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[preliminary research on bacterial diversity of parece vela basin, pacific ocean by culture-independent method].the environmental dna was directly extracted from the sediment in parece vela basin, pacific ocean, at a depth of 5010 m. bacterial 16s rrna gene library of 32 clones was generated using bacterial universal primers and 16s rdna sequences were analyzed phylogenetically. 17 phylotypes were obtained. the library was dominated by gamma-proteobacteria, alpha-proteobacteria and marine uncultured bacteria. sixty-two percent of the cloned sequences was highly related to the known bacteria in the genus h ...200515847151
[cloning and expression of endoglucanase of marine cold-adapted bacteria pseudoalteromonas sp. mb-1].the cold-adapted gram-negative rod bacterium mb-1 which could secret cellulase was screened from mud of the bottom of the huanghai. according to the sequence of 16s rdna, this bacterium screened was identified as one species of pseudoalteromonas and was named as pseudoalteromonas sp. mb-1. the gene cela encoding cold-adapted endogluanase was cloned and then jointed to pgex-4t-1 to construct expression plasmid pgex-cela which was expressed in e. coli bl21. analysis to the supernatant of e. coli s ...200515847183
structure of a full length psychrophilic cellulase from pseudoalteromonas haloplanktis revealed by x-ray diffraction and small angle x-ray scattering.pseudoalteromonas haloplanktis is a psychrophilic gram-negative bacterium isolated in antarctica, that lives on organic remains of algae. this bacterium converts the cellulose, highly constitutive of algae, into an immediate nutritive form by biodegrading this biopolymer. to understand the mechanisms of cold adaptation of its enzymatic components, we studied the structural properties of an endoglucanase, cel5g, by complementary methods, x-ray crystallography and small angle x-ray scattering. usi ...200515854656
the complete structure of the core carbohydrate backbone from the lps of marine halophilic bacterium pseudoalteromonas carrageenovora type strain iam 12662t.the complete novel structure of the components of the core oligosaccharide fraction from the los of the halophilic marine bacterium pseudoalteromonas carrageenovora was characterized. the fully de-acylated lipooligosaccharide was studied by means of compositional analysis, matrix-assisted laser desorption/ionization mass spectrometry and complete (1)h and (13)c and (31)p nmr spectroscopy. the core oligosaccharide is composed by a mixture of species differing for the length of the sugar chain and ...200515878450
structure of an acidic polysaccharide from the marine bacterium pseudoalteromonas aliena type strain kmm 3562t containing two residues of l-serine in the repeating unit.the structure of an acidic polysaccharide from pseudoalteromonas aliena type strain kmm 3562(t) has been elucidated. the polysaccharide was studied by component analysis, (1)h and (13)c nmr spectroscopy, including 2d nmr experiments. a (1)h, (13)c band-selective constant-time heteronuclear multiple-bond connectivity experiment was used to determine amide linkages, between serine and uronic acid (ua) residues, via (3)j(h,c) correlations between ser-alphah and ua-c-6. it was found that the polysac ...200515882858
biodegradation of cyclic nitramines by tropical marine sediment bacteria.undersea deposition of unexploded ordnance (uxo) constitutes a potential source of contamination of marine environments by hexahydro-1,3,5-trinitro-1,3,5-triazine (rdx) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (hmx). the goal of the present study was to determine microbial degradation of rdx and hmx in a tropical marine sediment sampled from a coastal uxo field in the region of oahu island in hawaii. sediment mixed cultures growing in marine broth 2216 (21 degrees c) anaerobically mi ...200515915354
identification and characterization of potentially algal-lytic marine bacteria strongly associated with the toxic dinoflagellate alexandrium catenella.the toxic dinoflagellate alexandrium catenella isolated from fjords in southern chile produces several analogues of saxitoxin and has been associated with outbreaks of paralytic shellfish poisoning. three bacterial strains, which remained in close association with this dinoflagellate in culture, were isolated by inoculating the dinoflagellate onto marine agar. the phenotypically different cultivable bacterial colonies were purified. their genetic identification was done by polymerase chain react ...200515926994
[characterization and gene cloning of the endoglucanase from pseudoalteromonas sp. dy3 strain].a bacteria strain dy3 with high endoglucanse activity was isolated from deep sea sediment sample es0109. the 16s rdna sequence of dy3 exhibits identity of 99% with those of the same genus bacteria pseudoalteromonas citrea and pseudoalteromonas elyakovii . the celx gene of dy3 obtained by pcr method is 1479bp in length and encodes a protein of 492 amino acids. the protein encoded by celx gene exhibits 95% sequence identity with endoglucanase celg from pseudoalteromonas haloplanktis. there are two ...200415969114
exocellular peptides from antarctic psychrophile pseudoalteromonas haloplanktis.a novel diketopiperazine, named cyclo-(d-pipecolinyl-l-isoleucine) (dkp 1), and 7 known diketopiperazines were isolated from the cell-free culture supernatant of the antarctic psychrophilic bacterium pseudoalteromonas haloplanktis tac125. two diketopiperazines containing pipecolinyl moiety were isolated for the first time from a natural source. two new linear peptides, stable to bacterial proteolytic enzymes, were also characterized. the structures of the isolated compounds were elucidated by me ...200515988629
degradation of crude oil by an arctic microbial consortium.the ability of a psychrotolerant microbial consortium to degrade crude oil at low temperatures was investigated. the enriched arctic microbial community was also tested for its ability to utilize various hydrocarbons, such as long-chain alkanes (n-c24 to n-c34), pristane, (methyl-)naphthalenes, and xylenes, as sole carbon and energy sources. except for o-xylene and methylnaphthalenes, all tested compounds were metabolized under conditions that are typical for contaminated marine liquid sites, na ...200515999222
effects of incubation temperature on growth and production of exopolysaccharides by an antarctic sea ice bacterium grown in batch culture.the sea ice microbial community plays a key role in the productivity of the southern ocean. exopolysaccharide (eps) is a major component of the exopolymer secreted by many marine bacteria to enhance survival and is abundant in sea ice brine channels, but little is known about its function there. this study investigated the effects of temperature on eps production in batch culture by cam025, a marine bacterium isolated from sea ice sampled from the southern ocean. previous studies have shown that ...200516000756
pseudoalteromonas spongiae sp. nov., a novel member of the gamma-proteobacteria isolated from the sponge mycale adhaerens in hong kong waters.a gram-negative, non-spore-forming, short rod-shaped bacterium (ust010723-006(t)) was isolated from the surface of the sponge mycale adhaerens in hong kong waters. cells of ust010723-006(t) did not have flagella and were non-motile. colonies were pale orange in colour, 2-4 mm in diameter, convex with a smooth surface and an entire translucent margin. gas bubbles were observed in the colonies and also in the agar matrix underneath and adjacent to the colonies. ust010723-006(t) was heterotrophic, ...200516014487
chemical characterization of exopolysaccharides from antarctic marine bacteria.exopolysaccharides (eps) may have an important role in the antarctic marine environment, possibly acting as ligands for trace metal nutrients such as iron or providing cryoprotection for growth at low temperature and high salinity. ten bacterial strains, isolated from southern ocean particulate material or from sea ice, were characterized. whole cell fatty acid profiles and 16s rrna gene sequences showed that the isolates included representatives of the genera pseudoalteromonas, shewanella, pola ...200516052372
structure-activity relationship of alginate oligosaccharides in the induction of cytokine production from raw264.7 cells.guluronate and mannuronate oligomers with various degree of polymerization were prepared from polyguluronate (pg) and polymannuronate (pm) with an alginate lyase from a pseudoalteromonas sp., and their activities to induce cytokine secretion from mouse macrophage cell line raw264.7 cells were examined. enzymatically depolymerized unsaturated alginate oligomers induced tumor necrosis factor (tnf)-alpha secretion from raw264.7 cells in a structure-depending manner, while the activities of saturate ...200516055120
the active site is the least stable structure in the unfolding pathway of a multidomain cold-adapted alpha-amylase.the cold-active alpha-amylase from the antarctic bacterium pseudoalteromonas haloplanktis (aha) is the largest known multidomain enzyme that displays reversible thermal unfolding (around 30 degrees c) according to a two-state mechanism. transverse urea gradient gel electrophoresis (tug-ge) from 0 to 6.64 m was performed under various conditions of temperature (3 degrees c to 70 degrees c) and ph (7.5 to 10.4) in the absence or presence of ca2+ and/or tris (competitive inhibitor) to identify poss ...200516109961
role of disulfide bridges in the activity and stability of a cold-active alpha-amylase.the cold-adapted alpha-amylase from pseudoalteromonas haloplanktis unfolds reversibly and cooperatively according to a two-state mechanism at 30 degrees c and unfolds reversibly and sequentially with two transitions at temperatures below 12 degrees c. to examine the role of the four disulfide bridges in activity and conformational stability of the enzyme, the eight cysteine residues were reduced with beta-mercaptoethanol or chemically modified using iodoacetamide or iodoacetic acid. matrix-assis ...200516109962
the structure of the o-polysaccharide of the pseudoalteromonas rubra atcc 29570t lipopolysaccharide containing a keto sugar.the structure of the phenol-soluble polysaccharide from pseudoalteromonas rubra type strain atcc 29570t has been elucidated using 1h and 13c nmr spectroscopy, including 2d cosy, tocsy, gnoesy, roesy, 1h,13c ghmqc and ghmbc experiments. it is concluded that the trisaccharide repeating unit of the polysaccharide has the following structure: [carbohydrate structure: see text] where sug is 2-acetamido-2,6-dideoxy-d-xylo-hexos-4-ulose, am is acetimidoyl and acyl is a malic acid residue, which is o-ac ...200516126182
characterization and gene cloning of a cold-active cellulase from a deep-sea psychrotrophic bacterium pseudoalteromonas sp. dy3.the celx gene encoding an extracellular cold-active cellulase was isolated from a psychrotrophic bacterium, which was isolated from deep-sea sediment and identified as a pseudoalteromonas species. it encoded a protein consisting of 492 amino acids with a calculated molecular mass of 52.7 kda. the celx consisted of an n-terminal catalytic domain belonging to glycoside hydrolase family 5 and a c-terminal cellulose-binding domain belonging to carbohydrate-binding module family 5. the long linker se ...200616133657
resistance of marine bacterioneuston to solar radiation.a total of 90 bacterial strains were isolated from the sea surface microlayer (i.e., bacterioneuston) and underlying waters (i.e., bacterioplankton) from two sites of the northwestern mediterranean sea. the strains were identified by sequence analysis, and growth recovery was investigated after exposure to simulated solar radiation. bacterioneuston and bacterioplankton isolates were subjected to six different exposure times, ranging from 0.5 to 7 h of simulated noontime solar radiation. followin ...200516151115
calcium influences cellular and extracellular product formation during biofilm-associated growth of a marine pseudoalteromonas sp.bacteria undergo a variety of physiological changes following a switch from planktonic growth to surface-associated biofilm growth. here, it is shown that biofilm development of a marine isolate, pseudoalteromonas sp. 1398, results in global changes in its cytosolic and extracellular proteomes. calcium influences these proteome responses, and affects the amount of surface-associated biomass and extracellular matrix material produced by pseudoalteromonas sp. 1398. four extracellular proteins, cha ...200516151201
coping with cold: the genome of the versatile marine antarctica bacterium pseudoalteromonas haloplanktis tac125.a considerable fraction of life develops in the sea at temperatures lower than 15 degrees c. little is known about the adaptive features selected under those conditions. we present the analysis of the genome sequence of the fast growing antarctica bacterium pseudoalteromonas haloplanktis tac125. we find that it copes with the increased solubility of oxygen at low temperature by multiplying dioxygen scavenging while deleting whole pathways producing reactive oxygen species. dioxygen-consuming lip ...200516169927
the thiol-disulfide oxidoreductase system in the cold-adapted bacterium pseudoalteromonas haloplanktis tac 125: discovery of a novel disulfide oxidoreductase enzyme.in prokaryotes, protein disulfide bond oxidation, reduction and isomerization are catalyzed by members of the thioredoxin superfamily, characterized by the conserved c-x-x-c motif in their active site. thioredoxins and glutaredoxins contribute to the reducing power in the cytoplasm, while the dsb system catalyzes disulfide bonds formation in the periplasmic space. this paper addresses the question of disulfide bonds formation in a cold-adapted micro-organism, pseudoalteromonas haloplanktis tac 1 ...200616179963
the o-chain structure from the lps of marine halophilic bacterium pseudoalteromonas carrageenovora-type strain iam 12662t.the o-chain polysaccharide of the lipopolysaccharide from the halophilic marine bacterium pseudoalteromonas carrageenovora iam 12662t was characterized. the structure was studied by means of chemical analysis and 2d nmr spectroscopy of the de-o-acylated lipopolysaccharide and shown to be the following:col is colitose, 3,6-di-deoxy-l-xylo-hexose.200516198323
[taxonomical study of bacteria from genera alteromonas and pseudoalteromonas isolated from black sea water and invertebrates].nineteen (19) strains of bacteria have been isolated from the black sea water and invertebrates (mollusks and actinia). most of them have been identified as alteromonas macleodii, pseudoalteromonas citrea and p. haloplanktis on the basis of polyphasic taxonomical analysis. six strains showed 96-97 % similarity to 16s rrna sequence of the known species of pseudoalteromonas and obviously belonged to new species. the studied strains have been characterized by a wide spectrum of phenotypic features ...200516250230
pseudoalteromonas byunsanensis sp. nov., isolated from tidal flat sediment in korea.a gram-negative, motile, strictly aerobic, violet-pigment-producing bacterium, designated strain fr1199t, was isolated from tidal flat sediment of byunsan, south korea. phylogenetic analysis of the 16s rrna gene sequence revealed that strain fr1199t represents a distinct line of descent within the genus pseudoalteromonas. the phenotypic features of strain fr1199t were similar to those of pseudoalteromonas phenolica and pseudoalteromonas luteoviolacea, but several physiological and chemotaxonomic ...200516280520
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
[lipid composition of novel shewanella species isolated from far eastern seas].a comparative study of the lipid composition of 26 strains (including type strains) of marine gammaproteobacteria belonging to the genera shewanella, alteromonas, pseudoalteromonas, marinobacterium, microbulbifer, and marinobacter was carried out. the bacteria exhibited genus-specific profiles of ubiquinones, phospholipids, and fatty acids, which can serve as reliable chemotaxonomic markers for tentative identification of new isolates. the studied species of the genus shewanella were distinguish ...200516400986
mage: a microbial genome annotation system supported by synteny results.magnifying genomes (mage) is a microbial genome annotation system based on a relational database containing information on bacterial genomes, as well as a web interface to achieve genome annotation projects. our system allows one to initiate the annotation of a genome at the early stage of the finishing phase. mage's main features are (i) integration of annotation data from bacterial genomes enhanced by a gene coding re-annotation process using accurate gene models, (ii) integration of results o ...200616407324
bioinformatic analysis of an unusual gene-enzyme relationship in the arginine biosynthetic pathway among marine gamma proteobacteria: implications concerning the formation of n-acetylated intermediates in prokaryotes.the n-acetylation of l-glutamate is regarded as a universal metabolic strategy to commit glutamate towards arginine biosynthesis. until recently, this reaction was thought to be catalyzed by either of two enzymes: (i) the classical n-acetylglutamate synthase (nags, gene arga) first characterized in escherichia coli and pseudomonas aeruginosa several decades ago and also present in vertebrates, or (ii) the bifunctional version of ornithine acetyltransferase (oat, gene argj) present in bacteria, a ...200616409639
crystallization and preliminary x-ray crystallographic studies of a psychrophilic subtilisin-like protease apa1 from antarctic pseudoalteromonas sp. strain as-11.the psychrophilic alkaline serine protease apa1 secreted by the antarctic psychrotroph pseudoalteromonas sp. strain as-11 consists of a subtilisin-like region (293 residues) and an additional insert region (148 residues) that does not show a sequence homology to any proteins in the rcsb protein data bank. apa1 inhibited with phenylmethanesulfonyl fluoride has been crystallized and x-ray diffraction data have been collected to 1.78 a resolution. the crystals belong to space group c2, with unit-ce ...200516511027
[inhibition of prokaryote and eukaryote cells adhesion by sea proteobacteria pseudoalteromonas nigrifaciens kmm 156 lipopolysaccharide and its fragments].the impact of pseudoalteromonas nigrifaciens kmm 156 lipopolysaccharide and its fragments on adhesion of prokaryote and eukaryote cells was studied. the lipopolysaccharide and o-specific polysaccharide identical by its structure to capsular polysaccharide lowered the number of the yersinia pseudotuberculosis bacteria attached to sheep erythrocytes and adhesion of mouse neutrophils to plastic. the kora oligosaccharide had no effect on the processes.200516526601
effect of culture conditions on mycelial growth, antibacterial activity, and metabolite profiles of the marine-derived fungus arthrinium c.f. saccharicola.the effects of culture conditions and competitive cultivation with bacteria on mycelial growth, metabolite profile, and antibacterial activity of the marine-derived fungus arthrinium c.f. saccharicola were investigated. the fungus grew faster at 30 degrees c, at ph 6.5 and in freshwater medium, while exhibited higher antibacterial activity at 25 degrees c, at ph 4.5, 5.5, and 7.5, and in 34 ppt seawater medium. the fungus grew faster in a high-nitrogen medium that contained 0.5% peptone and/or 0 ...200616538484
the antimicrobial activity of marinocine, synthesized by marinomonas mediterranea, is due to hydrogen peroxide generated by its lysine oxidase activity.marinocine is a broad-spectrum antibacterial protein synthesized by the melanogenic marine bacterium marinomonas mediterranea. this work describes the basis for the antibacterial activity of marinocine and the identification of the gene coding for this protein. the antibacterial activity is inhibited under anaerobic conditions and by the presence of catalase under aerobic conditions. marinocine is active only in culture media containing l-lysine. in the presence of this amino acid, marinocine ge ...200616547036
identification of norharman as the cytotoxic compound produced by the sponge (hymeniacidon perleve)-associated marine bacterium pseudoalteromonas piscicida and its apoptotic effect on cancer cells.marine invertebrates harbour a wealth of micro-organisms in their bodies. most of these micro-organisms can catabolize antibiotic compounds as chemical-defence compounds. these compounds not only play an important protective role for their producer and for their hosts, but also have high potential in medicinal applications. in order to discover natural anticancer products, 29 marine bacterial strains have been isolated from the sponge hymeniacidon perleve, samples of which were collected from th ...200616579793
kinetics and energetics of ligand binding determined by microcalorimetry: insights into active site mobility in a psychrophilic alpha-amylase.a new microcalorimetric method for recording the kinetic parameters k(cat), k(m) and k(i) of alpha-amylases using polysaccharides and oligosaccharides as substrates is described. this method is based on the heat released by glycosidic bond hydrolysis. the method has been developed to study the active site properties of the cold-active alpha-amylase produced by an antarctic psychrophilic bacterium in comparison with its closest structural homolog from pig pancreas. it is shown that the psychrophi ...200616580683
oligosaccharide binding in family 8 glycosidases: crystal structures of active-site mutants of the beta-1,4-xylanase pxyl from pseudoaltermonas haloplanktis tah3a in complex with substrate and product.the structures of inactive mutants d144a and e78q of the glycoside hydrolase family 8 (gh-8) endo-beta-1,4-d-xylanase (pxyl) from the antarctic bacterium pseudoalteromonas haloplanktis tah3a in complex with its substrate xylopentaose (at 1.95 a resolution) and product xylotriose (at 1.9 a resolution) have been determined by x-ray crystallography. a detailed comparative analysis of these with the apo-enzyme and with other gh-8 structures indicates an induced fit mechanism upon ligand binding wher ...200616605248
molecular level damages of low power pulsed laser radiation in a marine bacterium pseudoalteromonas carrageenovora.to study the molecular level damages in a marine bacterium, pseudoalteromonas carrageenovora, exposed to low power pulsed laser radiation from an nd:yag laser.200616620213
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
secretion of psychrophilic alpha-amylase deletion mutants in pseudoalteromonas haloplanktis tac125.the nature and location of structural features responsible for the secretion of a cold-adapted alpha-amylase in the antarctic marine bacterium pseudoalteromonas haloplanktis tac125 was studied by deletion mutagenesis of the wild-type enzyme and of chimerical proteins derived from the fusion of the alpha-amylase with a reporter enzyme. domain c of the psychrophilic alpha-amylase contains secretion features involved in extracellular targeting.200616630257
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
the nature of plant growth-promoting effects of a pseudoalteromonad associated with the marine algae laminaria japonica and linked to catalase excretion.the goal of this study was to identify a marine algae-associated bacterium isolated from laminaria japonica and investigate this microorganism's growth-promoting effects on plants.200616703683
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
psychrophilic superoxide dismutase from pseudoalteromonas haloplanktis: biochemical characterization and identification of a highly reactive cysteine residue.a psychrophilic superoxide dismutase (sod) has been characterized from the antarctic eubacterium pseudoalteromonas haloplanktis (ph). phsod is a homodimeric iron-containing enzyme and displays a high specific activity, even at low temperature. the enzyme is inhibited by sodium azide and inactivated by hydrogen peroxide; it is also very sensitive to peroxynitrite, a physiological inactivator of the human mitochondrial mn-sod. even though phsod is isolated from a cold-adapted micro-organism, its h ...200616713057
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
immunohistochemistry of great scallop pecten maximus larvae experimentally challenged with pathogenic bacteria.three challenge experiments were carried out on larvae of the great scallop pecten maximus. larvae were bath-challenged with vibrio pectenicida and 5 strains resembling vibrio splendidus and one pseudoalteromonas sp. unchallenged larvae were used as negative controls. the challenge protocol was based on the use of a multidish system, where the scallop larvae (10, 13 and 15 d post-hatching in the 3 experiments, respectively) were distributed to 2 ml wells with stagnant seawater and exposed to the ...200616724560
recombinant expression of toluene o-xylene monooxygenase (tomo) from pseudomonas stutzeri ox1 in the marine antarctic bacterium pseudoalteromonas haloplanktis tac125.the psychrophilic bacterium pseudoalteromonas haloplanktis tac125, isolated from antarctic seawater, was used as recipient for a biodegradative gene of the mesophilic pseudomonas stutzeri ox1. tou cluster, coding for toluene o-xylene monooxygenase (tomo), was successfully cloned and expressed into a "cold expression" vector. apparent catalytic parameters of the recombinant microorganisms on three different substrates were determined and compared with those exhibited by escherichia coli recombina ...200616730836
[phylogenetic diversity and cold-adaptive hydrolytic enzymes of culturable psychrophilic bacteria associated with sea ice from high latitude ocean, artic].the phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from high latitude sea (77 degrees 30'n - 81 degrees 12'n), canadian basin and greenland sea arctic, was investigated. a total of 37 psychrophilic strains were isolated using three different methods of ( i ) spread plate method: 100 microl of each dilution ice-melt sample was spreaded onto the surface of marine 2216 agar (difco laboratories, detroit, mi) and incubated for 2 to 6 weeks at 4 degrees c; ( ii ) b ...200616736573
enhanced biofilm formation and increased resistance to antimicrobial agents and bacterial invasion are caused by synergistic interactions in multispecies biofilms.most biofilms in their natural environments are likely to consist of consortia of species that influence each other in synergistic and antagonistic manners. however, few reports specifically address interactions within multispecies biofilms. in this study, 17 epiphytic bacterial strains, isolated from the surface of the marine alga ulva australis, were screened for synergistic interactions within biofilms when present together in different combinations. four isolates, microbacterium phyllosphaer ...200616751497
cell-cell and cell-surface interactions in an illuminated biofilm: implications for marine sediment stabilization.most wetted surfaces that are illuminated support a population of phototrophs. the marine sediment is no exception and there the major component of the microphytobenthic population is diatoms. these organisms are credited with stabilizing the sediment against physical disturbance by virtue of the extracellular carbohydrate polymers that they elaborate. however, diatoms synthesize and secrete several carbohydrate polymers and it is not certain which of them is involved in the stabilization proces ...200116759422
biodiversity of moderately halophilic bacteria in hypersaline habitats in egypt.screening bacteria from different saline environments in alexandria. egypt, lead to the isolation of 76 gram-negative and 14 gram-positive moderately halophilic bacteria. the isolates were characterized taxonomically for a total of 155 features. these results were analyzed by numerical techniques using simple matching coefficient (ssm) and the clustering was achieved by the unweighed pair-group method of association (upgma). at 75% similarity level the gram-negative bacteria were clustered in 7 ...200616778349
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
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
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
optimization of recombinant human nerve growth factor production in the psychrophilic pseudoalteromonas haloplanktis.the optimization of production strategy is a very useful tool to attain high level of recombinant protein at a low cost. a promising biotechnological application of psychrophilic bacteria is their use as non-conventional host for the recombinant production of useful proteins. the lowering of the expression temperature can in fact facilitate the correct folding of heterologous proteins that accumulate in insoluble form as inclusion bodies when produced in escherichia coli. an example of such "dif ...200616859797
ecological advantages of autolysis during the development and dispersal of pseudoalteromonas tunicata biofilms.in the ubiquitous marine bacterium pseudoalteromonas tunicata, subpopulations of cells are killed by the production of an autocidal protein, alpp, during biofilm development. our data demonstrate an involvement of this process in two parameters, dispersal and phenotypic diversification, which are of importance for the ecology of this organism and for its survival within the environment. cell death in p. tunicata wild-type biofilms led to a major reproducible dispersal event after 192 h of biofil ...200616885293
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
concurrence of cat and tet genes in multiple antibiotic-resistant bacteria isolated from a sea cucumber and sea urchin mariculture farm in china.a basic understanding of abundance and diversity of antibiotic-resistant microbes and their genetic determinants is necessary for finding a way to prevent and control the spread of antibiotic resistance. for this purpose, chloramphenicol and multiple antibiotic-resistant bacteria were screened from a mariculture farm in northern china. both sea cucumber and sea urchin rearing ponds were populated with abundant antibiotic-resistant bacteria, especially marine vibrios. sixty-five percent chloramph ...200616909348
characterization of outer membrane vesicles released by the psychrotolerant bacterium pseudoalteromonas antarctica nf3.pseudoalteromonas antarctica nf3 is an antarctic psychrotolerant gram-negative bacterium that accumulates large amounts of an extracellular polymeric substance (eps) with high protein content. transmission electron microscopy analysis after high-pressure freezing and freeze substitution (hpf-fs) shows that the eps is composed of a capsular polymer and large numbers of outer membrane vesicles (omvs). these vesicles are bilayered structures and predominantly spherical in shape, with an average dia ...200616913913
[a novel method of transfection of marine bacteria pseudoalteromonas espejiana with deoxyribonucleic acid of bacteriophage pm2].dna of bacteriophage pm2 is a convenient test object for studying dna-damaging genotoxic agents. the extent of dna damage can be estimated by the ability of damaged dna for transfection of host cells, marine bacterium pseudoalteromonas espejiana (pae), str. bal-31. the efficiency of transfection of pae lines maintained for long periods without freezing was found to be very low upon the use of a widely accepted transfection method developed by van der schans et al. (1971). such cultures grown in ...200616915919
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
genome characterization of lipid-containing marine bacteriophage pm2 by transposon insertion mutagenesis.bacteriophage pm2 presently is the only member of the corticoviridae family. the virion consists of a protein-rich lipid vesicle, which is surrounded by an icosahedral protein capsid. the lipid vesicle encloses a supercoiled circular double-stranded dna genome of 10,079 bp. pm2 belongs to the marine phage community and is known to infect two gram-negative pseudoalteromonas species. in this study, we present a characterization of the pm2 genome made using the in vitro transposon insertion mutagen ...200616940538
the structure of gdp-4-keto-6-deoxy-d-mannose-3-dehydratase: a unique coenzyme b6-dependent enzyme.l-colitose is a 3,6-dideoxysugar found in the o-antigens of some gram-negative bacteria such as escherichia coli and in marine bacteria such as pseudoalteromonas tetraodonis. the focus of this investigation, gdp-4-keto-6-deoxy-d-mannose-3-dehydratase, catalyzes the third step in colitose production, which is the removal of the hydroxyl group at c3' of gdp-4-keto-6-deoxymannose. it is an especially intriguing plp-dependent enzyme in that it acts as both a transaminase and a dehydratase. here we p ...200616943443
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 mannose-sensitive haemagglutinin (msha)-like pilus promotes attachment of pseudoalteromonas tunicata cells to the surface of the green alga ulva australis.this study demonstrates that attachment of the marine bacterium pseudoalteromonas tunicata to the cellulose-containing surface of the green alga ulva australis is mediated by a mannose-sensitive haemagglutinin (msha-like) pilus. we have identified an msha pilus biogenesis gene locus in p. tunicata, termed msh/1/2jklmnegfbacdopq, which shows significant homology, with respect to its genetic characteristics and organization, to the msha pilus biogenesis gene locus of vibrio cholerae. electron micr ...200617005969
lipolytic activity of antarctic cold-adapted marine bacteria (terra nova bay, ross sea).the aim of this study was to investigate the lipolytic activity of cold-adapted antarctic marine bacteria and, furthermore, the combined effect of some environmental factors on this enzymatic process.200617040228
x-ray crystallographic native sulfur sad structure determination of laminarinase lam16a from phanerochaete chrysosporium.laminarinase lam16a from phanerochaete chrysosporium was recombinantly expressed in pichia pastoris, crystallized and the structure was solved at 1.34 a resolution using native sulfur sad x-ray crystallography. it is the first structure of a non-specific 1,3(4)-beta-d-glucanase from glycoside hydrolase family 16 (gh16). p. chrysosporium is a wood-degrading basidiomycete fungus and lam16a is the predominant extracellular protein expressed when laminarin is used as the sole carbon source. the prot ...200617057348
immobilized preparation of cold-adapted and halotolerant antarctic beta-galactosidase as a highly stable catalyst in lactose hydrolysis.a cold-active beta-galactosidase of antarctic marine bacterium pseudoalteromonas sp. 22b was synthesized by an escherichia coli transformant harboring its gene and immobilized on glutaraldehyde-treated chitosan beads. unlike the soluble enzyme the immobilized preparation was not inhibited by glucose, its apparent optimum temperature for activity was 10 degrees c higher (50 vs. 40 degrees c, respectively), optimum ph range was wider (ph 6-9 and 6-8, respectively) and stability at 50 degrees c was ...200717059485
metalloid reducing bacteria isolated from deep ocean hydrothermal vents of the juan de fuca ridge, pseudoalteromonas telluritireducens sp. nov. and pseudoalteromonas spiralis sp. nov.five strains of gram-negative, rod, curved rod and spiral-shaped bacteria were isolated from the vicinity of deep ocean hydrothermal vents along the main endeavour segment of the juan de fuca ridge in the pacific ocean. all strains showed remarkable resistance to high levels of toxic metalloid oxyanions, and were capable of reducing the oxyanions tellurite and selenite to their less toxic elemental forms. phylogenetic analysis of four strains identified these isolates as close relatives of the g ...200617066332
response of bdellovibrio and like organisms (balos) to the migration of naturally occurring bacteria to chemoattractants.a dual culture-based and non-culture-based approach was applied to characterize predator bacterial groups in surface water samples collected from apalachicola bay, florida. chemotaxis drop assays were performed on concentrated samples in an effort to isolate predator bacteria by their chemotactic ability. yeast extract (ye) and casamino acids (ca) proved to be strong chemoattractants and resulted in three visibly distinct bands; however, dextrose, succinate, pyruvate, and concentrated cells of v ...200617115104
molecular cloning and characterization of a novel beta-agarase, agab, from marine pseudoalteromonas sp. cy24.agarases are generally classified into glycoside hydrolase families 16, 50, and 86 and are found to degrade agarose to frequently generate neoagarobiose, neoagarotetraose, or neoagarohexaose as the main products. in this study we have cloned a novel endo-type beta-agarase gene, agab, from marine pseudoalteromonas sp. cy24. the novel agarase encoded by agab gene has no significant sequence similarity with any known proteins including all glycoside hydrolases. it degrades agarose to generate neoag ...200717166842
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
biofilm formation by pseudoalteromonas ruthenica and its removal by chlorine.the distribution of a recently described marine bacterium, sbt 033 genbank accession no. ay723742), pseudoalteromonas ruthenica, at the seawater intake point, outfall and mixing point of an atomic power plant is described, and its ability to form biofilm was investigated. the effectiveness of the antifouling biocide chlorine in the inactivation of planktonic as well as biofilm cells of p. ruthenica was studied in the laboratory. the results show that the planktonic cells were more readily inacti ...200617178570
pseudoalteromonas marina sp. nov., a marine bacterium isolated from tidal flats of the yellow sea, and reclassification of pseudoalteromonas sagamiensis as algicola sagamiensis comb. nov.two gram-negative, motile and strictly aerobic marine bacteria were isolated from a tidal flat sediment sample obtained from dae-chun, chung-nam, korea. they were preliminarily identified as pseudoalteromonas-like bacteria, based on 16s rrna gene sequence analysis showing nearly identical sequences (>99.7 % sequence similarity) and the highest similarity (98.4 %) to the species pseudoalteromonas undina. some phenotypic features of the newly isolated strains were similar to those of members of th ...200717220433
characterization of marine bacteria and the activity of their enzyme systems involved in degradation of the algal storage glucan laminarin.the algal storage glucan laminarin is one of the most abundant carbon sources for marine prokaryotes. its degradation was investigated in bacteria isolated during and after a spring phytoplankton bloom in the coastal north sea. on average, 13% of prokaryotes detected by epifluorescence counts were able to grow in most probable number dilution series on laminarin as sole carbon source. several bacterial strains were isolated from different dilutions, and phylogenetic characterization revealed tha ...200717233748
evidence for the involvement of pathogenic bacteria in summer mortalities of the pacific oyster crassostrea gigas.a study was conducted to investigate the involvement of bacteria in oyster mortalities during summer. moribund and apparently healthy oysters were sampled during mortality events along the french coast and in rearing facilities, usually when temperature reached 19 degrees c or higher, and oysters were in the gonadal maturation phase. hemolymph samples were aseptically withdrawn and submitted to bacteriological analysis. in healthy oysters, bacteria colonized hemolymph at low concentrations depen ...200717245611
chromosomal context directs high-frequency precise excision of is492 in pseudoalteromonas atlantica.dna rearrangements, including insertions, deletions, and inversions, control gene expression in numerous prokaryotic and eukaryotic systems, ranging from phase variation of surface antigens in pathogenic bacteria to generation of ig diversity in human b cells. we report here that precise excision of the mobile element is492 from one site on the pseudoalteromonas atlantica chromosome directly correlates with phase variation of peripheral extracellular polysaccharide ((p)eps) production from off ( ...200717264213
degradation of lambda-carrageenan by pseudoalteromonas carrageenovora lambda-carrageenase: a new family of glycoside hydrolases unrelated to kappa- and iota-carrageenases.carrageenans are sulfated galactans found in the cell walls of red seaweeds. they are classified according to the number and the position of sulfate ester groups. lambda-carrageenan is the most sulfated carrageenan and carries at least three sulfates per disaccharide unit. the sole known depolymerizing enzyme of lambda-carrageenan, the lambda-carrageenase from pseudoalteromonas carrageenovora, has been purified, cloned and sequenced. sequence analyses have revealed that the lambda-carrageenase, ...200717269933
the use of functional genomics for the identification of a gene cluster encoding for the biosynthesis of an antifungal tambjamine in the marine bacterium pseudoalteromonas tunicata.a large insert library was created in escherichia coli from the dna of the surface-associated marine bacterium pseudoalteromonas tunicata. screening of the library for antifungal activity resulted in the detection and identification of a large gene cluster encoding for the biosynthesis of an antifungal tambjamine. a biosynthetic pathway has been proposed based on analysis and annotation of the gene cluster.200717298379
intrinsic halotolerance of the psychrophilic alpha-amylase from pseudoalteromonas haloplanktis.the halotolerance of a cold adapted alpha-amylase from the psychrophilic bacterium pseudoalteromonas haloplanktis (aha) was investigated. aha exhibited hydrolytic activity over a broad range of nacl concentrations (0.01-4.5 m). aha showed 28% increased activity in 0.5-2.0 m nacl compared to that in 0.01 m nacl. in contrast, the corresponding mesophilic (bacillus amyloliquefaciens) and thermostable (b. licheniformis) alpha-amylases showed a 39 and 46% decrease in activity respectively. even at 4. ...200717310272
plant carbohydrate scavenging through tonb-dependent receptors: a feature shared by phytopathogenic and aquatic bacteria.tonb-dependent receptors (tbdrs) are outer membrane proteins mainly known for the active transport of iron siderophore complexes in gram-negative bacteria. analysis of the genome of the phytopathogenic bacterium xanthomonas campestris pv. campestris (xcc), predicts 72 tbdrs. such an overrepresentation is common in xanthomonas species but is limited to only a small number of bacteria. here, we show that one xcc tbdr transports sucrose with a very high affinity, suggesting that it might be a sucro ...200717311090
profiling the secretome of the marine bacterium pseudoalteromonas tunicata using amine-specific isobaric tagging (itraq).the eukaryote-associated marine bacterium pseudoalteromonas tunicata produces a range of target-specific compounds that inhibit different types of marine organisms including invertebrate larvae and algal spores, as well as a broad spectrum of fungi, protozoa, and bacteria. the ability to produce such bioactive compounds is correlated to the expression of a yellow and a purple pigment in p. tunicata. to investigate the regulation and biosynthesis of the pigments and bioactive compounds, the expre ...200717330939
bromoalterochromides a and a', unprecedented chromopeptides from a marine pseudoalteromonas maricaloris strain kmm 636t.the marine strain pseudoalteromonas maricaloris kmm 636t was found to produce an inseparable mixture of two brominated yellow main pigments, bromoalterochromide a and a', in a ratio of 3: 1. both pigments are thr-val-asn-asn-x pentapeptide lactones, where the amino group of thr is acylated with 9-(3-bromo-4-hydroxyphenyl)-nona-2,4,6,8-tetraenoic acid, and x is aile and leu, respectively. they possess cytotoxic effects on developing eggs of the sea urchin strongylocentrotus intermedius, but no an ...200717390587
metamorphosis of hydractinia echinata--natural versus artificial induction and developmental plasticity.many marine invertebrates reproduce through a larval stage. the settlement and metamorphosis of most of the species are synchronised and induced by environmental organisms, mainly bacteria. the hydrozoan hydractinia echinata has become a model organism for metamorphosis of marine invertebrates. in this species, bacteria, e.g. pseudoalteromonas espejiana, are the natural inducers of metamorphosis. like in other species of marine invertebrates, metamorphosis can be induced artificially by monovale ...200717394014
a marine bacterial adhesion microplate test using the dapi fluorescent dye: a new method to screen antifouling agents.to develop a method to screen antifouling agents against marine bacterial adhesion as a sensitive, rapid and quantitative microplate fluorescent test.200717397474
environmental stress determines the quality of bacterial lysate and its utilization efficiency in a simple microbial loop.heterotrophic bacteria provide the critical link in the microbial loop by converting dissolved organic matter (dom) into particulate form. in this study, dom was prepared from recently isolated estuarine bacterial strain vibrio sp. (dsm14379) grown at different salinities [0.2%, 0.5%, 3%, 5%, or 10% (w/v)], washed, concentrated, and lysed by autoclaving. the corresponding lysate-containing media were designated lm(0.2), lm(0.5), lm(3), lm(5), and lm(10). vibrio sp. cells grown at different salin ...200717406773
novel antifoulants: inhibition of larval attachment by proteases.we investigated the effect of commercially available enzymes (alpha-amylase, alpha-galactosidase, papain, trypsin, and lipase) as well as proteases from deep-sea bacteria on the larval attachment of the bryozoan bugula neritina l. the 50% effective concentrations (ec(50)) of the commercial proteases were 10 times lower than those of other enzymes. crude proteases from six deep-sea pseudoalteromonas species significantly decreased larval attachment at concentrations of 0.03 to 1 miu ml(-1). the e ...200717436046
combinatorial materials research applied to the development of new surface coatings iii. utilisation of a high-throughput multiwell plate screening method to rapidly assess bacterial biofilm retention on antifouling surfaces.the authors recently reported on the development of a novel multiwell plate screening method for the high-throughput assessment of bacterial biofilm retention on surfaces. two series of biocide containing coatings were prepared to assess the ability of the developed assay to adequately discern differences in antifouling performance: i) a commercially available poly(methyl methacrylate) (pmma) and silicone elastomer (dc) physically blended with an organic antifouling biocide sea-nine 211 (sn211) ...200717453727
structural characterization and ecological roles of a novel exopolysaccharide from the deep-sea psychrotolerant bacterium pseudoalteromonas sp. sm9913.pseudoalteromonas sp. sm9913 is a psychrotolerant bacterium isolated from deep-sea sediment. the structural characterization and ecological roles of the exopolysaccharide (eps) secreted by this strain were studied in this work. the yield of the eps increased as the culture temperature decreased in the range 30-10 degrees c, and it reached 5.25 g l(-1) (dry weight) under optimal growth conditions (15 degrees c, 52 h). eps fraction was purified and its structure was identified by the combination o ...200717464071
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
a cold-adapted esterase from psychrotrophic pseudoalteromas sp. strain 643a.a psychrotrophic bacterium producing a cold-adapted esterase upon growth at low temperatures was isolated from the alimentary tract of antarctic krill euphasia superba dana, and classified as pseudoalteromonas sp. strain 643a. a genomic dna library of strain 643a was introduced into escherichia coli top10f', and screening on tributyrin-containing agar plates led to the isolation of esterase gene. the esterase gene (esta, 621 bp) encoded a protein (esta) of 207 amino acid residues with molecular ...200717516048
molecular and functional properties of the psychrophilic elongation factor g from the antarctic eubacterium pseudoalteromonas haloplanktis tac 125.the molecular and functional properties of the elongation factor (ef) g from the psychrophilic antarctic eubacterium pseudoalteromonas haloplanktis (ph) were studied. phef-g catalyzed protein synthesis in vitro that was inhibited by fusidic acid, an antibiotic specifically acting on ef-g. the ef interacted with gdp only in the presence of p. haloplanktis ribosome and fusidic acid with an affinity similar to that displayed by escherichia coli ef-g. the psychrophilic translocase elicited a ribosom ...200717541754
the psychrophilic bacterium pseudoalteromonas halosplanktis tac125 possesses a gene coding for a cold-adapted feruloyl esterase activity that shares homology with esterase enzymes from gamma-proteobacteria and yeast.the complete genome of the psychrophilic bacteria pseudoalteromonas haloplanktis tac 125, recently published, owns a gene coding for a putative esterase activity corresponding to the orf pshaa1385, also classified in the carbohydrate active enzymes database (cazy) belonging to family 1 of carbohydrate esterase proteins. this orf is 843 bp in length and codes for a protein of 280 amino acid residues. in this study we characterized and cloned the pshaa1385 gene in escherichia coli. we also charact ...200717543477
a novel lysis system in pm2, a lipid-containing marine double-stranded dna bacteriophage.in this study we investigated the lysis system of the lipid-containing double-stranded dna bacteriophage pm2 infecting gram-negative marine pseudoalteromonas species. we analysed wt and lysis-deficient phage-induced changes in the host physiology and ascribed functions to two pm2 gene products (gp) involved in lysis. we show that bacteriophage pm2 uses a novel system to disrupt the infected cell. the novelty is based on the following findings: (i) gp k is needed for the permeabilization of the c ...200717555443
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
effect of agitation on violacein production in pseudoalteromonas luteoviolacea isolated from a marine sponge.experiments were designed to investigate the effect of agitation on the production of violacein by a marine bacterium pseudoalteromonas luteoviolacea.200717576224
the truncated hemoglobins in the antarctic psychrophilic bacterium pseudoalteromonas haloplanktis tac125.the genome sequence of the antarctic gram-negative marine eubacterium pseudoalteromonas haloplanktis tac125 is a potential source of useful data on proteins from a cold-adapted microorganism. identifying the bases of protein adaptation to higher or lower temperatures is important to understand the relationship between structure/function and life history on the earth. the p. haloplanktis tac125 genome contains three genes in distinct positions on chromosome i, named pshaa0030, pshaa2217 and pshaa ...200717582708
[taxonomic composition of bacteria associated with cultivated mollusks crassostrea lugubris and perna viridis and with the water of the gulf of nha trang lagoon, vietnam].one hundred and four strains of heterotrophic bacteria have been isolated and characterized from two species of bivalve mollusks cultivated in the gulf of nha trang (vietnam) and from the water of a mariculture farm. the isolates have been identified on the basis of morphological, physiological, biochemical, and chemotaxonomic properties, as well as by the content of g+c bases in dna. in the microflora of mollusks, vibrio alginolyticus was predominant; the pathogenic species v. harveyi and v. sp ...200717583223
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