A rare urinary tract infection of multidrug-resistant Chryseobacterium urinae sp. nov. isolated from a diabetic, non-catheterized patient

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA-DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis.

Genome analysis deciphered Chryseobacterium indicum is a distinct species associated with freshwater pufferfish

A bacterium, strain PS-8T of the genus Chryseobacterium, was isolated from the skin of freshwater pufferfish (Tetraodon cutcutia). Strain PS-8T is a Gram-negative, aerobic, non-motile, and rod-shaped bacterium. Colonies appear in yellowish-orange colors. The major cellular fatty acids were C15:0 iso, C17:0 iso 3OH, C15:0 iso 3OH, and C11:0 anteiso. The predominant polar lipids were phosphatidylethanolamine and amino lipids. The genome size is 4.83 Mb. The G + C content was 35.6%. The in silico dDDH homology, ANI, and AAI were below the cutoff value, 70% and 95% to 96%, respectively, suggesting that strain PS-8T represents a defined species. The phylogenetic tree based on core and the non-recombinant genes showed the strain PS-8T clustered with Chryseobacterium gambrini DSM 18014T. Genome-wide analysis decodes several virulence factors of the genus Chryseobacterium, including genes for adherence, biofilm and stability, proliferation, resistance to immune response, and host-defense evasion system. The cladogram of the virulence genes showed a phylogenetic relationship among the Chryseobacterium species. Knowledge of the association of Chryseobacterium with freshwater pufferfish adds a new ecological niche to this bacterium.

Reduction of Chromate via Biotic and Abiotic Pathways in the Presence of Three Co-contaminating Electron Acceptors

Bioreduction of Cr(VI) to Cr(III) is a promising technology for removing Cr(VI), but Cr(VI) reduction alone cannot support microbial growth. This study investigated the reduction of Cr(VI) in the presence of three electron acceptors that typically coexist with Cr(VI): NO3-, SO42-, and Fe(III). All three systems could reduce Cr(VI) to Cr(III), but the fate of Cr, its impacts on reduction of the other acceptors, and its impact on the microbial community differed. Although Cr(VI) was continuously removed in the NO3--reduction systems, batch tests showed that denitrification was inhibited primarily through impeding nitrite reduction. The SO42- and Fe(III) reduction systems reduced Cr(VI) using a combination of biotic and abiotic processes. Across all three systems, the abundance of genera capable of reducing Cr(VI) increased following the introduction of Cr(VI). Conversely, the abundance of genera that cannot reduce or resist Cr(VI) decreased, leading to restructuring of the microbial community. Furthermore, the abundance of sulfide oxidizers and Fe(II) oxidizers substantially increased after the introduction of chromate. This study provides fundamental knowledge about how Cr(VI) bioreduction interacts with bioreductions of three other co-contaminating electron acceptors.

Chryseobacterium pyrolae sp. nov., isolated from the rhizosphere soil of Pyrola calliantha H

A novel Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, designated pc2-12T, was isolated from the rhizosphere soil of the herb Pyrola calliantha collected from arid areas of Tibet. The strain grew most vigorously with 1 % (w/v) NaCl, at pH 7.0 and at 25 °C. According to the results of 16S rRNA gene sequence analysis, pc2-12T was closely related to the members of the genus Chryseobacterium, with highest levels of sequence similarity to Chryseobacterium viscerum 687B-08T (98.42 %), Chryseobacterium oncorhynchi 701B-08T (98.11 %) and Chryseobacterium ureilyticum DSM 18017T (97.98 %). The average nucleotide identity values between pc2-12T and C. viscerum 687B-08T, C. oncorhynchi 701B-08T and C. ureilyticum DSM 18017T were 79.71, 79.49 and 79.26 %, respectively. The in silico DNA-DNA hybridisation values between pc2-12T and C. viscerum 687B-08T, C. oncorhynchi 701B-08T and C. ureilyticum DSM 18017T were 23.30, 23.00 and 22.90 %, respectively. The draft genome sequence of pc2-12T was 4.64 Mb long, with DNA G+C content of 37.0 mol%. The fatty acids contained in the cells of pc2-12T were mainly composed of iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The main polar lipid was phosphatidylethanolamine. MK-6 was the sole respiratory quinone. On the basis of the results of analysis of all the data described, pc2-12T is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium pyrolae sp. nov., is proposed. The type strain is pc2-12T (=GDMCC 1.3256T= JCM 35712T).

Chryseobacterium oryctis sp. nov., isolated from the gut of the beetle Oryctes rhinoceros, and Chryseobacterium kimseyorum sp. nov., isolated from a stick insect rearing cage

Two strains of Chryseobacterium identified from different experiments are proposed to represent new species. Strain WLa1L2M3T was isolated from the digestive tract of an Oryctes rhinoceros beetle larva. Strain 09-1422T was isolated from a cage housing the stick insect Eurycantha calcarata. Sequence analysis of the 16S rRNA and rpoB genes found both strains to be similar but not identical to other Chryseobacterium species. Whole-genome sequencing suggested the isolates represent new species, with average nucleotide identity values ranging from 74.6 to 80.5 %. Genome-to-genome distance calculations produced values below 25.3 %, and digital DNA-DNA hybridization values were 13.7-29.9 %, all suggesting they are distinct species. The genomic DNA G+C content of WLa1L2M3T is approximately 32.53 %, and of 09-1422T is approximately 35.89 %. The predominant cellular fatty acids of strain WLa1L2M3T are C15 : 0 iso, summed feature 9 (C16 : 0 10OH or C17 : 1 iso ω6c), C17 : 0 iso 3OH, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0 iso 3OH, C15 : 0 anteiso and C13 : 0 iso, and those of strain 09-1422T are C15 : 0 iso, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C17 : 0 iso 3OH, C15 : 0 anteiso, C15 : 0 iso 3OH, C16 : 1 ω7c, C17 : 0 2OH and C18 : 0. In addition, physiological and biochemical tests revealed phenotypic differences from related Chryseobacterium type strains. These cumulative data indicate that the two strains represent novel species of the genus Chryseobacterium for which the names Chryseobacterium oryctis sp. nov. and Chryseobacterium kimseyorum sp. nov. are proposed with WLa1L2M3T (=BCRC 81350T=JCM 35215T=CIP 112035T) and 09-1422T (=UCDFST 09-1422T=BCRC 81359T=CIP 112165T), as type strains, respectively.

Chryseobacterium faecale sp. nov., isolated from camel feces

Strain F4T (=KACC 22401T=JCM 34836T), a novel Gram-stain-negative, aerobic, non-spore-forming, non-motile and rod-shaped bacterium, was isolated from camel (Camelus bactrianus) faeces. The newly identified bacterial strain F4T was grown in Reasoner's 2A medium [0–2 % (w/v) NaCl (optimum, 0 %), pH 7.0–8.0 (optimum, pH 7.0), and 18–40 °C (optimum, 30 °C)]. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain F4T belonged to the genus Chryseobacterium , with its closest neighbours being Chryseobacterium haifense DSM 19056T (98.0 %), Chryseobacterium anthropi CCUG 52764T (97.3 %), Chryseobacterium montana WG4T (95.7 %) and Chryseobacterium koreensis Chj70T (94.7 %). Complete genome sequence of strain F4T was obtained using a hybrid assembly pipeline integrating sequences obtained using both the Oxford Nanopore and Illumina platforms. Genomic comparisons of strain F4T with type species in the genus Chryseobacterium were conducted using digital DNA–DNA hybridization, average nucleotide identity and average amino acid identity, resulting in values of ≤20.5, ≤77.9 and ≤80.8 %, respectively. The genomic DNA G+C content of type strain F4T was 39.7 mol%. The major fatty acids of the strain F4T were anteiso-C15 : 0 and iso-C18 : 3, and MK-6 was its major respiratory quinone. Moreover, the major polar lipid of strain F4T was phosphatidylethanolamine. The genome of strain F4T harbours only one antibiotic resistance gene (blaCME-1) encoding a β-lactamase, which attributes β-lactam antibiotic resistance. Based on the results of our chemotaxonomic, genotypic and phenotype analyses, strain F4T is identified as a novel species of the genus Chryseobacterium , for which the name Chryseobacterium faecale sp. nov. is proposed.

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.

Pathogenic Potential and Control of Chryseobacterium Species from Clinical, Fish, Food and Environmental Sources

Chryseobacterium species are isolated and taxonomically evaluated from a wide range of sources. While C. gleum and C. indologenes have been implicated in human disease, the potential pathogenicity of numerous other species have not been investigated. The aims were therefore to evaluate 37 Chryseobacterium species and Elizabethkingia meningoseptica from environmental, food, fish, water and clinical sources for production of haemolysis, growth at 37 °C, and production of virulence enzymes. The control of these strains were investigated by determination of antimicrobial and disinfectant resistance. All the species produced α- or β-haemolysis. In terms of growth at 37 °C and production of virulence enzymes, C. soldanellicola (environmental), C. oranimense (food) and C. koreense (natural mineral water) could be potential human pathogens. Chryseobacterium piscium might be pathogenic to fish. Trimethoprim could be the most effective antimicrobial for the treatment of a Chryseobacterium species infection, while the disinfectants that contain poly-dimethyl ammonium chloride or benzalkonium chloride could be regarded as the most effective for decontamination of surfaces contaminated with Chryseobacterium species.

Chryseobacterium schmidteae sp. nov. a novel bacterial species isolated from planarian Schmidtea mediterranea

Marseille-P9602T is a Chryseobacterium-like strain that we isolated from planarian Schmidtea mediterranea and characterized by taxono-genomic approach. We found that Marseille-P9602T strain exhibits a 16S rRNA gene sequence similarity of 98.76% with Chryseobacterium scophthalmum LMG 13028T strain, the closest phylogenetic neighbor. Marseille-P9602T strain was observed to be a yellowish-pigmented, Gram-negative, rod-shaped bacterium, growing in aerobic conditions and belonging to the Flavobacteriaceae family. The major fatty acids detected are 13-methyl-tetradecanoic acid (57%), 15-methylhexadecenoic acid (18%) and 12-methyl-tetradecanoic acid (8%). Marseille-P9602 strain size was found from genome assembly to be of 4,271,905 bp, with a 35.5% G + C content. The highest values obtained for Ortho-ANI and dDDH were 91.67% and 44.60%, respectively. Thus, hereby we unravel that Marseille-P9602 strain is sufficiently different from other closed related species and can be classified as a novel bacterial species, for which we propose the name of Chryseobacterium schmidteae sp. nov. Type strain is Marseille-P9602T (= CSUR P9602T = CECT 30295T).

Draft genome and description of Chryseobacterium manosquense strain Marseille-Q2069T sp. nov., a new bacterium isolated from human healthy skin

In 2019, by culturing a skin swab from the hand of a 35-year-old healthy woman using culturomics methods, we isolated the new bacterial strain Marseille-Q2069^T =CSUR-Q2069. Matrix-assisted desorption/ionization time-of-flight mass spectrometry failed to identify this isolate. Analysis of the 16S rRNA gene and Genome-to-Genome comparison suggested that this taxon belongs to a novel bacterial species within the family Flavobacteriaceae in the phylum Bacteroidetes. We described here the main phenotypic characteristics, genome sequence and annotation of Chryseobacterium manosquense strain Marseille-Q2069^T, a new member of the Chryseobacterium genus, that we propose as type strain.

Division of the genus Chryseobacterium: Observation of discontinuities in amino acid identity values, a possible consequence of major extinction events, guides transfer of nine species to the genus Epilithonimonas, eleven species to the genus Kaistella, and three species to the genus Halpernia gen. nov., with description of Kaistella daneshvariae sp. nov. and Epilithonimonas vandammei sp. nov. derived from clinical specimens

The genus Chryseobacterium in the family Weeksellaceae is known to be polyphyletic. Amino acid identity (AAI) values were calculated from whole-genome sequences of species of the genus Chryseobacterium, and their distribution was found to be multi-modal. These naturally-occurring non-continuities were leveraged to standardise genus assignment of these species. We speculate that this multi-modal distribution is a consequence of loss of biodiversity during major extinction events, leading to the concept that a bacterial genus corresponds to a set of species that diversified since the Permian extinction. Transfer of nine species (Chryseobacterium arachidiradicis, Chryseobacterium bovis, Chryseobacterium caeni, Chryseobacterium hispanicum, Chryseobacterium hominis, Chryseobacterium hungaricum,, Chryseobacterium pallidum and Chryseobacterium zeae) to the genus Epilithonimonas and eleven (Chryseobacterium anthropi, Chryseobacterium antarcticum, Chryseobacterium carnis, Chryseobacterium chaponense, Chryseobacterium haifense, Chryseobacterium jeonii, Chryseobacterium montanum, Chryseobacterium palustre, Chryseobacterium solincola, Chryseobacterium treverense and Chryseobacterium yonginense) to the genus Kaistella is proposed. Two novel species are described: Kaistella daneshvariae sp. nov. and Epilithonimonas vandammei sp. nov. Evidence is presented to support the assignment of Planobacterium taklimakanense to a genus apart from Chryseobacterium, to which Planobacterium salipaludis comb nov. also belongs. The novel genus Halpernia is proposed, to contain the type species Halpernia frigidisoli comb. nov., along with Halpernia humi comb. nov., and Halpernia marina comb. nov.

Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes

Although considerable progress has been made in recent years regarding the classification of bacteria assigned to the phylum Bacteroidetes, there remains a need to further clarify taxonomic relationships within a diverse assemblage that includes organisms of clinical, piscicultural, and ecological importance. Bacteroidetes classification has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees and a limited number of phenotypic features. Here, draft genome sequences of a greatly enlarged collection of genomes of more than 1,000 Bacteroidetes and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa proposed long ago such as Bacteroides, Cytophaga, and Flavobacterium but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which can be considered valuable taxonomic markers. We detected many incongruities when comparing the results of the present study with existing classifications, which appear to be caused by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. The few significant incongruities found between 16S rRNA gene and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences and the impediment in using ordinary bootstrapping in phylogenomic studies, particularly when combined with too narrow gene selections. While a significant degree of phylogenetic conservation was detected in all phenotypic characters investigated, the overall fit to the tree varied considerably, which is one of the probable causes of misclassifications in the past, much like the use of plesiomorphic character states as diagnostic features.

Bacterial community composition of biofilms in milking machines of two dairy farms assessed by a combination of culture-dependent and -independent methods

Dairy biofilms as a source of contamination of milk and its products are of great concern in the dairy industry. For a reliable risk assessment, knowledge about the microbial community composition of biofilms in the milking systems of dairy farms must be improved. In this work, swab samples of milking machine biofilms of two dairy farms were investigated by a combination of culture-dependent and -independent methods. Spots in the milking system with enhanced microbial colonization were identified by quantification on selective and non-selective media. In addition, stainless steel coupons were placed into the piping system of a milking machine, removed after several milking intervals, and investigated for colonization by cultivation and culture-independently. Isolates were differentiated and identified by a combination of chemotaxonomical methods and 16S rRNA sequencing. The culture-independent approach involved treatment of the samples with the viability dye propidium monoazide prior to direct DNA-extraction by enzymatic cell lysis and cloning to exclude bias from dead biomass. The milking equipment retainers and the outlet of the milk bulk tank were identified as highly colonized spots on both farms. A high bacterial diversity was detected covering the phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Presence of biofilms was demonstrated on several materials including stainless steel and plastic, which are frequently used in milking machines, but also in dairy processing plants. Growth of mainly Gram-positive bacteria with high percentages of the phylum Actinobacteria was detected on the stainless steel coupons after exposition in the milking system for two to three days. Knowledge about the heterogenic microbial load on different parts of the milking machines and the stainless steel coupons will help to identify primary colonizers of the milking system, to assess the risk potential of biofilms for raw milk, to improve sanitation processes and to identify parts of the milking machine, which should be improved by hygienic design.

Chryseobacterium mulctrae sp. nov., isolated from raw cow's milk

A Gram-stain-negative bacterial strain, designated CA10^T, was isolated from bovine raw milk sampled in Anseong, Republic of Korea. Cells were yellow-pigmented, aerobic, non-motile bacilli and grew optimally at 30 °C and pH 7.0 on tryptic soy agar without supplementation of NaCl. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain CA10^T belonged to the genus Chryseobacterium, family Flavobacteriaceae, and was most closely related to Chryseobacterium indoltheticum ATCC 27950^T (98.75 % similarity). The average nucleotide identity and digital DNA-DNA hybridization values of strain CA10^T were 94.4 and 56.9 %, respectively, relative to Chryseobacterium scophthalmum DSM 16779^T, being lower than the cut-off values of 95-96 and 70 %, respectively. The predominant respiratory quinone was menaquinone-6; major polar lipid, phosphatidylethanolamine; major fatty acids, iso-C_15 : 0, summed feature 9 (iso-C_17 : 1ω9c and/or C_16 : 0 10-methyl), summed feature 3 (iso-C_15 : 0 2-OH and/or C_16 : 1ω7c) and iso-C_17 : 0 3-OH. The results of physiological, chemotaxonomic and biochemical analyses suggested that strain CA10^T is a novel species of genus Chryseobacterium, for which the name Chryseobacterium mulctrae sp. nov. is proposed. The type strain is CA10^T (=KACC 21234^T=JCM 33443^T).

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.

The golden death bacillus Chryseobacterium nematophagum is a novel matrix digesting pathogen of nematodes

BACKGROUND

Nematodes represent important pathogens of humans and farmed animals and cause significant health and economic impacts. The control of nematodes is primarily carried out by applying a limited number of anthelmintic compounds, for which there is now widespread resistance being reported. There is a current unmet need to develop novel control measures including the identification and characterisation of natural pathogens of nematodes.

RESULTS

Nematode killing bacilli were isolated from a rotten fruit in association with wild free-living nematodes. These bacteria belong to the Chryseobacterium genus (golden bacteria) and represent a new species named Chryseobacterium nematophagum. These bacilli are oxidase-positive, flexirubin-pigmented, gram-negative rods that exhibit gelatinase activity. Caenorhabditis elegans are attracted to and eat these bacteria. Within 3 h of ingestion, however, the bacilli have degraded the anterior pharyngeal chitinous lining and entered the body cavity, ultimately killing the host. Within 24 h, the internal contents of the worms are digested followed by the final digestion of the remaining cuticle over a 2-3-day period. These bacteria will also infect and kill bacterivorous free-living (L1-L3) stages of all tested parasitic nematodes including the important veterinary Trichostrongylids such as Haemonchus contortus and Ostertagia ostertagi. The bacteria exhibit potent collagen-digesting properties, and genome sequencing has identified novel metalloprotease, collagenase and chitinase enzymes representing potential virulence factors.

CONCLUSIONS

Chryseobacterium nematophagum is a newly discovered pathogen of nematodes that rapidly kills environmental stages of a wide range of key nematode parasites. These bacilli exhibit a unique invasion process, entering the body via the anterior pharynx through the specific degradation of extracellular matrices. This bacterial pathogen represents a prospective biological control agent for important nematode parasites.

Chryseobacterium phosphatilyticum sp. nov., a phosphate-solubilizing endophyte isolated from cucumber (Cucumis sativus L.) root

A bacterial strain, designated as ISE14^T, with Gram-stain-negative and non-motile rod-shaped cells, was isolated from the root of a cucumber plant collected in a field in Iksan, Republic of Korea and was characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ISE14^T represented a member of the genus Chryseobacterium and was closely related to Chryseobacterium viscerum 687B-08^T (16S rRNA gene sequence similarity of 98.50 %), Chryseobacterium lactis NCTC 11390^T (98.49 %), Chryseobacterium ureilyticum F-Fue-04IIIaaaa^T (98.49 %) and Chryseobacterium oncorhynchi 701B-08^T (98.04 %). Average nucleotide identity values between genome sequences of strain ISE14^T and the closely related species ranged from 81.44 to 83.15 %, which were lower than the threshold of 95 % (corresponding to a DNA-DNA hybridization value of 70 %). The DNA G+C content of strain ISE14^T was 36.3 mol%. The dominant fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1ω9c and/or C16 : 0 10-methyl), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and eight unidentified lipids; the predominant respiratory quinone was MK-6. On the basis of the evidence presented in this study, strain ISE14^T can be distinguished from closely related species belonging to the genus Chryseobacterium. Thus, strain ISE14^T is a novel species of the genus Chryseobacterium, for which the name Chryseobacteriumphosphatilyticum sp. nov. is proposed. The type strain is ISE14^T (=KACC 19820^T=JCM 32876^T).

Draft Genome Sequences of Chryseobacterium lactis NCTC11390T Isolated from Milk, Chryseobacterium oncorhynchi 701B-08T from Rainbow Trout, and Chryseobacterium viscerum 687B-08T from Diseased Fish

The genus Chryseobacterium, belonging to the family Flavobacteriaceae, contains Gram-negative, yellow-pigmented, rod-shaped, and non-spore-forming bacterial species, which may be free living or parasitic. Here, we report draft genome sequences of type strains of three species of Chryseobacterium containing genes related to biological control and plant growth promotion.

The genus Chryseobacterium, belonging to the family Flavobacteriaceae, contains Gram-negative, yellow-pigmented, rod-shaped, and non-spore-forming bacterial species, which may be free living or parasitic. Here, we report draft genome sequences of type strains of three species of Chryseobacterium containing genes related to biological control and plant growth promotion.

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).

Description of Gramella forsetii sp. nov., a marine Flavobacteriaceae isolated from North Sea water, and emended description of Gramella gaetbulicola Cho et al. 2011

Strain KT0803^T was isolated from coastal eutrophic surface waters of Helgoland Roads near the island of Helgoland, North Sea, Germany. The taxonomic position of the strain, previously known as 'Gramella forsetii' KT0803, was investigated by using a polyphasic approach. The strain was Gram-stain-negative, chemo-organotrophic, heterotrophic, strictly aerobic, oxidase- and catalase-positive, rod-shaped, motile by gliding and had orange-yellow carotenoid pigments, but was negative for flexirubin-type pigments. It grew optimally at 22-25 °C, at pH 7.5 and at a salinity between 2-3 %. Strain KT0803^T hydrolysed the polysaccharides laminarin, alginate, pachyman and starch. The respiratory quinone was MK-6. Polar lipids comprised phosphatidylethanolamine, six unidentified lipids and two unidentified aminolipids. The predominant fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω7c and iso-C17 : 1ω7c, with smaller amounts of iso-C15 : 0 2-OH, C15 : 0, anteiso-C15 : 0 and C17 : 1ω6c. The G+C content of the genomic DNA was 36.6 mol%. The 16S rRNA gene sequence identities were 98.6 % with Gramella echinicola DSM 19838^T, 98.3 % with Gramella gaetbulicola DSM 23082^T, 98.1 % with Gramella aestuariivivens BG-MY13^T and Gramella aquimixticola HJM-19^T, 98.0 % with Gramella lutea YJ019^T, 97.9 % with Gramella portivictoriae DSM 23547^T and 96.9 % with Gramella marina KMM 6048^T. The DNA-DNA relatedness values were <35 % between strain KT0803^T and type strains with >98.2 % 16S rRNA gene sequence identity. Based on the chemotaxonomic, phenotypic and genomic characteristics, strain KT0803^T has been assigned to the genus Gramella, as Gramella forsetii sp. nov. The type strain is KT0803^T (=DSM 17595^T=CGMCC 1.15422^T). An emended description of Gramella gaetbulicolaCho et al. 2011 is also proposed.

Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment

Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions on the bacterial composition of the microbiota in biofilms.

Spoilage potential of a novel group of bacteria isolated from dairy products

Abstract Cold-tolerant bacteria, also known as psychrotrophic bacteria, are notorious contaminants of milk in the refrigerated dairy food chain. These organisms, especially the pseudomonads, may produce heat-resistant enzymes that are responsible for the breakdown of proteins and lipids in milk and dairy products. Such reactions result in a variety of defects in the raw or unprocessed milk that may affect the suitability of such milk for further processing. The enzymes produced may cause defects in long-life dairy products such as cheese, butter and long-life milk. In the present study, a range of 18 yellow pigmented psychrotrophic bacteria, collectively known as flavobacteria, were isolated from local dairy products. One aim of this study was to identify these bacteria to species level using molecular techniques. A second aim was to determine the spoilage potential of these organisms based on profiles generated by the BIOLOG system (that may relate to hydrolytic enzymes produced). Of the 18 isolates, 14 belonged to the genus Chryseobacterium while 4 were identified as Empedobacter isolates. The most active spoilage organisms in this group were shown to be C. bovis, C. shigense and E. brevis. These findings illustrate that enzymatically catalysed defects in dairy products should not be attributed solely to acknowledged psychrotrophic bacteria such as the pseudomonads, but that flavobacterial species may also be actively involved.

Bacterial populations on brewery filling hall surfaces as revealed by next-generation sequencing

Due to the presence of moisture and nutrients, brewery filling line surfaces are susceptible to unwanted microbial attachment. Knowledge of the attaching microbes will aid in designing hygienic control of the process. In this study the bacterial diversity present on brewery filling line surfaces was revealed by next generation sequencing. The two filling lines studied maintained their characteristic bacterial community throughout three sampling times (13-163 days). On the glass bottle line, γ-proteobacteria dominated (35-82% of all OTUs), whereas on the canning line α-, β- and γ-proteobacteria and actinobacteria were most common. The most frequently detected genera were Acinetobacter, Propinobacterium and Pseudomonas. The halophilic genus Halomonas was commonly detected, which might be due to its tolerance to alkaline foam cleaners. This study has revealed a detailed overall picture of the bacterial groups present on filling line surfaces. Further effort should be given to determine the efficacy of washing procedures on different bacterial groups.

Chryseobacterium panacis sp. nov., isolated from ginseng soil

A novel strain, DCY107(T), was isolated from soil collected from a ginseng field in Gochang, Republic of Korea. Strain DCY107(T) is Gram-negative, yellow pigmented, non-motile, non-flagellate, rod-shaped and aerobic. The strain was found to grow optimally at 25-30 °C and pH 6.5-7. Phylogenetically, strain DCY107(T) is closely related to Chryseobacterium polytrichastri DSM 26899(T) (98.49 % 16S rRNA gene sequence similarity), Chryseobacterium yeoncheonense JCM 18516(T) (97.78 %), Chryseobacterium aahli LMG 27338(T) (97.74 %), Chryseobacterium limigenitum LMG28734(T) (97.74 %), Chryseobacterium ginsenosidimutans JCM 16719(T) (97.47 %) and Chryseobacterium gregarium LMG 24052(T) (97.31 %). The DNA-DNA relatedness values between strain DCY107(T) and reference strains were found to be clearly below 70 %. The DNA G+C content of strain DCY107(T) was determined to be 34.2 mol%. The predominant quinone was identified menaquinone 6 (MK-6). The major polar lipids were identified as phosphatidylethanolamine and unidentified lipids: aminolipids AL1, AL2 and lipid L2. C16:00, iso-C15:00, iso-C15:02OH, iso-C17:03OH and summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl) were identified as the major fatty acids present in strain DCY107(T). The results of physiological and biochemical tests allowed strain DCY107(T) to be differentiated phenotypically from other recognised species belonging to the genus Chryseobacterium. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Chryseobacterium panacis sp. nov. is proposed, with the type strain designated as DCY107(T) (=CCTCC AB 2015195(T) = KCTC 42750(T)).

Chryseobacterium frigidum sp. nov., isolated from high-Arctic tundra soil, and emended descriptions of Chryseobacterium bernardetii and Chryseobacterium taklimakanense

A yellow, Gram-reaction-negative, non-motile, aerobic bacterium, designated D07^T, was isolated from a tundra soil near Ny-Ålesund, Svalbard archipelago, Norway (78° N). Growth occurred at 4-37 °C (optimum 28-30 °C) and at pH 6.0-9.0 (optimum pH 7.0-8.0). The strain produced flexirubin-type pigments. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain D07^T belonged to the genus Chryseobacterium in the family Flavobacteriaceae. The 16S rRNA gene sequence of this strain showed 93.83 and 93.31 % sequence similarity, respectively, to those of Chryseobacterium contaminans C26^T and Chryseobacterium taklimakanense X-65^T. Strain D07^T contained anteiso-C_15 : 0 (25.91 %), iso-C_15 : 0 (16.05 %), iso-C_16 : 0 3-OH (9.64 %), iso-C_16 : 0 (9.42 %) and iso-C_14 : 0 (7.36 %) as the predominant cellular fatty acids, MK-6 as the major respiratory quinone and phosphatidylethanolamine, five unknown aminolipids and three unknown lipids as the main polar lipids. The DNA G+C content was 49.3 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain D07^T is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium frigidum sp. nov. is proposed. The type strain is D07^T ( = CCTCC AB 2011160^T = KCTC 42897^T). Emended descriptions of Chryseobacterium bernardetii and Chryseobacterium taklimakanense are also provided.

Chryseobacterium sediminis sp. nov., isolated from a river sediment

A slightly yellow-pigmented strain (IMT-174T) isolated from a river sediment in Guyana was studied in detail for its taxonomic position. Cells of the isolate appeared rod-shaped and stained Gram-negative. Comparative 16S rRNA gene sequence analysis showed that the isolate had the highest sequence similarities to type strains of Chryseobacterium rhizoplanae (99.0 %), Chryseobacterium viscerum (98.9 %), Chryseobacterium lactis (98.8 %) and Chryseobacterium indologenes (98.6 %). The 16S rRNA gene sequence similarities to all other species of the genus Chryseobacterium were below 98.5 %. Fatty acid analysis of whole-cell hydrolysates of the strain resulted in a pattern typical of members of the genus Chryseobacterium, with fatty acids iso-C15 : 0, iso-C15 : 0 2-OH, iso-C17 : 1ω9c and iso-C17 : 0 3-OH as major compounds. The polyamine pattern contained predominantly sym-homospermidine. The major quinone was menaquinone MK-6 and the only lipid identified in the polar lipid profile was phosphatidylethanolamine. In addition, 13 unidentified lipids were detected in moderate to major amounts. DNA-DNA hybridizations with type strains of C. rhizoplanae, C. viscerum, C. lactis and C. indologenes resulted in values below 70 %. In addition to the genotypic differences, differentiating biochemical and chemotaxonomic properties confirmed that isolate IMT-174T represents a novel species, for which the name Chryseobacterium sediminis sp. nov. (type strain IMT-174T = LMG 28695T = CIP 110895T) is proposed.

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 shandongense sp. nov., isolated from soil

YF-3T is a Gram-stain-negative, non-motile, non-spore-forming, yellow-orange, rod-shaped bacterium. Optimal growth conditions were at 30 °C, pH 7.0 and 1 % (w/v) NaCl. Phylogenetic analysis, on the basis of the 16S rRNA gene sequence, showed that strain YF-3T was closely related to the strains Chryseobacterium hispalense AG13T and Chryseobacterium taiwanense Soil-3-27T with 98.71 % and 96.93 % sequence similarity, respectively. Strain YF-3T contained MK-6 as the main menaquinone and had a polyamine pattern with sym-homospermidine as the major component. Its major polar lipid was phosphatidylethanolamine. The dominant fatty acids of strain YF-3T were iso-C15 : 0, iso-C17 : 0 3-OH, summed feature 9 (comprising iso-C17 : 1ω9c and/or C16 : 0 10-methyl) and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). The DNA G+C content of strain YF-3T was 37 mol%. The DNA-DNA relatedness levels between strain YF-3T and the most closely related strains, C. hispalense AG13T and C. taiwanense Soil-3-27T, were 31.7 ± 2.1 % and 28.4 ± 5.4 %, respectively. Based on these results, a novel species named Chryseobacterium shandongense sp. nov. is proposed. The type strain is YF-3T ( = CCTCC AB 2014060T = JCM 30154T).

Emerging flavobacterial infections in fish: A review

Flavobacterial diseases in fish are caused by multiple bacterial species within the family Flavobacteriaceae and are responsible for devastating losses in wild and farmed fish stocks around the world. In addition to directly imposing negative economic and ecological effects, flavobacterial disease outbreaks are also notoriously difficult to prevent and control despite nearly 100 years of scientific research. The emergence of recent reports linking previously uncharacterized flavobacteria to systemic infections and mortality events in fish stocks of Europe, South America, Asia, Africa, and North America is also of major concern and has highlighted some of the difficulties surrounding the diagnosis and chemotherapeutic treatment of flavobacterial fish diseases. Herein, we provide a review of the literature that focuses on Flavobacterium and Chryseobacterium spp. and emphasizes those associated with fish.

Epilithonimonas xixisoli sp. nov., isolated from wetland bank-side soil

A novel Gram-staining-negative, non-motile and rod-shaped bacterial strain containing flexirubin-type pigments, designated S31(T), was isolated from bank-side soil of the Xixi wetland in Zhejiang province, China. Growth occurred at 10-37 °C (optimum, 32 °C), pH 6-8 (optimum, pH 7) and with 0-2 % (w/v) NaCl (optimum, 1 %). Strain S31(T) shared highest 16S rRNA gene sequence similarities with Epilithonimonas lactis H1(T) (96.2 %) and Chryseobacterium molle DW3(T) (96.4 %). Phylogenetic analysis suggested that strain S31(T) was a member of the genus Epilithonimonas. The dominant respiratory quinone was MK-6 and the DNA G+C content was 33.3 mol%. The major fatty acids were iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and anteiso-C15 : 0. The major polar lipids of strain S31(T) were phosphatidylethanolamine, three unidentified aminolipids and four unidentified polar lipids. Based on its phenotypic and chemotaxonomic characteristics and phylogenetic data, strain S31(T) represents a novel species of the genus Epilithonimonas, for which the name Epilithonimonas xixisoli sp. nov. (type strain S31(T) = CGMCC 1.12802(T) = NBRC 110387(T)) is proposed.

Simultaneous heterotrophic nitrification and aerobic denitrification by Chryseobacterium sp. R31 isolated from abattoir wastewater

A heterotrophic carbon utilizing microbe (R31) capable of simultaneous nitrification and denitrification (SND) was isolated from wastewater of an Indian slaughterhouse. From an initial COD value of 583.0 mg/L, 95.54% was removed whilst, from a starting NH₄⁺-N concentration of 55.7 mg/L, 95.87% was removed after 48 h contact. The concentrations of the intermediates hydroxylamine, nitrite, and nitrate were low, thus ensuring nitrogen removal. Aerobic denitrification occurring during ammonium removal by R31 was confirmed by utilization of both nitrate and nitrite as nitrogen substrates. Glucose and succinate were superior while acetate and citrate were poor substrates for nitrogen removal. Molecular phylogenetic identification, supported by chemotaxonomic and physiological properties, assigned R31 as a close relative of Chryseobacterium haifense. The NH₄⁺-N utilization rate and growth of strain R31 were found to be higher at C/N = 10 in comparison to those achieved with C/N ratios of 5 and 20. Monod kinetic coefficients, half saturation concentration (K_s), maximum rate of substrate utilization (k), yield coefficient, (Y) and endogenous decay coefficient (K_d) indicated potential application of R31 in large-scale SND process. This is the first report on concomitant carbon oxidation, nitrification, and denitrification in the genus Chryseobacterium and the associated kinetic coefficients.

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.

Chryseobacterium angstadtii sp. nov., isolated from a newt tank

As part of an undergraduate microbiology course, a yellow-orange-pigmented, Gram-staining negative, rod-shaped, non-motile bacterial strain was isolated from a glass tank housing several red-spotted newts (Notophthalmus viridescens). The sequence of the 16S rRNA gene of this strain, designated KM(T), was 97.4-98.0 % similar to those of the type strains of Chryseobacterium luteum, C. shigense and C. vrystaatense, while the similarity levels for protein-coding genes were less than 94.7 % for rpoB, less than 92.1 % for groEL and less than 87.1 % for gyrB. These values are lower than for many other established distinct species. Polyphasic characterization and comparison to these relatives revealed that strain KM(T) was similar to other Chryseobacterium strains in that it contained MK-6 as its major respiratory quinone and phosphatidylethanolamine as the most abundant polar lipid, produced flexirubin-type pigments, oxidase and catalase and primarily contained the fatty acids iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). Based on the results of this study, strain KM(T) represents a novel species, for which the name Chryseobacterium angstadtii sp. nov. is proposed. The type strain is KM(T) ( = ATCC BAA-2160(T) = NRRL B-59516(T) = KCTC 23297(T)).

Chryseobacterium hispalense sp. nov., a plant-growth-promoting bacterium isolated from a rainwater pond in an olive plant nursery, and emended descriptions of Chryseobacterium defluvii, Chryseobacterium indologenes, Chryseobacterium wanjuense and Chryseobacterium gregarium

A novel non-motile, Gram-staining-negative, yellow-pigmented bacterium, designated AG13(T), isolated from a rain water pond at a plant nursery in Spain and characterized as a plant-growth-promoting bacterium, was investigated to determine its taxonomic status. The isolate grew best over a temperature range of 15-40 °C, at pH 5.0-8.0 and with 0-4 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Chryseobacterium. The DNA G+C content of the novel strain was 37.2 mol%. The strain had a polyamine pattern with sym-homospermidine as the major compound and produced flexirubin-type pigments. MK-6 was the dominant menaquinone and the major cellular fatty acids were iso-C15 : 0, C17 : 1ω9c and iso-C17 : 0 3-OH. The main polar lipids were phosphatidylethanolamine, aminolipids and several unidentified lipids. The 16S rRNA gene showed 92.0-97.2 % sequence similarity with those of the members of the genus Chryseobacterium. Based on chemotaxonomic and phenotypic traits, and DNA-DNA hybridizations with the type strains of the most closely related species, the isolate is proposed to represent a novel species, Chryseobacterium hispalense, type strain AG13(T) ( = DSM 25574(T) = CCUG 63019(T)). Emended descriptions of the species Chryseobacterium defluvii, Chryseobacterium indologenes, Chryseobacterium wanjuense and Chryseobacterium gregarium are also provided.

High-quality-draft genome sequence of the yellow-pigmented flavobacterium Joostella marina type strain (En5(T))

At present, Joostella marina Quan et al. 2008 is the sole species with a validly published name in the genus Joostella, family Flavobacteriacae, phylum Bacteriodetes. It is a yellow-pigmented, aerobic, marine organism about which little has been reported other than the chemotaxonomic features required for initial taxonomic description. The genome of J. marina strain En5(T) complements a list of 16 Flavobacteriaceae strains for which complete genomes and draft genomes are currently available. Here we describe the features of this bacterium, together with the complete genome sequence, and annotation. This is the first member of the genus Joostella for which a complete genome sequence becomes available. The 4,508,243 bp long single replicon genome with its 3,944 protein-coding and 60 RNA genes is part of the G enomic E ncyclopedia of Bacteria and Archaea project.

Chryseobacterium frigidisoli sp. nov., a psychrotolerant species of the family Flavobacteriaceae isolated from sandy permafrost from a glacier forefield

During diversity studies of the glacier forefields of the Larsemann Hills, East Antarctica, a novel psychrotolerant, non-motile Gram-negative, shiny yellow, rod-shaped, aerobic bacterium, designated strain PB4(T) was isolated from a soil sample. Strain PB4(T) produces indole from tryptophan and hydrolyses casein. It grows between 0 and 25 °C with an optimum growth temperature of 20 °C. A wide range of substrates are used as sole carbon sources and acid is produced from numerous carbohydrates. The major menaquinone is MK-6. Identified polar lipids are ethanolamines and ornithine lipids. Major fatty acids (>10 %) are iso-C15 : 0 (13.0 %) and iso-2OH-C15 : 0 (51.2 %). G+C content is 33.7 mol%. The polyamine pattern is composed of sym-homospermidine (25.1 µmol g(-1) dry weight), minor amounts of cadaverine (0.2 µmol g(-1) dry weight) and spermidine (0.4 µmol g(-1) dry weight) and traces of putrescine and spermine (<0.1 µmol g(-1) dry weight). Strain PB4(T) had highest 16S rRNA gene similarities with the type strains of Chryseobacterium humi (97.0 %) and Chryseobacterium marinum (96.5 %). Considering phenotypic and genotypic characterization, strain PB4(T) represents a novel species in the genus Chryseobacterium (family Flavobacteriaceae), for which the name Chryseobacterium frigidisoli sp. nov. is proposed. The type strain is PB4(T) ( = DSM 26000(T) = LMG 27025(T)).

Chryseobacterium viscerum sp. nov., isolated from diseased fish

A taxonomic study was carried out on five Gram-staining-negative, catalase- and oxidase-positive, rod-shaped bacteria isolated from the gills and livers of five diseased rainbow trout. The five novel isolates were designated strains 687B-08T, 445-08, 452-08, 453B-08 and 967B-08. In phylogenetic analyses based on 16S rRNA gene sequences, the five novel strains appeared almost identical (99.0–100 % sequence similarity) and to belong to the genus Chryseobacterium . Strain 687B-08T (the strain selected to represent the five novel isolates) was found to be most closely related to Chryseobacterium oncorhynchi 701B-08T (98.9 % sequence similarity), Chryseobacterium ureilyticum F-Fue-04IIIaaaaT (98.6 %), Chryseobacterium indologenes ATCC 29897T (98.3 %), Chryseobacterium jejuense JS17-8T (98.1 %) and Chryseobacterium gleum ATCC 35910T (98.1 %). In DNA–DNA hybridizations, DNA–DNA relatedness values of 99–100 % were recorded between the five novel strains. Lower DNA–DNA relatedness values (21–57 %) were recorded between strain 687B-08T and C. oncorhynchi 701B-08T, C. ureilyticum F-Fue-04IIIaaaaT and the type strains of other closely related, established species of the genus Chryseobacterium . The predominant respiratory quinone of strain 687B-08T was MK-6 and the major cellular fatty acids were iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and C16 : 1ω6c. The G+C content of the genomic DNA of strain 687B-08T was 38.6 mol%. Based on the phenotypic and genotypic evidence, the five novel strains isolated from rainbow trout represent a single, novel species of the genus Chryseobacterium , for which the name Chryseobacterium viscerum sp. nov. is proposed. The type strain is 687B-08T ( = CECT 7793T  = CCUG 60103T).

Aquamicrobium ahrensii sp. nov. and Aquamicrobium segne sp. nov., isolated from experimental biofilters

Two groups of Gram-negative, aerobic bacterial strains previously isolated from experimental biofilters were investigated to determine their taxonomic position. Based on their 16S rRNA gene sequences, these isolates formed two distinct groups within the genus Aquamicrobium . The gene sequence similarities of the new isolates to the type strains of Aquamicrobium species were below 98.3 %. The presence of ubiquinone-10, C18 : 1 cis 11 as the predominant fatty acid and a polar lipid pattern with phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and phosphatidylethanolamine was in accordance with the characteristics of this genus. The results of DNA–DNA hybridization, biochemical tests and chemotaxonomic properties allowed genotypic and phenotypic differentiation of the strains from all recognized species of the genus Aquamicrobium . Therefore, the isolates were assigned to two novel species of this genus for which the names Aquamicrobium ahrensii sp. nov. (type strain 905/1T = DSM 19730T = CCUG 55251T) and Aquamicrobium segne sp. nov. (type strain 1006/1T = DSM 19714T = CCUG 55250T) are proposed. An emended description of the genus Aquamicrobium is also presented.

Chryseobacterium taihuense sp. nov., isolated from a eutrophic lake, and emended descriptions of the genus Chryseobacterium, Chryseobacterium taiwanense, Chryseobacterium jejuense and Chryseobacterium indoltheticum

Bacterial strain THMBM1(T) was isolated from decomposing algal scum that was collected during an algal bloom in Lake Taihu, Wuxi City, Jiangsu Province, China. Cells of strain THMBM1(T) were Gram-negative, facultatively anaerobic, non-motile rods. Colonies on tryptic soy agar were translucent and shiny with entire edges; yellow flexirubin-type pigments were produced. Growth was observed at 15-45 °C (optimum 30-37 °C), at pH 5.0-9.0 (optimum pH 8.0) and in the presence of 0-4.0 % (w/v) NaCl (optimum 0-1.0 %). Strain THMBM1(T) contained MK-6 as the sole respiratory quinone and sym-homospermidine as the predominant polyamine. The predominant cellular fatty acids were iso-C15 : 0 (53.2 %), iso-C17 : 0 3-OH (15.6 %) and iso-C17 : 1ω9c (11.9 %). The polar lipid profile consisted of phosphatidylethanolamine and five unidentified lipids. The DNA G+C content was 36.8 mol% (Tm). Strain THMBM1(T) was closely related to members of the genus Chryseobacterium, with 16S rRNA gene sequence similarities ranging from 92.9 to 97.2 %, the highest sequence similarities being with Chryseobacterium taiwanense BCRC 17412(T) (97.2 %) and C. gambrini 5-1St1a(T) (97.1 %). DNA-DNA relatedness between strain THMBM1(T) and C. taiwanense JCM 21767(T) and C. gambrini DSM 18014(T) was 34.1  and 23.0 %, respectively. Based on these results, it is concluded that strain THMBM1(T) represents a novel species, for which the name Chryseobacterium taihuense sp. nov. is proposed. The type strain is THMBM1(T) ( = CGMCC 1.10941(T)  = NBRC 108747(T)). Emended descriptions of the genus Chryseobacterium and C. taiwanense, C. jejuense and C. indoltheticum are also proposed.

Analysis of the microbial community structure in a membrane bioreactor during initial stages of filtration

Membrane biofouling was investigated during the early stages of filtration in a laboratory-scale membrane bioreactor operated on molasses wastewater. The bacterial diversity and composition of the membrane biofilm and activated sludge were analyzed using terminal restriction fragment length polymorphism coupled with 16S rRNA clone library construction and sequencing. The amount of extracellular polymeric substances produced by bacteria was investigated using spectroscopic methods. The results reveal that the bacterial community of activated sludge differs significantly from that of the membrane biofilm, especially at the initial phase. Phylogenetic analysis based on 16S rRNA gene sequences identified 25 pioneer OTUs responsible for membrane surface colonization. Also, the relationship between the identified bacterial strains and the system specifications was explored.

Chryseobacterium piperi sp. nov., isolated from a freshwater creek

As part of an undergraduate microbiology course, a yellow–orange pigmented, Gram-staining negative, rod-shaped, non-motile bacterial strain, designated CTMT, was isolated from a creek in North-central Pennsylvania during the winter of 2006. The 16S rRNA gene sequence of the strain showed ~97 % similarity to that of Chryseobacterium soldanellicola PSD1-4T and Chryseobacterium soli JS6-6T, while the protein-coding gyrB gene sequence of strain CTMT showed <87 % similarity to those of its two closest relatives. Using a polyphasic approach, strain CTMT was characterized and compared to these and other closely related species of the genus Chryseobacterium. Strain CTMT was similar to other strains of the genus Chryseobacterium in that it contained MK-6 as its major respiratory quinone, produced flexirubin-type pigments, oxidase and catalase, hydrolysed DNA, gelatin and aesculin and contained the fatty acids iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω6c, C16 : 1ω7c and/or iso-C15 : 0 2-OH). Based on the results of this study, strain CTMT represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium piperi sp. nov. is proposed. The type strain is CTMT ( = ATCC BAA-1782T  = CCUG 57707T  = JCM 15960T  = DSM 22249T  = KCTC 23267T).

Molecular analysis of microbial diversity in corrosion samples from energy transmission towers

Microbial diversity in corrosion samples from energy transmission towers was investigated using molecular methods. Ribosomal DNA fragments were used to assemble gene libraries. Sequence analysis indicated 10 bacterial genera within the phyla Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. In the two libraries generated from corroded screw-derived samples, the genus Acinetobacter was the most abundant. Acinetobacter and Clostridium spp. dominated, with similar percentages, in the libraries derived from corrosion scrapings. Fungal clones were affiliated with 14 genera belonging to the phyla Ascomycota and Basidiomycota; of these, Capnobotryella and Fellomyces were the most abundant fungi observed. Several of the microorganisms had not previously been associated with biofilms and corrosion, reinforcing the need to use molecular techniques to achieve a more comprehensive assessment of microbial diversity in environmental samples.

Chryseobacterium chaponense sp. nov., isolated from farmed Atlantic salmon (Salmo salar)

Two bacterial strains, designated Sa 1147-06T and Sa 1143-06, were isolated from Atlantic salmon (Salmo salar) farmed in Lake Chapo, Chile, and were studied using a polyphasic approach. Both isolates were very similar; cells were rod-shaped, formed yellow-pigmented colonies and were Gram-reaction-negative. Based on 16S rRNA gene sequence analysis, strains Sa 1147-06T and Sa 1143-06 shared 100 % sequence similarity and showed 98.9 and 97.5 % sequence similarity to Chryseobacterium jeonii AT1047T and Chryseobacterium antarcticum AT1013T, respectively. Sequence similarities to all other members of the genus Chryseobacterium were below 97.3 %. The major fatty acids of strain Sa 1147-06T were iso-C13 : 0, iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 1 ω9c, with iso-C15 : 0 3-OH, iso-C16 : 0 3-OH and iso-C17 : 0 3-OH constituting the major hydroxylated fatty acids. DNA–DNA hybridizations with C. jeonii JMSNU 14049T and C. antarcticum JMNSU 14040T gave relatedness values of 20.7 % (reciprocal 15.1 %) and 15.7 % (reciprocal 25.7 %), respectively. Together, the DNA–DNA hybridization results and differentiating biochemical properties showed that strains Sa 1147-06T and Sa 1143-06 represent a novel species, for which the name Chryseobacterium chaponense sp. nov. is proposed. The type strain is Sa 1147-06T (=DSM 23145T =CCM 7737T).