Wheat Rhizosphere-Derived Bacteria Protect Soybean from Soilborne Diseases

Soybean (Glycine max [L.] Merr.) is an important oilseed crop with a high economic value. However, three damaging soybean diseases, soybean cyst nematode (SCN; Heterodera glycines Ichinohe), Sclerotinia stem rot caused by the fungus Sclerotinia sclerotiorum (Lid.) de Bary, and soybean root rot caused by Fusarium spp., are major constraints to soybean production in the Great Plains. Current disease management options, including resistant or tolerant varieties, fungicides, nematicides, and agricultural practices (crop rotation and tillage), have limited efficacy for these pathogens or have adverse effects on the ecosystem. Microbes with antagonistic activity are a promising option to control soybean diseases with the advantage of being environmentally friendly and sustainable. In this study, 61 bacterial strains isolated from wheat rhizospheres were used to examine their antagonistic abilities against three soybean pathogens. Six bacterial strains significantly inhibited the growth of Fusarium graminearum in the dual-culture assay. These bacterial strains were identified as Chryseobacterium ginsengisoli, C. indologenes, Pseudomonas poae, two Pseudomonas spp., and Delftia acidovorans by 16S rRNA gene sequencing. Moreover, C. ginsengisoli, C. indologenes, and P. poae significantly increased the mortality of SCN second-stage juveniles (J2), and two Pseudomonas spp. inhibited the growth of S. sclerotiorum in vitro. Further growth chamber tests found that C. ginsengisoli and C. indologenes reduced soybean Fusarium root rot disease. C. ginsengisoli and P. poae dramatically decreased SCN egg number on SCN-susceptible soybean 'Williams 82'. Two Pseudomonas spp. protected soybean plants from leaf damage and collapse after being infected by S. sclerotiorum. These bacteria exhibit versatile antagonistic potential. This work lays the foundation for further research on the field control of soybean pathogens.

Chryseobacterium metallicongregator, sp. nov., a bacterium possessing metallophore activity towards rare earth elements

A polyphasic taxonomic study was carried out on strain ES2T, isolated from sediment of a wetland created to remediate acid drainage from a coal mine. The rod-shaped bacterium formed yellow/orange pigmented colonies and produced the pigment flexirubin. The 16S rRNA gene sequence results assigned the strain to Chryseobacterium, with 98.9 and 98.3 % similarity to Chryseobacterium vietnamense and Chryseobacterium cucumeris, respectively. Computation of the average nucleotide identity and digital DNA-DNA hybridization values with the closest phylogenetic neighbours of ES2T revealed genetic differences at the species level, which were further substantiated by differences in several physiological characteristics. The dominant fatty acids of strain ES2T were iso-C15 : 0, iso-C17 : 1 ω9c, iso C17 : 0 3-OH, and iso-C15 : 0 2-OH. The DNA G+C content was 35.5 mol%. The major polar lipid was phosphatidylethanolamine while menaquinone-6 was the only menaquinone found. This bacterium has been previously shown to possess metallophore activity towards rare earth elements, and based on genome sequencing, possesses all required genes for siderophore production/activity, possibly identifying the source of this unique ability. On the basis of the results obtained here, this bacterium is assigned to the genus Chryseobacterium as representing a new species with the name Chryseobacterium metallicongregator sp. nov., type strain ES2T (=NRRL B-65679T=KCTC 102120T).

Revealing the Tick Microbiome: Insights into Midgut and Salivary Gland Microbiota of Female Ixodes ricinus Ticks

The ectoparasite Ixodes ricinus is an important vector for many tick-borne diseases (TBD) in the northern hemisphere, such as Lyme borreliosis, rickettsiosis, human granulocytic anaplasmosis, or tick-borne encephalitis virus. As climate change will lead to rising temperatures in the next years, we expect an increase in tick activity, tick population, and thus in the spread of TBD. Consequently, it has never been more critical to understand relationships within the microbial communities in ticks that might contribute to the tick's fitness and the occurrence of TBD. Therefore, we analyzed the microbiota in different tick tissues such as midgut, salivary glands, and residual tick material, as well as the microbiota in complete Ixodes ricinus ticks using 16S rRNA gene amplicon sequencing. By using a newly developed DNA extraction protocol for tick tissue samples and a self-designed mock community, we were able to detect endosymbionts and pathogens that have been described in the literature previously. Further, this study displayed the usefulness of including a mock community during bioinformatic analysis to identify essential bacteria within the tick.

Genomic analysis of Chryseobacterium indologenes and conformational dynamics of the selected DD-peptidase

Chrysobacterium indologenes is an emerging MDR pathogen that belongs to the family Flavobacteriaceae. The genome of the C. indologenes, isolated from the nephrotic patient, was sequenced through Illumina MiSeq. The pangenomics of available 56 C. indologenes strains using BPGA revealed an open pangenome (n=5553 CDS), core genome (2141), and accessory genome (2013). The CEG/DEG database identified 662 essential genes that drastically reduced to 68 genes after non-homology analyses towards human and gut microbiome. Further filtering the data for other drug target prioritizing parameters resulted in 32 putative targets. Keeping in view the crucial role played in cell wall biosynthesis, dacB was selected as the final target that encodes D-alanyl-d-alanine carboxypeptidase/endopeptidase (DD-peptidase). The 3D structure of dacB was modelled and rendered to docking analyses against two compound libraries of African plants (n=6842) and Tibetan medicines (n=52). The ADMET profiling exhibited the physicochemical properties of final compounds. The MD simulations showed the stability of inhibitor-DD-peptidase complex and interactions in terms of RMSD, RMSF, binding free energy calculation and H-bonding. We propose that the novel compounds Leptopene and ZINC95486338 from our findings might be potent DD-peptidase inhibitors that could aid in the development of new antibiotic-resistant therapy for the emerging MDR C. indologenes.

Polar lipid characterization and description of Chryseobacterium capnotolerans sp. nov., isolated from high CO2-containing atmosphere and emended descriptions of the genus Chryseobacterium, and the species C. balustinum, C. daecheongense, C. formosense, C. gleum, C. indologenes, C. joostei, C. scophthalmum and C. ureilyticum

Modified atmosphere (MA) packaging plays an important role in improving food quality and safety. By using different gas mixtures and packaging materials the shelf life of fresh produce can significantly be increased. A Gram-negative-staining, rod-shaped, orange-pigmented strain DH-B6T, has been isolated from MA packed raw pork sausage (20% CO2, 80% O2). The strain produced biofilms and showed growth at high CO2 levels of up to 40%. Complete 16S rRNA gene and whole-genome sequences revealed that strain DH-B6T belongs to the genus Chryseobacterium , being closely related to strain Chryseobacterium indologenes DSM 16777T (98.4%), followed by Chryseobacterium gleum NCTC11432T (98.3%) and Chryseobacterium lactis KC1864T (98.2%). Average nucleotide identity value between DH-B6T and C. indologenes DSM 16777T was 81.1% and digital DNA–DNA hybridisation was 24.9%, respectively. The DNA G+C content was 35.51 mol%. Chemotaxonomical analysis revealed the presence of the rare glycine lipid cytolipin, the serine-glycine lipid flavolipin and the sulfonolipid sulfobacin A, as well as phosphatidylethanolamine, monohexosyldiacylglycerol and ornithine lipid, including the hydroxylated forms. Major fatty acids were iC15 : 0 (50.7%) and iC17 : 1 cis 9 (28.7%), followed by iC15 : 0 2-OH (7.0%) and iC17 : 0 3-OH (6.2%). The isolated strain contained MK-6 as the only respiratory quinone and flexirubin-like pigments were detected as the major pigments. Based on the phenotypic, chemotaxonomic and phylogenetic characteristics, the strain DH-B6T (=DSM 110542T=LMG 31915T) represents a novel species of the genus Chryseobacterium , for which the name Chryseobacterium capnotolerans sp. nov. is proposed. Emended descriptions of the genus Chryseobacterium and eight species of this genus based on polar lipid characterisation are also proposed.

Prevalence of mouthpart sensilla and protease producing symbiotic gut bacteria in the forensic fly Chrysomya megacephala (Fabricius, 1794): Insight from foraging to digestion

The blow fly, Chrysomya megacephala (Fabricius, 1794) is a globally prevalent forensically important species that helps to estimate accurate postmortem interval since the death. This fly occasionally causes cutaneous myiasis and transmits several pathogenic bacteria. To understand their ability of corpse detection and digestion of protein-rich meal, the present study describes the mouthpart sensilla and assessment of protease producing symbiotic gut bacteria. Scanning electron microscopy (SEM) showed the prevalence of trichoid sensilla (Tr), basiconic sensilla (Ba) and microtrichia (Mr) on labellar lobes, haustellum and maxillary palps of mouthparts. Bacterial particles of both rod (small and large) and spherical shaped were detected in the gut of C. megacephala using SEM. The bacterial density was higher on the foregut and midgut in comparison to the hindgut. From 72 bacterial isolates, 10 isolates from the foregut region showed considerable protease-producing efficacy ranging between 3.98 - 6.83 GHR and 9.73 - 34.68 U/ml protease. Among these, the most promising protease-producing bacterial isolate showed 16S rDNA sequence similarity (99.85%) with Chryseobacterium artocarpi DNA. This bacterium was the first report from flies. The findings of the study might help in better understanding of the role of sensilla in host perception and foregut symbiotic bacterial association in protein digestion in C. megacephala.

Chryseobacterium candidae sp. nov., isolated from a yeast (Candida tropicalis)

A Gram-stain-negative, rod shaped, non-motile, aerobic bacterium (strain JC507^T) was isolated from a yeast (Candida tropicalis JY101). Strain JC507^T was oxidase- and catalase-positive. Complete 16S rRNA gene sequence comparison data indicated that strain JC507^T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium indologenes NBRC 14944^T (98.7 %), followed by Chryseobacterium arthrosphaerae CC-VM-7^T (98.6 %), Chryseobacterium gleum ATCC 35910^T (98.5 %) and less than 98.5 % to other species of the genus Chryseobacterium.The genomic DNA G+C content of strain JC507^T was 36.0 mol%. Strain JC507^T had phosphatidylethanolamine, four unidentified amino lipids and four unidentified lipids. MK-6 was the only respiratory quinone. The major fatty acids (>10 %) were anteiso-C_11 : 0, iso-C_15 : 0 and iso-C_17 : 03OH. The average nucleotide identity and in silico DNA-DNA hybridization values between strain JC507^T and C. indologenes NBRC 14944^T, C. arthrosphaerae CC-VM-7^T and C. gleum ATCC 35910^T were 80.2, 83.0 and 87.0 % and 24, 26.7 and 32.7 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses support the inclusion of strain JC507^T as a representative of a new species of the genus Chryseobacterium, for which the name Chryseobacteriumcandidae sp. nov. is proposed. The type strain is JC507^T (=KCTC 52928^T=MCC 4072^T=NBRC 113872^T).

Chryseobacterium indologenes and Chryseobacterium gleum interact and multiply intracellularly in Acanthamoeba castellanii

Chryseobacterium indologenes and Chryseobacterium gleum are Gram negative environmental bacteria that have been frequently reported to implicate in fatal nosocomial infections, such as bacteraemia and ventilator-associated pneumonia in immunocompromised individuals in the past decades. The interaction between Chryseobacterium spp. and Acanthamoeba castellanii, a free-living amoeba ubiquitous in the environment, has not been explored previously. In this study, C. indologenes and C. gleum were co-cultured with A. castellanii trophozoites and their interactions were evaluated. Our results showed that when co-cultured with A. castellanii, bacterial numbers of C. indologenes and C. gleum increased significantly (p < 0.05), indicating growth-supporting role of A. castellanii. Specifically, our findings showed that C. indologenes and C. gleum were able to associate, invade and/or taken up by A. castellani trophozoites, and multiply intracellularly at similar rates (p > 0.05). Interestingly, the two Chryseobacterium spp. associated, invaded and/or taken up by A. castellanii at significantly higher rates than Escherichia coli K1, a neuropathogenic bacterial strain known to interact and replicate intracellularly in A. castellanii (p < 0.05). However, the ability of both Chryseobacterium spp. to multiply in A. castellanii was significantly weaker than E. coli K1 (p < 0.001). This is the first time that Chryseobacterium spp. and A. castellanii were shown to interact with each other. The ability to survive intracellularly in A. castellanii may confer protection to C. indologenes and C. gleum and assist in the survival and transmission of Chryseobacterium spp. to susceptible hosts within a hospital setting. Future studies will determine the ability of C. indologenes and C. gleum survival in A. castellanii cysts and the possible molecular mechanisms involved in such interactions.

Phylogenetic insights into the diversity of Chryseobacterium species

The genus Chryseobacterium was formally established in 1994 and contains 112 species with validly published names. Most of these species are yellow or orange coloured, and contain a flexirubin-type pigment. The genomes of 83 of these 112 species have been sequenced in view of their importance in clinical microbiology and potential applications in biotechnology. The National Center for Biotechnology Information taxonomy browser lists 1415 strains as members of the genus Chryseobacterium, of which the genomes of 94 strains have been sequenced. In this study, by comparing the 16S rDNA and the deduced proteome sequences, at least 20 of these strains have been proposed to represent novel species of the genus Chryseobacterium. Furthermore, a yellow-coloured bacterium isolated from dry soil in the USA (and identified as Flavobacterium sp. strain B-14859) has also been reconciled as a novel member of the genus Chryseobacterium based on the analysis of 16S rDNA sequences and the presence of flexirubin. Yet another bacterium (isolated from a water sample collected in the Western Ghats of India and identified as Chryseobacterium sp. strain WG4) was also found to represent a novel species. These proposals need to be validated using polyphasic taxonomic approaches.

Comparison of the Vitek MS and Bruker Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Systems for Identification of Chryseobacterium Isolates from Clinical Specimens and Report of Uncommon Chryseobacterium Infections in Humans

Matrix-assisted laser desorption ionization-time of flight mass spectrometry is becoming more popular and is replacing traditional identification methods in the clinical microbiology laboratory. We aimed to compare the Vitek mass spectrometry (MS) and Bruker Biotyper systems for the identification of Chryseobacterium isolated from clinical specimens and to report uncommon Chryseobacterium infections in humans. The microbial database from a hospital was searched for records between 2005 and 2016 to identify cultures that yielded Chryseobacterium Species identification by the Vitek MS and Bruker Biotyper systems was compared to identification by 16S rRNA gene sequencing. Over the study period, 140 Chryseobacterium isolates were included. Based on 16S rRNA gene sequencing, 78 isolates were C. indologenes, 39 were C. gleum, 12 were uncommon Chryseobacterium species (C. arthrosphaerae, C. culicis, C. cucumeris, C. bernardetii, C. artocarpi, and C. daecheongense), and the remaining 11 isolates were only identified at the genus level. The Vitek MS and Bruker Biotyper systems correctly identified 98.7% and 100% of C. indologenes isolates, respectively. While the Bruker Biotyper accurately identified 100% of C. gleum isolates, the Vitek MS system correctly identified only 2.6% of isolates from this species. None of the uncommon Chryseobacterium species were successfully identified by either of these two systems. The overall accuracies of Chryseobacterium identification at the species level by the Vitek MS and Bruker Biotyper systems were 60.5% and 90.7%, respectively. An upgrade and correction of the Vitek MS and Bruker Biotyper databases is recommended to correctly identify Chryseobacterium species.

Pigments from Soil Bacteria and Their Therapeutic Properties: A Mini Review

Advancement in research on dyes obtained from natural sources e.g., plants, animals, insects and micro-organisms is widening the application of natural dyes in various fields. The natural dyes substituted their synthetic analogs at the beginning of twentieth century due to their improved quality, value, ease of production, ease of dyeing and some other factors. This era of dominance ended soon when toxic effects of synthetic dyes were reported. In the last few decades, pigments from micro-organisms especially soil derived bacteria is replacing dyes from other natural sources because of the increasing demand for safe, non-toxic, and biodegradable natural product. Apart from application in agriculture practices, cosmetics, textile, food and paper industries, bacterial pigments have additional biological activities e.g., anti-tumor, anti-fungal, anti-bacterial, immunosuppressive anti-viral, and many more which make them a potential candidate for pharmaceutical industry. Optimization of culture conditions and fermentation medium is the key strategies for large scale production of these natural dyes. An effort has been done to give an overview of pigments obtained from bacteria of soil origin, their dominance over dyes from other sources (natural and synthetic) and applications in the medical world in the underlying study.

Chryseobacterium salipaludis sp. nov., isolated at a wild ass sanctuary

A Gram-stain-negative, rod-shaped, non-motile, aerobic bacterium was isolated from a sediment sample obtained from a wild ass sanctuary in Gujarat, India. The strain designated JC490^T was oxidase- and catalase-positive. The 16S rRNA gene sequence analysis and sequence comparison data indicated that strain JC490^T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium jeonii AT1047^T (96.4 %) and with other members of the genus Chryseobacterium (<96.3 %). The DNA G+C content of strain JC490^T was 34 mol%. Strain JC490^T had phosphatidylethanolamine, two unidentified aminolipids, two unidentified phospholipids and five unidentified polar lipids. Menaquinone-6 was the only respiratory quinone found. Iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH were the major fatty acids of strain JC490^T. On the basis of physiological, genotypic, phylogenetic and chemotaxonomic analyses, it is concluded that strain JC490^T constitutes a novel species of the genus Chryseobacterium, for which the name Chryseobacterium salipaludis sp. nov. is proposed. The type strain is JC490^T (=KCTC 52835^T=LMG 30048^T).

Description of Chryseobacterium timonianum sp. nov., isolated from a patient with pneumonia

Using a polyphasic taxonomic strategy, an aerobic, Gram-negative, non-motile, yellow pigmented rod isolated from a sputum sample of a patient with pneumonia was characterised. This bacterial strain, designated G972^T, could not be identified by our systematic MALDI-TOF screening on a MicroFlex. This led to the sequencing of the 16S rRNA gene, which shows 98.57% sequence identity with that of Chryseobacterium indologenes 16777^T, the phylogenetic closely related type strain of a species with standing in nomenclature, which putatively classifies it as a new species. The major cell fatty acids were identified as 13-methyl-tetradecanoic acid (61%), 3-hydroxy-heptadecanoic acid (16%) and 15-methyl-11-hexadecenoic acid (11%). D-glucose, D-mannose, aesculin, D-maltose, D-trehalose, and gentibiose are the main carbon source. Digital DNA-DNA hybridization (dDDH) estimation and average nucleotide identity values (ANI) of the strain G972^T against genomes of the type strains of related species ranged between 18.9 and 32.8% and between 71.46 and 83.61%, respectively, thus confirming again the new species status of the strain. Here, we describe the characteristics of this organism, complete genome sequence and annotation. The 5,390,132 bp size genome contains 4867 protein-coding genes, 89 RNAs (three genes are 5S rRNA, one gene is 16S rRNA, one gene is 23S rRNA and 84 tRNAs) with 35.51% GC content. Finally, on the basis of these polyphasic data, consisting of phenotypic and genomic analyses, we conclude that strain strain G972^T (= DSM 103388^T = CSUR P2233^T) represents a novel species for which we propose the name Chryseobacterium timonianum. The 16S rRNA and genome sequences are available in GenBank database under accession numbers LT161886 and FJVD00000000.

Draft Genome Sequence of Chryseobacterium sp. JV274 Isolated from Maize Rhizosphere

We report the draft genome sequence of Chryseobacterium sp. JV274. This strain was isolated from the rhizosphere of maize during a greenhouse experiment. JV274 harbors genes involved in flexirubin production (darA and darB genes), bacterial competition (type VI secretion system), and gliding (bacterial motility; type IX secretion system).

Chryseobacterium cucumeris sp. nov., an endophyte isolated from cucumber (Cucumis sativus L.) root, and emended description of Chryseobacterium arthrosphaerae

The Gram-stain-negative, yellow-pigmented, rod-shaped bacterial strain GSE06^T, isolated from the surface-sterilized root of a cucumber plant grown in a field in Gunsan, Korea, was characterized by not only cultural and morphological features but also physiological, biochemical and molecular analyses. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain GSE06^T was most closely related to species of the genus Chryseobacterium. Furthermore, strain GSE06^T exhibited the highest sequence similarities with the type strains Chryseobacterium indologenes ATCC 29897^T (98.9 %), Chryseobacterium gleum ATCC 35910^T (98.8 %), Chryseobacterium arthrosphaerae CC-VM-7^T (98.7 %), Chryseobacterium contaminans C26^T (98.5 %), Chryseobacterium artocarpi UTM-3^T (98.3 %), and Chryseobacterium gallinarum 100^T (97.9 %). Average nucleotide identity values between genome sequences of strain GSE06^T and the above-mentioned reference strains ranged from 81.2 to 86.9 %, which were lower than the threshold of 95 % (corresponding to a DNA-DNA reassociation value of 70 %). The DNA G+C content of strain GSE06^T was 36.1 mol%; the predominant respiratory quinone of the strain was MK-6. The major fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three aminolipids, one aminophospholipid, four glycolipids and one unidentified lipid. These results of phenotypic and genotypic characteristics could differentiate strain GSE06^T from closely related type strains belonging to the genus Chryseobacterium. Thus, strain GSE06^T is proposed as a representative of a novel species in the genus Chryseobacterium, Chryseobacterium cucumeris sp. nov. The type strain is GSE06^T (=KACC 18798^T=JCM 31422^T).

Draft Genome Sequences of Chryseobacterium artocarpi UTM-3T and Chryseobacterium contaminans C26T, Isolated from Rhizospheres, and Chryseobacterium arthrosphaerae CC-VM-7T, Isolated from the Feces of a Pill Millipede

Species of the genus Chryseobacterium belonging to the family Flavobacteriaceae are nonmotile, yellow-pigmented, and rod-shaped bacteria, some of which were frequently isolated from soil or plant-related materials. Here, we present draft genome sequences of three type strains of Chryseobacterium, which contain genes related to plant growth promotion, colonization, or stress adaptation.

Development of Culture Medium for the Isolation of Flavobacterium and Chryseobacterium from Rhizosphere Soil

An effective medium designated phosphate separately autoclaved Reasoner’s 2A supplemented with cycloheximide and tobramycin (PSR2A-C/T) has been developed for the isolation of Flavobacterium and Chryseobacterium strains from the plant rhizosphere. It consists of Reasoner’s 2A agar (R2A) prepared by autoclaving phosphate and agar separately and supplementing with 50 mg L⁻¹ cycloheximide and 1 mg L⁻¹ tobramycin. A comparison was made among the following nine media: PSR2A-C/T, PSR2A-C/T supplemented with NaCl, R2A agar, R2A agar supplemented with cycloheximide and tobramycin, 1/4-strength tryptic soy agar (TSA), 1/10-strength TSA, soil-extract agar, Schaedler anaerobe agar (SAA), and SAA supplemented with gramicidin, for the recovery of Flavobacterium and Chryseobacterium strains from the Welsh onion rhizosphere. Flavobacterium strains were only isolated on PSR2A-C/T, and the recovery rate of Chryseobacterium strains was higher from PSR2A-C/T than from the eight other media. In order to confirm the effectiveness of PSR2A-C/T, bacteria were isolated from onion rhizosphere soil with this medium. Flavobacterium and Chryseobacterium strains were successfully isolated from this sample at a similar rate to that from the Welsh onion rhizosphere.

Chryseobacterium echinoideorum sp. nov., isolated from sea urchins (Tripneustes gratilla)

A Gram-stain-negative, aerobic, non-motile, rod-shaped, flexirubin-producing bacterium, designated strain CC-CZW010T, was isolated from the edible sea urchin Tripneustes gratilla in Penghu Island, Taiwan. The isolate grew optimally at pH 7.0 and 30 °C in the presence of 2 % (w/v) NaCl. The most closely related strains in terms of 16S rRNA gene sequence similarity were Chryseobacterium taihuense NBRC 108747T (97.6 %) and Chryseobacterium aquaticum KCTC 12483T (96.7 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed a distinct taxonomic position attained by strain CC-CZW010T with respect to other species of the genus Chryseobacterium. Strain CC-CZW010T possessed iso-C15 : 0, anteiso-C15 : 0, iso-C17 :  0 3-OH, summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c) and summed feature 9 (comprising C16 :  0 10-methyl/iso-C17 : 1ω9c) as predominant fatty acids. The major polar lipid profile consisted of phosphatidylethanolamine, two unidentified lipids and five aminolipids. The polyamine pattern contained the major compound sym-homospermidine. Menaquinone 6 (MK-6) was the predominant respiratory quinone, and the G+C content of the genomic DNA was 36.4 mol%. According to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-CZW010T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium echinoideorum sp. nov. is proposed. The type strain is CC-CZW010T ( = BCRC 80786T = JCM 30470T).

Chryseobacterium solani sp. nov., isolated from field-grown eggplant rhizosphere soil

Strain THG-EP9T, a Gram-stain-negative, aerobic, motile, rod-shaped bacterium was isolated from field-grown eggplant (Solanum melongena) rhizosphere soil collected in Pyeongtaek, Gyeonggi–do, Republic of Korea. Based on 16S rRNA gene sequence comparisons, strain THG-EP9T had closest similarity with Chryseobacterium ginsenosidimutans THG 15T (97.3  % 16S rRNA gene sequence similarity), Chryseobacterium soldanellicola PSD1-4T (97.2 %), Chryseobacterium zeae JM-1085T (97.2 %) and Chryseobacterium indoltheticum LMG 4025T (96.8 %). DNA–DNA hybridization showed 5.7 % and 9.1 % DNA reassociation with Chryseobacterium ginsenosidimutans KACC 14527T and Chryseobacterium soldanellicola KCTC 12382T, respectively. Chemotaxonomic data revealed that strain THG-EP9T possesses menaquinone–6 as the only respiratory quinone and iso-C15 : 0 (29.0 %), C16 : 0 (12.5 %) and iso-C17 : 0 3-OH (11.9 %) as the major fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, an unidentified aminophospholipid, two unidentified glycolipids, six unidentified aminolipids and two unidentified polar lipids. The DNA G+C content was 35.3 mol%. These data corroborated the affiliation of strain THG–EP9T to the genus Chryseobacterium. Thus, the isolate represents a novel species of this genus, for which the name Chryseobacterium solani sp. nov. is proposed, with THG-EP9T ( = KACC 17652T = JCM 19456T) as the type strain.

Chryseobacterium arachidiradicis sp. nov., isolated from the geocarposphere (soil around the peanut) of very immature peanuts (Arachis hypogaea)

A yellow-pigmented bacterial strain, 91A-612(T), isolated from the geocarposphere (soil around the peanut) of very immature peanuts (Arachis hypogaea) in Alabama, USA, was studied for its taxonomic position. Cells of the isolate were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequence with the sequences of the type strains of the most closely related species showed that the strain belongs to the genus Chryseobacterium, showing the highest sequence similarities to the type strains of Chryseobacterium molle (98.4%), C. pallidum (98.3%) and C. hominis (97.8%). The 16S rRNA gene sequence similarities to the type strains of all other species of the genus Chryseobacterium were below 97.0%. The fatty acid profile of strain 91A-612(T) consisted of the major fatty acids iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH/C16 : 1ω7c) and iso-C17 : 0 3-OH. Major compounds in the polar lipid profile were phosphatidylethanolamine and several unidentified lipids, including two lipids that did not contain a sugar moiety, an amino group or a phosphate group (L3, L8), and an aminolipid (AL1). The quinone system was composed mainly of MK-6. The polyamine pattern contained sym-homospermidine as the major compound and moderate amounts of spermidine and spermine. DNA-DNA hybridizations between strain 91A-612(T) and the type strains of C. molle, C. pallidum and C. hominis resulted in relatedness values well below 70%. These data and the differentiating biochemical and chemotaxonomic properties showed that isolate 91A-612(T) represents a novel species of the genus Chryseobacterium, for which we propose the name Chryseobacterium arachidiradicis sp. nov. (type strain 91A-612(T) = LMG 27814(T)= CCM 8490(T) = CIP 110647(T)).