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characterization of mela: a gene encoding melanin biosynthesis from the marine bacterium shewanella colwelliana.a recombinant plasmid with the ability to impart melanin synthesis to an escherichia coli host was isolated from a shewanella colwelliana genomic library. the genetic determinant of the mel+ phenotype is carried on a 1.3-kb dna fragment and sequence analysis of this revealed a single intact open reading frame that was sufficient for melanin synthesis (mel). this gene is expressed as a monocistronic transcript and a putative transcription start point is located 115 nucleotides upstream from the t ...19911756973
nucleotide sequences of 5s ribosomal rnas from three marine eubacteria: shewanella hanedai, alteromonas colwelliana and vibrio mediterranei. 19892473444
cloning and expression of a gene encoding a t-cell reactive protein from coccidioides immitis: homology to 4-hydroxyphenylpyruvate dioxygenase and the mammalian f antigen.the gene which encodes a previously described t-cell reactive protein (tcrp) of the human fungal pathogen coccidioides immitis (ci) was cloned and sequenced. both the genomic and cdna sequences were determined. the transcription start point was confirmed. the tcrp gene has three introns and a 1197-bp orf which translates to a 399-amino-acid (aa) protein (45.2 kda). the predicted protein has approx. 50% aa sequence identity and 70% similarity to mammalian 4-hydroxyphenylpyruvate dioxygenase (hppd ...19957642122
production and characterization of monoclonal antibodies specific for shewanella colwelliana exopolysaccharide.six monoclonal antibodies were produced to whole cells of shewanella colwelliana (aco1 to aco6) and two (aco22 to aco23) to purified exopolysaccharide (eps). aco1, -4 to -6, -22, and -23 bound to both the cell surface and the purified eps, while aco2 and -3 bound to cells only. the eps of s. colwelliana was antigenically unique from those of nine other species of marine bacteria that were tested. mapping studies revealed that all of the eps-specific monoclonal antibodies bound to the same epitop ...19937686001
homogentisic acid is the primary precursor of melanin synthesis in vibrio cholerae, a hyphomonas strain, and shewanella colwelliana.the enzyme p-hydroxyphenylpyruvate hydroxylase (hpph) is involved in pigmentation (pyomelanin) via homogentisic acid (hga). pyomelanin formation is correlated with hga production and expression of hpph in three disparate marine species: vibrio cholerae, a hyphomonas strain, and shewanella colwelliana. induction of pigmentation in v. cholerae 569b by nutrient limitation also correlated with production of hga.19957747976
the protein encoded by the shewanella colwelliana mela gene is a p-hydroxyphenylpyruvate dioxygenase.the identity of the product of the mela gene from shewanella colwelliana with the enzyme p-hydroxyphenylpyruvic dioxygenase is shown. cloning of the mela gene endowed escherichia coli with the capacity to synthesize melanin-like pigments from l-tyrosine. e. coli contained transaminases that transforms l-tyrosine into p-hydroxyphenylpyruvate. this keto acid was detected in the cultures. on the other hand, e. coli containing mela was able to go further in the catabolic pathway, releasing a great a ...19947813886
homogentisic acid is the product of mela, which mediates melanogenesis in the marine bacterium shewanella colwelliana d.shewanella colwelliana d is a marine procaryote which produces a diffusible brown pigment that correlates with mela gene expression. previously, mela had been cloned, sequenced, and expressed in escherichia coli; however, the reaction product of mela had not been identified. this report identifies that product as homogentisic acid, provides evidence that the pigment is homogentisic acid-melanin (pyomelanin), and suggests that mela is p-hydroxyphenylpyruvate hydroxylase. this is the first report ...19948085836
sequence determination and mutational analysis of the lly locus of legionella pneumophila.the lly (legiolysin) locus codes for a 39-kda protein which confers hemolysis, pigment production, and fluorescence on recombinant escherichia coli k-12 clones carrying the lly gene. the nucleotide sequences of the lly genes from two legionella pneumophila isolates were determined. the lly loci exhibited identical nucleotide sequences. they contained open reading frames of 348 amino acid residues, encoding proteins with a deduced molecular mass of 38.9 kda. n-terminal amino acid sequencing furth ...19948112844
the mela gene is essential for melanin biosynthesis in the marine bacterium shewanella colwelliana.the surface-adhering, gram-negative marine bacterium shewanella colwelliana synthesizes a red-brow melanin in the late stage of exponential growth in laboratory culture. previous studies identified a single gene, mela, from s. colwelliana that could impart the ability to produce melanin to an e. coli host. however, these studies did not demonstrate a requirement for mela during melanization in s. colwelliana. in this paper, genetic analyses, using a broad host range conjugation system to generat ...19938336107
human 4-hydroxyphenylpyruvate dioxygenase. primary structure and chromosomal localization of the gene.we report the primary structure of 4-hydroxyphenylpyruvate dioxygenase [4-hydroxyphenyl-pyruvate:oxygen oxidoreductase (hydroxylating, decarboxylating)]. the work is based on the isolation of cdna clones from human liver lambda gt11 libraries. several overlapping clones covering the coding sequence were characterized. in parallel, peptides from four different digests of the purified protein were analysed for their amino-acid sequence. these peptide sequences covered 86% of the cdna-derived amino ...19938504803
study of a melanic pigment of proteus mirabilis.the present study sought to determine whether the pigment produced by proteus mirabilis from the l-forms of various aromatic amino acids under aerobic conditions is melanic in nature. it is a black-brown pigment which behaves like a melanin in many respects, namely solubility features, bleaching by oxidizing agents and positive response to the fontana-masson assay. in the present study, for the first time, it was shown by electron spin resonance analysis that a bacterial melanin is able to act a ...19968761735
upstream sequence of the parahydroxyphenyl-pyruvate dioxygenase (mela) coding region leading to enhanced expression in shewanella colwelliana.hyperexpression of the enzyme, parahydroxyphenylpyruvate dioxygenase (phpph; mela), in the tyrosine degradative pathway yields excess homogentisic acid which oxidatively polymerizes to pyomelanin. depression of mela in shewanella colwelliana strain d was found to result from a single base pair transition upstream of the promoter. this was the sole lesion detected in phpph hyperexpressing strains. it is suggested that a t to c transition alters the mrna structure, exposing the ribosome binding si ...19968885416
cloning and sequence analysis of a novel hemolysin gene (vlly) from vibrio vulnificus.a gene (vlly) encoding a novel hemolysin of vibrio vulnificus ckm-1 has been cloned and sequenced. when the vlly gene was expressed in minicells, a unique peptide of approximately 40 kda was identified. subcellular fractionation of escherichia coli cells carrying the vlly gene indicated that the vlly protein was distributed in both the cytoplasmic and the periplasmic fractions, with the notable ability to appear in the latter compartment. nucleotide sequence analysis predicted a single open read ...19979327548
magnification of tributyl tin toxicity to oyster larvae by bioconcentration in biofilms of shewanella colwelliana.the toxic effects of dissolved versus bioconcentrated tributyl tin (tbt) on oyster larvae were compared. water column tbt levels, which had no effect in solution, inhibited natural attachment and metamorphosis of oyster larvae on bottom surfaces due to bioconcentration by biofilms. this mechanism should be considered when evaluating heavy metal toxicity in the environment.19979327578
immunogenicity of a 48-kilodalton recombinant t-cell-reactive protein of coccidioides immitis.the outcome of coccidioidomycosis depends to a large extent on the effectiveness of the t-cell-mediated immune (cmi) response to the fungal pathogen. for this reason, identification of coccidioides immitis antigens which stimulate t cells is important for understanding the nature of host defense against the organism and essential for the development of an effective vaccine. here we describe the immunogenicity of a 48-kda t-cell-reactive protein (tcrp). the antigen is expressed by parasitic cells ...19989453590
complementation of the arabidopsis pds1 mutation with the gene encoding p-hydroxyphenylpyruvate dioxygenase.plastoquinone and tocopherols are the two major quinone compounds in higher plant chloroplasts and are synthesized by a common pathway. in previous studies we characterized two loci in arabidopsis defining key steps of this biosynthetic pathway. mutation of the pds1 locus disrupts the activity of p-hydroxyphenylpyruvate dioxygenase (hppdase), the first committed step in the synthesis of both plastoquinone and tocopherols in plants. although plants homozygous for the pds1 mutation could be rescue ...19989701587
acetone formation in the vibrio family: a new pathway for bacterial leucine catabolism.there is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. here, we determined that leucine-dependent acetone formation is widespread in the vibrionaceae. sixteen vibrio isolates, two listonella species, and two photobacterium angustum isolates produced acetone in the presence of l-leucine. shewanella isolates produced much less acetone. growth of vibrio splendidus and p. angustum in a fermentor with controlled aeration revealed th ...199910601206
brown pigments produced by yarrowia lipolytica result from extracellular accumulation of homogentisic acid.yarrowia lipolytica produces brown extracellular pigments that correlate with tyrosine catabolism. during tyrosine depletion, the yeast accumulated homogentisic acid, p-hydroxyphenylethanol, and p-hydroxyphenylacetic acid in the medium. homogentisic acid accumulated under all aeration conditions tested, but its concentration decreased as aeration decreased. with moderate aeration, equimolar concentrations of alcohol and p-hydroxyphenylacetic acid (1:1) were detected, but with lower aeration the ...200111472920
vant, a homologue of vibrio harveyi luxr, regulates serine, metalloprotease, pigment, and biofilm production in vibrio anguillarum.vibrio anguillarum possesses at least two n-acylhomoserine lactone (ahl) quorum-sensing circuits, one of which is related to the luxmn system of vibrio harveyi. in this study, we have cloned an additional gene of this circuit, vant, encoding a v. harveyi luxr-like transcriptional regulator. a v. anguillarum delta vant null mutation resulted in a significant decrease in total protease activity due to loss of expression of the metalloprotease empa, but no changes in either ahl production or virule ...200211872713
melanin production and use as a soluble electron shuttle for fe(iii) oxide reduction and as a terminal electron acceptor by shewanella algae bry.dissimilatory metal-reducing bacteria (dmrb) utilize numerous compounds as terminal electron acceptors, including insoluble iron oxides. the mechanism(s) of insoluble-mineral reduction by dmrb is not well understood. here we report that extracellular melanin is produced by shewanella algae bry. the extracted melanin served as the sole terminal electron acceptor. upon reduction the reduced, soluble melanin reduced insoluble hydrous ferric oxide in the absence of bacteria, thus demonstrating that ...200211976119
isolation of antibiotics turbomycin a and b from a metagenomic library of soil microbial dna.to access the genetic and biochemical potential of soil microorganisms by culture-independent methods, a 24,546-member library in escherichia coli with dna extracted directly from soil had previously been constructed (m. r. rondon, p. r. august, a. d. bettermann, s. f. brady, t. h. grossman, m. r. liles, k. a. loiacono, b. a. lynch, i. a. macneil, m. s. osburne, j. clardy, j. handelsman, and r. m. goodman, appl. environ. microbiol. 66:2541-2547, 2000). three clones, p57g4, p89c8, and p214d2, pro ...200212200279
antibiotic production by a roseobacter clade-affiliated species from the german wadden sea and its antagonistic effects on indigenous isolates.a strain affiliated with the roseobacter clade and producing a new antibiotic named tropodithietic acid (l. liang, ph.d. thesis, university of göttingen, göttingen, germany, 2003) was isolated from the german wadden sea. the compound showed strong inhibiting properties with respect to marine bacteria of various taxa and marine algae. antibiotic production was found to occur during the complete growth phase. strain mutants without antagonistic properties appeared several times spontaneously.200415066861
shewanella affinis sp. nov., isolated from marine invertebrates.four marine bacterial strains, designated kmm 3587t, kmm 3586, kmm 3821 and kmm 3822, were isolated from the sipuncula phascolosoma japonicum, a common inhabitant of troitza bay in the gulf of peter the great (sea of japan region), and from an unidentified hydrocoral species collected in makarov bay (iturup islands), kuril islands, north-west pacific ocean. the strains were characterized to clarify their taxonomic position. 16s rrna gene sequences of kmm 3587t and kmm 3586 indicated 99% similari ...200415280274
electricity generation from cysteine in a microbial fuel cell.in a microbial fuel cell (mfc), power can be generated from the oxidation of organic matter by bacteria at the anode, with reduction of oxygen at the cathode. proton exchange membranes used in mfcs are permeable to oxygen, resulting in the diffusion of oxygen into the anode chamber. this could either lower power generation by obligate anaerobes or result in the loss in electron donor from aerobic respiration by facultative or other aerobic bacteria. in order to maintain anaerobic conditions in c ...200515743641
identification of shewanella baltica as the most important h2s-producing species during iced storage of danish marine fish.shewanella putrefaciens has been considered the main spoilage bacteria of low-temperature stored marine seafood. however, psychrotropic shewanella have been reclassified during recent years, and the purpose of the present study was to determine whether any of the new shewanella species are important in fish spoilage. more than 500 h2s-producing strains were isolated from iced stored marine fish (cod, plaice, and flounder) caught in the baltic sea during winter or summer time. all strains were id ...200516269698
microbial diversity in coastal subsurface sediments: a cultivation approach using various electron acceptors and substrate gradients.microbial communities in coastal subsurface sediments are scarcely investigated and have escaped attention so far. but since they are likely to play an important role in biogeochemical cycles, knowledge of their composition and ecological adaptations is important. microbial communities in tidal sediments were investigated along the geochemical gradients from the surface down to a depth of 5.5 m. most-probable-number (mpn) series were prepared with a variety of different carbon substrates, each a ...200516332756
interactions between shewanella colwelliana, oyster larvae, and hydrophobic organophosphate pesticides.shewanella colwelliana (strain d) is a periphytic estuarine bacterium that forms biofilms beneficial to oyster set. our study examined whether these and other films concentrated two hydrophobic, organophosphate pesticides, abate and malathion, that are detected in chesapeake bay oyster waters. both biofilms and purified exopolysaccharide of s. colwelliana did not adsorb more of the abate or malathion than could be accounted for by adsorption to control surfaces. similar results were obtained by ...199016348382
spatial and temporal deposition of adhesive extracellular polysaccharide capsule and fimbriae by hyphomonas strain mhs-3.hyphomonas strain mhs-3, a member of a genus of primary colonizers of surfaces immersed in marine water, synthesizes two structures that mediate adhesion to solid substrata, namely, capsular exopolysaccharide and fimbriae. specific stains, gold-labelled lectins, and monoclonal antibodies, along with transmission electron microscopy of synchronized populations, revealed that both structures are polarly and temporally expressed. the timed synthesis and placement of the fimbriae and capsule correla ...199816349537
cryptococcus neoformans can utilize the bacterial melanin precursor homogentisic acid for fungal melanogenesis.cryptococcus neoformans melanizes in the environment and in mammalian tissues, but the process of melanization in either venue is mysterious given that this microbe produces melanin only from exogenous substrates. understanding the process of melanization is important because melanization is believed to protect against various stresses in the environment, including uv radiation, and pigment production is associated with virulence. melanization in c. neoformans requires the availability of diphen ...200717098915
cryptococcus neoformans can utilize the bacterial melanin precursor homogentisic acid for fungal melanogenesis.cryptococcus neoformans melanizes in the environment and in mammalian tissues, but the process of melanization in either venue is mysterious given that this microbe produces melanin only from exogenous substrates. understanding the process of melanization is important because melanization is believed to protect against various stresses in the environment, including uv radiation, and pigment production is associated with virulence. melanization in c. neoformans requires the availability of diphen ...200717098915
description of shewanella glacialipiscicola sp. nov. and shewanella algidipiscicola sp. nov., isolated from marine fish of the danish baltic sea, and proposal that shewanella affinis is a later heterotypic synonym of shewanella colwelliana.two novel species belonging to the genus shewanella are described on the basis of a polyphasic taxonomic approach. a total of 40 strains of gram-negative, psychrotolerant, h2s-producing bacteria were isolated from marine fish (cod and plaice) caught in the baltic sea off denmark. strains belonging to group 1 (seven strains) were a lactate-assimilating variant of shewanella morhuae with a g+c content of 44 mol%. the strains of group 2 (33 strains) utilized lactate, n-acetylglucosamine and malate ...200717267977
the secreted pyomelanin pigment of legionella pneumophila confers ferric reductase activity.the virulence of legionella pneumophila is dependent upon its capacity to acquire iron. to identify genes involved in expression of its siderophore, we screened a mutagenized population of l. pneumophila for strains that were no longer able to rescue the growth of a ferrous transport mutant. however, an unusual mutant was obtained that displayed a strong inhibitory effect on the feob mutant. due to an insertion in hmga that encodes homogentisate 1,2-dioxygenase, the mutant secreted increased lev ...200717548481
diatom-derived carbohydrates as factors affecting bacterial community composition in estuarine sediments.microphytobenthic biofilms in estuaries, dominated by epipelic diatoms, are sites of high primary productivity. these diatoms exude large quantities of extracellular polymeric substances (eps) comprising polysaccharides and glycoproteins, providing a substantial pool of organic carbon available to heterotrophs within the sediment. in this study, sediment slurry microcosms were enriched with either colloidal carbohydrates or colloidal eps (ceps) or left unamended. over 10 days, the fate of these ...200717675437
gammaproteobacteria as a possible source of eicosapentaenoic acid in anoxic intertidal sediments.eicosapentaenoic acid (epa; n-20:5omega3) was found to be a constituent of phospholipids in three mesophilic strains of gammaproteobacteria, which were isolated from anoxic most probable number series prepared with sediments from an intertidal flat of the german north sea coast. their partial 16s rrna gene sequences identified the isolates as close relatives of shewanella colwelliana, vibrio splendidus, and photobacterium lipolyticum. so far, eicosapentaenoic acid has mainly been reported to occ ...200918777187
role of melanin pigment in expression of vibrio cholerae virulence factors.we identified the mutated gene locus in a pigment-overproducing vibrio cholerae mutant of strain a1552. the deduced gene product is suggested to be an oxidoreductase based on partial homology to putative homogentisate 1,2-dioxygenase in pseudomonas aeruginosa and mesorhizobium loti, and we propose that the gene vc1345 in the v. cholerae genome be denoted hmga in accordance with the nomenclature for other species. the hmga::mini-tn5 mutant showed a nonpigmented phenotype after complementation wit ...200919103773
role of melanin pigment in expression of vibrio cholerae virulence factors.we identified the mutated gene locus in a pigment-overproducing vibrio cholerae mutant of strain a1552. the deduced gene product is suggested to be an oxidoreductase based on partial homology to putative homogentisate 1,2-dioxygenase in pseudomonas aeruginosa and mesorhizobium loti, and we propose that the gene vc1345 in the v. cholerae genome be denoted hmga in accordance with the nomenclature for other species. the hmga::mini-tn5 mutant showed a nonpigmented phenotype after complementation wit ...200919103773
a large-scale epidemiological study to identify bacteria pathogenic to pacific oyster crassostrea gigas and correlation between virulence and metalloprotease-like activity.a 4-year bacteriological survey (2003-2007) of four molluscs cultivated in france and faced with mortality episodes was performed by the french shellfish pathology network. the more abundant bacteria isolated during 92 mortality episodes, occurring mainly in pacific oyster crassostrea gigas, were identified by genotyping methods. it allowed us both to confirm the representativeness of vibrio splendidus and vibrio aestuarianus bacterial strains and to identify both a large number of vibrio harvey ...201020012275
a novel conico-cylindrical flask aids easy identification of critical process parameters for cultivation of marine bacteria.a polymethylmethacrylate (pmma) conico-cylindrical flask (ccf) with an inner arrangement consisting of eight equidistantly spaced rectangular strips mounted radially on a circular disk to provide additional surface area for microbial attachment and ports to allow air supply was employed for melanin production by shewanella colwelliana and antibiotic production by pseudoalteromonas rubra. the design allowed comparison of production between (1) ccf with hydrophobic surface (pmma-ccf), (2) ccf with ...201121210106
pyomelanin formation in aspergillus fumigatus requires hmgx and the transcriptional activator hmgr but is dispensable for virulence.the opportunistic human pathogenic fungus aspergillus fumigatus is able to produce the dark brown pigment pyomelanin by degradation of l-tyrosine. pyomelanin was shown to protect the fungus against reactive oxygen intermediates as well as cell wall disturbing compounds and is therefore assumed to protect against immune effector cells during the infection process. several genes for tyrosine degradation and pyomelanin formation are organized in a cluster in the genome of a. fumigatus. here, we aim ...201122046314
biotechnological applications of functional metagenomics in the food and pharmaceutical industries.microorganisms are found throughout nature, thriving in a vast range of environmental conditions. the majority of them are unculturable or difficult to culture by traditional methods. metagenomics enables the study of all microorganisms, regardless of whether they can be cultured or not, through the analysis of genomic data obtained directly from an environmental sample, providing knowledge of the species present, and allowing the extraction of information regarding the functionality of microbia ...201526175729
extracellular matrix assembly in diatoms (bacillariophyceae). iii. organization of fucoglucuronogalactans within the adhesive stalks of achnanthes longipesachnanthes longipes is a marine, biofouling diatom that adheres to surfaces via adhesive polymers extruded during motility or organized into structures called stalks that contain three distinct regions: the pad, shaft, and collar. four monoclonal antibodies (al.c1-al.c4) and antibodies from two uncloned hybridomas (al.e1 and al.e2) were raised against the extracellular adhesives of a. longipes. antibodies were screened against a hot-water-insoluble/hot-bicarbonate-soluble-fraction. the hot-water ...19989536061
bioactive pigments from marine bacteria: applications and physiological roles.research into natural products from the marine environment, including microorganisms, has rapidly increased over the past two decades. despite the enormous difficulty in isolating and harvesting marine bacteria, microbial metabolites are increasingly attractive to science because of their broad-ranging pharmacological activities, especially those with unique color pigments. this current review paper gives an overview of the pigmented natural compounds isolated from bacteria of marine origin, bas ...201121961023
melanin-templated rapid synthesis of silver nanostructures.as a potent antimicrobial agent, silver nanostructures have been used in nanosensors and nanomaterial-based assays for the detection of food relevant analytes such as organic molecules, aroma, chemical contaminants, gases and food borne pathogens. in addition silver based nanocomposites act as an antimicrobial for food packaging materials. in this prospective, the food grade melanin pigment extracted from sponge associated actinobacterium nocardiopsis alba msa10 and melanin mediated synthesis of ...201424885756
living in an extremely polluted environment: clues from the genome of melanin-producing aeromonas salmonicida subsp. pectinolytica 34melt.aeromonas salmonicida subsp. pectinolytica 34mel(t) can be considered an extremophile due to the characteristics of the heavily polluted river from which it was isolated. while four subspecies of a. salmonicida are known fish pathogens, 34mel(t) belongs to the only subspecies isolated solely from the environment. genome analysis revealed a high metabolic versatility, the capability to cope with diverse stress agents, and the lack of several virulence factors found in pathogenic aeromonas. the mo ...201526025898
identification and molecular characterization of the homogentisate pathway responsible for pyomelanin production, the major melanin constituents in aeromonas media ws.the pigmentation of many aeromonas species has been thought to be due to the production of a l-dopa (l-3,4-dihydroxyphenylalanine) based melanin. however, in this study we found that although l-dopa synthesis occurs in the high-melanin-yielding aeromonas media strain ws, it plays a minor, if any, role in pigmentation. instead, the pigmentation of a. media strain ws is due to the production of pyomelanin through hga (homogentisate). gene products of phha (encodes phenylalanine hydroxylase), tyrb ...201525793756
lipids of prokaryotic origin at the base of marine food webs.in particular niches of the marine environment, such as abyssal trenches, icy waters and hot vents, the base of the food web is composed of bacteria and archaea that have developed strategies to survive and thrive under the most extreme conditions. some of these organisms are considered "extremophiles" and modulate the fatty acid composition of their phospholipids to maintain the adequate fluidity of the cellular membrane under cold/hot temperatures, elevated pressure, high/low salinity and ph. ...201223342392
fermentation technologies for the optimization of marine microbial exopolysaccharide production.in the last decades, research has focused on the capabilities of microbes to secrete exopolysaccharides (eps), because these polymers differ from the commercial ones derived essentially from plants or algae in their numerous valuable qualities. these biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications. in marine microorganisms the produced eps provide an instrument to survive in adverse conditions: they are fou ...201424857960
coexistence of microaerophilic, nitrate-reducing, and phototrophic fe(ii) oxidizers and fe(iii) reducers in coastal marine sediment.iron is abundant in sediments, where it can be biogeochemically cycled between its divalent and trivalent redox states. the neutrophilic microbiological fe cycle involves fe(iii)-reducing and three different physiological groups of fe(ii)-oxidizing microorganisms, i.e., microaerophilic, anoxygenic phototrophic, and nitrate-reducing fe(ii) oxidizers. however, it is unknown whether all three groups coexist in one habitat and how they are spatially distributed in relation to gradients of o2, light, ...201626682861
glucose metabolism and polysaccharide accumulation in the marine bacterium, shewanella colwelliana.shewanella colwelliana, a marine bacterium isolated in association with the oyster crassostrea virginica, produces an abundant exopolysaccharide with potential commercial value as an adhesive under aqueous conditions. its utilization of glucose was modulated by stoichiometric concentrations of yeast extract. in brain heart infusion medium containing glucose, growth was diauxic with delayed glucose utilization and incorporation into exopolysaccharide. data from radio-respirometry protocols indica ...199424421130
factors influencing bacterial production of inducers of settlement behavior of larvae of the oystercrassostrea gigas.dissolved chemical inducers of settlement behavior of veliger larvae of the oystercrassostrea gigas are found in supernatants of both pigmented species of bacteria (alteromonas colwelliana, vibrio cholerae strain htx) as well as nonpigmented bacteria (excherichia coli, vibrio cholerae strain 596-b). usually less than 10% of veligers exhibited settlement behavior in response to supernatants from the early bacterial growth phases, whereas 30-90% of larvae responded when exposed to supernatant from ...198924197287
enhanced biofilm formation and melanin synthesis by the oyster settlement-promoting shewanella colwelliana is related to hydrophobic surface and simulated intertidal environment.a direct relationship between biofilm formation and melanogenesis in shewanella colwelliana with increased oyster recruitment is already established. previously, s. colwelliana was grown in a newly patented biofilm-cultivation device, the conico-cylindrical flask (ccf), offering interchangeable hydrophobic/hydrophilic surfaces. melanization was enhanced when s. colwelliana was cultivated in a hydrophobic vessel compared with a hydrophilic vessel. in the present study, melanogenesis in the ccf wa ...201525959367
dissimilatory nitrogen reduction in intertidal sediments of a temperate estuary: small scale heterogeneity and novel nitrate-to-ammonium reducers.the estuarine nitrogen cycle can be substantially altered due to anthropogenic activities resulting in increased amounts of inorganic nitrogen (mainly nitrate). in the past, denitrification was considered to be the main ecosystem process removing reactive nitrogen from the estuarine ecosystem. however, recent reports on the contribution of dissimilatory nitrate reduction to ammonium (dnra) to nitrogen removal in these systems indicated a similar or higher importance, although the ratio between b ...201526528270
enhanced biotransformation of fluoranthene by intertidally derived cunninghamella elegans under biofilm-based and niche-mimicking conditions.the aims of the investigation were to ascertain if surface attachment of cunninghamella elegans and niche intertidal conditions provided in a bioreactor influenced biotransformation of fluoranthene by c. elegans. a newly designed polymethylmethacrylate (pmma) conico-cylindrical flask (ccf) holding eight equidistantly spaced rectangular strips mounted radially on a circular disc allowed comparison of fluoranthene biotransformation between ccfs with a hydrophobic surface (pmma-ccf) and a hydrophil ...201324038685
effects of dietary supplementation of probiotic shewanella colwelliana wa64, shewanella olleyana wa65 on the innate immunity and disease resistance of abalone, haliotis discus hannai ino.the effects of dietary administration of two probiotics, shewanella colwelliana wa64 and shewanella olleyana wa65, on the innate immunity of abalone (haliotis discus hannai ino), and survival of juvenile abalone challenged with vibrio harveyi have been studied. two groups of abalone were fed with three different diets: one control, and two diets supplemented with 10(9) cell g(-1) of probiotic wa64 (wa64 diet) and wa65 (wa65 diet) for up to four weeks. results showed that abalone fed diets contai ...201323602848
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