Description of Chryseobacterium fluminis sp. nov., a keratinolytic bacterium isolated from a freshwater river

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated MMS21-Ot14T, was isolated from a freshwater river, and shown to represent a novel species of the genus Chryseobacterium on the basis of the results from a polyphasic approach. The 16S rRNA gene sequence analysis revealed that MMS21-Ot14T represented a member of the genus Chryseobacterium of the family Weeksellaceae and was closely related to Chryseobacterium hagamense RHA2-9T (97.52 % sequence similarity), Chryseobacterium gwangjuense THG A18T (97.46 %) and Chryseobacterium gregarium P 461/12T (97.27 %). The optimal growth of MMS21-Ot14T occurred at 25-30 °C, pH 6.0-7.0 and in the absence of NaCl. MMS21-Ot14T was capable of hydrolysing casein, starch, DNA, Tween 20 and tyrosine. The strain also showed keratinolytic activity with keratin azure and decolourising activity with remazol brilliant blue R (RBBR), which indicated potential ability to degrade keratin and lignin. The main polar lipids of MMS21-Ot14T were phosphatidylethanolamine, unidentified aminophospholipids, unidentified aminolipids, an unidentified phospholipid and several unidentified lipids. The predominant fatty acids of MMS21-Ot14T were iso-C15 : 0 and iso-C17 : 0 3-OH, and the major isoprenoid quinone was menaquinone 6 (MK-6). The whole genome of MMS21-Ot14T was 5 062 016 bp in length with a DNA G+C content of 37.7 %. The average nucleotide identity and digital DNA-DNA hybridisation values between MMS21-Ot14T and phylogenetically related members of the genus Chryseobacterium were well below the threshold values for species delineation. It is evident from the results of this study that MMS21-Ot14T should be classified as representing a novel species of the genus Chryseobacterium, for which the name Chryseobacterium fluminis sp. nov. (type strain, MMS21-Ot14T = KCTC 92255T = LMG 32529T) is proposed.

Chryseobacterium tagetis sp. nov., a plant growth promoting bacterium with an antimicrobial activity isolated from the roots of medicinal plant (Tagetes patula)

A novel plant growth-promoting and indole acetic acid (IAA) producing strain designated RG1^T was isolated from the roots of Tagetes patula (marigold) collected from Goyang, South Korea. The cells of strain RG1^T is aerobic, yellow, Gram-stain-negative, pleomorphic and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RG1^T belongs to the genus Chryseobacterium and is closely related to Chryseobacterium gwangjuense THG-A18^T (98.6%). The strain produced IAA (70.5 µg ml^-1) in the presence of _L-tryptophan and showed antimicrobial activity against Gram-negative bacterium Xanthomonas campestris pv. campestris KACC 10377^T. The isolate had a significant positive effect on rice plant shoot and root growth. The novel strain RG1^T had a draft genome size of 4,430,189 bp, with ten scaffolds and 3969 protein-coding genes. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain RG1^T and other closely related members ranged from 21.5 to 36.6% and from 79.2 to 86.6%, respectively. The genomic DNA G + C content was 34.8 mol%. Furthermore, anti-SMASH analysis of the whole genome revealed six putative biosynthetic gene clusters responsible for various secondary metabolites. The major respiratory quinone was MK-6 and the major fatty acids were iso-C_15:0, summed feature 3 (comprising C_16: 1ω7c and/or C_16: 1ω6c) and summed feature 9 (comprising iso-C_17: 1 ω9c and/or 10-methyl C_16:0). The major polar lipid is phosphatidylethanolamine. Based on the genotypic, chemotaxonomic and physiological data, strain RG1^T represents a novel species, for which the name Chryseobacterium tagetis sp. nov. is proposed. The type strain is designated as RG1^T ( = KCTC 82696^T = NBRC 115057^T).

Volatiles from the Psychrotolerant Bacterium Chryseobacterium polytrichastri

The flavobacterium Chryseobacterium polytrichastri was investigated for its volatile profile by use of a closed-loop stripping apparatus (CLSA) and subsequent GC-MS analysis. The analyses revealed a rich headspace extract with 71 identified compounds. Compound identification was based on a comparison to library mass spectra for known compounds and on a synthesis of authentic standards for unknowns. Important classes were phenylethyl amides and a series of corresponding imines and pyrroles.

Chryseobacterium chengduensis sp. nov. isolated from the air of captive giant panda enclosures in Chengdu, China

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated 25-1(T), was isolated from the air inside giant panda enclosures at the Chengdu Research Base of Giant Panda Breeding, China. Strain 25-1(T) grew optimally at pH 7.0-8.0, at 28-30 °C and in the presence of NaCl concentrations from 0.0% to 0.5 %. 16S rRNA gene sequence analysis indicated that strain 25-1(T) belongs to the genus Chryseobacterium within the family Flavobacteriaceae and is related most closely to C. carnis G81(T) (96.4% similarity), C. lathyri RBA2-6(T) (95.8% similarity), and C. zeae JM1085(T) (95.8% similarity). Its genomic DNA G+C molar composition was 36.2%. The major cellular fatty acids were iso-C15:0 (44.0%), iso-C17:0 3OH (19.8%) and C16:1 ω7c/16:1 ω6c (12.7%). The only isoprenoid quinone was menaquinone 6 (MK-6). The major polar lipids were phosphatidylethanolamine, two unidentified amino lipids and two unidentified lipids. The DNA-DNA relatedness between strain 25-1(T) and C. lathyri RBA2-6(T) was 38%. Phenotypic, genotypic, and phylogenetic characteristics indicated that strain 25-1(T) is a novel member of the genus Chryseobacterium, for which the name C. chengduensis sp. nov. is proposed. The type strain is 25-1(T) (CCTCC AB2015133(T)=DSM 100396(T)).

Chryseobacterium reticulitermitis sp. nov., isolated from the gut of Reticulitermes aculabialis

A Gram-stain-negative, non-motile, aerobic and rod-shaped bacterium, strain Ra1T, was isolated from the gut of a wood-feeding lower termite, Reticulitermes aculabialis. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain was closely related to Chryseobacterium rigui JCM 18078T (96.7 % similarity). Growth was observed at 15-45 °C (optimum 30 °C), at pH 6.0-9.0 (optimum pH 8.0) and in the presence of 0-2 % (w/v) NaCl (optimum 0 %). The DNA G+C content of strain Ra1T was 39.9 mol%. Cells contained menaquinone MK-6 as the sole respiratory quinone and the major fatty acids were iso-C15 : 0, iso-C17 : 0, summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 9 (comprising C16 : 0 10-methyl and/or iso-C17 : 1ω9c). The predominant polyamine was sym-homospermidine. The cellular polar lipids consisted of one phosphatidylethanolamine, three unidentified aminolipids, one unidentified phospholipid and one unidentified lipid. Based on phenotypic, genotypic and phylogenetic studies, it is concluded that strain Ra1T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium reticulitermitis sp. nov. is proposed. The type strain is Ra1T (=CCTCC AB 2015431T=KCTC 52230T).

Chryseobacterium montanum sp. nov. isolated from mountain soil

A Gram-staining-negative, strictly aerobic, non-spore-forming, rod-shaped bacterium, designated WG4T, was isolated from soil of the Tianmen Mountain located in Hunan province, PR China. 16S rRNA gene sequence analysis showed that the strain belongs to the genus Chryseobacterium in the family Flavobacteriaceae, with 97.4 % and 97.1 % sequence identities to Chryseobacterium anthropi NF 1366T and Chryseobacterium haifense H38T, respectively. In comparison with the other strains representing the genus Chryseobacterium, the 16S rRNA gene sequence identities were less than 97.0 %. The DNA-DNA relatedness values were 63.3 % (±1) between C. anthropi NF 1366T and strain WG4T and 62.7 % (±2) between C. haifense DSM 19056T and strain WG4T. The DNA G+C content of strain WG4T was 37.7 mol%. The predominant fatty acids of strain WG4T were iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three unidentified lipids and two unidentified aminolipids. The major menaquinone of strain WG4T was menaquinone 6. Strain WG4T showed some unique physiological and biochemical characteristics, such as being negative for gelatin hydrolysis, and valine arylamidase and α-glucosidase activity, and positive for acid production from cellobiose. Based on the differentiating phylogenetic inference and biochemical data, strain WG4T represents a novel species, for which the name Chryseobacterium montanum sp. nov. is proposed, with the type strain WG4T (=KCTC 52204T=CCTCC AB 2016058T).

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)).

Chryseobacterium takakiae sp. nov., a member of the phylum Bacteroidetes isolated from Takakia lepidozioides

A Gram-stain-negative, rod-shaped and non-endospore-forming bacterium, designated strain AG1-2T, was isolated from Takakia lepidozioides collected from the Gawalong glacier in Tibet, China and characterized using a polyphasic taxonomic approach. The predominant fatty acids of strain AG1-2T were iso-C15 : 0 (36.0 %), iso-C17 : 0 3-OH (20.2 %), summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl, 16.4 %) and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 11.1 %). The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and two unidentified lipids. Strain AG1-2T contained MK-6 as the dominant menaquinone, and the genomic DNA G+C content was 37.3 mol%. The phylogenetic analysis based on the 16S rRNA gene sequences showed that strain AG1-2T was affiliated to species of the genus Chryseobacterium , and its closest related species were Chryseobacterium taiwanense Soil-3-27T, Chryseobacterium hispalense AG13T, Chryseobacterium camelliae THG C4-1T and Chryseobacterium taeanense PHA3-4T with a sequence similarity of 98.0, 97.8, 97.3 and 97.1 %, respectively. However, the DNA–DNA relatedness values between these strains and strain AG1-2T were 29, 21, 21 and 45 %, respectively. Based on phylogenetic inference and phenotypic data, strain AG1-2T is considered to represent a novel species of the genus Chryseobacterium , for which the name Chryseobacterium takakiae sp. nov. is proposed. The type strain is AG1-2T ( = CGMCC 1.12488T = DSM 26898T).

Chryseobacterium gallinarum sp. nov., isolated from a chicken, and Chryseobacterium contaminans sp. nov., isolated as a contaminant from a rhizosphere sample

Two yellow-pigmented bacterial strains (100T and C26T), showing 98.4 % 16S rRNA gene sequence similarity to each other and isolated from a chicken in Germany and as a contaminant from an agar plate of a rhizosphere sample in Alabama, were studied by using a polyphasic taxonomic approach. Cells of both isolates were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequences of the two organisms with the sequences of the type strains of the most closely related species of the genus Chryseobacterium showed the highest sequence similarities of strains 100T and C26T to the type strains of Chryseobacterium joostei (respectively 97.5 and 98.2 %), C. viscerum (96.6, 97.8 %), C. gleum (97.1, 97.7 %), C. arthrosphaerae (97.3%, 97.7 %), C. indologenes (97.2, 97.7 %), C. tructae (96.6, 97.6 %), C. jejuense (97.0, 97.6 %) and C. oncorhynchi (96.3, 97.5 %); 16S rRNA gene sequence similarities to members of all other species of the genus Chryseobacterium were below 97.5 %. The fatty acid profiles of both strains consisted of the major fatty acids iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C17 : 1ω9c and iso-C17 : 0 3-OH, but also showed slight differences (absence or presence of C16 : 0 3-OH and iso-C15 : 1 F). DNA–DNA hybridizations between the two strains and between the novel strains and the type strains of C. joostei , C. indologenes , C. jejuense , C. tructae and C. viscerum resulted in relatedness values clearly below 70 %. These DNA–DNA hybridization results and the differentiating biochemical and chemotaxonomic properties showed that both strains 100T and C26T represent novel species, for which the names Chryseobacterium gallinarum sp. nov. (type strain 100T = LMG 27808T = CCM 8493T) and Chryseobacterium contaminans sp. nov. (type strain C26T = LMG 27810T = CCM 8492T) are proposed.