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Applied and Environmental Microbiology Apr 2022Marine bacteria usually contain polysaccharide utilization loci (PUL) for metabolizing red algae polysaccharides. They are of great significance in the carbon cycle of...
Marine bacteria usually contain polysaccharide utilization loci (PUL) for metabolizing red algae polysaccharides. They are of great significance in the carbon cycle of the marine ecosystem, as well as in supporting marine heterotrophic bacterial growth. Here, we described the whole κ-carrageenan (KC), ι-carrageenan (IC), and partial λ-carrageenan (LC) catabolic pathways in a marine Gram-negative bacterium, Flavobacterium algicola, which is involved carrageenan polysaccharide hydrolases, oligosaccharide sulfatases, oligosaccharide glycosidases, and the 3,6-anhydro-d-galactose (d-AHG) utilization-related enzymes harbored in the carrageenan-specific PUL. In the pathways, the KC and IC were hydrolyzed into 4-sugar-unit oligomers by specific glycoside hydrolases. Then, the multifunctional G4S sulfatases would remove their nonreducing ends' G4S sulfate groups, while the ι-neocarratetrose (Nι4) product would further lose the nonreducing end of its DA2S group. Furthermore, the neocarrageenan oligosaccharides (NCOSs) with no G4S and DA2S groups in their nonreducing ends would completely be decomposed into d-Gal and d-AHG. Finally, the released d-AHG would enter the cytoplasmic four-step enzymatic process, and an l-rhamnose-H transporter (RhaT) was preliminarily verified for the function for transportation of d-AHG. Moreover, comparative analysis with the reported carrageenan metabolism pathways further implied the diversity of microbial systems for utilizing the red algae carrageenan. Carrageenan is the main polysaccharide of red macroalgae and is composed of d-AHG and d-Gal. The carrageenan PUL (CarPUL)-encoded enzymes exist in many marine bacteria for decomposing carrageenan to provide self-growth. Here, the related enzymes in Flavobacterium algicola for metabolizing carrageenan were characterized for describing the catabolic pathways, notably, although the specific polysaccharide hydrolases existed that were like previous studies. A multifunctional G4S sulfatase also existed, which was devoted to the removal of G4S or G2S sulfate groups from three kinds of NCOSs. Additionally, the transformation of three types of carrageenans into two monomers, d-Gal and d-AHG, occurred outside the cell with no periplasmic reactions that existed in previously reported pathways. These results help to clarify the diversity of marine bacteria using macroalgae polysaccharides.
Topics: Carrageenan; Ecosystem; Flavobacterium; Glycoside Hydrolases; Oligosaccharides; Polysaccharides; Rhodophyta; Seaweed; Sulfatases; Sulfates
PubMed: 35293779
DOI: 10.1128/aem.00256-22 -
Journal of Applied Microbiology Apr 2013To aim of the study was to describe the genetic relationship between isolates of Flavobacterium psychrophilum with a main emphasis of samples from Chile and Norway. The...
AIMS
To aim of the study was to describe the genetic relationship between isolates of Flavobacterium psychrophilum with a main emphasis of samples from Chile and Norway. The isolates have been obtained from farmed salmonids in Norway and Chile, and from wild salmonids in Norway, but isolates from North America and European countries are also included in the analysis.
METHODS AND RESULTS
The study is based on phylogenetic analysis of 16S rRNA and seven housekeeping genes (HG), gyrB, atpA, dnaK, trpB, fumC, murG and tuf, and the use of a multilocus sequence typing (MLST) system, based on nucleotide polymorphism in the HG, as an alternative to the phylogenies. The variation within the selected genes was limited, and the phylogenetic analysis gave little resolution between the isolates. The MLST gave a much better resolution resulting in 53 sequence types where the same sequences types could be found in Chile, North America and European countries, and in different host species.
CONCLUSIONS
Multilocus sequence typing give a relatively good separation of different isolates of Fl. psychrophilum and show that there are no distinct geographical or host-specific isolates in the studied material from Chile, North America and Europe. Nor was it possible to separate between isolates from ulcers and systemic infections vs isolates from the surface of healthy salmonids.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study shows a wide geographical distribution of Fl. psychrophilum, indicating that the bacterium has a large potential for transmission over long distances, and between different salmonid hosts species. This knowledge will be important for future management of salmonids diseases connected to Fl. psychrophilum.
Topics: Animals; Bacterial Typing Techniques; Chile; Europe; Fish Diseases; Flavobacterium; Genes, Bacterial; Genetic Variation; Genotype; Multilocus Sequence Typing; North America; Norway; Phylogeny; Polymorphism, Genetic; RNA, Ribosomal, 16S; Salmonidae; Sequence Analysis, DNA
PubMed: 23289591
DOI: 10.1111/jam.12121 -
BMC Microbiology Apr 2014Flavobacterium psychrophilum is the agent of Bacterial Cold Water Disease and Rainbow Trout Fry Syndrome, two diseases leading to high mortality. Pathogen detection is...
BACKGROUND
Flavobacterium psychrophilum is the agent of Bacterial Cold Water Disease and Rainbow Trout Fry Syndrome, two diseases leading to high mortality. Pathogen detection is mainly carried out using cultures and more rapid and sensitive methods are needed.
RESULTS
We describe a qPCR technique based on the single copy gene β' DNA-dependent RNA polymerase (rpoC). Its detection limit was 20 gene copies and the quantification limit 103 gene copies per reaction. Tests on spiked spleens with known concentrations of F. psychrophilum (106 to 101 cells per reaction) showed no cross-reactions between the spleen tissue and the primers and probe. Screening of water samples and spleens from symptomless and infected fishes indicated that the pathogen was already present before the outbreaks, but F. psychrophilum was only quantifiable in spleens from diseased fishes.
CONCLUSIONS
This qPCR can be used as a highly sensitive and specific method to detect F. psychrophilum in different sample types without the need for culturing. qPCR allows a reliable detection and quantification of F. psychrophilum in samples with low pathogen densities. Quantitative data on F. psychrophilum abundance could be useful to investigate risk factors linked to infections and also as early warning system prior to potential devastating outbreak.
Topics: Animals; Bacteriological Techniques; Fish Diseases; Flavobacteriaceae Infections; Flavobacterium; Oncorhynchus mykiss; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity; Water Microbiology
PubMed: 24767577
DOI: 10.1186/1471-2180-14-105 -
Journal of Bacteriology Jun 2016Gliding motility is common in members of the phylum Bacteroidetes, including Flavobacterium johnsoniae and Cellulophaga algicola. F. johnsoniae gliding has been... (Comparative Study)
Comparative Study
UNLABELLED
Gliding motility is common in members of the phylum Bacteroidetes, including Flavobacterium johnsoniae and Cellulophaga algicola. F. johnsoniae gliding has been extensively studied and involves rapid movement of the cell surface adhesin SprB. Genetic analysis of C. algicola allowed a comparative analysis of gliding. Sixty-three HimarEm1-induced mutants that formed nonspreading colonies were characterized. Each had an insertion in an ortholog of an F. johnsoniae motility gene, highlighting similarities between the motility systems. Differences were also observed. C. algicola lacks orthologs of the F. johnsoniae motility genes gldA, gldF, and gldG that are thought to encode the components of an ATP-binding cassette (ABC) transporter. In addition, mutations in any of 12 F. johnsoniae gld genes result in complete loss of motility, whereas all C. algicola gld mutants retained slight residual motility. This may indicate that C. algicola has multiple motility systems, that the motility proteins exhibit partial redundancy of function, or that essential components of the motility machinery of both C. algicola and F. johnsoniae remain to be discovered.
IMPORTANCE
The development of genetic tools for C. algicola and comparative analysis of F. johnsoniae and C. algicola motility mutants identified similarities and differences between their gliding motility machineries. Gliding motility is common in the phylum Bacteroidetes Proteins that are important for gliding in both C. algicola and F. johnsoniae are potential core components of the Bacteroidetes gliding motility machinery.
Topics: ATP-Binding Cassette Transporters; Bacterial Proteins; Bacteroidetes; Flavobacterium; Gene Expression Regulation, Bacterial
PubMed: 27044627
DOI: 10.1128/JB.01020-15 -
FEBS Letters Dec 1986A series of tetrapeptides, Cbz(Bz)-Gly-X-Leu-Gly, were synthesized and the kinetic parameters, kcat and kcat/Km, determined for their hydrolyses by prolyl endopeptidase...
A series of tetrapeptides, Cbz(Bz)-Gly-X-Leu-Gly, were synthesized and the kinetic parameters, kcat and kcat/Km, determined for their hydrolyses by prolyl endopeptidase from Flavobacterium. The peptides with X = N-Me-Ala, Sar and Ala as well as the standard substrate (X = Pro) were found to be good substrates, while those with X = alpha-aminobutyryl, Hyp, Ser and Gly were poor substrates, and those with X = pipecolyl, alpha-aminoisobutyryl, N-Me-Val, N-Me-Leu, Hyp(O-Bzl) and Ser(O-Bzl) were not cleaved at all. These results suggest that the specificity-determining site or S1 subsite of the enzyme is designed to fit exactly the proline residue of the substrate with allowance for the residues carrying substituents at the N and/or C alpha which must not exceed the size of the pyrrolidine ring of proline.
Topics: Binding Sites; Endopeptidases; Flavobacterium; Kinetics; Prolyl Oligopeptidases; Serine Endopeptidases; Substrate Specificity
PubMed: 3539636
DOI: 10.1016/0014-5793(86)81118-8 -
Applied and Environmental Microbiology Apr 1978The metabolism of polyethylene glycol (PEG) was investigated with a synergistic, mixed culture of Flavobacterium and Pseudomonas species, which are individually unable...
The metabolism of polyethylene glycol (PEG) was investigated with a synergistic, mixed culture of Flavobacterium and Pseudomonas species, which are individually unable to utilize PEGs. The PEG dehydrogenase linked with 2,6-dichlorophenolindophenol was found in the particulate fraction of sonic extracts and catalyzed the formation of a 2,4-dinitrophenylhydrazine-positive compound, possibly an an aldehyde. The enzyme has a wide substrate specificity towards PEGs: from diethylene glycol to PEG 20,000 Km values for tetraethylene glycol (TEG), PEG 400, and PEG 6,000 were 11, 1.7, and 15 mM, respectively. The metabolic products formed from TEG by intact cells were isolated and identified by combined gas chromatography-mass spectrometry as triethylene glycol and TEG-monocarboxylic acid plus small amounts of TEG-dicarboxylic acid, diethylene glycol, and ethylene glycol. From these enzymatic and analytical data, the following metabolic pathway was proposed for PEG: HO(CH2CH2O)nCH2CH2OH leads to HO(CH2CH2O)nCH2CHO leads to HO(CH2CH2O)nCH2COOH leads to HO(CH2CH2O)n-1CH2CH2OH.
Topics: Chemical Phenomena; Chemistry; Flavobacterium; Oxidation-Reduction; Oxidoreductases; Oxygen Consumption; Polyethylene Glycols; Pseudomonas; Substrate Specificity
PubMed: 646355
DOI: 10.1128/aem.35.4.679-684.1978 -
Veterinary Research Mar 2015The interactions of Flavobacterium columnare isolates of different virulence with the gills of carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum)...
The interactions of Flavobacterium columnare isolates of different virulence with the gills of carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum) were investigated. Both fish species were exposed to different high (HV) or low virulence (LV) isolates and sacrificed at seven predetermined times post-challenge. Histopathological and ultrastructural examination of carp and rainbow trout inoculated with the HV-isolate disclosed bacterial invasion and concomitant destruction of the gill tissue, gradually spreading from the filament tips towards the base, with outer membrane vesicles surrounding most bacterial cells. In carp, 5-10% of the fish inoculated with the LV-isolate became moribund and their gill tissue displayed the same features as described for the HV-isolate, albeit to a lesser degree. The bacterial numbers retrieved from the gill tissue were significantly higher for HV- compared to LV-isolate challenged carp and rainbow trout. TUNEL-stained and caspase-3-immunostained gill sections demonstrated significantly higher apoptotic cell counts in carp and rainbow trout challenged with the HV-isolate compared to control animals. Periodic acid-Schiff/alcian blue staining demonstrated a significantly higher total gill goblet cell count for HV- and LV-isolate challenged compared to control carp. Moreover, bacterial clusters were embedded in a neutral matrix while being encased by acid mucins, resembling biofilm formation. Eosinophilic granular cell counts were significantly higher in the HV-isolate compared to LV-isolate inoculated and control carp. The present data indicate a high colonization capacity, and the destructive and apoptotic-promoting features of the HV-isolate, and point towards important dynamic host mucin-F. columnare interactions warranting further research.
Topics: Animals; Carps; Caspase 3; Fish Diseases; Flavobacteriaceae Infections; Flavobacterium; Gills; In Situ Nick-End Labeling; Oncorhynchus mykiss; Virulence
PubMed: 25889257
DOI: 10.1186/s13567-015-0164-5 -
Proceedings of the National Academy of... Mar 2018Naturally occurring photonic structures are responsible for the bright and vivid coloration in a large variety of living organisms. Despite efforts to understand their...
Naturally occurring photonic structures are responsible for the bright and vivid coloration in a large variety of living organisms. Despite efforts to understand their biological functions, development, and complex optical response, little is known of the underlying genes involved in the development of these nanostructures in any domain of life. Here, we used colonies as a model system to demonstrate that genes responsible for gliding motility, cell shape, the stringent response, and tRNA modification contribute to the optical appearance of the colony. By structural and optical analysis, we obtained a detailed correlation of how genetic modifications alter structural color in bacterial colonies. Understanding of genotype and phenotype relations in this system opens the way to genetic engineering of on-demand living optical materials, for use as paints and living sensors.
Topics: Bacterial Proteins; Color; Flavobacterium; Genetic Engineering; Photons; Seaweed
PubMed: 29472451
DOI: 10.1073/pnas.1716214115 -
Journal of Clinical Microbiology Oct 1989Published reports disagree on the best features for detecting and distinguishing between Flavobacterium meningosepticum (biovar IIa) and Flavobacterium species CDC group... (Comparative Study)
Comparative Study
Published reports disagree on the best features for detecting and distinguishing between Flavobacterium meningosepticum (biovar IIa) and Flavobacterium species CDC group IIb (biovar IIb; Flavobacterium indologenes). This report discloses that at least some of these disagreements may reflect the methods used. To detect production of indole, a modified Kovács reagent (not Ehrlich) and a buffered tryptophan medium were optimal, but not all strains of these two biovars produced indole. To distinguish the two biovars, hydrolysis of corn starch was preferable to that of soluble potato starch. Both biovars may hydrolyze DNA; the differentiation achieved varied with the methods used. Both biovars presented pigmented growth; only IIb, however, was obviously pigmented on a 2-day blood agar plate. Acidification of D-arabinose definitively distinguished these two biovars; several additional features were useful but not definitive.
Topics: Bacteriological Techniques; Carbohydrate Metabolism; Deoxyribonucleases; Flavobacterium; Indoles; Pigmentation; Species Specificity; Starch
PubMed: 2685029
DOI: 10.1128/jcm.27.10.2309-2315.1989 -
Scientific Reports Feb 2016Interest in the interaction of microorganisms with cesium ions (Cs(+)) has arisen, especially in terms of their potent ability for radiocesium bioaccumulation and their...
Interest in the interaction of microorganisms with cesium ions (Cs(+)) has arisen, especially in terms of their potent ability for radiocesium bioaccumulation and their important roles in biogeochemical cycling. Although high concentrations of Cs(+) display toxic effects on microorganisms, there have been only limited reports for Cs(+)-tolerant microorganisms. Here we report enrichment and isolation of Cs(+)-tolerant microorganisms from soil microbiota. Microbial community analysis revealed that bacteria within the phylum Bacteroidetes, especially Flavobacterium spp., dominated in enrichment cultures in the medium supplemented with 50 or 200 mM Cs(+), while Gammaproteobacteria was dominant in the control enrichment cultures (in the presence of 50 and 200 mM K(+) instead of Cs(+)). The dominant Flavobacterium sp. was successfully isolated from the enrichment culture and was closely related to Flavobacterium chungbukense with 99.5% identity. Growth experiments clearly demonstrated that the isolate has significantly higher tolerance to Cs(+) compared to its close relatives, suggesting the Cs(+)-tolerance is a specific trait of this strain, but not a universal trait in the genus Flavobacterium. Measurement of intracellular K(+) and Cs(+) concentrations of the Cs(+)-tolerant isolate and its close relatives suggested that the ability to maintain low intracellular Cs(+) concentration confers the tolerance against high concentrations of external Cs(+).
Topics: Adaptation, Biological; Cesium; Chlorides; Escherichia coli; Flavobacterium; Intracellular Space; Ions; Phylogeny; Potassium; RNA, Ribosomal, 16S; Soil; Soil Microbiology
PubMed: 26883718
DOI: 10.1038/srep20041