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isolation and characterization of pseudoalteromonas strains with divergent polycyclic aromatic hydrocarbon catabolic properties.fifteen strains of polycyclic aromatic hydrocarbon (pah)-catabolizing bacteria, identified as pseudoalteromonas spp. were isolated from eagle harbor, puget sound, usa, using a most probable number procedure in which naphthalene or phenanthrene was the sole carbon and energy source. despite having identical 16s rdna sequences, some catabolized many pahs, whereas others oxidized only naphthalenes. a putative naphthalene 1,2-dioxygenase gene fragment was polymerase chain reaction-amplified from the ...200616343332
unravelling the role of the toxr-like transcriptional regulator wmpr in the marine antifouling bacterium pseudoalteromonas tunicata.the dark-green-pigmented marine bacterium pseudoalteromonas tunicata produces several target-specific compounds that act against a range of common fouling organisms, including bacteria, fungi, protozoa, invertebrate larvae and algal spores. the toxr-like regulator wmpr has previously been shown to regulate expression of bioactive compounds, type iv pili and biofilm formation phenotypes which all appear at the onset of stationary phase. in this study a comparison of survival under starvation or s ...200616622055
ultrastructural analysis of the extracellular matter secreted by the psychrotolerant bacterium pseudoalteromonas antarctica nf3.the psychrotolerant strain pseudoalteromonas antarctica nf3, a gram-negative bacterium isolated from muddy soil samples of antarctica, secretes large amounts of a mucoid exopolymer with a high protein content. it has self-assembly properties and capacity to coat and protect liposomes against surfactants. we examined the ultrastructure of p. antarctica and the extracellular matter it secretes by transmission electron microscopy (tem) after high-pressure freezing, freeze substitution (hpf-fs), and ...200616645922
lipl32 is an extracellular matrix-interacting protein of leptospira spp. and pseudoalteromonas tunicata.lipl32 is the major outer membrane protein in pathogenic leptospira. it is highly conserved throughout pathogenic species and is expressed in vivo during human infection. while these data suggest a role in pathogenesis, a function for lipl32 has not been defined. outer membrane proteins of gram-negative bacteria are the first line of molecular interaction with the host, and many have been shown to bind host extracellular matrix (ecm). a search for leptospiral ecm-interacting proteins identified ...200818285490
effect of incubation temperature on growth parameters of pseudoalteromonas antarctica nf and its production of extracellular polymeric substancesdagger.to evaluate the effect of temperature on growth parameters and on extracellular polymeric substance (eps) production for pseudoalteromonas antarctica nf(3).200818298522
purine nucleoside phosphorylase from pseudoalteromonas sp. bsi590: molecular cloning, gene expression and characterization of the recombinant protein.the gene encoding purine nucleoside phosphorylase (pnp) from the cold-adapted marine bacterium pseudoalteromonas sp. bsi590 was identified, cloned and expressed in escherichia coli. the gene encodes a polypeptide of 233 amino acids with a calculated molecular weight of 25,018 da. pseudoalteromonas sp. bsi590 pnp (pipnp) shares 60% amino sequence identity and conservation of amino acid residues involved in catalysis with mesophilic escherichia coli deod-encoded purine nucleoside phosphorylase (ec ...200818299797
glutathionylation of the iron superoxide dismutase from the psychrophilic eubacterium pseudoalteromonas haloplanktis.our previous work showed that the adduct between beta-mercaptoethanol and the single cysteine residue (cys57) in superoxide dismutase from the psychrophilic eubacterium pseudoalteromonas haloplanktis (phsod) reduces the enzyme inactivation by peroxynitrite. in this work, immunoblotting experiments prove that peroxynitrite inactivation of phsod involves formation of nitrotyrosine residue(s). in order to study the role of cys57 as a redox-sensor residue modifiable by cellular thiols, a recombinant ...200818328273
rapid chemotactic response enables marine bacteria to exploit ephemeral microscale nutrient patches.because ocean water is typically resource-poor, bacteria may gain significant growth advantages if they can exploit the ephemeral nutrient patches originating from numerous, small sources. although this interaction has been proposed to enhance biogeochemical transformation rates in the ocean, it remains questionable whether bacteria are able to efficiently use patches before physical mechanisms dissipate them. here we show that the rapid chemotactic response of the marine bacterium pseudoalterom ...200818337491
flocculation behavior and mechanism of an exopolysaccharide from the deep-sea psychrophilic bacterium pseudoalteromonas sp. sm9913.flocculation behavior and mechanism of the exopolysaccharide secreted by pseudoalteromonas sp. sm9913 (eps sm9913), a psychrophilic bacterium isolated from 1855m deep-sea sediment, has been studied in this paper. eps sm9913 showed a peak flocculating activity of 49.3 in 1g/l kaolin suspension with 4.55mmol/l cacl2 and the optimum ph range of 5-8. it appears that the flocculating activity of eps sm9913 was stimulated by ca2+ and fe2+. this study found that eps sm9913 showed a better flocculation ...200818353634
phylogenetic and enzymatic diversity of deep subseafloor aerobic microorganisms in organics- and methane-rich sediments off shimokita peninsula."a meta-enzyme approach" is proposed as an ecological enzymatic method to explore the potential functions of microbial communities in extreme environments such as the deep marine subsurface. we evaluated a variety of extra-cellular enzyme activities of sediment slurries and isolates from a deep subseafloor sediment core. using the new deep-sea drilling vessel "chikyu", we obtained 365 m of core sediments that contained approximately 2% organic matter and considerable amounts of methane from offs ...200818368287
cloning, expression and physicochemical characterization of a di-heme cytochrome c (4) from the psychrophilic bacterium pseudoalteromonas haloplanktis tac 125.the 20-kda di-heme cytochrome c (4) from the psycrophilic bacterium pseudoalteromonas haloplanktis tac 125 was cloned and expressed in escherichia coli and investigated through uv-vis and (1)h nmr spectroscopies and protein voltammetry. the model structure was computed using the x-ray structure of pseudomonas stutzeri cytochrome c (4) as a template. the protein shows unprecedented properties within the cytochrome c (4) family, including (1) an almost nonpolar surface charge distribution, (2) the ...200818386080
role of lysine versus arginine in enzyme cold-adaptation: modifying lysine to homo-arginine stabilizes the cold-adapted alpha-amylase from pseudoalteramonas haloplanktis.the cold-adapted alpha-amylase from pseudoalteromonas haloplanktis (aha) is a multidomain enzyme capable of reversible unfolding. cold-adapted proteins, including aha, have been predicted to be structurally flexible and conformationally unstable as a consequence of a high lysine-to-arginine ratio. in order to examine the role of low arginine content in structural flexibility of aha, the amino groups of lysine were guanidinated to form homo-arginine (hr), and the structure-function-stability prop ...200616705665
complete assignment of 1h and 13c nmr spectra of gigartina skottsbergii lambda-carrageenan using carrabiose oligosaccharides prepared by enzymatic hydrolysis.lambda-carrageenan extracted from gigartina skottsbergii tetrasporophyte was completely digested by a purified pseudoalteromonas carrageenovora lambda-carrageenase. the main digestion products were fractionated and analysed by (1)h and (13)c nmr spectroscopy. all the oligosaccharides observed belong to the neo-carrabiose oligosaccharide series indicating that the lambda-carrageenase cleaves the beta-(1-->4) glycosidic bonds. (1)h and (13)c nmr spectra recorded on oligomers from dp 2 to dp 8 were ...200616716278
biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the middle atlantic ridge.the bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (pahs) in deep sea subsurface environments are largely unknown. in order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the middle atlantic ridge with a gravity column sampler. the sediments were promptly enriched with either crude oil or a mixture of pahs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched with ...200818445026
molecular structure of endotoxins from gram-negative marine bacteria: an update.marine bacteria are microrganisms that have adapted, through millions of years, to survival in environments often characterized by one or more extreme physical or chemical parameters, namely pressure, temperature and salinity. the main interest in the research on marine bacteria is due to their ability to produce several biologically active molecules, such as antibiotics, toxins and antitoxins, antitumor and antimicrobial agents. nonetheless, lipopolysaccharides (lpss), or their portions, from g ...200718463721
proteomic identification of a two-component regulatory system in pseudoalteromonas haloplanktis tac125.the capability of microorganisms to utilize different carbohydrates as energy source reflects the availability of these substrates in their habitat. investigation of the proteins involved in carbohydrate usage, in parallel with analysis of their expression, is then likely to provide information on the interaction between microorganisms and their ecosystem. we analysed the growth behaviour of the marine antarctic bacterium pseudoalteromonas haloplanktis tac125 in the presence and in the absence o ...200616791470
adsorption of tributyltin by tributyltin resistant marine pseudoalteromonas sp. cells.the isolate, pesudoalteromonas sp. tbt1, could grow to overcome the toxicity of tributyltin chloride (tbtcl) up to 30 microm in the absence of cl(-) in the medium until the cells reached an exponential phase of growth. the viability, however, was reduced after the cells reached a stationary phase. the degradation products, such as dibutyltin (dbt) and monobutyltin (mbt), were not detected in the growth medium, indicating that the isolate has no ability to degrade tbt into less toxic dbt and mbt. ...200818468645
crystallization and preliminary x-ray diffraction studies of a psychrophilic iron superoxide dismutase from pseudoalteromonas haloplanktis.the antarctic eubacterium pseudoalteromonas haloplanktis (ph) produces a cold-active iron superoxide dismutase (sod). phsod is a homodimeric enzyme, that displays a high catalytic activity even at low temperature. using hanging-drop vapour-diffusion technique, phsod has been successfully crystallized in two different crystal forms. both crystal forms are monoclinic with space group p2(1) and diffract to 2.1 a resolution. form i has unit-cell parameters a=45.49a b=103.63a c=50.37a beta=108.2 degr ...200818473957
influence of subtilisin on the adhesion of a marine bacterium which produces mainly proteins as extracellular polymers.the nature of exopolymers involved in the adhesion of a marine biofilm-forming bacterium pseudoalteromonas sp. d41 was investigated to evaluate and understand the antifouling potential of subtilisin.200818489561
hydrogen peroxide linked to lysine oxidase activity facilitates biofilm differentiation and dispersal in several gram-negative bacteria.the marine bacterium pseudoalteromonas tunicata produces an antibacterial and autolytic protein, alpp, which causes death of a subpopulation of cells during biofilm formation and mediates differentiation, dispersal, and phenotypic variation among dispersal cells. the alpp homologue (loda) in the marine bacterium marinomonas mediterranea was recently identified as a lysine oxidase which mediates cell death through the production of hydrogen peroxide. here we show that alpp in p. tunicata also act ...200818502869
the macromolecule with antimicrobial activity synthesized by pseudoalteromonas luteoviolacea strains is an l-amino acid oxidase.two purple pigmented bacterial strains, cpmor-1 and cpmor-2, have been newly isolated from the mediterranean sea. 16s rna sequencing and phenotypic characteristics indicate that they belong to the species pseudoalteromonas luteoviolacea. the synthesis of macromolecules with antimicrobial activity is a capacity described in many strains of this species although the nature of those macromolecules has not been reported up to now. the search for antimicrobial compounds in the two new strains describ ...200818504575
short peptide induces an "uncultivable" microorganism to grow in vitro.microorganisms comprise the bulk of biodiversity, but only a small fraction of this diversity grows on artificial media. this phenomenon was noticed almost a century ago, repeatedly confirmed, and termed the "great plate count anomaly." advances in microbial cultivation improved microbial recovery but failed to explain why most microbial species do not grow in vitro. here we show that at least some of such species can form domesticated variants capable of growth on artificial media. we also pres ...200818515474
histopathology of antarctic krill, euphausia superba, bearing black spots.small black spots have been noticed on the cephalothorax of antarctic krill, euphausia superba, since january, 2001. to study the nature of the black spots, the krill were sampled in the winter of 2003, 2006, and 2007 in the south georgia region, the antarctic ocean. histological observations revealed that the black spots were melanized nodules that were composed of hemocytes surrounding either bacteria or amorphous material. in the 2007 samples, 42% of the krill had melanized nodules. most of t ...200818534613
emulsifying and metal ion binding activity of a glycoprotein exopolymer produced by pseudoalteromonas sp. strain tg12.in this study, we describe the isolation and characterization of a new exopolymer that exhibits high emulsifying activities against a range of oil substrates and demonstrates a differential capacity to desorb various mono-, di-, and trivalent metal species from marine sediment under nonionic and seawater ionic-strength conditions. this polymer, pe12, was produced by a new isolate, pseudoalteromonas sp. strain tg12 (accession number ef685033), during growth in a modified zobell's 2216 medium amen ...200818552188
[antibacterial activity of sponge associated marine bacterium pseudoalteromonas sp. nj6-3-1 regulated by quorum sensing].we chose a sponge-associated marine-bacterium pseudoalteromonas piscicida nj6-3-1 to study whether its antibacterial activity were regulated by quorum sensing.200818590244
quorum sensing signaling molecules involved in the production of violacein by pseudoalteromonas.the production of violacein by pseudoalteromonas sp. 520p1 has many features of quorum sensing. signaling molecules were extracted from bacterial culture and subsequently identified as n-(3-oxooctanoyl)-homoserine lactone and n-tetradecanoyl-homoserine lactone. the former but not the latter induced the production of violacein in strain 520p1. we conclude that n-(3-oxooctanoyl)-homoserine lactone is a signaling molecule involved in the production of violacein.200818603795
a quick in vitro pathway from prokaryotic genomic libraries to enzyme discovery.screening of prokaryotic genomes in order to identify enzymes with a desired catalytic activity can be performed in vivo in bacterial cells. we propose a strategy of in vitro expression screening of large prokaryotic genomic libraries based on escherichia coli cell-free transcription-translation systems. because cell-based expression may be limited by poor yield or protein misfolding, cell-free expression systems may be advantageous in permitting a more comprehensive screen under conditions opti ...200818611168
molecular characterization of a cryptic plasmid from the psychrotrophic antarctic bacterium pseudoalteromonas sp. 643a.we report the identification and nucleotide sequence analysis of pkw1, a plasmid of the psychrotrophic bacterium pseudoalteromonas sp. 643a isolated from the stomach of antarctic krill euphasia superba. pkw1 consists of 4583 bp, has a g+c content of 43% and seven putative open reading frames (orfs). the deduced amino acid sequence from orf-1 shared significant similarity with the plasmid replicase protein of psychrobacter cryohalolentis, strain k5. the dna region immediately downstream of the or ...200818611409
extracellular proteases and possible disease related virulence mechanisms of two marine bacteria implicated in an opportunistic bacterial infection of nephrops norvegicus.the extracellular products (ecp) secreted by two strains of gram-negative bacteria isolated from nephrops norvegicus exhibiting signs of an opportunistic bacterial infection were investigated with the objective of understanding their role in the spoilage of host muscle tissue and identifying disease related virulence mechanisms. ecp from vibrio sp. demonstrated no proteolytic activity. ecp from pseudoalteromonas sp. (isolate n10) degraded several substrates, including azocasein and host muscle t ...200818617185
dose-dependent significance of monosaccharides on intracellular alpha-l-rhamnosidase activity from pseudoalteromonas sp.intracellular alpha-l-rhamnosidase (ec 3.2.1.40) from the psychrotolerant pseudoalteromonas sp. 005nj showed a dose-dependent inhibition for l-rhamnose (ic(50) = 20 mm) and d-ribose (ic(50) = 95 mm), whereas d-glucose and l-fucose presented a lower inhibition, with ic(50) values as high as >0.5 and >0.2 m, respectively. on the other hand, d-fructose enhanced enzyme activity threefold, reaching a plateau of maximum specific activity between 0.2 and 0.4 m of this monosaccharide. both effects, low ...200818663413
extracellular proteases from the antarctic marine pseudoalteromonas sp. p96-47 strain.the extracellular protease-production capacity of 33 bacterial isolates taken from marine biotopes in king george island, antarctica, was evaluated in liquid cultures. the p96-47 isolate was selected due to its high production capacity and was identified as pseudoalteromonas sp. the optimal growth temperature was 20 degrees c and the optimal for protease production was 15 degrees c. proteases were purified from culture supernatants, developing a multiple-band profile in zymograms. they were clas ...200818669056
extracellular secretion of pseudoalteromonas sp. cold-adapted esterase in escherichia coli in the presence of pseudoalteromonas sp. components of abc transport system.recently we described identification and characterization of gdsl esterase esta from psychrotrophic bacterium pseudoalteromonas sp. 643a. attempts to obtain heterologous overexpression of this enzyme in escherichia coli system were not satisfactory. the esta protein was expressed as inclusion bodies, most of that were inactive after purification step, and the recovery of esterolytic activity was very low after refolding. based on the sequence analysis we found that the esterase esta gene is clus ...200818700165
optimization of kappa-carrageenase production by pseudoalteromonas sp. aj5.to optimize the culture conditions of pseudoalteromonas sp. aj5 for a higher production of extracellular kappa-carrageenase.200818720840
pseudoalteromonas arctica sp. nov., an aerobic, psychrotolerant, marine bacterium isolated from spitzbergen.a novel aerobic, psychrotolerant marine bacterium was isolated at 4 degrees c from seawater samples collected from spitzbergen in the arctic. the strain was a polar-flagellated, gram-negative bacterium that grew optimally at 10-15 degrees c and ph 7-8 in media containing 2-3% nacl (w/v), using various carbohydrates and organic acids as substrates. the main fatty acid components included 16:0 (12.7% of total fatty acids), straight-chain saturated fatty acid methyl ester (fame) and 16:1omega7c (40 ...200818768597
a novel extracellular phospholipase c purified from a marine bacterium, pseudoalteromonas sp. j937.marine bacterial isolates were screened for phospholipase c (plc) activity on pcy agar plates containing phosphatidylcholine (pc) as substrate. the strain that showed the highest activity on a pcy screening agar plate and a thin-layer chromatography was identified as a strain of pseudoalteromonas and subsequently designated pseudoalteromonas sp. j937. the extracellular plc of the strain j937 was purified to a specific activity of 33 u mg(-1) protein by serial ion exchange and gel filtration colu ...200918784905
analysis of the pseudoalteromonas tunicata genome reveals properties of a surface-associated life style in the marine environment.colonisation of sessile eukaryotic host surfaces (e.g. invertebrates and seaweeds) by bacteria is common in the marine environment and is expected to create significant inter-species competition and other interactions. the bacterium pseudoalteromonas tunicata is a successful competitor on marine surfaces owing primarily to its ability to produce a number of inhibitory molecules. as such p. tunicata has become a model organism for the studies into processes of surface colonisation and eukaryotic ...200818813346
purification and characterization of antibacterial substances produced by a marine bacterium pseudoalteromonas haloplanktis strain.to purify and characterize compounds with antimicrobial activity from pseudoalteromonas haloplanktis inhibition (inh) strain.200818828792
larval settlement of the common australian sea urchin heliocidaris erythrogramma in response to bacteria from the surface of coralline algae.bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. here we tested the effects of biofilms on settlement of the sea urchin heliocidaris erythrogramma. larvae settled on many surfaces including various algal species, rocks, sand and shells. settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. these results, and molecular and culture-based analyses, suggested that the bacterial community on ...200616794830
hydrolysis of insoluble collagen by deseasin mcp-01 from deep-sea pseudoalteromonas sp. sm9913: collagenolytic characters, collagen-binding ability of c-terminal polycystic kidney disease domain, and implication for its novel role in deep-sea sedimentary particulate organic nitrogen degradation.collagens are the most abundant proteins in marine animals and their degradation is important for the recycling of marine nitrogen. however, it is rather unclear how marine collagens are degraded because few marine collagenolytic proteases are studied in detail. deseasins are a new type of multidomain subtilases. here, the collagenolytic activity of deseasin mcp-01, the type example of deseasins, was studied. mcp-01 had broad substrate specificity to various type collagens from terrestrial and m ...200818977758
selective control of the prorocentrum minimum harmful algal blooms by a novel algal-lytic bacterium pseudoalteromonas haloplanktis afmb-008041.in this study, we examined the algal-lytic activities and biological control mechanisms of pseudoalteromonas haloplanktis afmb-08041, which was isolated from surface seawater obtained at masan bay in korea. in addition, we assessed whether afmb-08041 could be used as a biocontrol agent to regulate harmful dinoflagellate prorocentrum minimum. from these experiments, we found that the inoculation of afmb-08041 at a final density of 2.5 x 10(4) cfu ml(-1) caused p. minimum cells to degrade (>90%) w ...200919048341
resource patch formation and exploitation throughout the marine microbial food web.exploitation of microscale (microm-mm) resource patches by planktonic microorganisms may influence oceanic trophodynamics and nutrient cycling. however, examinations of microbial behavior within patchy microhabitats have been precluded by methodological limitations. we developed a microfluidic device to generate microscale resource patches at environmentally realistic spatiotemporal scales, and we examined the exploitation of these patches by marine microorganisms. we studied the foraging respon ...200919053839
molecular cloning, expression and characterization of alpha-amylase gene from a marine bacterium pseudoalteromonas sp. my-1.a gene (amya) encoding an extracellular alpha-amylase from a marine bacterium pseudoalteromnonas sp. my-1 was cloned and expressed in escherichia coli. it comprised an open-reading-frame of 2,007 base pairs and encoded a protein of 669 amino acids with a predicted molecular weight of 73,770 daltons and a pi of 5.15. the entire amino acid sequence of amya gene showed 86% similarity to the alpha-amylase preproprotein from pseudoalteromonas haloplanktis. it consisted of a signal peptide, alpha-amyl ...200819069841
engineered marine antarctic bacterium pseudoalteromonas haloplanktis tac125: a promising micro-organism for the bioremediation of aromatic compounds.the recombinant antarctic pseudoalteromonas haloplanktis tac125 (p. haloplanktis tac/tou) expressing toluene-o-xylene monooxygenase (tomo) can efficiently convert several aromatic compounds into their corresponding catechols in a broad range of temperature. when the genome of p. haloplanktis tac125 was analysed in silico, the presence of a dna sequence coding for a putative laccase-like protein was revealed. it is well known that bacterial laccases are able to oxidize dioxygenated aromatic compo ...200919120609
characterisation of an extracellular vibriolysin of the fish pathogen moritella viscosa.moritella viscosa causes winter ulcer disease in salmonids. the aim of the present work was to isolate and partially characterise an extracellular peptidase from m. viscosa, and to study its role in virulence. the peptidase, termed mvp1, was a 38-kda metallopeptidase produced in late exponential growth. the optimum temperature for mvp1 was 40 degrees c, but the enzyme was active over a broad range of temperatures. mvp1 was non-lethal to salmon at concentrations up to 0.22microg/g fish, but extra ...200919147307
production of oligosaccharide from alginate using pseudoalteromonas agarovorans.a marine bacterium was isolated from seawater near the korean south coast for efficient saccharification from alginate. based on 16s rdna sequence, the isolated strain was identified as pseudoalteromonas agarovorans. various environmental factors affecting saccharification of alginate using p. agarovorans cho-12 have been investigated in flask cultures. the optimum concentration of sugar was obtained at 30 rpm and 29 degrees c. among various nacl concentrations, when nacl concentration was incre ...200919160071
[enrichment and diversity analyis of arsenite-resistant bacteria in deep sea sediment samples from southwest indian ocean ridge].the aim of this study was to assess the diversity of arsenite-resistant bacteria in deep sea sediment of the southwest indian ocean ridge.200819160816
coral mucus-associated bacteria: a possible first line of defense.interactions among microorganisms found in coral mucus can be either symbiotic or competitive. it has been hypothesized that microbial communities found on the surface of coral play a role in coral holobiont defense, possibly through production of antimicrobial substances. selected microorganisms isolated from the mucus layer of a number of coral species were grown using agar-plating techniques. screening for antimicrobial substances was performed using overlay and drop techniques, employing sev ...200919161430
co-immunopurification of multiprotein complexes containing rna-degrading enzymes.co-immunopurification is a classical technique in which antiserum raised against a specific protein is used to purify a multiprotein complex. we describe work from our laboratory in which co-immunopurification was used to characterize the rna degradosome of escherichia coli, a multiprotein complex involved in rna processing and mrna degradation. polyclonal rabbit antibodies raised against either rnase e or pnpase, two rna degrading enzymes in the rna degradosome, were used in co-immunopurificati ...200819161838
antimicrobial properties of resident coral mucus bacteria of oculina patagonica.the inhibitory properties of the microbial community of the coral mucus from the mediterranean coral oculina patagonica were examined. out of 156 different colony morphotypes that were isolated from the coral mucus, nine inhibited the growth of vibrio shiloi, a species previously shown to be a pathogen of this coral. an isolate identified as pseudoalteromonas sp. was the strongest inhibitor of v. shiloi. several isolates, especially one identified as roseobacter sp., also showed a broad spectrum ...200919191871
biofilms.biofilms of bacteria, frequently in association with algae, protozoa and fungi, are found on all submerged structures in the marine environment. although it is likely that for the majority of organisms a biofilmed surface is not a pre-requisite for settlement, in practice, colonization by spores and larvae of fouling organisms almost always takes place via a biofilmed surface. therefore, the properties of the latter may be expected to influence colonization, positively or negatively. biofilms ar ...200616805442
isolation, phylogenetic analysis and screening of marine mollusc-associated bacteria for antimicrobial, hemolytic and surface activities.this study was undertaken to survey culturable heterotrophic bacteria associated with the marine ark shell anadara broughtoni inhabiting in the sea of japan, and to test isolates for their antimicrobial, hemolytic and surface activities with an emphasis on low-molecular-weight metabolites search. a total of 149 strains were isolated and identified phenotypically. a total of 27 strains were selected to be investigated phylogenetically by 165 rrna gene sequence analysis. the most bacteria were aff ...200819216104
novel use for the osmolyte trimethylamine n-oxide: retaining the psychrophilic characters of cold-adapted protease deseasin mcp-01 and simultaneously improving its thermostability.the low thermostability of cold-adapted enzymes is a main barrier for their application. a simple and reliable method to improve both the stability and the activity of cold-adapted enzymes is still rare. as a protein stabilizer, the effect of trimethylamine n-oxide (tmao) on a cold-adapted enzyme or protein has not been reported. in this study, effects of tmao on the structure, activity, and stability of a cold-adapted protease, deseasin mcp-01, were studied. deseasin mcp-01 is a new type of sub ...200919255806
detection of uvbr-sensitive and -tolerant bacteria in surface waters of the western north pacific.in order to evaluate the effects of solar ultraviolet radiation (uvr) on eubacterial community composition, we examined the tolerance of eubacterial phylotypes to solar uv radiation in surface waters of the western north pacific during september 2005. bromodeoxyuridine (brdu), a halogenated thymine analogue, was used for labeling newly synthesized dna in proliferating cells. thymine dimers (td), which are specifically formed in dna by biologically harmful ultraviolet b radiation (uvbr; 280-315nm ...200919285879
diversity of both the cultivable protease-producing bacteria and their extracellular proteases in the sediments of the south china sea.protease-producing bacteria are known to play an important role in degrading sedimentary particular organic nitrogen, and yet, their diversity and extracellular proteases remain largely unknown. in this paper, the diversity of the cultivable protease-producing bacteria and their extracellular proteases in the sediments of the south china sea was investigated. the richness of the cultivable protease-producing bacteria reached 10(6) cells/g in all sediment samples. analysis of the 16s rrna gene se ...200919301066
accelerator analysis of tributyltin adsorbed onto the surface of a tributyltin resistant marine pseudoalteromonas sp. cell.tributyltin (tbt) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. we isolated a tbt resistant marine pseudoalteromonas sp. tbt1 from sediment of a ship's ballast water. the isolate (10(9.3 +/- 0.2) colony-forming units ml(-1)) adsorbed tbt in proportion to the concentrations of tbtcl externally added up to 3 mm, where the number of tbt adsorbed by a single cell was estimated to be 10(8.2). the value was reduced to about one-fifth ...200819325731
anti-methicillin-resistant staphylococcus aureus (mrsa) activity of mc21-b, an antibacterial compound produced by the marine bacterium pseudoalteromonas phenolica o-bc30t.the aim of this study was to purify, characterise and evaluate the in vitro activity of mc21-b, an antibiotic produced by the marine bacterium pseudoalteromonas phenolica o-bc30(t). mc21-b was purified by sequential silica and cosmosil chromatography followed by high-performance liquid chromatography (hplc). the chemical structure of mc21-b was determined by ultraviolet, infrared, electron impact mass and nuclear magnetic resonance spectrometric analyses. to evaluate its antibacterial activity, ...200919329285
evaluation of various metallic coatings on steel to mitigate biofilm formation.in marine environments and water systems, it is easy for many structures to form biofilms on their surfaces and to be deteriorated due to the corrosion caused by biofilm formation by bacteria. the authors have investigated the antibacterial effects of metallic elements in practical steels so far to solve food-related problems, using escherichia coli and staphylococcus aureus. however, from the viewpoint of material deterioration caused by bacteria and their antifouling measures, we should consid ...200919333421
molecular phylogeny and modular structure of hybrid nrps/pks gene fragment of pseudoalteromonas sp. nj6-3-2 isolated from marine sponge hymeniacidon perleve.among 12 marine bacterial strains from the china coast that exhibited interesting bioactivity (positive for both antimicrobial and cytotoxic activities), only four strains, namely, nj6-3-1, nj6-3-2, nb-6, and ythm-17, had a ks domain or a domain when screened for pks and nrps genes using a pcr. interestingly, two of these strains belonging to pseudoalteromonas and associated with the marine sponge hymeniacidon perleve were positive for both pks and nrps, whereas the other two strains of pseudoal ...200919349747
[biosorption of pb2+ and cu2+ by an exopolysaccharide from the deep-sea psychrophilic bacterium pseudoalteromonas sp. sm9913].biosorption of pb2+ and cu2+ by exopolysaccharide (eps) from the deep-sea psychrophilic bacterium pseudoalteromonas sp. sm9913 was investigated. the influence of eps dosage, ph, equilibrium time and coexisted-ions on adsorption property and the adsorption isotherm of this eps were studied. the results show that the equilibrium adsorption capacity (qe) decreases with the increase of eps dosage. the optimum ph for the adsorption of pb2+ is 4.5-5.5, and for the adsorption of cu2+ is 4.5-6.0. the ad ...200919353881
sequencing and modular analysis of the hybrid non-ribosomal peptide synthase - polyketide synthase gene cluster from the marine sponge hymeniacidon perleve-associated bacterium pseudoalteromonas sp. strain nj631.in the present study, we sought to confirm a putative non-ribosomal peptide synthase (nrps) - polyketide synthase (pks) gene cluster in marine sponge-associated bacterium with cytotoxic activity and elucidate the gene's structural information. the genomic library of the marine sponge hymeniacidon perleve-associated bacterium pseudoalteromonas sp. strain nj631 was constructed using a pcc1fos fosmid. positive clones that covered the whole gene cluster region of hybrid nrps-pks were selected for sh ...200919370064
the haloprotease cpi produced by the moderately halophilic bacterium pseudoalteromonas ruthenica is secreted by the type ii secretion pathway.the gene (cpo) encoding the extracellular protease cpi produced by the moderately halophilic bacterium pseudoalteromonas ruthenica cp76 was cloned, and its nucleotide sequence was analyzed. the cpo gene encodes a 733-residue protein showing sequence similarity to metalloproteases of the m4 family. the type ii secretion apparatus was shown to be responsible for secretion of the haloprotease cpi.200919376897
microbial colonization and competition on the marine alga ulva australis.pseudalteromonas tunicata and roseobacter gallaeciensis are biofilm-forming marine bacteria that are often found in association with the surface of the green alga ulva australis. they are thought to benefit the plant host by producing inhibitory compounds that are active against common fouling organisms. we investigated factors that influence the ability of p. tunicata and r. gallaeciensis to attach to and colonize the plant surface and also the competitive interactions that occur between these ...200616885308
structure and dynamics of cold-adapted enzymes as investigated by ft-ir spectroscopy and md. the case of an esterase from pseudoalteromonas haloplanktis.psychrophiles are cold-adapted organisms that produce enzymes that display a high catalytic efficiency at low temperatures. in recent years, these low-temperature working enzymes have attracted the attention of scientists because of their peculiar properties that render them particularly useful in investigating the relationship between enzyme stability and flexibility. recently, a new esterase was identified and isolated from the cold-adapted organism pseudoalteromonas haloplanktis. the enzyme, ...200919435327
nitrogen regulates chitinase gene expression in a marine bacterium.ammonium concentration and nitrogen source regulate promoter activity and use for the transcription of chia, the major chitinase gene of pseudoalteromonas sp. s91 and s91cx, an s91 transposon lacz fusion mutant. the activity of chia was quantified by beta-galactosidase assay of s91cx cultures containing different ammonium concentrations (nh4+; 0, 9.5 or 191 mm) and with different nitrogen sources (n-acetylglucosamine (glcnac) or glutamate (glt)). s91 chia expression was found to depend on both t ...200919440232
[phylogenetic diversity of cultivable bacteria associated with a sea anemone from coast of the naozhou island in zhanjiang, china].to understand the diversity of cultivable bacteria isolated from a sea anemone collected from the coastal water of the naozbou island in the leizhou bay on south china sea.200919445182
nutrient regime regulates complex transcriptional start site usage within a pseudoalteromonas chitinase gene cluster.the chitinase gene cluster of the marine bacterium pseudoalteromonas sp. s91, chiabc, which produces the major chitinases of this sp., was transcribed as an operon and from each individual gene. chia, chib and chic were found to possess multiple transcriptional start points (tsps), the use of which was determined by the nutrient regime used for s91 growth. in minimal medium containing glutamate, chia, chib and chic each used 3, 1 and 1 tsp, respectively. upon the addition of the chitin monomer n ...200919458654
enzymatic degradation of κ-carrageenan in aqueous solution.enzymatic degradation of standard κ-carrageenan and the low-gelling hybrid κ-/μ-carrageenan were conducted using recombinant pseudoalteromonas carrageenovora κ-carrageenase. the initial velocity of the enzyme was determined as a function of varying tris or nai concentrations and at constant 200 mm cosolutes concentration, adjusting nai and tris concentrations accordingly. in both cases, we observed strong inhibition of the enzyme with increasing amounts of iodide. the characterization of the κ- ...200919459672
analysis of effects induced by a pollock protein hydrolysate on early development, innate immunity and the bacterial community structure of first feeding of atlantic halibut (hippoglossus hippoglossus l.) larvae.a pollock protein hydrolysate was used for enrichment of the live feed offered to halibut larvae from the onset of exogenous feeding and the effects of treatment on selected innate immune parameters studied. the effects of treatment on the bacterial community structure of larvae were furthermore studied using the pcr-dgge method. c3 and lysozyme were identified in larvae already at the onset of first feeding and low concentrations of igm detected at this stage indicate maternal origin. endogenou ...200919465132
a novel beta-agarase with high ph stability from marine agarivorans sp. lq48.a novel endo-type beta-agarase gene, agaa, was cloned from a newly isolated marine bacterium, agarivorans sp. lq48. it encodes a protein of 457 amino acids with a calculated molecular mass of 51.2 kda. the deduced protein contains a typical n-terminal signal peptide of 25 amino acid residues, followed by a catalytic module, which is homologous to that of glycoside hydrolase family 16. a sequence similar to a carbohydrate-binding module is found in the c-terminal region of the enzyme. the overall ...201019484308
cloning, expression and characterization of a new agarase-encoding gene from marine pseudoalteromonas sp.the beta-agarase gene agaa, cloned from a marine bacterium, pseudoalteromonas sp. cy24, consists of 1,359 nucleotides encoding 453 amino acids in a sequence corresponding to a catalytic domain of glycosyl hydrolase family 16 (gh16) and a carbohydrate-binding module type 13 (cbm13). the recombinant enzyme is an endo-type agarase that hydrolyzes beta-1,4-linkages of agarose, yielding neoagarotetraose and neoagarohexaose as the predominant products. in two cleavage patterns, agaa digested the small ...200919504047
cold-adapted esterases and lipases: from fundamentals to application.micro-organisms that thrive at low temperatures produce cold-adapted enzymes which display high catalytic efficiency, generally associated with low thermal stability. in the recent past, researchers and industries have focused the attention on cold-adapted enzymes, whose peculiar properties make them particularly interesting either for investigating stability/flexibility relationships, or for their potential application in industrial processes. among these enzymes, lipases and esterases, have po ...200919508185
quantification of water and biomass in small colony variant pao1 biofilms by confocal raman microspectroscopy.the raman spectra, water content, and biomass density of wild-type (wt) pseudomonas aeruginosa pao1, small colony variant (scv) pao1, and pseudoalteromonas sp. ncimb 2021 biofilms were compared in order to determine their variation with strain and species. living, fully submerged biofilms were analyzed in situ by confocal raman microspectroscopy for up to 2 weeks. water to biomass ratios (w/brs), which are the ratios of the o-h stretching vibration of water at 3,450 cm(-1) to the c-h stretching ...200919529929
biodegradation of crude oil by an arctic psychrotrophic bacterium pseudoalteromomas sp. p29.a psychrotrophic petroleum-degrading bacterium pseudoalteromonas sp. p29 was isolated from marine sediment, which was collected during 2nd chinese arctic scientific expedition. the phenotypic character and biodegradation efficiency on mixed oil or vacuum oil were tested at low temperature. the strain pseudoalteromonas sp. p29 grew in a range of temperature from 5 to 35 degrees c and the optimum temperature was 25 degrees c. gas chromatography analysis indicated that the strain might preferential ...200919543945
molecular analysis of the gene encoding a cold-adapted halophilic subtilase from deep-sea psychrotolerant bacterium pseudoalteromonas sp. sm9913: cloning, expression, characterization and function analysis of the c-terminal ppc domains.only a few cold-adapted halophilic proteases have been reported. here, the gene mcp03 encoding a cold-adapted halophilic protease mcp-03 was cloned from deep-sea psychrotolerant bacterium pseudoalteromonas sp. sm9913, which contains a 2,130-bp orf encoding a novel subtilase precursor. the recombinant mcp-03, expressed in escherichia coli bl21 and purified from fermented broth, is a multi-domain protein with a catalytic domain and two ppc domains. compared to mesophilic subtilisin carlsberg, mcp- ...200919544039
diterpenoids from the mediterranean brown alga dictyota sp. evaluated as antifouling substances against a marine bacterial biofilm.four new cyclized diterpenes, one xenicane (1) and three dolabellanes (2-4), were isolated, along with seven previously reported metabolites [3beta-hydroxydilophol (5), dictyols e (6) and c (7), hydroxycrenulide (8), 9-acetoxy-15-hydroxy-1,6-dollabelladiene (9), hydroxyacetyldictyolal (10), and fucoxanthin], from a mediterranean species of dictyota sp. collected in le brusc lagoon (french mediterranean coast). their structures, as well as their relative configurations, were determined through ex ...200919548693
influence of bacterial lysate quality on growth of two bacterioplankton species.all physico-chemical parameters that affect bacterial growth rate will also affect bacterial molecular composition, which in turn influences the chemical composition of bacterial lysate and its turnover rate in the ecosystem. to produce qualitatively different lysates, vibrio sp. cells were grown under different ph, salt, or temperature conditions in rich growth media and then washed and lysed by autoclaving. both the absolute concentrations and the ratios between elements in the lysates varied ...201019582501
molecular cloning and functional expression of a new amylosucrase from alteromonas macleodii.the presence of amylosucrase in 12 alteromonas and pseudoalteromonas strains was examined. two alteromonas species (alteromonas addita kctc 12195 and alteromonas macleodii kctc 2957) possessed genes that had high sequence homology to known amylosucrases. genomic clones containing the asase analogs were obtained from a. addita and a. macleodii, and the deduced amino acid sequences of the corresponding genes (aaas and amas, respectively) revealed that they were highly similar to the asases of neis ...200919584557
an assessment of bacterial dysbiosis in pouchitis using terminal restriction fragment length polymorphisms of 16s ribosomal dna from pouch effluent microbiota.previous studies on dysbiosis and pouchitis using conventional culture techniques have been disappointing because of inherent limitations associated with the technique. this study was designed to use terminal restriction fragment length polymorphism to evaluate patients with and without pouchitis.200919617766
molecular characterization and therapeutic potential of a marine bacterium pseudoalteromonas sp. kmm 701 alpha-galactosidase.an alpha-galactosidase capable of converting b red blood cells into the universal blood type cells at the neutral ph was produced by a novel obligate marine bacterium strain kmm 701 (vkm b-2135 d). the organism is heterotrophic, aerobic, and halophilic and requires na+ ions and temperature up to 34 degrees c for its growth. the strain has a unique combination of polysaccharide-degrading enzymes. its single intracellular alpha-galactosidase exceeded other glycoside hydrolases in the level of expr ...201019629597
cellulase production from pseudoalteromonas sp. no3 isolated from the sea squirt halocynthia rorentzi.pseudoalteromonas sp. no3 was isolated from the hemolymph of diseased sea squirts (halocynthia rorentzi) with symptoms of soft tunic syndrome. the strain was found to produce an extracellular cellulase (cely) that consisted of a 1,476 bp open reading frame encoding 491 amino acid residues with an approximate molecular mass of 52 kda. homologies of the deduced amino acid sequence of cely with the products of the cela, celx, celg and cel5z genes were 92.6, 93.3, 92.6, and 59.1%, respectively. addi ...200919639353
identification of the transcription factor responsible for l-malate-dependent regulation in the marine antarctic bacterium pseudoalteromonas haloplanktis tac125.two-component systems are widespread in nature and constitute the most common mechanism of transmembrane signal transduction in bacteria. recently, a functionally active two-component system consisting of mals and malr genes possibly involved in the expression of a c4-dicarboxylate transporter system (dctab operon) was identified in the marine antarctic bacterium pseudoalteromonas haloplanktis tac125. in this paper, we performed a functional analysis of the two-component system and demonstrated ...200919646180
repulsion and metabolic switches in the collective behavior of bacterial colonies.bacteria inoculated on surfaces create colonies that spread out, forming patterns shaped by their mutual interactions. here, by a combination of experiments and modeling, we address two striking phenomena observed when colonies spread out circularly, without dendritic instabilities. first, the velocity of spreading is generically found to decrease as levels of nutrients initially deposited on the surface increase. we demonstrate that the slowdown is due to phenomena of differentiation, leading t ...200919651027
site-specific insertion of is492 in pseudoalteromonas atlantica.reversible insertion of is492 at a site within epsg on the pseudoalteromonas atlantica chromosome controls peripheral extracellular polysaccharide production and biofilm formation by p. atlantica. high-frequency precise excision of is492 from epsg requires 5 and 7 bp of flanking dna, suggesting that is492 transposition involves a site-specific recombination mechanism. the site specificity of is492 insertion was examined in p. atlantica and shown to be specific for a 7-bp target, 5'-cttgtta-3'. c ...200919684137
structure of a polysaccharide from the lipopolysaccharides of vibrio vulnificus strains cect 5198 and s3-i2-36, which is remarkably similar to the o-polysaccharide of pseudoalteromonas rubra atcc 29570.high-molecular-mass polysaccharides were released by mild acid degradation of the lipopolysaccharides of two wild-type vibrio vulnificus strain, a flagellated motile strain cect 5198 and a non-flagellated non-motile strain s3-i2-36. studies by sugar analysis and partial acid hydrolysis along with (1)h and (13)c nmr spectroscopies showed that the polysaccharides from both strains have the same trisaccharide repeating unit of the following structure: -->4)-beta-d-glcpnac3nacylan-(1-->4)-alpha-l-ga ...200919695563
antifouling activities expressed by marine surface associated pseudoalteromonas species.abstract members of the marine bacterial genus pseudoalteromonas have been found in association with living surfaces and are suggested to produce bioactive compounds against settlement of algal spores, invertebrate larvae, bacteria and fungi. to determine the extent by which these antifouling activities and the production of bioactive compounds are distributed amongst the members of the genus pseudoalteromonas, 10 different pseudoalteromonas species mostly derived from different host organisms w ...200219709238
effect of bacterial epiflora on egg hatching of the atlantic sardine (sardina pilchardus).the aim of this work was to study the influence of bacterial epiflora on egg hatching of the sardine (sardina pilchardus) obtained from a natural environment (ría de vigo, spain) during the spawning season of the sardine (from january to june). total bacteria, viable bacteria or the presence of specific potential pathogens for eggs, such as pseudoalteromonas piscicida and tenacibaculum (flexibacter) ovolyticus, did not affect the viability of sardine eggs. additionally, no relationship was obser ...200419712369
pseudoalteromonas bacteria are capable of degrading paralytic shellfish toxins.marine bacterial isolates cultured from the digestive tracts of blue mussels (mytilus edulis) contaminated with paralytic shellfish toxins (psts) were screened for the ability to reduce the toxicity of a pst mixture. seven isolates reduced the overall toxicity of the algal extract by > or = 90% within 3 days. these isolates shared at least 99% 16s rrna gene sequence similarity with five pseudoalteromonas spp. phenotypic tests suggested that all are novel strains of pseudoalteromonas haloplanktis ...200919717625
a novel enzyme, lambda-carrageenase, isolated from a deep-sea bacterium.a lambda-carrageenan-degrading pseudoalteromonas bacterium, strain cl19, was isolated from a deep-sea sediment sample. a lambda-carrageenase from the isolate was purified to homogeneity from cultures containing lambda-carrageenan as a carbon source. this is the first report of the isolation of lambda-carrageenase together with the gene sequence for the enzyme. the molecular mass of the purified enzyme was approximately 100 kda on both sds-page and gel-filtration chromatography, suggesting that t ...200616926183
characterization of proteolytic bacteria from the aleutian deep-sea and their proteases.six deep-sea proteolytic bacteria taken from aleutian margin sediments were screened; one of them produced a cold-adapted neutral halophilic protease. these bacteria belong to pseudoalteromonas spp., which were identified by the 16s rdna sequence. of the six proteases produced, two were neutral cold-adapted proteases that showed their optimal activity at ph 7-8 and at temperature close to 35 degrees c, and the other four were alkaline proteases that showed their optimal activity at ph 9 and at t ...200716932887
inhibition of fungal colonization by pseudoalteromonas tunicata provides a competitive advantage during surface colonization.the marine epiphytic bacterium pseudoalteromonas tunicata produces a range of extracellular secondary metabolites that inhibit an array of common fouling organisms, including fungi. in this study, we test the hypothesis that the ability to inhibit fungi provides p. tunicata with an advantage during colonization of a surface. studies on a transposon-generated antifungal-deficient mutant of p. tunicata, fm3, indicated that a long-chain fatty acid-coenzyme a ligase is involved in the production of ...200616957232
an effective cold inducible expression system developed in pseudoalteromonas haloplanktis tac125.a regulative two-component system previously identified in pseudoalteromonas haloplanktis tac125 was used to construct a cold inducible expression system that is under the control of l-malate. performances of the inducible system were tested for both psychrophilic and mesophilic protein production using two "difficult" proteins as control. the results obtained demonstrated that both psychrophilic beta-galactosidase and yeast alpha-glucosidase are produced in a fully soluble and catalytically com ...200716959351
a novel genetic system for recombinant protein secretion in the antarctic pseudoalteromonas haloplanktis tac125.the final aim of recombinant protein production is both to have a high specific production rate and a high product quality. it was already shown that using cold-adapted bacteria as host vectors, some "intractable" proteins can be efficiently produced at temperature as low as 4 degrees c.200617169153
fish protein hydrolysis by a psychrotrophic marine bacterium isolated from the gut of hake (merluccius hubbsi).the aims of this study were to identify a psychrotrophic bacterium, strain cr41, producing a cold adapted protease during growth at low temperatures and to evaluate the ability of the cells to hydrolyze hake fish protein. the strain was isolated from the intestinal tract of hake collected from the san jorge gulf (patagonia, argentina) and it was identified as pseudoalteromonas. growth and fish protein hydrolysis were determined using an aerated simple mineral medium plus 10% fish protein concent ...200617473897
diversity and enzyme properties of protease-producing bacteria isolated from sub-antarctic sediments of isla de los estados, argentina.protease-producing bacteria isolated from sub-antarctic marine sediments of isla de los estados (argentina) were characterized, and the thermal inactivation kinetics of their extracellular proteases compared. isolates were affiliated with the genera pseudoalteromonas, shewanella, colwellia, planococcus, and a strain to the family flavobacteriaceae. colwellia strains were moderate psychrophiles (optimal growth at about 15 degrees c, maximum growth temperature at around 25 degrees c). 16s rrna phy ...200717487446
molecular investigation of the distribution, abundance and diversity of the genus pseudoalteromonas in marine samples.the genus pseudoalteromonas has attracted interest because it has frequently been found in association with eukaryotic hosts, and because many pseudoalteromonas species produce biologically active compounds. one distinct group of pseudoalteromonas species is the antifouling subgroup containing pseudoalteromonas tunicata and ps. ulvae, which both produce extracellular compounds that inhibit growth and colonization by different marine organisms. pcr primers targeting the 16s rrna gene of the genus ...200717573938
the linker region plays a key role in the adaptation to cold of the cellulase from an antarctic bacterium.the psychrophilic cellulase, cel5g, from the antarctic bacterium pseudoalteromonas haloplanktis is composed of a catalytic module (cm) joined to a carbohydrate-binding module (cbm) by an unusually long, extended and flexible linker region (lr) containing three loops closed by three disulfide bridges. to evaluate the possible role of this region in cold adaptation, the lr was sequentially shortened by protein engineering, successively deleting one and two loops of this module, whereas the last di ...200717635108
inhibition of fouling by marine bacteria immobilised in kappa-carrageenan beads.antifouling solutions that leave little or no impact in the world's oceans are constantly being sought. this study employed the immobilisation of the antifouling bacterium pseudoalteromonas tunicata in kappa-carrageenan to demonstrate how a surface may be protected from fouling by bacteria, i.e. a 'living paint'. attempts so far to produce a 'living paint' have been limited in both longevity of effectiveness and demonstration of applicability, most noticeably regarding the lack of any field data ...200717653938
biodegradative potential and characterization of psychrotolerant polychlorinated biphenyl-degrading marine bacteria isolated from a coastal station in the terra nova bay (ross sea, antarctica).antarctic marine bacteria were screened for their ability to degrade polychlorinated biphenyls (pcb) as the sole carbon and energy source at both 4 degrees c and 15 degrees c. pcb-degrading isolates (7.1%) were identified by sequencing their 16s rdna as pseudoalteromonas, psychrobacter and arthrobacter members. one representative isolate per genera was selected for evaluating the biodegradative potential under laboratory scale and phenotypically characterized. removal of individual pcb congeners ...200717854841
isolation and characterization of two groups of novel marine bacteria producing violacein.thirteen strains of novel marine bacteria producing a purple pigment were isolated from the pacific coast of japan. they were divided into two groups based on their 16s ribosomal rna gene sequences, and both groups of bacteria belonged to the genus pseudoalteromonas. the uv-visible spectrum of the pigment was identical to those of violacein, a pigment produced by several species of bacteria including chromobacterium violaceum, an opportunistic pathogen. further analysis of the chemical structure ...200817968625
cholest-4-en-3-one-delta 1-dehydrogenase, a flavoprotein catalyzing the second step in anoxic cholesterol metabolism.the anoxic metabolism of cholesterol was studied in the denitrifying bacterium sterolibacterium denitrificans, which was grown with cholesterol and nitrate. cholest-4-en-3-one was identified before as the product of cholesterol dehydrogenase/isomerase, the first enzyme of the pathway. the postulated second enzyme, cholest-4-en-3-one-delta(1)-dehydrogenase, was partially purified, and its n-terminal amino acid sequence and tryptic peptide sequences were determined. based on this information, the ...200817993555
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