Paenibacillus lupini sp. nov., isolated from nodules of Lupinus albus

Prevalence, diversity and applications potential of nodules endophytic bacteria: a systematic review

Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the Rhizobiaceae familiy, leading to the establishment of symbiotic root nodules. Within these nodules, rhizobia play a pivotal role in converting atmospheric nitrogen into a plant-assimilable form. However, it has been discerned that root nodules of legumes are not exclusively inhabited by rhizobia; non-rhizobial endophytic bacteria also reside within them, yet their functions remain incompletely elucidated. This comprehensive review synthesizes available data, revealing that Bacillus and Pseudomonas are the most prevalent genera of nodule endophytic bacteria, succeeded by Paenibacillus, Enterobacter, Pantoea, Agrobacterium, and Microbacterium. To date, the bibliographic data available show that Glycine max followed by Vigna radiata, Phaseolus vulgaris and Lens culinaris are the main hosts for nodule endophytic bacteria. Clustering analysis consistently supports the prevalence of Bacillus and Pseudomonas as the most abundant nodule endophytic bacteria, alongside Paenibacillus, Agrobacterium, and Enterobacter. Although non-rhizobial populations within nodules do not induce nodule formation, their presence is associated with various plant growth-promoting properties (PGPs). These properties are known to mediate important mechanisms such as phytostimulation, biofertilization, biocontrol, and stress tolerance, emphasizing the multifaceted roles of nodule endophytes. Importantly, interactions between non-rhizobia and rhizobia within nodules may exert influence on their leguminous host plants. This is particularly shown by co-inoculation of legumes with both types of bacteria, in which synergistic effects on plant growth, yield, and nodulation are often measured. Moreover these effects are pronounced under both stress and non-stress conditions, surpassing the impact of single inoculations with rhizobia alone.

Pan-Genome Analyses of the Genus Cohnella and Proposal of the Novel Species Cohnella silvisoli sp. nov., Isolated from Forest Soil

Two strains, designated NL03-T5T and NL03-T5-1, were isolated from a soil sample collected from the Nanling National Forests, Guangdong Province, PR China. The two strains were Gram-stain-positive, aerobic, rod-shaped and had lophotrichous flagellation. Strain NL03-T5T could secrete extracellular mucus whereas NL03-T5-1 could not. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains belong to the genus Cohnella, were most closely related to Cohnella lupini LMG 27416T (95.9% and 96.1% similarities), and both showed 94.0% similarity with Cohnella arctica NRRL B-59459T, respectively. The two strains showed 99.8% 16S rRNA gene sequence similarity between them. The draft genome size of strain NL03-T5T was 7.44 Mbp with a DNA G+C content of 49.2 mol%. The average nucleotide identities (ANI) and the digital DNA-DNA hybridization (dDDH) values between NL03-T5T and NL03-T5-1 were 99.98% and 100%, indicating the two strains were of the same species. Additionally, the ANI and dDDH values between NL03-T5T and C. lupini LMG 27416T were 76.1% and 20.4%, respectively. The major cellular fatty acids of strain NL03-T5T included anteiso-C15:0 and iso-C16:0. The major polar lipids and predominant respiratory quinone were diphosphatidylglycerol (DPG) and menaquinone-7 (MK-7). Based on phylogenetic analysis, phenotypic and chemotaxonomic characterization, genomic DNA G+C content, and ANI and dDDH values, strains NL03-T5T and NL03-T5-1 represent novel species in the genus Cohnella, for which the name Cohnella silvisoli is proposed. The type strain is NL03-T5T (=GDMCC 1.2294T = JCM 34999T). Furthermore, comparative genomics revealed that the genus Cohnella had an open pan-genome. The pan-genome of 29 Cohnella strains contained 41,356 gene families, and the number of strain-specific genes ranged from 6 to 1649. The results may explain the good adaptability of the Cohnella strains to different habitats at the genetic level.

Lupin, a Unique Legume That Is Nodulated by Multiple Microsymbionts: The Role of Horizontal Gene Transfer

Lupin is a high-protein legume crop that grows in a wide range of edaphoclimatic conditions where other crops are not viable. Its unique seed nutrient profile can promote health benefits, and it has been proposed as a phytoremediation plant. Most rhizobia nodulating Lupinus species belong to the genus Bradyrhizobium, comprising strains that are phylogenetically related to B. cytisi, B. hipponenese, B. rifense, B. iriomotense/B. stylosanthis, B. diazoefficiens, B. japonicum, B. canariense/B. lupini, and B. retamae/B. valentinum. Lupins are also nodulated by fast-growing bacteria within the genera Microvirga, Ochrobactrum, Devosia, Phyllobacterium, Agrobacterium, Rhizobium, and Neorhizobium. Phylogenetic analyses of the nod and nif genes, involved in microbial colonization and symbiotic nitrogen fixation, respectively, suggest that fast-growing lupin-nodulating bacteria have acquired their symbiotic genes from rhizobial genera other than Bradyrhizobium. Horizontal transfer represents a key mechanism allowing lupin to form symbioses with bacteria that were previously considered as non-symbiotic or unable to nodulate lupin, which might favor lupin’s adaptation to specific habitats. The characterization of yet-unstudied Lupinus species, including microsymbiont whole genome analyses, will most likely expand and modify the current lupin microsymbiont taxonomy, and provide additional knowledge that might help to further increase lupin’s adaptability to marginal soils and climates.

Paenibacillus glycanilyticus subsp. hiroshimensis subsp. nov., isolated from leaf soil collected in Japan

Strain CCI5, an oligotrophic bacterium, was isolated from leaf soil collected in Japan. Strain CCI5 grew at temperatures between 25 °C and 43 °C (optimum temperature, 40 °C) and at pHs between 6.0 and 10.0 (optimum pH, 9.0). Its major fatty acids were anteiso-C_15:0 and iso-C_16:0, and menaquinone 7 was the only detected quinone system. In a phylogenetic analysis based on 16S rRNA gene sequences, strain CCI5 presented as a member of the genus Paenibacillus. Moreover, multilocus sequence analysis based on partial sequences of the atpD, dnaA, gmk, and infB genes showed that strain CCI5 tightly clustered with P. glycanilyticus DS-1^T. The draft genome of strain CCI5 consisted of 6,864,972 bp with a G+C content of 50.7% and comprised 6,189 predicted coding sequences. The genome average nucleotide identity value (97.8%) between strain CCI5 and P. glycanilyticus DS-1^T was below the cut-off value for prokaryotic subspecies delineation. Based on its phenotypic, chemotaxonomic, and phylogenetic features, strain CCI5 (= HUT-8145^T = KCTC 43270^T) can be considered as a novel subspecies within the genus Paenibacillus with the proposed name Paenibacillus glycanilyticus subsp. hiroshimensis subsp. nov.

Functional Analysis and Genome Mining Reveal High Potential of Biocontrol and Plant Growth Promotion in Nodule-Inhabiting Bacteria Within Paenibacillus polymyxa Complex

Bacteria belonging to the genus Paenibacillus were frequently isolated from legume nodules. The nodule-inhabiting Paenibacillus as a resource of biocontrol and plant growth-promoting endophytes has rarely been explored. This study explored the nodule-inhabiting Paenibacillus' antifungal activities and biocontrol potentials against broad-spectrum important phytopathogenic fungi. We collected strains which were isolated from nodules of Robinia pseudoacacia, Dendrolobium triangulare, Ormosia semicastrata, Cicer arietinum, Acacia crassicarpa, or Acacia implexa and belong to P. peoriae, P. kribbensis, P. endophyticus, P. enshidis, P. puldeungensis, P. taichungensis, or closely related to P. kribbensis, or P. anseongense. These nodule-inhabiting Paenibacillus showed diverse antagonistic activities against five phytopathogenic fungi (Fusarium graminearum, Magnaporthe oryzae, Rhizoctonia solani, Sclerotinia sclerotiorum, and Botrytis cinerea). Six strains within the P. polymyxa complex showed broad-spectrum and potent activities against all the five pathogens, and produced multiple hydrolytic enzymes, siderophores, and lipopeptide fusaricidins. Fusaricidins are likely the key antimicrobials responsible for the broad-spectrum antifungal activities. The nodule-inhabiting strains within the P. polymyxa complex were able to epiphytically and endophytically colonize the non-host wheat plants, produce indole acetic acids (IAA), and dissolve calcium phosphate and calcium phytate. P. peoriae strains RP20, RP51, and RP62 could fix N2. P. peoriae RP51 and Paenibacillus sp. RP31, which showed potent plant colonization and plant growth-promotion competence, effectively control fungal infection in planta. Genome mining revealed that all strains (n = 76) within the P. polymyxa complex contain ipdC gene encoding indole-3-pyruvate decarboxylase for biosynthesis of IAA, 96% (n = 73) contain the fus cluster for biosynthesis of fusaricidins, and 43% (n = 33) contain the nif cluster for nitrogen fixation. Together, our study highlights that endophytic strains within the P. polymyxa complex have a high probability to be effective biocontrol agents and biofertilizers and we propose an effective approach to screen strains within the P. polymyxa complex.

Paenibacillus puerhi sp. nov., isolated from the rhizosphere soil of Pu-erh tea plants (Camellia sinensis var. assamica)

An aerobic, Gram-staining-positive, rod-shaped, endospore-forming and motile bacterial strain, designated SJY2^T, was isolated from the rhizosphere soil of tea plants (Camellia sinensis var. assamica) collected in the organic tea garden of the Jingmai Pu-erh tea district in Pu'er city, Yunnan, southwest China. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the genus Paenibacillus. The closest phylogenetic relative was Paenibacillus filicis DSM 23916^T (98.1% similarity). The major fatty acids (> 10% of the total fatty acids) were anteiso-C_15:0 and isoC_16:0. The major respiratory quinone was MK-7 and the major polar lipid was diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine. The peptidoglycan contained glutamic acid, serine, alanine and meso-diaminopimelic acid. Genome sequencing revealed a genome size of 6.71 Mbp and a G + C content of 53.1%. Pairwise determined whole genome average nucleotide identity (gANI) values and digital DNA-DNA hybridization (dDDH) values suggested that strain SJY2^T represents a new species, for which we propose the name Paenibacillus puerhi sp. nov. with the type strain SJY2^T (= CGMCC 1.17156^T = KCTC 43242^T).

Characterization and Metabolism Effect of Seed Endophytic Bacteria Associated With Peanut Grown in South China

Endophytes are considered to be excellent biocontrol agents and biofertilizers, and are associated with plant growth promotion and health. In particular, seed-endophytic bacteria benefit the host plant’s progeny via vertical transmission, and can play a role in plant growth and defense. However, seed-associated endophytic bacteria have not been fully explored, with very little known about how they interact with peanut (Arachis hypogaea), for example. Here, 10 genera of endophytic bacteria were isolated from the root tips of peanut seedlings grown either aseptically or in soil. Forty-two bacterial colonies were obtained from peanut seedlings grown in soil, mostly from the genus Bacillus. Eight colonies were obtained from aseptic seedling root tips, including Bacillus sp., Paenibacillus sp., and Pantoea dispersa. Four Bacillus peanut strains GL1–GL4 (B.p.GL1-GL4) produced bio-films, while B.p.GL2 and Paenibacillus glycanilyticus YMR3 (P.g.YMR3) showed strong amylolytic capability, enhanced peanut biomass, and increased numbers of root nodules. Conversely, P. dispersa YMR1 (P.d.YMR1) caused peanut plants to wilt. P.g.YMR3 was distributed mainly around or inside vacuoles and was transmitted to the next generation through gynophores and ovules. Hexanoate, succinate, and jasmonic acid (JA) accumulated in peanut root tips after incubation with P.g.YMR3, but linolenate content decreased dramatically. This suggests that strain P.g.YMR3 increases JA content (14.93-fold change) and modulates the metabolism of peanut to facilitate nodule formation and growth. These findings provide new insight into plant–seed endophytic bacterial interactions in peanut.

Paenibacillus rhizophilus sp. nov., a nitrogen-fixing bacterium isolated from the rhizosphere of wheat (Triticum aestivum L.)

A novel Gram-stain-variable, endospore-forming, motile, rod-shaped, facultative aerobic bacterium, designated 7197^T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) collected from Yakeshi County, Inner Mongolia, PR China. This isolate was found to have the highest 16S rRNA gene sequence similarity to Paenibacillussabinae T27^T (98.0 %), followed by Paenibacillussophorae S27^T (97.9 %) and Paenibacillusforsythiae T98^T (97.7 %). To ascertain the genomic relatedness of this strain to its phylogenetic neighbours, its genome sequence was determined. The average nucleotide identity values of genome sequences between the novel isolate and the type strains of related species P. sabinae T27^T, P. sophorae S27^T and P. forsythiae T98^T were 87.9 %, 85.8 and 83.9 %, respectively. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified aminophospholipids and one unidentified aminolipid. The major cellular fatty acids were anteiso-C_15 : 0 (56.3 %), C_16 : 0 (15.7 %) and iso-C_15 : 0 (14.1 %).The genome size of strain 7197^T was 5.21 Mb, comprising 4879 predicted genes with a DNA G+C content of 51.9 mol%. Menaquinone-7 was reported as the major respiratory quinone. The diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Based on phylogenetic, genomic, chemotaxonomic and phenotypic characteristics, strain 7197^T was classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus rhizophilus sp. nov. is proposed. The type strain of Paenibacillus rhizophilus is 7197^T (=DSM 103168^T=CGMCC 1.15699^T).

Isolation, identification and plant growth promotion ability of endophytic bacteria associated with lupine root nodule grown in Tunisian soil

The present study aims to characterize nodule endophytic bacteria of spontaneous lupine plants regarding their diversity and their plant growth promoting (PGP) traits. The potential of PGPR inoculation was investigated to improve white lupine growth across controlled, semi-natural and field conditions. Lupinus luteus and Lupinus angustifolius nodules were shown inhabited by a large diversity of endophytes. Several endophytes harbor numerous plant growth promotion traits such as phosphates solubilization, siderophores production and 1-aminocyclopropane-1-carboxylate deaminase activity. In vivo analysis confirmed the plant growth promotion ability of two strains (Paenibacillus glycanilyticus LJ121 and Pseudomonas brenneri LJ215) in both sterilized and semi-natural conditions. Under field conditions, the co-inoculation of lupine by these strains increased shoot N content and grain yield by 25% and 36%, respectively. These two strains Paenibacillus glycanilyticus LJ121 and Pseudomonas brenneri LJ215 are effective plant growth-promoting bacteria and they may be used to develop an eco-friendly biofertilizer to boost white lupine productivity.

Paenibacillus luteus sp. nov., isolated from soil

A novel Gram-stain-positive, strictly aerobic, motile, spore-forming and rod-shaped bacterial strain, designated R-3^T, was isolated from a soil sample obtained from the shore of Lake Panyang, Sichuan Province, PR China. Strain R-3^T hydrolysed starch and casein. It could not assimilate d-glucose as a carbon source, or produce acid from d-glucose and l-arabinose. Phylogenetic, phenotypic, chemotaxonomic and molecular studies were performed on the new isolate. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R-3^T was a member of the genus Paenibacillus, exhibiting the highest sequence similarity to Paenibacillus sinopodophylli TEGR-3^T (98.4 %). The organism grew at 4-38 °C (optimum, 28-30 °C), at pH 6.0-10.0 (pH 7.0-7.5) and with 0-2.5 % (w/v) NaCl (1 %). The predominant menaquinone was MK-7. Anteiso-C15 : 0 (60.7 %) and C16 : 0 (15.5 %) were the major fatty acids. The cellular polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The DNA G+C content of strain R-3^T was determined to be 47.0 mol%. The DNA-DNA relatedness between strain R-3^T and P. sinopodophylli TEGR-3^T was 21.2 %. Based on the results obtained in this study, strain R-3^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillusluteus sp. nov. is proposed. The type strain is R-3^T (=CGMCC 1.16135^T=KCTC 33912^T).

Paenibacillus esterisolvens sp. nov., isolated from soil

A Gram-stain-positive, aerobic, motile with peritrichous flagella, rod-shaped bacterium, designated CFH S0170^T, was isolated from a soil sample collected from Catba island in Ha Long Bay, Hai Phong City, Vietnam. Comparison of the 16S rRNA gene sequences showed that strain CFH S0170^T belonged to the genus Paenibacillus and showed closest relationship with Paenibacillus vulneris CCUG 53270^T (98.1 % similarity). Phylogenetic analysis demonstrated that the novel candidate formed a coherent branch with P. vulneris CCUG 53270^T and Paenibacillus yunnanensis YN2^T. Furthermore, the novel strain shared 87.2 % rpoB gene sequence similarity with P. vulneris CCUG 53270^T. Growth of strain CFH S0170^T occurred at 10-40 °C, pH 6.0-8.0 and with 0-2.0 % (w/v) NaCl. Strain CFH S0170^T contained mannose, glucose and rhamnose as the major whole-cell sugars. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid, lysine and aspartic acid. The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, glycolipids and phospholipids. The dominant cellular fatty acids included anteiso-C15 : 0 and C15 : 0. The genomic DNA G+C content was 50.9 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analysis, strain CFH S0170^T is affiliated to the genus Paenibacillus, but could be distinguished from other valid species of this genus. It is concluded that strain CFH S0170^T should be considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus esterisolvens sp. nov. is proposed. The type strain is CFH S0170^T (=KCTC 33624^T=BCRC 80802^T).

Paenibacillus albidus sp. nov., isolated from grassland soil

A novel bacterial strain, designed Q4-3^T, was isolated from a soil sample obtained from Qilian grassland, Qinghai, China. Phylogenetic, phenotypic, chemotaxonomic and molecular analyses were performed on the new isolate. Cells were Gram-stain-positive, facultatively anaerobic, spore-forming, motile rods with peritrichous flagella. Phylogenetic analysis based on 16S rRNA gene sequences placed strain Q4-3^T in the genus Paenibacillus, and its closest relatives were Paenibacillus odorifer JCM 21743^T, Paenibacillus typhae DSM 25190^T, Paenibacillus borealis DSM 13188^T and Paenibacillus etheri DSM 29760^T with 16S rRNA gene sequence similarities of 98.12, 97.89, 97.63 and 97.6 %, respectively. The isolate grew at 4-37 °C (optimum 28-30 °C), at pH 6.0-10.0 (optimum pH 7.5) and with 0-3 %(w/v) NaCl (optimum 1 %). The DNA of strain Q4-3^T was determined to be 48.6 mol%. The predominant menaquinone was MK-7 and the diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Anteiso-C15 : 0 (55.5 %), iso-C16 : 0 (14.5 %) and C16 : 0 (13.3 %) were the major fatty acids. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified lipid. Based on these results, strain Q4-3^T is considered to represent a novel of the genus Paenibacillus, for which the name Paenibacillusalbidus nov. is proposed. The type strain is Q4-3^T (=CGMCC 1.16134^T=KCTC 33911^T).

Paenibacillus konkukensis sp. nov., isolated from animal feed

A Gram-stain-positive, oxidase- and catalase-positive, aerobic, rod-shaped bacterium, designated strain SK-3146T, was isolated from animal feed. Phylogenetic analysis, based on 16S rRNA gene sequence comparisons, revealed that the strain formed a distinct lineage within the genus Paenibacillus that was closely related to Paenibacillusyunnanensis JCM 30953T (98.6 %), Paenibacillusvulneris CCUG 53270T (98.0 %) and Paenibacilluschinjuensis DSM 15045T (96.9 %). Cells were non-motile, endospore-forming and formed milky colonies on NA and R2A agar media. Growth of strain SK-3146T occurred at temperatures of 18-45 °C, at pH 6.0-9.5 and between 0.5-3.0 % NaCl (w/v). The major menaquinone was MK-7, with lesser amounts of MK-6 present. The cell wall peptidoglycan of strain SK-3146T contained meso-diaminopimelic acid. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 53.8 mol% and the DNA-DNA hybridization relatedness values between strain SK-3146T and P.yunnanensis JCM 30953T and P.vulneris CCUG 53270T were 26.13±0.8 % and 38.7±0.6 %, respectively. The phenotypic, phylogenetic and chemotaxonomic results indicate that strain SK-3146T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus konkukensis sp. nov. is proposed. The type strain is SK-3146T (=KACC 18876T=LMG 29568T).

Paenibacillusliaoningensis sp. nov., isolated from soil

A novel bacterial strain, designated as LNUB461T, was isolated from soil sample taken from the countryside of Shenyang, Liaoning Province, China. The isolate was a Gram-stain-positive, aerobiotic, motile, endospore-forming and rod-shaped bacterium. The organism grew optimally at 30-33 °C, pH 6.5-7.0 and in the absence of NaCl. Phylogenetic analysis based on the nearly full-length 16S rRNA gene sequence revealed high sequence similarity with Paenibacillus algorifonticola XJ259T (98.5 %), Paenibacillus xinjiangensis B538T (96.8 %), Paenibacillus glycanilyticus DS-1T (96.1 %) and Paenibacillus lupini RLAHU15T (96.1 %). The predominant cellular fatty acid and the only menaquinone were anteiso-C15:0 and MK-7, respectively. The main polar lipids of LNUB461T included phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC) and two unknown amino phospholipids (APL), and the cell-wall peptidoglycan was meso-diaminopimelic acid (A1γ). The DNA G+C content of LNUB461T was 49.1 mol%. The DNA-DNA hybridization value between LNUB461T and the most closely related species (P. algorifonticola) was 41.8 %. On the basis of these data, LNUB461T was classified as representing a novel species of the genus Paenibacillus, for which the name Paenibacillus liaoningensis sp. nov was proposed. The type strain is LNUB461T (=JCM 30712T=CGMCC 1.15101T).

Paenibacillus periandrae sp. nov., isolated from nodules of Periandra mediterranea

A bacterial strain designated PM10T was isolated from root nodules of Periandra mediterranea in Brazil. Phylogenetic analyses based on 16S rRNA gene sequences placed the isolate in the genus Paenibacillus with its closest relatives being Paenibacillus vulneris CCUG 53270T and Paenibacillus yunnanensis YN2T with 95.6 and 95.9% 16S rRNA gene sequence similarity, respectively. The isolate was a Gram-stain-variable, motile, sporulating rod that was catalase-negative and oxidase-positive. Caseinase was positive, amylase was weakly positive and gelatinase was negative. Growth was supported by many carbohydrates and organic acids as carbon sources. MK-7 was the only menaquinone detected and anteiso-C15 : 0 was the major fatty acid. Major polar lipids were diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol and two unidentified lipids. meso-Diaminopimelic acid was detected in the peptidoglycan. The DNA G+C content was 52.9 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain PM10T should be considered representative of a novel species of the genus Paenibacillus, for which the name Paenibacillus periandrae sp. nov. is proposed. The type strain is PM10T (=LMG 28691T=CECT 8827T).

Paenibacillus radicis sp. nov., an endophytic bacterium isolated from maize root

A novel Gram-stain-positive, aerobic, endospore-forming, and rod-shaped strain designated 694^T was isolated from surface-sterilized root tissue of a maize planted in the Fangshan District of Beijing, People's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain 694^T and Paenibacillus xinjiangensis DSM 30034^T (98.5 %) and Paenibacillus glycanilyticus (98.1 %), respectively. However, the DNA-DNA hybridization values between strain 694^T and its close relatives P. xinjiangensis 16970^T and Paenibacillus algorifonticola CGMCC 1.10223^T were 30.0 % and 36.7 % respectively. The DNA G+C content of strain 694^T was determined to be 46.9 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to be anteiso-C_15 : 0 (42.1 %), iso-C_15 : 0 (18.4 %), iso-C_16 : 0 (11.2 %) and C_16 : 0 (12.1 %). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 694^T from the closely related species in the genus Paenibacillus. Strain 694^T is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus radicis sp. nov. is proposed, with the type strain 694^T ( = CGMCC 1.15286^T = DSM 100762^T).

Paenibacillus medicaginis sp. nov. a chitinolytic endophyte isolated from a root nodule of alfalfa (Medicago sativa L.)

A Gram-stain-variable, short-rod-shaped, endospore-forming, strictly aerobic, non-motile, chitinolytic and endophytic bacterium, designated strain CC-Alfalfa-19T, exhibiting unusual bipolar appendages was isolated from a root nodule of alfalfa (Medicago sativa L.) in Taiwan and subjected to a polyphasic taxonomic study. Based on 16S rRNA gene sequence analysis, strain CC-Alfalfa-19T was found to be most closely related to Paenibacillus puldeungensis CAU 9324T (95.2 %), whereas other species of the genus Paenibacillus shared ≤ 95.0 % sequence similarity. The phylogenetic analysis revealed a distinct phyletic lineage established by strain CC-Alfalfa-19T with respect to other species of the genus Paenibacillus. Fatty acids comprised predominantly anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. Menaquinone 7 (MK-7) was identified as the sole respiratory quinone and the genomic DNA G+C content was 42.7 mol%. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, an unidentified glycolipid and an unidentified lipid. The diagnostic diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the polyphasic taxonomic evidence that was in line with the genus Paenibacillus and additional distinguishing characteristics, strain CC-Alfalfa-19T is considered to represent a novel species, for which the name Paenibacillus medicaginis sp. nov. (type strain CC-Alfalfa-19T = BCRC 80441T = JCM 18446T) is proposed.

Paenibacillus wenxiniae sp. nov., a nifH gene -harbouring endophytic bacterium isolated from maize

A novel Gram-positive, aerobic, motile, endospore-forming, rod-shaped bacterium, designated 373(T) was isolated from surface-sterilised root tissue of a maize planted in Fangshan District of Beijing, Peopole's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. The highest 16S rRNA gene sequence similarity was found between strain 373(T) and Paenibacillus hunanensis (98.1%), meanwhile the 16S rRNA gene sequence similarity between strain 373(T) and the type strains of other recognised members of the genus Paenibacillus were all below 95.6%. However, the DNA-DNA hybridization values between strain 373(T) and the type strain P. hunanensis DSM 22170(T) was 30.2%. The DNA G+C content of strain 373(T) was determined to be 46.0 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to consist of anteiso-C15: 0 (59.6%), anteiso-C17: 0 (12.8%) and C16: 0 (6.7%). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 373(T) from the closely related species in this genus Paenibacillus. Strain 373(T) is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus wenxiniae sp. nov. is proposed, with the type strain 373(T) (= CGMCC 1.15007 (T) = DSM100576 ).

Paenibacillus kyungheensis sp. nov., isolated from flowers of magnolia

A Gram-staining-positive, catalase-positive, oxidase-negative, facultatively anaerobic, rod-shaped bacterium designated strain DCY88T, was isolated from flowers of magnolia. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Paenibacillus that was closely related to Paenibacillus hordei RH-N24T (97.8 %). The other most closely related species were Paenibacillus illinoisensis NRRL NRS-1356T (94.3 %), Paenibacillus hunanensis DSM 22170T (94.2 %), Paenibacillus peoriae DSM 8320T (93.9 %), Paenibacillus kribbensis Am49T (93.8 %) and the type species of the genus, Paenibacillus polymyxa ATCC 842T (93.3 %). Cells of the strain were endospore-forming and motile by peritrichous flagella. Strain DCY88T formed pink-pigmented colonies on trypticase soy agar and R2A agar medium. Growth of strain DCY88T occurs at temperatures 5-37 °C, at pH 4-9 and 0.5-5.5 % NaCl (w/v). The menaquinone was MK-7.The cell wall peptidoglycan of strain DCY88T contained meso-diaminopimelic acid. The major fatty acids were anteiso-C15 : 0 (61.0 %) and C16 : 0 (11.0 %). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified polar lipid. The strain DCY88T contained spermidine as the major polyamine. The DNA G+C content was 51.6 mol%. The DNA-DNA hybridization relatedness between strain DCY88T and P. hordei RH-N24T was 48 ± 2 %. The phenotypic, phylogenetic and chemotaxonomic results indicate that the strain DCY88T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus kyungheensis sp. nov. is proposed. The type strain is DCY88T ( = JCM 19886T = KCTC 33429T).

Paenibacillus oenotherae sp. nov. and Paenibacillus hemerocallicola sp. nov., isolated from the roots of herbaceous plants

Two Gram-staining-positive, aerobic, endospore-forming, motile bacteria, strains DT7-4T and DLE-12T, were isolated from roots of evening primrose (Oenothera biennis) and day lily (Hemerocallis fulva), respectively, and subjected to taxonomic characterization. Analysis of 16S rRNA gene sequences indicated that the two strains fell into two distinct phylogenetic clusters belonging to the genus Paenibacillus. Strain DT7-4T was most closely related to Paenibacillus phyllosphaerae PALXIL04T and Paenibacillus taihuensis THMBG22T, with 96.3 % 16S rRNA gene sequence similarity to each, and strain DLE-12T was most closely related to Paenibacillus ginsengarvi Gsoil 139T and Paenibacillus hodogayensis SGT, with 96.6 and 93.3  % sequence similarity, respectively. Both isolates contained anteiso-C15 : 0 as the dominant fatty acid, meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan and MK-7 as the respiratory menaquinone. The cellular polar lipids were composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unidentified polar lipids. The DNA G+C contents of strains DT7-4T and DLE-12T were 50.1 ± 0.7 and 55.2 ± 0.5 mol%, respectively. The chemotaxonomic properties of both isolates were typical of members of the genus Paenibacillus. However, our biochemical and phylogenetic analyses distinguished each isolate from related species. Based on our polyphasic taxonomic analysis, strains DT7-4T and DLE-12T should be recognized as representatives of novel species of Paenibacillus, for which the names Paenibacillus oenotherae sp. nov. (type strain DT7-4T = KCTC 33186T = JCM 19573T) and Paenibacillus hemerocallicola sp. nov. (type strain DLE-12T = KCTC 33185T = JCM 19572T) are proposed.