (98.1 %). The major respiratory quinone was ubiquinone Q-10. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified lipid. The major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content was 69.3 mol%. On the basis of its differences from species of the genus Phreatobacter with validly published names, strain S-12T is identified as representing a novel species, for which the proposed name is Phreatobacter cathodiphilus sp. nov., with S-12T as the type strain (=KACC 18497T=JCM 31612T).

Although cadusafos, an aliphatic organophosphorus (OP) insecticide, is not approved by the European commission, it is used in several countries and sometimes detected as a residue in soils and agricultural products. In this study, two cadusafos-degrading Sphingobium sp. strains, K22212 and Cam5-1, were isolated and characterized for use as detoxifying agents of the insecticide. Both strains degraded 100 mg L−1 of cadusafos in mineral medium within 12 h through a common metabolite, which was supposed to be dimerized thiophosphates based on its molecular weight. Degradation of cadusafos increased cell growth for Cam5-1 but not for K22212. K2212 and Cam5-1 degraded cadusafos in soil (15 mg kg−1 dry soil) within 5 and 2 days, respectively. Both strains also degraded ethoprophos, phenthoate and phorate but not chlorpyrifos and diazinon, indicating that they are specialized for degradation of OP insecticides with at least one single bond connecting phosphorus and sulfur atoms (P S bond). For both strains, the degradation rate was the largest for ethoprophos, followed by cadusafos, phenthoate, and phorate. Our results indicate that these bacterial strains are effective degraders of OP insecticides with P S bonds, and in particular, Cam5-1 is more promising for removal of the OP insecticides in soils.

Two yellow-pigmented isolates, S5-249T and L9-754T, originating from surface-sterilized plant tissues of Jatropha curcas L. (Jatropha) cultivars were characterized using a polyphasic taxonomic approach. Strains S5-249T and L9-754T had 16S rRNA genes sharing 94.2 % sequence similarity with each other and 91.6–97.2 % sequence similarity with those of other species in the genus Sphingomonas , suggesting that they represent two potentially novel species. The 16S rRNA gene sequences of strains S5-249T and L9-754T shared the highest similarity to that of Sphingomonas sanguinis NBRC 13937T (96.1 and 97.2 %, respectively). The genomic DNA G+C contents of strains S5-249T and L9-754T were 66.9 and 68.5 mol%, respectively. The respiratory quinone was determined to be Q-10, and the major polyamine was homospermidine. Strains S5-249T and L9-754T contained summed feature 7 (comprising C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t), C16 : 1, C14 : 0 2-OH and summed feature 4 (C16 : 1ω7t, iso-C15 : 0 2-OH and C16 : 1ω7c) as the major cellular fatty acids. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and sphingoglycolipid. The average nucleotide identity (ANI) values between S. sanguinis NBRC 13937T and the two type strains (S5-249T and L9-754T) were 72.31 and 77.73 %, respectively. Digital DNA–DNA hybridization (dDDH) studies between the novel strains (S5-249T and L9-754T) and other species of the genus Sphingomonas were well below the thresholds used to discriminate between bacterial species. The results of dDDH and physiological tests allowed genotypic and phenotypic differentiation of the strains from each other as well as from the species of the genus Sphingomonas with validly published names. These data strongly support the classification of the strains as representatives of novel species, for which we propose the names Sphingomonas jatrophae sp. nov. (type strain S5-249T=DSM 27345T=KACC 17593T) and Sphingomonas carotinifaciens sp. nov. (type strain L9-754T=DSM 27347T=KACC 17595T).

The taxonomic position of a bacterial strain designated T16R-228T, isolated from a rhizosphere soil sample of a tomato plant collected from a farm in Buyeo, Chungcheongnam-do, Republic of Korea, was determined using a polyphasic approach. On the basis of morphological, genetic and chemotaxonomic characteristics, it was determined to belong to the genus Paenibacillus . It was an aerobic, Gram-stain-positive, non-motile, catalase-negative, oxidase-negative rod with peritrichous flagella. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, hydroxyl- phosphatidylethanolamine and one unidentified polar lipid. Menaquiones were MK-7. Predominant cellular fatty acids were anteiso-C15 : 0, C16 : 0 and iso-C16 : 0. DNA G+C content was 56.8 mol%. The phylogenetic tree constructed based on the 16S rRNA gene sequences showed the strain formed a clade with P. mucilaginosus VKPM B-7519T, P. edaphicus T7T, P. ehimensis KCTC 3748T, P. koreensis YC300T, P. tianmuensis B27T and P. elgii SD17T, showing the highest sequence similarity with P. mucilaginosus VKPM B-7519T (96.5 %). The polyphasic data supported that strain T16R-228T was clearly distinguished from its closely related species and represents a novel species of the genus Paenibacillus for which the name Paenibacillus solanacearum is proposed. The type strain is T16R-228T (=KACC 18654T=NBRC 111896T).

The bacterial strain Bacillus velezensis GH1-13, isolated from rice paddy soil in Korea, has been shown to promote plant growth and have strong antagonistic activities against pathogens. Here, we report the complete genome sequence of GH1-13, revealing that it possesses a single 4,071,980-bp circular chromosome with 46.2% GC-content. The chromosome encodes 3,930 genes, and we have also identified a unique plasmid in the strain that encodes a further 104 genes (71,628bp and 31.7% GC-content). The genome was found to contain various enzyme-encoding operons, including indole-3-acetic acid (IAA) biosynthesis proteins, 2,3-butanediol dehydrogenase, various non-ribosomal peptide synthetases, and several polyketide synthases. These properties are responsible for the promotion of plant growth and the biosynthesis of secondary metabolites. They therefore have multiple beneficial effects that could be applied to agriculture. Through curing, we found that the unique plasmid of GH1-13 has important roles in the production of phytohormones, such as IAA, and in shaping phenotypic and physiological characteristics. The plasmid therefore likely influences the biological activities of GH1-13. The complete genome sequence of B. velezensis GH1-13 contributes to our understanding of this beneficial strain and will encourage research into its development for agricultural or biotechnological applications, enhancing productivity and crop quality.

An aerobic, Gram-stain-negative, non-spore-forming, non-flagellated, rod-shaped or filamentous bacterial strain, T16R-86T, was isolated from rhizosphere of a tomato plant collected from a farm on Buyeo-gun, Chungcheongnam-do, South Korea. It grew at the temperature range 10–37 °C (optimum, 28 °C) and pH range 6.0–9.0 (optimum, pH 7.0), and tolerated up to 2 % (w/v) NaCl. According to 16S rRNA gene sequence analysis, strain T16R-86T shared the highest similarity with Chitinophaga barathri YLT18T (96.8 %) and C. pinensis DSM 2588T (96.7 %), forming a subcluster with C. barathri YLT18T, C. cymbidii R156-2T and C. niabensis JS13-10T in the phylogenetic tree. The major fatty acids were iso-C15 : 0, C16 : 1ω5c and iso-C17 : 0 3-OH. The predominant respiratory quinone was menaquinone MK-7. Polar lipids were phosphatidylethanolamine, five unknown aminolipids, an unknown aminophospholipid, one unknown phospholipid and two unknown lipids. The DNA G+C content was 53.6 mol%. The phenotypic, chemotaxonomic and phylogenetic data showed that strain T16R-86T represents a novel species of the genus Chitinophaga , for which the name Chitinophaga rhizosphaerae sp. nov. is proposed. The type strain is T16R-86T (=KACC 18790T=JCM 31600T).

A bacterial strain, designated T20R-70T, was isolated from tomato rhizosphere soil collected in Yecheon-gun, Gyeongsangbuk-do in South Korea. Growth was observed within the ranges 10–40 °C (optimally at 28–30 °C), pH 7.0–8.0 (optimally at pH 7.0) and 0–1 % NaCl (optimally at 0 %). The 16S rRNA gene sequence showed the highest similarities with those of Lysobacter hankyongensis KTCe-2T (98.7 %), Lysobacter brunescens KCTC 12130T (98.0 %), ‘ Lysobacter daecheongensis ' Dae08 (97.2 %) and Lysobacter oligotrophicus 107-E2T (97.1 %). The phylogenetic tree showed that strain T20R-70T formed a clade with Lysobacter hankyongensis KTCe-2T and Lysobacter brunescens KCTC 12130T. The dominant fatty acids (>10 %) were iso-C15 : 0, iso-C16 : 0, iso-C17 : 1ω9c and summed feature 3 (including iso-C15 : 0 2-OH and/or iso-C16 : 1ω7c). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major respiratory quinone was Q-8. DNA–DNA hybridization data revealed that strain T20R-70T had a hybridization value of 42±4 % (mean±sd) to the most closely related species of the genus Lysobacter . The DNA G+C content was 63.0 mol%. The physiological, biochemical and chemotaxonomic data allowed the discrimination of the new isolate from its phylogenetic relatives. Strain T20R-70T is thus considered to be a representative of a novel species of the genus Lysobacter , for which the name Lysobacter solanacearum sp. nov. is proposed. The type strain is T20R-70T (=KACC 18656T=NBRC 111881T).

A bacterial strain, designated 5GHs33-3T, was isolated from greenhouse soil collected from Yongin region, Gyeonggi province, South Korea. The strain was an aerobic, Gram-stain-positive, flagellated, rod-shaped bacterium. Strain 5GHs33-3T grew at 4–37 °C (optimally at 28–30 °C), pH 6.0–10.0 (optimally at pH 7.0) and with 0–7 % (w/v) NaCl (optimally with 0 %). The 16S rRNA gene sequence analysis revealed that strain 5GHs33-3T had high sequence similarity with Actinotalea suaedae EGI 60002T (98.4 %), Actinotalea ferrariae CF5-4T (96.4 %) and Actinotalea fermentans DSM 3133T (96.2 %), and less than 95.5 % sequence similarity against all the other species with validly published names. The phylogenetic tree revealed that strain 5GHs33-3T formed a robust independent monophyletic line with Actinotalea suaedae EGI 60002T. The predominant fatty acids of strain 5GHs33-3T were anteiso-C15 : 0 and iso-C14 : 0. The only quinone was MK-8(H4). Polar lipids were diphosphatidylglycerol, phosphatidylinositol, an unknown phosphoglycolipid and unknown lipids. The peptidoglycan type was A4β, with ornithine as the diagnostic diamino acid and an interpeptide bridge comprising l-Glu. The DNA G+C content is 69.0 mol%. Based on phylogenetic evidence and the results of phenotypic, genotypic and chemotaxonomic analyses, strain 5GHs33-3T represents a novel species of a new genus of the family Cellulomonadaceae , for which the name Pseudactinotalea terrae gen. nov., sp. nov. is proposed. The type strain of the type species is 5GHs33-3T (=KACC 16542T=NBRC 111006T). We also propose the reclassification of Actinotalea suaedae as Pseudactinotalea suaedae comb. nov. (type strain EGI 60002T=JCM 19624T=KACC 17839T=KCTC 29256T).

Plant microbiota is a key determinant of plant health and productivity. The composition and structure of plant microbiota varies according to plant tissue and compartment, which are specific habitats for microbial colonization. To investigate the structural composition of the microbiome associated with tomato roots under natural systems, we characterized the bacterial, archaeal, and fungal communities of three belowground compartments (rhizosphere, endosphere, and bulk soil) of tomato plants collected from 23 greenhouses in 7 geographic locations of South Korea. The microbial diversity and structure varied by rhizocompartment, with the most distinctive community features found in the endosphere. The bacterial and fungal communities in the bulk soil and rhizosphere were correlated with soil physicochemical properties, such as pH, electrical conductivity, and exchangeable cation levels, while this trend was not evident in the endosphere samples. A small number of core bacterial operational taxonomic units (OTUs) present in all samples from the rhizosphere and endosphere represented more than 60% of the total relative abundance. Among these core microbes, OTUs belonging to the genera Acidovorax, Enterobacter, Pseudomonas, Rhizobium, Streptomyces, and Variovorax, members of which are known to have beneficial effects on plant growth, were more relatively abundant in the endosphere samples. A co-occurrence network analysis indicated that the microbial community in the rhizosphere had a larger and more complex network than those in the bulk soil and endosphere. The analysis also identified keystone taxa that might play important roles in microbe-microbe interactions in the community. Additionally, profiling of predicted gene functions identified many genes associated with membrane transport in the endospheric and rhizospheric communities. Overall, the data presented here provide preliminary insight into bacterial, archaeal, and fungal phylogeny, functionality, and interactions in the rhizocompartments of tomato roots under real-world environments.

Salinity is one of the major abiotic stresses that cause reduction of plant growth and crop productivity. It has been reported that plant growth-promoting bacteria (PGPB) could confer abiotic stress tolerance to plants. In a previous study, we screened bacterial strains capable of enhancing plant health under abiotic stresses and identified these strains based on 16s rRNA sequencing analysis. In this study, we investigated the effects of two selected strains

A bacterial strain designated 5GH32-13T was isolated from greenhouse soil in Yongin-city, Republic of Korea. Cells were Gram-stain-negative, strictly aerobic, motile rods of two different shapes. The strain was catalase-positive and oxidasenegative. Flexirubin-like pigments were not detected. β-Carotene was produced. The strain grew in the range of 10-37°C (optimum of 28-30°C) and pH 6-8 (optimum of pH 7) and tolerated up to 1% (w/v) NaCl (optimum of 0%). According to the 16S rRNA gene sequence comparison, strain 5GH32-13T shared a sequence similarity of less than 96.0% with all validly named taxa, having the highest sequence similarity with Pseudoflavitalea soli KIS20-3T (95.8%), Pseudoflavitalea rhizosphaerae T16R-265T (95.4%), Flavitalea gansuensis JCN-23T (95.3%), Pseudobacter ginsenosidimutans Gsoil 221T (95.3%), and Flavitalea populi HY-50RT (95.2%). A phylogenetic tree showed that strain 5GH32-13T was not grouped consistently into any specific genus. Its only polyamine was homospermidine, and its major fatty acids (> 10% of total fatty acids) were iso-C15:0, iso-C17:0 3-OH, and iso-C15:1 G. The strain’s only respiratory quinone was MK-7, and its polar lipids were phosphatidylethanolamine, one unidentified phospholipid, six unidentified aminolipids and four unidentified lipids. Its DNA G + C content was 47.5 mol%. The results from chemotaxonomic, phenotypic and phylogenetic analyses indicated that strain 5GH32-13T represents a novel species of a novel genus of the family Chitinophagaceae, and the name Paraflavitalea soli gen. nov., sp. nov. is proposed. The type strain is 5GH32-13T (= KACC 17331T = JCM 33061T).

A Gram-stain-positive, rod-shaped, non-endospore-forming motile by means of peritrichous flagella, facultatively anaerobic bacterium designated TI45-13arT was isolated from Nuruk, a Korean traditional Makgeolli fermentation starter. It grew at 4-35°C (optimum, 28-30°C), pH 5.0-9.0 (optimum, pH 7.0) and NaCl concentrations up to 5% (w/v). Phylogenetic trees generated using 16S rRNA gene sequences revealed that strain TI45-13arT belonged to the genus Paenibacillus and showed the highest sequence similarities with Paenibacillus kyungheensis DCY88T (98.5%), Paenibacillus hordei RH-N24T (98.4%) and Paenibacillus nicotianae YIM h-19T (98.1%). The major fatty acid was anteiso-C15:0. The DNA G+C content was 39.0 mol%, and MK-7 was the predominant isoprenoid quinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified glycolipids, and one unidentified aminoglycolipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid. On the basis of polyphasic taxonomy study, it was suggested that strain TI45-13arT represents a novel species within the genus Paenibacillus for which the name Paenibacillus nuruki sp. nov. is proposed. The type strain was TI45-13arT (= KACC 18728T = NBRC 112013T).

Soil microorganisms play an essential role in soil ecosystem processes such as organic matter decomposition, nutrient cycling, and plant nutrient availability. The land use for greenhouse cultivation has been increasing continuously, which involves an intensive input of agricultural materials to enhance productivity; however, relatively little is known about bacterial communities in greenhouse soils. To assess the effects of environmental factors on the soil bacterial diversity and community composition, a total of 187 greenhouse soil samples collected across Korea were subjected to bacterial 16S rRNA gene pyrosequencing analysis. A total of 11,865 operational taxonomic units at a 97% similarity cutoff level were detected from 847,560 sequences. Among nine soil factors evaluated; pH, electrical conductivity (EC), exchangeable cations (Ca2+, Mg2+, Na+, and K+), available P2O5, organic matter, and NO3-N, soil pH was most strongly correlated with bacterial richness (polynomial regression, pH: R2 = 0.1683, P 1%), the relative abundances of Proteobacteria, Gemmatimonadetes, Acidobacteria, Bacteroidetes, Chloroflexi, and Planctomycetes were also more strongly correlated with pH and EC values, compared with other soil cation contents, such as Ca2+, Mg2+, Na+, and K+. Our results suggest that, despite the heterogeneity of various environmental variables, the bacterial communities of the intensively cultivated greenhouse soils were particularly influenced by soil pH and EC. These findings therefore shed light on the soil microbial ecology of greenhouse cultivation, which should be helpful for devising effective management strategies to enhance soil microbial diversity and improving crop productivity.

Fertilization and the response of the soil microbial community to the process significantly affect crop yield and the environment. In this study, the seasonal variation in the bacterial communities in rice field soil subjected to different fertilization treatments for more than 50 years was investigated using 16S rRNA sequencing. The simultaneous application of inorganic fertilizers and rice straw compost (CAPK) maintained the species richness of the bacterial communities at levels higher than that in the case of non-fertilization (NF) and application of inorganic fertilizers only (APK) in the initial period of rice growth. The seasonal variation in the bacterial community structure in the NF and APK plots showed cyclic behavior, suggesting that the effect of season was important; however, no such trend was observed in the CAPK plot. In the CAPK plot, the relative abundances of putative copiotrophs such as Bacteroidetes, Firmicutes, and Proteobacteria were higher and those of putative oligotrophs such as Acidobacteria and Plactomycetes were lower than those in the other plots. The relative abundances of organotrophs with respiratory metabolism, such as Actinobacteria, were lower and those of chemoautotrophs that oxidize reduced iron and sulfur compounds were higher in the CAPK plot, suggesting greater carbon storage in this plot. Increased methane emission and nitrogen deficiency, which were inferred from the higher abundances of Methylocystis and Bradyrhizobium in the CAPK plot, may be a negative effect of rice straw application; thus, a solution for these should be considered to increase the use of renewable resources in agricultural lands.

A rod-shaped, yellow, Gram-stain-negative, non-flagellated, aerobic bacterium, designated 5516J-17T, was isolated from an air sample collected from Jeju Island, Republic of Korea. It grew in the temperature range of 10-37 °C (optimum 28-30 °C), pH 6.0-11.0 (optimum, pH 7.0) and 0-1 % NaCl (w/v). Phylogenetic trees generated using 16S rRNA gene sequences revealed that strain 5516J-17T belongs to the genus Spirosoma, showing 96.9 % sequence similarity to the most closely related species, Spirosoma linguale DSM 74T. The cellular fatty acids comprised large amounts (>10 % of total fatty acids) of summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16:1ω5c, and moderate amounts (5-10 % of total fatty acids) of iso-C17:0 3-OH, iso-C15:0 and C16:0. The DNA G+C content was 55.7 mol % and MK-7 was the predominant isoprenoid quinone. Polar lipids were phosphatidylethanolamine, two unknown aminophospholipids, one unknown aminolipid and one unknown lipid. On the basis of this phenotypic and polyphasic taxonomy study, it is suggested that strain 5516J-17T represents a novel species within the genus Spirosoma, with the proposed name Spirosoma aerophilum. The type strain is 5516J-17T (= KACC 17323T = DSM 28388T = JCM 19950T).

A novel bacterium, strain 7515T-26T, was isolated from an air sample collected in Taean region, Republic of Korea. Cells were aerobic, Gram-stain-positive, non-flagellated cocci, growing in the temperature, pH and NaCl ranges of 10-33 °C, pH 5.0-9.0 and 0-2 % (w/v). It shared high 16S rRNA gene sequence similarity with Friedmanniella lacustris EL-17AT (97.6 %), Friedmanniella lucida FA2T (96.9 %) and Friedmanniella luteola FA1T (96.9 %), showing high sequence similarities of 96.5-97.6 % with members of the genus Friedmanniella. Phylogenetic trees based on 16S rRNA gene sequences showed that strain 7515T-26T and members of the genus Friedmanniella formed a compact cluster separable from other genera. The isolate contained anteiso-C15 : 0, iso-C14 : 0 3-OH and iso-C15 : 0 as the major cellular fatty acids, and MK-9(H4) as the predominant isoprenoid quinone. Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown phospholipids and one unknown lipid, and the DNA G+C content was 73.1 mol%. The peptidoglycan type was A3γ. It showed DNA-DNA hybridization values of less than 70 % with F. lacustris EL-17AT. On the basis of the evidence from this polyphasic study, a novel species, Friedmanniella aerolata sp. nov., is proposed. The type strain is 7515T-26T ( = KACC 17306T = DSM 27139T).

Strain 5GH22-11T, which was isolated from greenhouse soil in the Yangpyeong region, Gyeonggi province, Republic of Korea, was characterized to be an aerobic, Gram-stain-negative, flagellated, rod-shaped bacterium. It could grow at temperatures from 10 to 33 °C (optimum of 28–30 °C), in the pH range of 6.0–10.0 (optimum of pH 7.0) and without NaCl. 16S rRNA gene sequence analysis showed that strain 5GH18-14T showed the highest sequence similarities with Lysobacter niabensis GH34-4T (98.6 %), Lysobacter yangpyeongensis GH19-3T (98.1 %), ‘Lysobacter fragariae’ THG-DN8.7 (97.9 %), Lysobacter terrae THG-A13T (97.3 %), ‘Lysobacter rhizosphaerae’ THG-DN8.3 (97.2 %), ‘Lysobacter tyrosinelyticus’ THG-DN8.2 (97.2 %) and Lysobacter oryzae YC6269T (97.2 %), revealing less than 95.5 % sequence similarities with all other species with validly published names. Phylogenetic trees also indicated that strain 5GH18-14T formed a compact subcluster with L. niabensis GH34-4T, L. yangpyeongensis GH19-3T, L. terrae THG-A13T and L. oryzae YC6269T within the genus Lysobacter. The predominant quinone of strain 5GH18-14T was Q-8. The polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylmonomethylethanolamine in large amounts, and moderate or small amounts of three unknown phospholipids and two unknown aminophospholipids. DNA–DNA hybridization values with closely related species were below 70 %. The DNA G+C content was 65.9 mol%. Based on the phylogenetic, physiological and chemotaxonomic data, it has been demonstrated that strain 5GH18-14T represents a novel species of the genus Lysobacter, for which the name Lysobacter terricola sp. nov. is proposed. The type strain is 5GH18-14T ( = KACC 16954T = JCM 30862T).

A Gram-stain-negative, rod-shaped, non-flagellated, mesophilic, yellow-pigmented, aerobic bacterium, designated strain KIS20-3T, was isolated from a soil sample of Baengnyeong Island in Onjin county, Republic of Korea. According to 16S rRNA gene sequence analysis, the isolate showed highest similarities with Flavitalea populi HY-50RT (94.5 %), Niastella populi THYL-44T (94.2 %) and Flavitalea gansuensis JCN-23T (93.7 %). The neighbour-joining tree based on 16S rRNA gene sequences showed that strain KIS20-3T formed a subcluster with members of the genus Flavitalea, and this subcluster was closely related to members of the genera Niastella, Segetibacter and Parasegetibacter within the family Chitinophagaceae. The major fatty acids of strain KIS20-3T were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G, and the predominant isoprenoid quinone was menaquinone 7. The polar lipid profile comprised large amounts of phosphatidylethanolamine and one unknown polar lipid, and moderate or small amounts of four unknown aminophospholipids, two unknown aminolipids, three unknown lipids and one unknown phospholipid. The G+C content of the DNA of strain KIS20-3T was 55.7 mol%. On the basis of the results of the polyphasic characterization presented in this study, it is concluded that strain KIS20-3T represents a novel species of the genus Flavitalea, for which the name Flavitalea soli sp. nov. is proposed. The type strain is KIS20-3T ( = KACC 17319T = JCM 19937T).

A yellow-colored bacterium with gliding motility, strain KIS68-18T, was isolated from a soil sample at Bijin Island in Tongyeong city, Republic of Korea. The cells were strictly aerobic, Gram-staining-negative, non-spore-forming, and rod-shaped. The strain grew at the range of 10-35°C (optimum, 25-30°C), pH 5.5-8.0 (optimum, 6.0-7.5), and 0-0.5% (w/v) NaCl. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KIS68-18T was closely related to Chryseolinea serpens DSM 24574T (98.9%) and had low sequence similarities (below 92.6%) with other members of the family 'Cytophagaceae' in the phylum Bacteroidetes. The major respiratory quinone system was MK-7 and the predominant cellular fatty acids were C16:1ω5c (38.8%), iso-C15:0 (18.5%), and summed feature 3 (C16:1ω7c and/or C16:1ω6c, 10.6%). The polar lipids consisted of phosphatidylethanolamine, one unidentified phospholipid, three unidentified aminophospholipids, two unidentified aminolipids, and five unidentified lipids. The DNA G + C content was 50.9%. Based on the phylogenetic, physiological, and chemotaxonomic data, stain KIS68-18T represents a novel species of the genus Chryseolinea, for which the name Chryseolinea soli sp. nov. is proposed. The type strain of Chryseolinea soli is KIS68-18T (= KACC 17327T = NBRC 113100T).